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Do you need the newest test equipment?

March 18th, 2026 | Author:

Tektronix 475 - The Beats Keep Coming

A friend recently gifted me a Rigol spectrum analyzer and I've been having fun with it diagnosing and fixing problems with one of my antennas and looking for RF interference in the house, but that's for a future post. While that Rigol is nearly a decade old, it's far newer than my other test equipment, in some cases by more than 40 years.  Much of my test equipment is from the era of bell bottom jeans and Starsky and Hutch, because A) I'm generally cheap, and B) I just don't have that much disposable income to dispose on a hobby.  My experimenter board and oscilloscope are from the glorious 1970s, and my vacuum tube voltage meter is from the 1960s.  Summers were longer, Spring was greener, young adults were strung out.  Ah, the good old days.  

I restored the non-functioning multi-meter a few years back, but the experimenters board and oscilloscope are living on with what they were born with.

That new shiny spectrum analyzer with its digital goodness and assumed accuracy got me to wondering if my old "Craigslist find" oscilloscope is still accurate enough for my amateur uses.  I figured that the Tek 475 had probably drifted in accuracy, but when I was measuring the output of the function generator on my equally old Heathkit Electronic Design Experimenter Model ET-3100, the max frequency reported was nearly 65% higher than what the ET-3100 was supposed to be generate.  

That Heathkit experimenter board's signal generator was never intended to be accurate but 65% is a huge deviation from the expectation. So I decided to measure the accuracy of my oscilloscope.  



How to test?

Not having an actual signal generator I thought, well what can I trust to generate a  known frequency that I can measure?  The Tek 475 has a bandwidth of 200 MHz.  So testing a signal near the top of that range should prove challenging for the old scope and give me an idea of accuracy on the time scale side of things because that will push it to the limit of its abilities.  Regarding voltage measurements, I'd already compared it using a few stable voltage sources (batteries) against my multi-meter. They both measured exactly the same.

So, back to time-domain accuracy.  The 2m simplex calling frequency is 146.520 MHz.  That's pretty near the top of the scope's bandwidth.  If you key a FM transmitter with no input (no modulation) it will generate a carrier at that frequency. There will be harmonics but they are well away from the primary frequency. To measure that on the oscilloscope I need to know the time it takes a wavelength at that frequency to complete. A 146.52 MHz signal has a period of 6.83 nanoseconds (ns). That sounds difficult to measure.

The scope's fastest native setting is 10 ns/div (labeled as .01µs)

A single cycle of this signal (6.83 ns) will occupy roughly 0.68 divisions on the CRT, so less than one division, which may make it difficult to assess.  But if we engage the X10 Magnifier Switch we get an effective time division of 1 ns/div.  With the magnifier on, one full wave cycle will now stretch across 6.83 divisions (the little squares), creating a waveform that's relatively easy to measure.

I keyed the HT into a dummy load at its lowest power setting next to the oscilloscopes' probe and saw...



Note the time division at 0.1µs and the X10 magnification is pressed
 

Ladies and gentlemen that is 6 full divisions and crossing midway past the 4th hatch mark of the next division (representing 8) giving us very close to 6.83.  I don't have the start of the waveform exactly on the zero crossing so if that were a nudge to the left it would be crossing the 6.83 at the correct location.

I'd venture to say they don't make'em like they used to

Conclusions

Is an oscilloscope from the 70's as easy to use as a digital scope that has markers? No. 
Does a digital scope make you think about the actual length of a waveform? No.
Were engineers smarter in the 60's and 70's? Who knows.  They certainly had to work harder to get an answer to a question, but then they weren't being interrupted by messages and alerts on their phone every... hold on I got a message... 

The Tektronix 475 was a professional piece of equipment back in its day.  It likely was used in a lab that kept it calibrated until it became obsolete, probably sometime toward the end of the 80's. When I picked it up, it was pretty much as you see. The panel wasn't very dirty, the screen was clean and unmarked, there were no scratches on the case and there were still plastic caps over the rear connectors.  It seems to have lived a pampered life.

But, for the past decade the poor thing has been abused by someone (me) who doesn't know how to properly use it.  It serves as my silent electronics Elmer as I fumble around with it trying to confirm or deny my little hypotheses as I build equipment and alternatively let the smoke out of equipment (did I tell the story of how much kinetic energy a power transistor on a 1-watt transmitter can produce?)

So, if you are a nascent electronics experimenter looking to get some test equipment on the cheap, and you want to actually have to learn what your measuring, and you like to have a potential 50-70 year old fire hazard on your desk, keep an eye out for an old Tektronix scope from the good old days.

The Last of the Hybrids – Kenwood TS-830s

February 21st, 2026 | Author:

 Hybrid Goodness


A good friend dropped off a radio and mic that he had received from a SK.  It is a Kenwood TS-830s, which according to the serial number was manufactured December 1980.  

The TS-830s was the last of the Hybrid's manufactured by Kenwood.


The Golden Age of the Hybrid: Best of Both Worlds?


If you've spent any time scouring the used market for a "new-to-you" HF rig, you’ve likely bumped into the Hybrids. For those of us who love the glow of a filament but appreciate the reliability of solid-state components, these rigs represent a very specific, nostalgic era of amateur radio engineering.

So, what exactly makes a rig a "Hybrid"?

It’s all about the hand-off between technologies. These transceivers aren't "all-tube" in the boatanchor sense, nor are they fully solid-state like the modern SDRs sitting on our desks today. Instead, they used semiconductors for the heavy lifting in the low-level circuits—think oscillators and IF stages—while saving the vacuum tubes for the "muscle."

The Magic Formula: 12BY7 + 2x 6146B
Almost every classic hybrid followed a predictable, battle-tested recipe. If you pop the hood, you’re almost guaranteed to find this exact lineup:

The Driver: A single 12BY7 tube.

The Finals: A pair of 6146s.

This combination was the "Goldilocks" setup for the 1970s ham. It reliably pumped out about 100 watts—plenty of PEP to work the world from a modest backyard wire.

Why the 6146?


The 6146 wasn't just common; it was "The Finals Tube." It was rugged, relatively inexpensive, and offered great linearity. It’s the reason so many of these rigs are still on the air today.  NOS tubes are still available for less than $70/each.

You’ll find this exact "Hybrid" DNA across the most legendary gear of the era:

The Kenwood Line: From the TS-520 through the TS-820 and 830S (widely considered the pinnacle of the hybrid age).

The Heathkit "Hot Water" Series: The ubiquitous HW-100 and HW-101.

The SB-Series: The refined SB-101 and SB-102 "Green Giants."

There is just something satisfying about the "warm-up" period and the manual "Tune & Load" process that a modern rig can't replicate. It forces you to actually interact with your station. Plus, let's be honest—the smell of tubes in the shack is worth at least 3dB of "feel-good" gain.


Image of Finals from another site

Do old electrolytic capacitors always need replacement?


If you’ve spent any time on the forums or at a local hamfest, you’ve heard the mantra: "Friends don't let friends power up vintage gear without a recap." While there is some wisdom there, if we are being honest with our soldering irons, not all "old" capacitors are created equal.

