Recent 630m Fun!

26 February 2026 | by Steve VE7SL | Leave a Comment (0)

Working new stations on 630m at this time of the solar cycle can be a rare occasion but two 'new ones' recently found their way into my logbook!

The first was Frank, K6FOD, in South Pasadena, to the north-east of Los Angeles. Now if Frank can have success on 630m in this densely populated location, then most amateurs should be able to have fun on the 630m band!

Frank is running about 200W output into a short inverted-L. Up until recently, his antenna was a large wire loop pointing east-west with which he had a lot of success working stations towards the east. He and I had several skeds while he was using the loop but since I was directly in the null of the loop, I was never able to detect a trace of his signal, nor was he able to hear me! The break through came when the vertical was erected ... but I'll let Frank tell more of the story ...

As a long-time shortwave listener I had always been very curious about the realm below the AM broadcast band, so not too long after I got my ham license in 2018 I started working on a 630m rig.

Most ops on that band use inverted-L antennas, but they are highly dependent on a robust system of ground radials. At my location, there just isn’t enough open ground to lay out an extensive radial network. This seemed like a show-stopper.

However, John Langridge KB5NJD, who was writing the MF/LF column for CQ magazine, suggested that I try a vertical loop tuned by a vacuum variable capacitor, which does not use a ground connection at the feed point. He mentioned that this was being used at the time by Ben Gelb N1VF. Between Ben and John, they helped out greatly on getting it going. Mine ended up with a circumference of about 100 feet.

By adding a 630m class D amp to my K3S, which has an internal 630m transverter, I was able to get on the air with digital modes, which at the time were JT9 for two-way QSOs and WSPR for beacon modes. The winter of 2019-2020, I worked a dozen ops in six states, the most distant being South Dakota. My WSPR signal was heard from Hawaii to the Cayman Islands.

Due to their size compared with the wavelength of the 630m band, loop antennas like the one I built are notoriously inefficient. Based on measuring RF amperage to the antenna, I calculated that it was sending only 47 milliwatts into the atmosphere. On the other hand, the winter of 2019-2020 was near a solar minimum, the point in the 11-year solar cycle when conditions are best for the low bands. And there was also a lot of activity on 630m that year because it was a fairly newly approved band and was attracting a lot of experimenters.

One downside of the vertical loops is that they are fairly directional, with a deep null off their sides. Because mine pointed east-west, it was exceptionally difficult to hear or be heard by stations due north.

After that experience, other parts of life got in the way, and I didn’t get back onto the 630m band until the winter of 2024-25. That winter, I used the same rig and vertical loop antenna as before, and worked eight ops in six states and Mexico.

But due north was still unreachable. Steve VE7SL and I gave it a good try, but neither of us could hear the other. So in the fall of 2025, despite my limited ability to lay out ground radials, I thought I’d give an inverted-L antenna a try. John KB5NJD again provided great guidance, and Steve VE7SL also lent very useful ideas.

At my location, going super tall wasn’t going to be feasible, so I ended up with a lightweight aluminum mast of 36 feet height. Because of my lot’s dimensions, instead of having one top wire to form the inverted L, I used two top wires in opposite directions, each 50 feet long — making what some call a “Tee Antenna.”

Like inverted-L’s, its small size compared to the 630m wavelength meant it would require a substantial loading coil. I made this using a popular approach of a large coil wrapped around a 5-gallon plastic bucket, with a small coil inside it on a turnable rod, which allowed the total inductance to be adjusted. The big coil also had tap points. An impedance matching transformer was wrapped on a stack of four FT240-77 toroids. For a rig I decided to try an SDR transceiver which opened up possibilities of CW and SSB voice in addition to digital modes.

For the ground system, I tried laying out a set of 18 radial wires ranging in length from about 10 to 80 feet due to the site’s available space. My antenna analyzer indicated that R_feed was around 62 ohms. Measurement with an RF ammeter showed that about 1.25 watt was now getting into the atmosphere (this being the effective isotropic radiated power, or EIRP). The FCC limits 630m ham transmission to 5 watts EIRP, which means I have ample room for improvement, hopefully by adding however many more ground radial wires I can squeeze into my limited space.

After six weeks of operating in January-February 2026, this season I’ve worked six ops so far in three states and British Columbia. Hoping to add more if I can improve the antenna’s ground network.

