On How NCIS Maligned the Amateur Radio Service

EDIT: Please view the NEW article, in which the FULL VERSION of this video exists.

I’ve been reading some of the chatter regarding the NCIS episode in which they incorrectly portray the amateur radio service. I thought I would make a video (vlog) and express my thoughts.

I use my new headset mic to make the video. If you have a few moments, please check it out, and let me know how the mic sounds.

Of course, share your thoughts on the NCIS thing… thanks!

Yes, the video gets prematurely cut off.  The editing software on my cell phone chopped off the ending, and I did not realize it until after it posted the video.  I’ll record a follow-up video that includes the ending thoughts, but in a new vlog edition.

Cheers and 73 de NW7US

..


Tomas Hood, NW7US, is a regular contributor to AmateurRadio.com and writes from Nebraska, USA. Contact him at [email protected].

An Old Friend Found






Several years ago, like many other hams, I was stricken with 'Tuna Tin fever' and purchased a Tuna Tin II kit from the Norcal QRP group.





Escaping the summer heat a few months later, I put it together over one weekend in July. As it turned out, it was probably the best $13 I ever spent on my hobby.

I fired it up the next morning and put out my first 250mW 'CQ' on the 7040 KHz 40m QRP calling frequency. Back then, 7040 was ground-zero for forty meter QRP fanatics and there always seemed to be folks monitoring while working at the bench on their latest project. Given the time of day and the mid-summer propagation, I really didn't have high hopes but I was immediately answered by KJ7AN in Dallas, Oregon who gave me a 579 report!

Over the next three days I worked several more stations in Oregon, Washington, Idaho and even California. I was truly delighted with the little rig's performance but assumed that my pint-sized signal would probably not go much farther than the nearby western states and maybe, if I was very lucky, a few more Californians.

All that changed early on the morning of August 6th! About an hour after sunrise, my tentative hand-keyed 'CQ' was answered by Steve, NØTU in Colorado!! Steve had been enjoying his morning coffee while the quiet hiss of 7040 in the background was broken with my very weak 'CQ'. We had a good solid QSO and after it was over, I realized that the little Tin had a lot more potential than I had realized. It seemed to me that if my little signal could skip all the way to Colorado in August, then it should go a LOT further during the winter DX season ... perhaps far enough to work all fifty states? It was at that point that I decided to give it a try.

I re-pruned my 40m half-sloper as well as adding 35 buried radials and as the fall DX season approached, I watched 7040 every weekend ... the new states soon began piling up.


To shorten the story, in early December of that winter, I worked WG7Y in Wyoming for state #50 to claim the first-ever Tuna Tin 'Worked All States' ... all on 7040 KHz. Unfortunately the ARRL does not have any special endorsements for Tuna Tins but they did stamp my 'WAS' certificate with a 'QRP' notation!

At some point in the intervening years, the little Tin's final amplifier, the ubiquitous 2N2222, went south. As I removed and examined the tiny old battle-scarred soldier, I remembered so many hours of late-night pleasure it had brought me, along with some memorable sessions ... one being a snowy late Friday night opening to the east coast that put the last three needed New England states into my log in less than thirty-minutes.


I carefully placed the little transistor in a piece of anti-static foam, not that it needed protection, but as a keepsake and a reminder of its noble past. Possibly I would mount it on a nice hardwood base in the future.

Earlier this year I noticed, when cleaning the shack, that the little black keepsake could not be located ... I figured that it must have got sucked-up in the shop-vac during one of my rare shop clean-up days.

I always empty the shop-vac, which consists mostly of fine sawdust or wood shavings, onto my large pile of lawn-mower clippings, which seems to stay about three-feet high no matter how much I keep adding.

Emptying the grass catcher last week, during the final mowing of the season, a small black object sticking out from mid-pile caught my eye. It was indeed my old friend and, after reaching out to 50 states, she still had enough left for one last call to me! I'll take much better care of her now and keep her in a safe place, away from the nasty shop-vac.


I eventually went on to build a 20m Tuna Tin, also crystal-controlled on which, at last check, had brought 46 states and a DXCC total of 21 countries. This inspired a 'mini-tuna', built into a small cat-food tin and using just a barebones 2N2222 crystal oscillator. This one has brought 33 states over the years.



I have more Tuna Tin info, along with circuit information on my main web site here ... but be warned -- 'Tuna Tin fever' can strike anywhere at anytime.

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

Your Opinion, Please (first of several)

I am asking for opinions on audio, in my videos. I am in the process of choosing the better of several mics. Right now, I have two comparisons. One is a lapel mic. One is a headset boom mic.

Your opinion is appreciated on the best of two microphones used in upcoming videos I hope to create on my channel on YouTube ( https://YouTube.com/NW7US ), during those times when I want to vlog from my moving vehicle.

I am assessing several things: background noise level, clarity of voice, ease of understanding my words in context to background noise, and, ease of listenability–you know, I am seeking opinions on which of the two mics makes the audio pleasant and not fatiguing.

The two videos are listed here:

http://blog.nw7us.us/post/167110007307/i-need-your-opinion-please

Please leave a comment on your preference of one or the other mic, and why.