In fact, there’s a strong argument to be made that the electrolytic caps found in a 1980 Kenwood TS-830s are actually more reliable than the junk found in 1990s consumer electronics.

Here is the breakdown of why "older" often meant "sturdier" in the world of vintage RF gear.

1. The "Capacitor Plague" of the 90s

The primary reason 70s and 80s caps get a bad rap is that people lump them in with the "Capacitor Plague" of the late 90s and early 2000s. During that era, a massive industrial espionage blunder led to a faulty electrolyte formula being used across the industry.

These 90s caps didn't just drift in value; they were "time bombs" that would bulge, leak corrosive fluid, and fail catastrophically within just a few years. By contrast, the Japanese-made caps from the 70s and early 80s (like those from Nichicon or United Chemi-Con) were over-engineered and built with stable, well-understood chemistry.

2. Physical Size and Heat Dissipation

In the 70s and 80s, we weren't trying to fit a transceiver into a pocket. Components were physically larger. A 1000µF capacitor from 1980 is often twice the size of a modern equivalent with the same rating.

Surface Area: Larger cans dissipate heat better.

Electrolyte Volume: More physical space meant more electrolyte fluid. Since the primary failure mode of an electrolytic is the fluid drying out over decades, having more "juice" to start with gave these old components a much longer runway.

3. Operating Margins

Back in the "Hybrid" glory days, engineers weren't shaving every penny off the Bill of Materials. If a circuit needed a 25V capacitor, you’d often find a 35V or 50V part in there just for the headroom.

Modern manufacturing in the 90s moved toward "just enough" specs. When you run a capacitor right at its voltage or temperature limit, its lifespan drops exponentially. Those beefy 70s components were often "loafing" along, which is why you can still find 50-year-old Heathkits that hold a steady voltage.

The "Don't Be Reckless" Disclaimer

While those 70s and early 80s caps were built like tanks, physics eventually wins. Even the best electrolyte will eventually dry out or the rubber seals will perish.

If you're bringing a rig out of a 20-year slumber, don't just "flip the switch." Use a Variac to slowly reform the capacitors. 

That being said, my friend had already purchased replacement caps so I went ahead and replaced the 500V HV caps because the originals showed an arc-over and spattered solder from sometime in the past.

Original HV caps

See the solder splash and arc-over on the lead to the left 500v cap?

Replaced

Replaced with modern caps

When you go to replace these old caps you realize they don't make 'em like they used to. The old beefy "can" capacitors had four tall, sturdy solder posts. Kenwood designers used those extra lugs as convenient tie-points, daisy-chaining multiple wires for the high-voltage rails and ground returns directly onto the capacitor itself.

But the modern replacement is a "snap-in" style cap with two tiny, stubby pins designed for a PCB, not a bundle of 18-gauge hookup wire.

Trying to cram three or four vintage wires onto one miniature modern post was not fun.  I ended up using the leads of the bleed resistor as solder posts.

Finally on the air after a rookie mistake


After replacing the caps I tested the voltage at the caps and all seemed good.  I buttoned it up and attempted to tune into a dummy load while watching an amp meter to see if the rig was drawing the prescribed current... and found that I had no bias current. 

I freaked out!  No bias means the tubes run wide open and turn into oven elements.    

I took everything back apart and started tracing the bias circuit. It simply had no power. I calmed down and thought "How could replacing the HV caps have crippled the bias current?".  Well it shouldn't.  Then I vaguely recalled brushing a switch on the back of the radio as I had turned it over.  What is that switch?  The manual calls it the "Screen Grid Switch" and apparently it's used when neutralizing the tubes, or some such hollow-state magic that I never learned to do.  What I did learn is that if it's switched off, you ain't got no bias current, or any other current needed to test transmit.  

Whew! Panic averted.

Operation

The "Tune-Up" Dance

If you’re coming from the world of modern "no-tune" solid-state rigs, the front panel of a vintage hybrid will have some controls with unfamiliar names like DRIVE, LOAD, PLATE, CARRIER, etc. Before you throw your callsign out there, you have to perform the "Tune, Dip, and Load" ritual.

This isn't just for nostalgia; it’s about matching the high impedance of those vacuum tubes to your 50-ohm antenna system and bringing the tank circuit into resonance. Skip this step, and you aren't just risking "band splatter"—you’re asking those precious 6146B finals to cook themselves to death.

The Warm-Up: Low Power into the Dummy Load

Never tune up "live" on the air if you can help it. I always start by switching over to a dummy load. After a good look at the manual, I set the mode to TUNE, the meter to ALC, and set the CARRIER knob to about a quarter turn.

With the DRIVE knob centered, I flipped the switch to SEND. I peaked the DRIVE and tweaked the CARRIER until the meter stayed happily within the ALC range, then flipped back to REC. This gets our low-level stages talking to the finals without stressing the tubes.

The "Dip": Finding Resonance

Next comes the most satisfying part of hybrid operation: Dipping the Plate.

  1. Set the meter to IP (Plate Current).

  2. Pre-set the PLATE knob to the segment of the band I’m targeting.

  3. Flip to SEND and carefully sweep the PLATE control until the needle "dips" to its lowest point.

This "dip" is the signal that your circuit is in resonance. You want to center the needle right at the bottom of that valley and flip back to REC quickly—tubes don't like sitting in a non-resonant state for more than a few seconds!

Putting "Fire in the Wire"

Now that we’re resonant in low-power mode, it’s time to give those 6146s their legs. I switched the mode from TUNE to CW to get the full HV (High Voltage) on the plates.

Keep an eye on that plate current! You want to stay at or below 265mA. Use the CARRIER knob to keep the drive power in check.

I noticed something interesting during this stage: the LOAD peaked at a different spot in full power than it did in the low-power TUNE mode. This required another quick "re-dip" of the PLATE. Some folks say a shifting peak like that points to a "soft" 12BY7 driver tube, but since I’m seeing a solid 100 Watts out on 40m and 30m, I’m not ready to convict the driver just yet.

It’s quite a process compared to pushing a button on a modern rig, but there’s a soul to this machine that makes every contact feel earned.


On-Air Performance and Operating Impressions


Voice Operations on 40m

I started by making several Phone contacts on the 40-meter band. Audio reports were positive, and the rig stayed stable on frequency. Before getting on the air, I spent some time balancing the gain between the D-104 microphone and the radio’s internal mic gain. To do this, I monitored the meter in ALC mode while watching the RF output on my dummy load to ensure I wasn't over-driving the gain.

CW Operations on 30m

Moving up to 30 meters for some CW, I sent out a single call—primarily to check my frequency on the Reverse Beacon Network (RBN). I was immediately answered by KB6UN. We had a productive 25-minute ragchew discussing antennas, hamfests, and vintage gear. The TS-830S performed admirably throughout the contact.

Operating Oddities

While the TS-830S is feature-rich compared to my Ten-Tec Century/21 or Heathkit HW-101, it has several design quirks that take some adjustment.