When not in use for 630m, I’ve also attached the Tee Antenna to a multicoupler serving a small “skimmer farm” of SDRs that monitor FT8, CW and WSPR signals on ham bands from 630 to 10 meters. In addition, I’ve used it with an SDR for receive-only DX listening for non-directional beacons (NDBs), airport beacons that transmit below the AM broadcast band in North America. So far the Tee Antenna seems more sensitive than a number of other antenna designs I’ve tried for NDB listening. I also plan to use a remote tuner placed at the antenna to allow it to be used for CW, FT8 and voice QSOs on the HF bands.

K6FOD - 36' 'T' for 630m

Loading coil / variometer

Antenna impedance matching transformer

The other new contact was with fellow-Canadian, Karl, VE6KDX, in eastern central Alberta.

The antenna is a 160m Inv-L to which I switch in the Loading coil and matching transformer. It's all build to the N1FD Diagrams. https://www.n1fd.org/2019/10/27/630m-match/ I'm running 8 raised radials approximately 20m long 24" above ground on wooded survey stakes.

The LPF is a 5^th Order Butterworth design good for 800W using 3 big Amidon T-225-2 cores and 4 Capacitors, It's housed in an old Palomar 1-30mHz filter case.

Icom IC-705 TX/RX on 80m 3.674.20mHz into the XVTR

The MiniKits XVTR is from AUS which I had to build and enjoyed doing so. https://www.minikits.com.au/eme223

I drive the tranverter with 1W from the IC-705 and the XVTR Drives the Amp with 1-2W. The 630m Amp is powered with 24v for 220W output into the home built LPF. (36v gets 510w Output)

The Amp is from Greece and came assembled on it's PCB but I had to add the heatsink, The only thing you have to watch out for is the heatsink is at full input positive voltage so make putting it into an enclosure a little challenging. https://www.dxworld-e.com/product-page/am-cw-digi-linear-amplifier-800w-mf-hf-0-4-3mhz

The Auto Sensing Antenna RX-TX Switch is also from Greece and DX World. https://www.dxworld-e.com/product-page/auto-rx-tx-switch-1-80mhz-1200w

Karl has put together a great looking station and should provide a lot of excitement for the guys back east when they hear a VE6 on 630!

Steve McDonald, VE7SL, is a regular contributor to AmateurRadio.com and writes from British Columbia, Canada. Contact him at [email protected].

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ARRL DX CW contest

23 February 2026 | by Mike VE9KK | Leave a Comment (0)

I spent a lot of time in the contest chair this weekend. While the Olympics were on and on Sunday, the much-anticipated U.S. vs. Canada hockey matchup sparked sports fever in our house, but it belongs to my wife, not me. For me, it was all about contesting, so I happily settled behind the radio.

I began early Saturday morning and continued until Sunday evening, wrapping up at 23:45. Conditions fluctuated significantly: on Sunday morning, I noticed a lot of what I call “wobbling” in station signals. Solar activity picked up on Sunday, and I found many stations calling me were just above the noise floor. I ran for about 90% of the contest and enjoyed every minute. I can always tell when I’m spotted suddenly as the floodgates open with callers!

By the end of each evening, fatigue started to set in, and I found myself mixing up S and H or 7 and 8. When that happens, I know it’s time to pull the plug and walk away before frustration takes over.

The station, PC, and antenna all operated flawlessly. I had contacts from South America, Hawaii, and even Africa. There were also quite a few QRP stations reporting just 5 watts I double-checked, thinking they meant 500, but nope, it was 5! One of my many pins now claims South Korea, though I know that’s not accurate. When I looked up the call, I realized my mistake, but by then, the station had already moved on.

All in all, it was a memorable weekend of contesting, full of challenges and highlights.

Mike Weir, VE9KK, is a regular contributor to AmateurRadio.com and writes from New Brunswick, Canada. Contact him at [email protected].

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ARRL DX CW contest

23 February 2026 | by Mike VE9KK | Leave a Comment (0)

I spent a lot of time in the contest chair this weekend. While the Olympics were on and on Sunday, the much-anticipated U.S. vs. Canada hockey matchup sparked sports fever in our house, but it belongs to my wife, not me. For me, it was all about contesting, so I happily settled behind the radio.