Tomas Hood, NW7US, is a regular contributor to AmateurRadio.com and writes from Nebraska, USA. Contact him at [email protected].

FA- VA4 antenna analyzer kit.

The condo kit corner.
About a month ago my FA-VA4 vector antenna analyzer kit came in and it has sat idle until Friday. I had the day off and with everything done that needed to be done, I say "everything that needed to be done" because there is always something to get done! I decided it was time to put the kit together. This really is the first kit I have attempted to assemble since moving into our small condo in Toronto. I no longer have the huge desk, nice lighting and the room to place all my equipment around me. Now it's a roll top desk with 2 slide out shelves, that is my only choice for kit work now. Trying to get the exhaust fan, soldering station and other small miscellaneous items in place is a real challenge. What was also a challenge was remembering where the heck I placed things in the dam condo! I have a nice Panavise setup for holding my boards in place while soldering. I could find the arms but I was not able to locate the base. I looked everywhere but had no luck and nothing bothers me more than knowing it's somewhere but just not able to find that "somewhere". I had to settle for placing just the Panavise arms on the slide out and do my best. I found very quickly that working in a tight space one has to be very aware of cords and tools, a few times moving the soldering iron in place almost had the soldering iron cord take the make shift Panavise (holding the circuit board) onto the floor. The kit from Box73 comes from Germany, the shipping time was fantastic as well as packaging. There is no SMD work to be done that was done and I only had to mount some connectors, power on switch, pushbuttons and the LCD display. After being away from kit building for a very long time this was a nice way to jump back into things. I first took an inventory of the parts and this is something I always do. I hate getting to the point when a part can't be found and your not sure if it was not shipped or misplaced by me? Doing the inventory allows me to contact the vendor and in the case of large projects the part arrives in time for that point in the assembly. Everything was there and it was now time for the next important step...read over ALL the assembly instructions. In my case I go the extra step and check out YouTube videos and the internet to see if there are any pointers that others have come across to make things easier or things to avoid.  One of the builder beware tips I read was from John AE5X blog to not use lithium batteries as the voltage is to high and the FA-VA4 will repeatedly reboot. This type of information is invaluable when kit building. It saves trouble shooting time and going down possibly a long road of parts testing.
This kit does have SMD parts that I said are factory installed BUT some of the items that the builder needs to install are very close to some SMD parts. This brings me to another important part of kit building....spend the money to get the right tools for the job. In this case my Weller WES51 has a large variety of soldering tips. I find the fine chisel tip (Weller ETM) worked great for soldering the LCD terminals, the larger tip for the BNC connector (Weller ETD) and finally the intermediate tip for the components beside SMD parts( Weller ETB).
The instructions had me installing the ON/OFF slider switch first and this was a great start for this old rusty kit builder.  I then moved onto the 3 rails in which the LCD would eventually plug into. You will notice from the picture these are raised up on the board. Each pin has a "collar" so the rail will be at the proper hight but the builder has to be cautious and make sure the rail is firmly seated and upright and straight. One rail is 20 pins and once it's in....it's in! In the past I have had to remove these types of components due to my own lack of attention. IT IS NOT FUN and I have a Hakko desoldering tool  which make desoldering a pleasure but even with that tool removing a 20 pin rail is not fun at all. Take the time to set these parts up for first time correct soldering. My method was taping the rail in place, solder the 2 opposite end pins, check for upright correctness and firm seating on the board. If all is good solder the remaining pins. The other components were easy to solder in place when using the proper tips. I have a magnifier head set  and use it to make sure all connections are soldered properly and that all were done. You would be surprised how many times when multiple pins are involved how easy it is to miss a pin.  The LCD needed to be soldered to the backlight, it involved a 20 pin connection on one side. The instructions said I only "had" to solder the 2 outside pins. I chose to solder all 20 and then on the opposite side of the LCD there were 2 sets of 3 pin connections that need all pins soldered. To make sure the LCD was firmly against the backlight I used some tape. Once the LCD was ready to go again I took time to inspect the pins that were going to plug into the 20 pin and two 3 pin rails. I did find one of the 3 pin setups ups on the LCD was bent! I corrected this but if I failed to see this could had resulted in broken or bent pins.
There is two AA battery holders that need to be soldered in and all I can say is check and double check this. Mixing this up polarity can bring smoke to the smoke test. Believe me it can happen. One of the Elecraft K2 kits I put together almost ended in disaster when I was not paying attention and soldered up a power cable with Anderson pole connectors. I soldered red wire to Anderson black connector and black wire to Anderson red connector. It gets better.....I then plunged it into the K2 and powered the K2 on!! The Astron power supply made a noise and both the inline fuses on the main Astron power supply blew. I was very luck and now double check everything.
It was now time for the "smoke test" and I was so proud of my first kit in over 4 years I had my dear wife Julie come over for the ceremony.......I flipped the switch and........yup you guessed it...NOTHING!!!!! Yup nothing.....but no smoke and that is a good sign. Julie giggled and moved on to other tasks. I made a mental note to always solo a smoke test and avoid the embarrassment. The problem was one of the AA batteries was not firmly in place. Once looked after the power on test was a success. I called Julie over for her to check out the kit but it just did not have the same excitement. That was it for the kit building for the day I still have to preform the calibration. Over all the kit was a  joy to put together and by way of some side notes. The case is a brushed aluminum with attention to detail such as counter sunk screws for securing case, the LCD and buttons lined up perfectly and a nice touch was not having stick on rubber feet (that always over time seem to come off and get lost) This kit came with pull through rubber feet. I still have to calibrate the unit and actually use it but that will be another day.
Completed kit
Smoke test 
Bent LCD pins 
Supporting the 20 pin connector.
Completed LCD pins 

Mike Weir, VE3WDM, is a regular contributor to AmateurRadio.com and writes from Ontario, Canada. Contact him at [email protected].