CW Offset and Tuning

On a modern transceiver, the VFO display typically indicates your actual transmit frequency. On the TS-830S, the transmit frequency is offset by 800 Hz from the indicated frequency. This may be common in older gear, but without a digital VFO on my other vintage rigs, the offset is much more apparent here.

Zero-Beating Without a Filter

The sidetone on this rig is fixed at 800 Hz. While you can use the RIT to adjust the listening frequency, you must be careful not to do so until you have zero-beat the other station. Unlike my modern rigs, there is no "spot" function or visual indicator for zero-beating.

On my HW-101, the sharp 250 Hz CW filter helps peak the signal when you are on frequency. Since this TS-830S lacks a narrow CW filter, I have to rely on a manual tone-match:

  1. Switch the gain knob to turn off break-in mode.

  2. Hold down the key to hear the internal 800 Hz sidetone.

  3. Match the pitch of the incoming signal to that sidetone.

Interestingly, the RF meter peaks when the station is not at a zero-beat, so the needle cannot be used as a tuning aid. Additionally, since this radio predates built-in keyers, you’ll need an external unit or a mechanical key. The jack is wired for a standard "tip = dit" configuration.

The AF/Sidetone Conflict

My primary complaint involves the sidetone volume. In this design, the sidetone level is tied directly to the AF (audio frequency) gain control. I prefer to operate with the RF gain turned down and the AF gain turned up to manage band noise, but this makes the sidetone deafeningly loud during transmission.

Currently, I have to manually turn the AF gain down before every transmission and back up to listen. I am planning to research a modification to separate the sidetone level from the main volume control to make CW operation more practical.

Filtering and Narrow-Band Operation

This transceiver predates the era of Digital Signal Processing (DSP), relying entirely on analog circuitry and crystal filters. While the TS-830S offered optional crystal filters for CW, this particular unit is only equipped with the standard SSB crystal filter. There is no digital noise reduction or sharp audio peaking for CW signals.

What this rig does provide—which was likely a novel feature at the time—is a Variable Bandwidth Tuning (VBT) control. This allows you to linearly narrow the IF bandwidth down to approximately 500 Hz with a 6 dB slope. It is certainly not "sharp" by modern standards; even with the bandwidth dialed all the way down, I can still hear stations within 2 kHz of my frequency.

To help manage interference, the radio includes:

  • Adjustable Notch Filter: Useful for knocking down a specific nearby CW carrier.

  • IF Shift: This allows you to move the passband relative to the signal to further reject adjacent QRM.

While these controls are effective for an analog design, they are a far cry from a modern rig like my Yaesu FT-DX10. On the Yaesu, I can achieve a razor-sharp focus on a single CW signal and essentially make the rest of the band disappear. On the hybrid, you are always operating with a much wider "window" into the RF spectrum.

The things I like


Thermal management and fan noise

One thing I immediately noticed about the TS-830S is how quiet the fan is. Despite the fact that the vacuum tubes generate a significant amount of heat—essentially operating at "oven" levels—the fan is variable speed and remains very quiet even when moving a large volume of air.

I have complained about the fan noise on my FT-DX10 numerous times. Operating the Kenwood reminds me of the design choices Yaesu has made with their modern rigs; simply mounting a standard muffin fan on the back is a far less sophisticated solution compared to the integrated thermal design found in this older equipment.


Sound

The TS-830S is technically a dual-conversion transceiver utilizing two intermediate frequencies: 8.83 MHz and 455 kHz. However, its architecture differs from the traditional "Collins type" designs, like the older TS-520. In the TS-830S, the bandwidth of both IF stages is narrowed simultaneously during VBT operation. Because of this specific implementation, it essentially functions like a single-conversion transceiver with an 8.83 MHz IF.

Despite the lack of modern filtering, the receiver is very pleasant to listen to. In fact, other than the volume control issue I mentioned previously, the sidetone on this rig sounds far better than the raspy, digitized sidetone on my Yaesu FT-DX10.

The audio out of the case is excellent.  It has a very good speaker that is well isolated, and can go to high volumes without distorting.  The case itself has felt / damping materials where edges mate with other panels, to reduce resonance.  It is nicely designed. Speaking of the case itself, it is thick metal.  Not car ramp thick, but sturdy, not bendy.

There is a definite appeal to switching off the modern SDR rigs and their "super-filtered" audio. Sometimes it’s worth returning to a simpler design that down-converts RF to the audible range without sending the signal through light-years of digital processing before it reaches your ears.

Little things


Having a built-in power supply is nice, especially since it would require a multi-voltage external supply like my HW-101 if it was not built in.

The controls are well laid out.  After just a couple minutes of operation everything fell to hand without searching for the control

Lastly, the VFO moves with the perfect amount of resistance. For a radio that is 46 years old that doesn't appear to have visited a service center (there are no service stickers), to have a reduction drive geared VFO that operates this smoothly, again speaks to the quality of manufacture of these old Kenwoods.


Conclusions


I plan to spend more time with the rig.  Hopefully, I can record some QSOs so that folks who began operating with more modern rigs can see what it's like to get on the air with these beauties. 

They don't make them like they used to.

This is NOT a QRP rig, so I won't offer my normal "Lower your power and raise your expectations", but I will say "Sometimes traveling the older paths leads you to a new revelation"

That's all for now

73 
AA4OO Rich

The Last of the Hybrids – Kenwood TS-830s

February 21st, 2026 | Author:

 Hybrid Goodness


A good friend dropped off a radio and mic that he had received from a SK.  It is a Kenwood TS-830s, which according to the serial number was manufactured December 1980.  

The TS-830s was the last of the Hybrid's manufactured by Kenwood.


The Golden Age of the Hybrid: Best of Both Worlds?


If you've spent any time scouring the used market for a "new-to-you" HF rig, you’ve likely bumped into the Hybrids. For those of us who love the glow of a filament but appreciate the reliability of solid-state components, these rigs represent a very specific, nostalgic era of amateur radio engineering.

So, what exactly makes a rig a "Hybrid"?

It’s all about the hand-off between technologies. These transceivers aren't "all-tube" in the boatanchor sense, nor are they fully solid-state like the modern SDRs sitting on our desks today. Instead, they used semiconductors for the heavy lifting in the low-level circuits—think oscillators and IF stages—while saving the vacuum tubes for the "muscle."

The Magic Formula: 12BY7 + 2x 6146B
Almost every classic hybrid followed a predictable, battle-tested recipe. If you pop the hood, you’re almost guaranteed to find this exact lineup:

The Driver: A single 12BY7 tube.

The Finals: A pair of 6146s.

This combination was the "Goldilocks" setup for the 1970s ham. It reliably pumped out about 100 watts—plenty of PEP to work the world from a modest backyard wire.

Why the 6146?


The 6146 wasn't just common; it was "The Finals Tube." It was rugged, relatively inexpensive, and offered great linearity. It’s the reason so many of these rigs are still on the air today.  NOS tubes are still available for less than $70/each.