I began early Saturday morning and continued until Sunday evening, wrapping up at 23:45. Conditions fluctuated significantly: on Sunday morning, I noticed a lot of what I call “wobbling” in station signals. Solar activity picked up on Sunday, and I found many stations calling me were just above the noise floor. I ran for about 90% of the contest and enjoyed every minute. I can always tell when I’m spotted suddenly as the floodgates open with callers!

By the end of each evening, fatigue started to set in, and I found myself mixing up S and H or 7 and 8. When that happens, I know it’s time to pull the plug and walk away before frustration takes over.

The station, PC, and antenna all operated flawlessly. I had contacts from South America, Hawaii, and even Africa. There were also quite a few QRP stations reporting just 5 watts I double-checked, thinking they meant 500, but nope, it was 5! One of my many pins now claims South Korea, though I know that’s not accurate. When I looked up the call, I realized my mistake, but by then, the station had already moved on.

All in all, it was a memorable weekend of contesting, full of challenges and highlights.

Mike Weir, VE9KK, is a regular contributor to AmateurRadio.com and writes from New Brunswick, Canada. Contact him at [email protected].

» Leave a Comment (0)

ARRL DX CW contest

23 February 2026 | by Mike VE9KK | Leave a Comment (0)

I spent a lot of time in the contest chair this weekend. While the Olympics were on and on Sunday, the much-anticipated U.S. vs. Canada hockey matchup sparked sports fever in our house, but it belongs to my wife, not me. For me, it was all about contesting, so I happily settled behind the radio.

I began early Saturday morning and continued until Sunday evening, wrapping up at 23:45. Conditions fluctuated significantly: on Sunday morning, I noticed a lot of what I call “wobbling” in station signals. Solar activity picked up on Sunday, and I found many stations calling me were just above the noise floor. I ran for about 90% of the contest and enjoyed every minute. I can always tell when I’m spotted suddenly as the floodgates open with callers!

By the end of each evening, fatigue started to set in, and I found myself mixing up S and H or 7 and 8. When that happens, I know it’s time to pull the plug and walk away before frustration takes over.

The station, PC, and antenna all operated flawlessly. I had contacts from South America, Hawaii, and even Africa. There were also quite a few QRP stations reporting just 5 watts I double-checked, thinking they meant 500, but nope, it was 5! One of my many pins now claims South Korea, though I know that’s not accurate. When I looked up the call, I realized my mistake, but by then, the station had already moved on.

All in all, it was a memorable weekend of contesting, full of challenges and highlights.

Mike Weir, VE9KK, is a regular contributor to AmateurRadio.com and writes from New Brunswick, Canada. Contact him at [email protected].

» Leave a Comment (0)

ICQPodcast Episode 477 – ARRL Bylaw 46 Changes

22 February 2026 | by Colin M6BOY | Leave a Comment (0)

In this episode, we join Martin Butler M1MRB, Dan Romanchik KB6NU, Caryn Eve Murray KD2GUT, Edmund Spicer M0MNG, and Ed Durrant DD5LP to discuss the latest Amateur / Ham Radio news. Colin Butler (M6BOY) rounds up the news in brief, and the episode's feature is ARRL Bylaw 46 Changes.

We would like to thank our monthly and annual subscription donors for keeping the podcast advert free. To donate, please visit - http://www.icqpodcast.com/donate

Colin Butler, M6BOY, is the host of the ICQ Podcast, a weekly radio show about Amateur Radio. Contact him at [email protected].

» Leave a Comment (0)

The Last of the Hybrids – Kenwood TS-830s

21 February 2026 | by Richard AA4OO | Leave a Comment (0)

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.

Set the meter to IP (Plate Current).
Pre-set the PLATE knob to the segment of the band I’m targeting.
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:

Switch the gain knob to turn off break-in mode.
Hold down the key to hear the internal 800 Hz sidetone.
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

Richard Carpenter, AA4OO, is a regular contributor to AmateurRadio.com and writes from North Carolina, USA. Contact him at [email protected].

» Leave a Comment (0)

The Last of the Hybrids – Kenwood TS-830s

21 February 2026 | by Richard AA4OO | Leave a Comment (1)

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.

Set the meter to IP (Plate Current).
Pre-set the PLATE knob to the segment of the band I’m targeting.
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:

Switch the gain knob to turn off break-in mode.
Hold down the key to hear the internal 800 Hz sidetone.
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

Richard Carpenter, AA4OO, is a regular contributor to AmateurRadio.com and writes from North Carolina, USA. Contact him at [email protected].

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