You’ll find this exact "Hybrid" DNA across the most legendary gear of the era:

The Kenwood Line: From the TS-520 through the TS-820 and 830S (widely considered the pinnacle of the hybrid age).

The Heathkit "Hot Water" Series: The ubiquitous HW-100 and HW-101.

The SB-Series: The refined SB-101 and SB-102 "Green Giants."

There is just something satisfying about the "warm-up" period and the manual "Tune & Load" process that a modern rig can't replicate. It forces you to actually interact with your station. Plus, let's be honest—the smell of tubes in the shack is worth at least 3dB of "feel-good" gain.


Image of Finals from another site

Do old electrolytic capacitors always need replacement?


If you’ve spent any time on the forums or at a local hamfest, you’ve heard the mantra: "Friends don't let friends power up vintage gear without a recap." While there is some wisdom there, if we are being honest with our soldering irons, not all "old" capacitors are created equal.

In fact, there’s a strong argument to be made that the electrolytic caps found in a 1980 Kenwood TS-830s are actually more reliable than the junk found in 1990s consumer electronics.

Here is the breakdown of why "older" often meant "sturdier" in the world of vintage RF gear.

1. The "Capacitor Plague" of the 90s

The primary reason 70s and 80s caps get a bad rap is that people lump them in with the "Capacitor Plague" of the late 90s and early 2000s. During that era, a massive industrial espionage blunder led to a faulty electrolyte formula being used across the industry.

These 90s caps didn't just drift in value; they were "time bombs" that would bulge, leak corrosive fluid, and fail catastrophically within just a few years. By contrast, the Japanese-made caps from the 70s and early 80s (like those from Nichicon or United Chemi-Con) were over-engineered and built with stable, well-understood chemistry.

2. Physical Size and Heat Dissipation

In the 70s and 80s, we weren't trying to fit a transceiver into a pocket. Components were physically larger. A 1000µF capacitor from 1980 is often twice the size of a modern equivalent with the same rating.

Surface Area: Larger cans dissipate heat better.

Electrolyte Volume: More physical space meant more electrolyte fluid. Since the primary failure mode of an electrolytic is the fluid drying out over decades, having more "juice" to start with gave these old components a much longer runway.

3. Operating Margins

Back in the "Hybrid" glory days, engineers weren't shaving every penny off the Bill of Materials. If a circuit needed a 25V capacitor, you’d often find a 35V or 50V part in there just for the headroom.

Modern manufacturing in the 90s moved toward "just enough" specs. When you run a capacitor right at its voltage or temperature limit, its lifespan drops exponentially. Those beefy 70s components were often "loafing" along, which is why you can still find 50-year-old Heathkits that hold a steady voltage.

The "Don't Be Reckless" Disclaimer

While those 70s and early 80s caps were built like tanks, physics eventually wins. Even the best electrolyte will eventually dry out or the rubber seals will perish.

If you're bringing a rig out of a 20-year slumber, don't just "flip the switch." Use a Variac to slowly reform the capacitors. 

That being said, my friend had already purchased replacement caps so I went ahead and replaced the 500V HV caps because the originals showed an arc-over and spattered solder from sometime in the past.

Original HV caps

See the solder splash and arc-over on the lead to the left 500v cap?

Replaced

Replaced with modern caps

When you go to replace these old caps you realize they don't make 'em like they used to. The old beefy "can" capacitors had four tall, sturdy solder posts. Kenwood designers used those extra lugs as convenient tie-points, daisy-chaining multiple wires for the high-voltage rails and ground returns directly onto the capacitor itself.

But the modern replacement is a "snap-in" style cap with two tiny, stubby pins designed for a PCB, not a bundle of 18-gauge hookup wire.

Trying to cram three or four vintage wires onto one miniature modern post was not fun.  I ended up using the leads of the bleed resistor as solder posts.

Finally on the air after a rookie mistake


After replacing the caps I tested the voltage at the caps and all seemed good.  I buttoned it up and attempted to tune into a dummy load while watching an amp meter to see if the rig was drawing the prescribed current... and found that I had no bias current. 

I freaked out!  No bias means the tubes run wide open and turn into oven elements.    

I took everything back apart and started tracing the bias circuit. It simply had no power. I calmed down and thought "How could replacing the HV caps have crippled the bias current?".  Well it shouldn't.  Then I vaguely recalled brushing a switch on the back of the radio as I had turned it over.  What is that switch?  The manual calls it the "Screen Grid Switch" and apparently it's used when neutralizing the tubes, or some such hollow-state magic that I never learned to do.  What I did learn is that if it's switched off, you ain't got no bias current, or any other current needed to test transmit.  

Whew! Panic averted.

Operation

The "Tune-Up" Dance

If you’re coming from the world of modern "no-tune" solid-state rigs, the front panel of a vintage hybrid will have some controls with unfamiliar names like DRIVE, LOAD, PLATE, CARRIER, etc. Before you throw your callsign out there, you have to perform the "Tune, Dip, and Load" ritual.

This isn't just for nostalgia; it’s about matching the high impedance of those vacuum tubes to your 50-ohm antenna system and bringing the tank circuit into resonance. Skip this step, and you aren't just risking "band splatter"—you’re asking those precious 6146B finals to cook themselves to death.

The Warm-Up: Low Power into the Dummy Load

Never tune up "live" on the air if you can help it. I always start by switching over to a dummy load. After a good look at the manual, I set the mode to TUNE, the meter to ALC, and set the CARRIER knob to about a quarter turn.

With the DRIVE knob centered, I flipped the switch to SEND. I peaked the DRIVE and tweaked the CARRIER until the meter stayed happily within the ALC range, then flipped back to REC. This gets our low-level stages talking to the finals without stressing the tubes.

The "Dip": Finding Resonance

Next comes the most satisfying part of hybrid operation: Dipping the Plate.

  1. Set the meter to IP (Plate Current).

  2. Pre-set the PLATE knob to the segment of the band I’m targeting.

  3. Flip to SEND and carefully sweep the PLATE control until the needle "dips" to its lowest point.

This "dip" is the signal that your circuit is in resonance. You want to center the needle right at the bottom of that valley and flip back to REC quickly—tubes don't like sitting in a non-resonant state for more than a few seconds!

Putting "Fire in the Wire"

Now that we’re resonant in low-power mode, it’s time to give those 6146s their legs. I switched the mode from TUNE to CW to get the full HV (High Voltage) on the plates.

Keep an eye on that plate current! You want to stay at or below 265mA. Use the CARRIER knob to keep the drive power in check.

I noticed something interesting during this stage: the LOAD peaked at a different spot in full power than it did in the low-power TUNE mode. This required another quick "re-dip" of the PLATE. Some folks say a shifting peak like that points to a "soft" 12BY7 driver tube, but since I’m seeing a solid 100 Watts out on 40m and 30m, I’m not ready to convict the driver just yet.

It’s quite a process compared to pushing a button on a modern rig, but there’s a soul to this machine that makes every contact feel earned.


On-Air Performance and Operating Impressions


Voice Operations on 40m

I started by making several Phone contacts on the 40-meter band. Audio reports were positive, and the rig stayed stable on frequency. Before getting on the air, I spent some time balancing the gain between the D-104 microphone and the radio’s internal mic gain. To do this, I monitored the meter in ALC mode while watching the RF output on my dummy load to ensure I wasn't over-driving the gain.

CW Operations on 30m

Moving up to 30 meters for some CW, I sent out a single call—primarily to check my frequency on the Reverse Beacon Network (RBN). I was immediately answered by KB6UN. We had a productive 25-minute ragchew discussing antennas, hamfests, and vintage gear. The TS-830S performed admirably throughout the contact.

Operating Oddities

While the TS-830S is feature-rich compared to my Ten-Tec Century/21 or Heathkit HW-101, it has several design quirks that take some adjustment.

CW Offset and Tuning

On a modern transceiver, the VFO display typically indicates your actual transmit frequency. On the TS-830S, the transmit frequency is offset by 800 Hz from the indicated frequency. This may be common in older gear, but without a digital VFO on my other vintage rigs, the offset is much more apparent here.

Zero-Beating Without a Filter

The sidetone on this rig is fixed at 800 Hz. While you can use the RIT to adjust the listening frequency, you must be careful not to do so until you have zero-beat the other station. Unlike my modern rigs, there is no "spot" function or visual indicator for zero-beating.

On my HW-101, the sharp 250 Hz CW filter helps peak the signal when you are on frequency. Since this TS-830S lacks a narrow CW filter, I have to rely on a manual tone-match:

  1. Switch the gain knob to turn off break-in mode.

  2. Hold down the key to hear the internal 800 Hz sidetone.

  3. Match the pitch of the incoming signal to that sidetone.

Interestingly, the RF meter peaks when the station is not at a zero-beat, so the needle cannot be used as a tuning aid. Additionally, since this radio predates built-in keyers, you’ll need an external unit or a mechanical key. The jack is wired for a standard "tip = dit" configuration.

The AF/Sidetone Conflict

My primary complaint involves the sidetone volume. In this design, the sidetone level is tied directly to the AF (audio frequency) gain control. I prefer to operate with the RF gain turned down and the AF gain turned up to manage band noise, but this makes the sidetone deafeningly loud during transmission.

Currently, I have to manually turn the AF gain down before every transmission and back up to listen. I am planning to research a modification to separate the sidetone level from the main volume control to make CW operation more practical.

Filtering and Narrow-Band Operation

This transceiver predates the era of Digital Signal Processing (DSP), relying entirely on analog circuitry and crystal filters. While the TS-830S offered optional crystal filters for CW, this particular unit is only equipped with the standard SSB crystal filter. There is no digital noise reduction or sharp audio peaking for CW signals.

What this rig does provide—which was likely a novel feature at the time—is a Variable Bandwidth Tuning (VBT) control. This allows you to linearly narrow the IF bandwidth down to approximately 500 Hz with a 6 dB slope. It is certainly not "sharp" by modern standards; even with the bandwidth dialed all the way down, I can still hear stations within 2 kHz of my frequency.

To help manage interference, the radio includes:

  • Adjustable Notch Filter: Useful for knocking down a specific nearby CW carrier.

  • IF Shift: This allows you to move the passband relative to the signal to further reject adjacent QRM.

While these controls are effective for an analog design, they are a far cry from a modern rig like my Yaesu FT-DX10. On the Yaesu, I can achieve a razor-sharp focus on a single CW signal and essentially make the rest of the band disappear. On the hybrid, you are always operating with a much wider "window" into the RF spectrum.

The things I like


Thermal management and fan noise

One thing I immediately noticed about the TS-830S is how quiet the fan is. Despite the fact that the vacuum tubes generate a significant amount of heat—essentially operating at "oven" levels—the fan is variable speed and remains very quiet even when moving a large volume of air.

I have complained about the fan noise on my FT-DX10 numerous times. Operating the Kenwood reminds me of the design choices Yaesu has made with their modern rigs; simply mounting a standard muffin fan on the back is a far less sophisticated solution compared to the integrated thermal design found in this older equipment.


Sound

The TS-830S is technically a dual-conversion transceiver utilizing two intermediate frequencies: 8.83 MHz and 455 kHz. However, its architecture differs from the traditional "Collins type" designs, like the older TS-520. In the TS-830S, the bandwidth of both IF stages is narrowed simultaneously during VBT operation. Because of this specific implementation, it essentially functions like a single-conversion transceiver with an 8.83 MHz IF.

Despite the lack of modern filtering, the receiver is very pleasant to listen to. In fact, other than the volume control issue I mentioned previously, the sidetone on this rig sounds far better than the raspy, digitized sidetone on my Yaesu FT-DX10.

The audio out of the case is excellent.  It has a very good speaker that is well isolated, and can go to high volumes without distorting.  The case itself has felt / damping materials where edges mate with other panels, to reduce resonance.  It is nicely designed. Speaking of the case itself, it is thick metal.  Not car ramp thick, but sturdy, not bendy.

There is a definite appeal to switching off the modern SDR rigs and their "super-filtered" audio. Sometimes it’s worth returning to a simpler design that down-converts RF to the audible range without sending the signal through light-years of digital processing before it reaches your ears.

Little things


Having a built-in power supply is nice, especially since it would require a multi-voltage external supply like my HW-101 if it was not built in.

The controls are well laid out.  After just a couple minutes of operation everything fell to hand without searching for the control

Lastly, the VFO moves with the perfect amount of resistance. For a radio that is 46 years old that doesn't appear to have visited a service center (there are no service stickers), to have a reduction drive geared VFO that operates this smoothly, again speaks to the quality of manufacture of these old Kenwoods.


Conclusions


I plan to spend more time with the rig.  Hopefully, I can record some QSOs so that folks who began operating with more modern rigs can see what it's like to get on the air with these beauties. 

They don't make them like they used to.

This is NOT a QRP rig, so I won't offer my normal "Lower your power and raise your expectations", but I will say "Sometimes traveling the older paths leads you to a new revelation"

That's all for now

73 
AA4OO Rich

Sliderule Emulator with Equation Solver

February 9th, 2026 | Author:

Hemmi/Post 1460 Versalog Slide Rule

A classic slide rule replica implemented in JavaScript. All scales are programmatically drawn from reverse-engineered mathematical equations.

Open in Full Screen →

How to Use

  • Drag the rule or cursor with your mouse
  • Scroll with mouse wheel to zoom in/out
  • Right-click on cursor or scale to enter values:
    • Numbers: 3.14
    • Constants: pi, e
    • Degrees: 2:30:26
  • Use the Equation feature to solve mathematical expressions
  • Toggle Markings and Display options in the control panel

No RCV Port? No Problem – DXE RTR-1A

January 8th, 2026 | Author:

The Sweetness of Noise Free Copy


I have been using my Receive only Loop on Ground antenna at my station for the past few weeks.  It was connected to my SDR through my receiver protection switch from OK1RP .  That switch protects my SDR from overcurrent during transmit.  I built this receiver protection switch from a kit nearly 8 years ago to protect my SDR when using it as the panadapter display for my Ten-Tec Eagle.  Back then I didn't use the audio from the SDRPlay RSP1 for listening because it was connected to the noisy antenna in my attic so audio from it sounded worse than my outdoor antenna but the signal was sufficient to use as input to the panadapter.  

But now, with the low noise, outdoor receive antenna at my station I can use the SDR as a receiver for listening during a QSO or just monitoring.

How you can use a receive antenna on a radio without a RCV port but with an outboard SDR?


For those of us that have radios lacking a dedicated antenna receive (RCV) port we need something able to listen to that the receive antenna that stays in sync with our transceiver.  Software Defined Radios (SDRs) have become very common in our hobby and entry level, dongle style SDRs are quite affordable.  They are receivers that connect to your PC via USB and generally offer wide receiver coverage.  In the case of the SDRPlay RSP1 that I use, it makes an excellent outboard receiver.  By syncing the SDR with the transceiver via OmniRig it tracks the frequency changes you are making from your radio.  Additionally it can sync the radio frequency and mode when you work with the SDR software running on your PC.

The receiver needs protection


Using a separate receiver when you have a transmitter at your station requires that you protect the receiver front end from transmit currents.  The SDR protection switch I built from OK1RP years ago is triggered by the Yaesu FT-DX10 transmit ground switch accessible through the optional Yaesu SCU-28 cable.  On transmit the FT-DX10 grounds the TX GND pin2 on the SCU-28.  This in turn is used by the OK1RP switch to disconnect the antenna input and protect the SDR on transmit.  There are RF switches that use RF-sensing to switch rather than a hardware cable, but results vary on how well they work and whether they can protect the receiver if they lose power, things get disconnected, etc.  So having a hardware triggered switch with some failsafes like the OK1RP can save you from an Oopsie that lets the magic smoke out of your receiver.

I had the FT-DX10's antenna port connected to my transmit antenna switch. That 2 position switch connected either my attic Doublet or the 80m OCF.  The transceiver was not connected to the receive only antenna in any way in that configuration.

I listened to stations coming through the LoG Receive antenna through PC speakers generated by SDRPlay's SDRUno software rather than through the transceiver because the receive only antenna offered a greater signal to noise ratio.  I turned down the AF volume on the FT-DX10 coming from the transmit antenna in order to hear only the receive antenna during QSOs.  The sidetone volume is separate from the AF volume so having it down on the transceiver during a QSO was not an issue.  Again, the transceiver was not connected to the LoG receive antenna so I couldn't use the radio controls during receive for filtering. SDRUno obviously did not offer the same features for shaping and adjusting the received signal as a dedicated amateur radio.  It provided choices for bandwidth, NR and CW-Peak. 

Switching from SDRUno to HDSDR


This is somewhat of an aside but I think it is worth mentioning.  I have been using SDRUno with my SDRPlay RSP1 SDR for the past few years to "listen" to the SDR as a receiver.  It works well enough but it has issues when I want to take the IQ output from it to software like CWSkimmer to provide a cluster server for stations I am hearing.   When I set SDRUno to output IQ it offers a number of bandwidths but they are not consistent across the ham bands.  For instance, 80, 40 and 20 offer 192 kHz as an available output bandwidth but 30, 17, 15 do not.  If I need to change bandwidths it requires modifying the Virtual Audio Cable or configuring different VAC's for the different bands, etc.  If I try using just 48 kHz for all bands that doesn't seem to work with CWSkimmer even though it has the option.   So I have switched to use HDSDR since it supports the 192 kHz bandwidth IQ output for all bands.  It also doesn't seem to lose it's mind when the computer goes to sleep like SDRUno. YMMV.


Anyway, let's get to the point


This setup has worked pretty well, but I really wanted to hear the Receive antenna directly through the transceiver to make use of all the additional filtering and controls it brings to the table. Also, listening to the receive audio from the PC when I'm working a station just feels a bit disconnected from the normal process of using the transceiver.  I also wanted to continue to feed the SDR in parallel with the transceiver to have the panadapter and local cluster server functionality.  I couldn't do that whilst using the SDR as an audio receiver.  I needed more stuff.

The DX-Engineering RTR-1A


There was a new-in-box DX-Engineering RTR-1A available on a famous auction site.  This is the discontinued version of what is now sold as the RTR-2A.  I actually prefer the connections offered on the older switch plus it was far less than the cost of a new RTR-2A.  These switches don't come up used very often so beggars sometimes can't be choosers, although I'm sure something will pop-up for a steal now that I've purchased one.






The RTR-1A is a switch designed to allow a transceiver such as the FT-DX10 that only has a single antenna connection to make use of a Receive Only antenna.  It offers additional protection that a traditional transceiver with Receive Antenna ports does not have, because most transceivers simply ground the Receive antenna but don't offer any additional current protection coming in that port during receive.  The RTR devices not only switch out the RCV port during operation they also offer active front end protection on the RX ANT IN port while sending the signal to the transceiver antenna input.

For convenience it has a choice of 2 types of RX ANT IN connections, not for using both at once.

The two RX ANT IN ports are in parallel


This is important to note.  I initially thought that the 2 RX ANT IN ports were isolated from one another so that I could run the RCV antenna in one port and feed my SDR from the other RX ANT IN port.  But if I'd simply read the label "literally" it would have been clear even without reading the manual.  Those are both RX ANT IN, not OUT. They are in parallel.  If you run a connector to the SDR antenna input from the RX ANT IN port you will be loading the input and significantly reducing the sensitivity of the receive antenna.  Additionally, the SDR is not protected from transmit currents if you connect it in parallel with the receive antenna.  Whatever is received on the RCV antenna entering that port will be passed straight through to the other connector.  Since there's no protection, your SDR becomes a Red Shirt.

Because of this I can't feed my SDR with the receive antenna while using the RTR-1A without using a RF-splitter. Instead, I am using MAIN ANT OUT to route signals to the SDR for panadapter and skimmer logging only.  I lose the nice receive functionality directly on the SDR with this configuration. 

I could purchase or build an RF Splitter to use ahead of the RX ANT IN to split the output to the SDR.  If I did I would need to also use my OK1RP antenna relay protection switch to disconnect the SDR.  That would mean more than double the wiring, plus I would lose a minimum of another 3 dB on receive due to the splitter, and unless I buy a high quality HF $plitter from mini-circuits or DXE the lack of isolation would likely cause even greater losses due to loading across the circuits.  I researched making a 1.6 MHz to 60 MHz HF splitter with 30+ dB separation and it involves building a very tight circuit. Even a couple extra mm of wire change the circuit inductance.  I just don't think I'm up to that. Maybe I'll get a good splitter for my birthday, but for now I'll just use the TX ANT OUT to route to the SDR for panadapter use.   I love our hobby but it seems I always am one part shy of my optimal solution.  One thing I will say is that I learned a lot about RF splitting while researching the topic.  It's a heck of a lot more than building a Y-cable.

Connecting the RTR


Let's get this wired up.  More cables and wires at the station.  Who doesn't love more things to connect and get tangled up?  Even better, who doesn't love having to connect things with dissimilar connections?  I'm fairly confident that I have over 25 adapters for RF and DC connector types yet I still have to order more adapters for every new project. I never have just the right single adapter and end up having to connect 3 - 4 adapters in series to get the combination I need.  But I digress. 

Connections on the RTR-1A switch  

  • The main TX antenna goes to the connector helpfully labeled MAIN ANT IN.  It's a PL259 to help insure that you are connecting a real antenna there, especially if you are trying to connect things in the blind (not advisable).
  • The Receive Only antenna goes to either of the RX ANT IN ports.  One is a female F-Type connector commonly used for TV / cable coax.  That is the one I am using with the coax coming in from the LoG antenna.  Additionally I have a quick disconnect F-Type on the end of the coax so I can pull it free when I'm not at the station.  
  • I run a cable from the MAIN ANT OUT port to my SDR, in-line with a passive diode based front-end protector.  The switch is supposed to offer protection for the SDR on disconnect, but I'm paranoid.  That ends up being a RCA male to male phono cable to the front-end protector, which outputs to a male to BNC female adapter, which connects to a male BNC to male sma cable to the SDR (whew!)
  • The next port connects the switch to your transceiver and is helpfully labeled RADIO.  Connect the ANT port on your transceiver to this connector using a male to male PL259.  Since it is also PL259 that helps you avoid connecting non-radiating bits to radiating bits.  
  • The last connection is labeled TRANSMIT GROUND.  This connection is what tells the switch to switch from RX ant to TX antenna.  It uses a RCA plug style connector to ground the center pin to shield when the radio goes into transmit.  It can ONLY work with a connector that goes to ground, no positive voltage keying.  My Ten-Tec Eagle had a TX GND RCA female connector built right into the back of the radio but as I mentioned above you will need to take the appropriate wires from the SCU-28 port on the Yaesu FT-DX10 (pin 2 to ground) for which I built a break out box from the SCU-28 with the appropriate connectors.
  • Lastly the switch needs 12v DC power to operate.  You could take that from the radio's SCU-28 cable or from an external supply assuming you have a common DC ground.  If the switch is not powered it defaults connecting the MAIN ANT IN port to the RADIO port and grounds the RX ANT IN and MAIN ANT OUT ports, thus saving your SDR.  If the switch is unpowered nothing goes out the MAIN ANT OUT port so my SDR sees nothing.
Okay that was simple right?  The transmit and radio cables are using PL259, the switch is using RCA, F-Type and PL259 (and a barrel for power), the receive antenna has a F-Type and the SDR has a female SMA.  If I add a splitter; well I'm not even going to go into all the additional connection adapters and cables I'd need.  

All this so that we can participate in a hobby that communicates wirelessly


Connections


In operation

Noise free reception

The RTR-1A isn't exactly a small box and it weighs more than I would have expected.  It just fits on top of the DX10 at my cramped station.  You want it easily accessible to operate the RX / MAIN switch on front panel to either momentary or fully switch from receive to main antennas.  Down is momentary, up is latched.

My LoG receive antenna is about 9 -12 dB down on receive compared to the 80m OCF.  So in most cases you want at least the first preamp on and sometimes the second preamp engaged although PRE-1 is usually sufficient.  There is so little noise on the LoG that all you are really bringing up is the signal when you turn up AF.  However when switching back to the main antenna you will be hit with a wall of sound and the waterfall will just turn white with the preamps engaged on lower bands.

I wish there was a dedicated button for the preamp on the DX10.  It requires leaving the EXTEND menu up and touching the screen to change preamp settings.  I have to touch it twice, once to get the IPO menu and the next to choose the setting.  I may look into getting a LNA to run prior to the RTR for convenience of not having to mess with the IPO menu.  I searched but I see no CAT command that I can send that will change the IPO setting from the computer.

Many signals from the LoG are so clean that they are completely copyable without budging the S-meter.  I had lengthy ragchews with 3 stations today on 30m using my attic antenna (my only efficient antenna for 30) that were completely buried in the noise of my attic antenna.  I was receiving 549 to 579 reports from these invisible stations.  The Doublet in my attic is good for transmit but blinded by noise on receive, so the LoG is a complete game changer for me on WARC bands.  It's also far less impacted by static crashes on 80m than the OCF.

Similarly, this evening I worked 6 WWA stations (II3WWA, CR6WWA, VE9WWA, YO0WWA, SN4WWA, EG1WWA) on 40m in quick succession where I couldn't reliably copy 3 of them on my 80m OCF but could hear them on the LoG.  I'm flabbergasted at how much this changes home station operation. 




That's all for now.

So lower your power and power your radio with receive antenna switch

72/73 AA4OO

Licensed Amateurs by State

December 29th, 2025 | Author:

 How Extra is Your State?

My amateur radio license was set to expire early in 2026, so I sat down to navigate the FCC’s renewal process. I don’t recall a separate payment system (CORES) needing to be tethered to an FRN a decade ago, but it’s there now, and hopefully at your next renewal you will enjoy the game of Bureaucratic Twister as much as I did. I'll spare you that particular headache for this post.

While I was clicking through the digital maze, it reminded me of the time I spent a decade ago studying to upgrade from General to Extra. I wanted the extra band privileges and the ability to help out as a VE, but it made me wonder: how many amateurs actually bother with the climb to the top of the licensing hill?

Back in 2006, the upgrade from Technician to General still required the 5 WPM Morse test. If I’d had the audacity to try for Extra at that time, I would have needed to demonstrate 20 WPM. Since I was already struggling to keep my head above water at 5 WPM, the prospect of hitting 20 felt about as realistic as me winning the lottery.

The FCC eventually dropped the Morse requirement in 2007, but I didn't give the upgrade serious thought until 2015 when I started playing with QRP rigs and CW again. The reality is that if you enjoy working CW, there are exclusive neighborhoods in the bands that you simply can’t enter without an Extra ticket—and that’s usually where the best DX is hiding.
Amateur Extras - Percentage by State




Show me the data

That was a wordy intro, so what’s this really about? I wanted to be able to query the FCC database. There was supposedly an API at one time, but that seems to be defunct now. However, you can still download the entire FCC database as a zip file: https://data.fcc.gov/download/pub/uls/complete/l_amat.zip That download provides a collection of pipe-delimited files containing the raw data from the FCC amateur license database. Many of these are large files, containing data that is related by call sign or fccid records.

If you were so inclined, you could load those records into the database of your choice, a Jupyter Notebook, or any other tool to query it.  I would guess they are too large for Excel but not having Excel I can't be sure. Fortunately, a helpful ham created a bash script that downloads and parses these files into a MySQL database. You can find the repository for that script at: https://github.com/k3ng/hamdb

I had to modify the script slightly to get it running under Windows, but otherwise, it worked as expected. The script includes some simple commands to send SQL to the database server to look up a record by call sign or return all call signs for a specific zip code. In my initial testing, I found it interesting that there are 257 licensed operators in my zip code.

However, if you want to obtain interesting insights that requires writing SQL (Structured Query Language), which is the standard for relational databases like MySQL or PostgreSQL. If you haven’t spent time as a software developer, that might seem a little daunting. 

But in this bold new age of "I don't need to know nothin because I have an AI assistant" 

Anyone can now generate a SQL script to return the results they are looking for.

Specifically, I wanted to know how many amateur operators held Extra Class licenses across all states. It was a bit tricky to pull the correct data because the operator class is part of a table that contains every upgrade and renewal. Since there are multiple records for many call signs, you have to build a query that returns only the most recent result from the updates (hd) table.

Example SQL Query:

SELECT 
    e.state,
    -- Total count of all active licenses in the state
    COUNT(*) AS total_licenses,
    -- Count of Extra Class specifically
    SUM(CASE WHEN a.class = 'E' THEN 1 ELSE 0 END) AS extra_class_count,
    -- Percentage of the state's total that is Extra Class
    ROUND(SUM(CASE WHEN a.class = 'E' THEN 1 ELSE 0 END) * 100.0 / COUNT(*), 2) AS state_extra_percentage,
    -- Distribution of other classes (optional context)
    SUM(CASE WHEN a.class = 'G' THEN 1 ELSE 0 END) AS general_count,
    SUM(CASE WHEN a.class = 'T' THEN 1 ELSE 0 END) AS technician_count
FROM fcc_amateur.am AS a
JOIN fcc_amateur.en AS e ON a.fccid = e.fccid
INNER JOIN (
    -- Get the single highest fccid (most recent) for every callsign
    SELECT MAX(fccid) AS latest_fccid
    FROM fcc_amateur.hd
    WHERE status = 'A'
    GROUP BY callsign
) AS latest ON a.fccid = latest.latest_fccid
WHERE e.state IS NOT NULL AND e.state != ''
GROUP BY e.state
ORDER BY extra_class_count DESC;

I joined those results with census data into a Google Sheet to provide the following:

Results



Conclusion

That table shows that Idaho has the highest percentage of Amateur Radio licenses  by population but one of the lowest percentage of operators upgraded to Extra class. 

The column "One out of every" I find interesting just to demonstrate how rare licensed operators are in the population.  For example, in the state of North Carolina where I reside while there are 25,924 licensed operators, given the total population of the state only one out of every 42,609 persons are a licensed operator.  There are more doctors in the state than licensed amateur operators.

As to my original question of how many upgraded to Extra there are only 5,705 amateurs in NC or 22% of the licensed operators.  So almost a quarter of operators in NC upgraded to Extra.  It ranks slightly better than other states in that regard (see map above).

Play around with the table and let me know in a comment if you find anything surprising or interesting.



That's all for now

72/73 de Richard AA4OO

AI Analysis of Logs for Antenna Directionality

December 21st, 2025 | Author:

Where is this dang thing pointing?

Wire antennas generally have directionality broadside to the antenna but multi-band antennas have "lobes" of directionality that vary greatly as you go up in frequency from their fundamental frequency.  I can generate a KML file of my contacts from the Log4OM logging software, but it is a bit overwhelming and I don't have the ability to break it down by band.



I wondered what Google Gemini AI would determine from evaluating the contacts from my LOTW logs and how that differed from the theoretical directionality of the antenna.  I have over 2800 logged QSOs in LOTW that I provided for evaluation.

I have made a lot of contacts when portable but I paper log those and they rarely make it back into my electronic logs, so nearly all of these logs are from my station operation and 95% of those have been on the 80m OCF.

Gemini provided me with this evaluation


  • 80m: Broad "figure-8" pattern with maximum radiation broadside to the wire at 55° (NE) and 235° (SW).
  • 40m: A "four-leaf clover" pattern. Your strongest performance is at 45° and 315°, perfectly hitting Europe and the US Midwest.
  • 20m: Four sharp lobes that pull closer to the wire axis. Your log shows high-gain "spikes" at 35° (Europe) and 330° (West Coast).
  • 10m: Eight or more very narrow lobes. Your 10m contacts are extremely directional, primarily clustering at 50° and 130°.

I then asked Gemini to evaluate how my log results differ from the theoretical directionality of the antenna.  In general the results match the theoretical performance of the antenna.  I also asked it to include the results from 30m and 17m in this analysis:

  • 80m, Broad Figure-8, Strongly Biased NE/SW: Contacts cluster at 55° and 235°. Coverage is broad but noticeably stronger toward the Northeast US/Canada. High: Matches the broadside radiation of a dipole.
  • 40m, 4-Leaf Clover, 4 Strong Peaks: Contacts are highly concentrated at 45°, 135°, 225°, and 315°. You are successfully hitting Europe and the US West Coast via these distinct lobes. Very High: Confirms the 2nd harmonic pattern.
  • 30m, Distorted 6-Lobe, NW Dominant: You have a massive cluster toward the Northwest (330°). This band is notoriously asymmetrical on an OCF antenna, and your log shows you've "found" the dominant lobe. Moderate: The theoretical pattern is messy; your data simplifies it.
  • 20m, 4 Long, Sharp Lobes, Sharp Spikes: Contacts are extremely localized at 35° (Northern Europe) and 330° (Washington/Oregon). This matches the narrowing of lobes as frequency increases. High: Matches the "tilting" of lobes toward the wire axis.
  • 17m, 6 Very Sharp Lobes , Strategic Clusters: Contacts cluster at 13° (New York/New England) and 225° (Mexico). The narrowness of these clusters indicates you are operating within high-gain "fingers" of radiation.  High: Confirms the 5th harmonic pattern.
  • 10m, 8+ Needle-Thin Lobes, Pinpoint DX: You have specific, isolated successes at 50° and 130°. Many other directions show "nulls" where no contacts were made. Moderate: High-QSB (fading) makes this band less predictable.

Conclusions

Using AI to provide me with analysis of my antenna directionality was certainly faster than manually breaking down all the data and plotting it myself.  I can also see how much I'm likely missing on 20m and 10m due to the severe directionality of the few lobes.  I would be well served by having separate antennas for those bands, but I am very limited where I can put outdoor antennas given the lack of tall support structures at my house. The OCF works because the tallest thing in my lot is the peak of my roof and I have too short a distance to the tree in front of my house for a fan dipole to work.

I did look at some tools for evaluating directionality based on logs such as https://qsomap.org but the ones I found are visual and require manually evaluating the graphics.  There are likely other tools that would do what the AI is doing but I'm not aware of them yet.  Please leave a comment if there are log analysis tools that you use for this purpose.

The analysis of the 30m being severely clumped showed me that I could likely do better using my attic antenna for that band, but I had pretty much given up using the attic antenna years ago due to high receive noise given it's proximity to all the noise in the house.  Now that I have a Loop on Ground receive antenna that allows for quiet receive I will begin using the attic antenna for transmitting and try to determine how its directionality differs for the for the WARC bands that the 80m OCF is extremely inefficient on.

That's all for now,

Lower your power and raise your expectations, or let AI tell you what you should expect.

DE AA4OO - Rich
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