More Power For VHF SOTA

For years now, I’ve been doing Summits On The Air (SOTA) activations using VHF and higher frequencies. The GO TO band/mode for VHF SOTA is 2-meter FM because of its overall popularity. Just about everyone has a 2m FM radio (well, almost everyone). Still, if you are on a remote peak you may not find anyone within range to work. Because of this, it really helps to optimize the performance of your portable VHF station.

Antennas

I’ve already written that the first step is to upgrade the rubber duck antenna to something that actually radiates. My measurements indicate that a half-wave antenna performs 8 to 10 dB better than your typical rubber duck. That’s a big difference. I tend to favor the collapsible half-wave antennas because they are compact and don’t require any support. Another option is the J-pole or Slim Jim antennas, typically build out of twin lead or ladder line.

The next step up is to use a small yagi antenna, such as the 3-element Arrow antenna. Although Arrow does not specific the gain of this antenna, it has been measured at the Central States VHF Society conference as having ~6 dBd of gain. I’ve been on the lookout for a higher gain antenna but I have not found one that has significantly more gain while still being backpack portable.

Modulation

Frequency Modulation performs very badly when signals are weak. The well-known threshold effect means as the signal level decreases at the receiver it simply crashes into the noise. Linear modes such as CW and SSB work much better when signals are weak, which is why they are popular with the serious VHF crowd. I’ve used my Yaesu FT-817 to make SOTA contacts on both 2m and 70cm SSB and CW. My all time best distance on 2m during a SOTA activation was 229 miles, a QSO with N7KA from Capulin Mountain using CW. However, the problem with SSB/CW is that there are much fewer radio amateurs that operate that mode. I estimate that on a typical day, there are 10 to 100 times more hams on 2m FM than are on 2m SSB/CW.

More Power on FM

I’ve noticed that I sometimes hear stations on 2m FM but they cannot hear me. Further investigation revealed that they were typically running more power than me. I had my little HT putting out 5W and they were running a 50W mobile. That got me thinking about whether I could increase my power while still having a backpack-compatible station. SOTA operation is typically QRP, around 5 or 10 W of power. However, SOTA does not specifically state a required power level…it’s really driven by the need to operate backpack portable. Hence, there are very few 1 KW amplifiers in use on SOTA summits.

Tytera TH-8600 2m / 70cm transceiver

Some of the Chinese manufacturers now offer compact dualband (and even quadband) VHF/UHF transceivers that output 10 to 30 watts of RF power. I purchased the Tytera MD-8600 based on my experience with other Tytera products. The radio’s specified output power is 25 watts on 2 meters. The DC power current is rated as 0.2 A on receiver and 4A on transmit, not too bad for battery operation. I paired it with a 13.2V LiFe battery rated at 4300 mAH. In theory, that would provide over an hour of transmit time or 21 hours of receive. That should be plenty for the typical SOTA activation. The size is a slightly larger than 4″ W x 1.5″ H x 5″ D and it weighs about 2 pounds. All in all, this setup is very compatible with the typical backpack portable operation.

Let’s do a little math to understand the difference in transmit signal. The TH-8600 puts out 25W compared to the 5W from FT-60. The difference in dB is 10 log (25/5) = 7 dB. Someone said to me “hey, that’s only a little more than one S unit, which is normally defined as 6 dB. Is that really enough to make a difference?” To which I responded, “yes, 7 dB can make the difference between making the radio contact or not…when signals are near the noise floor of the receiver.” For strong signals, it just doesn’t matter.

I’ve used this configuration on three SOTA activations and I like the results. On two of the activations, I compared the TH-8600 (25W) to the Yaesu FT-60 (5W) that my hiking partner (Joyce/K0JJW) was using. Both radios were connected to 1/2-wave vertical antennas, operating on 2m FM. The radios performed the same on receive, as expected. But the weaker stations we were working had trouble hearing the FT-60. Again: if signals were strong, it didn’t matter but the extra power made the difference when near the noise floor.

I checked out the basic performance of the radio on my test bench and found it to be adequate. The transmit frequency was spot on, the harmonics and spurious on 2m were about 60 dB below the carrier. The receiver sensitivity was about 0.2 microvolts. The RF output power was low, 22.4 W on 2m and 17.7W on 70cm (compared to the specs at 25W and 20W).

I was hoping the receiver performance would be better with regards to rejecting adjacent channel signals and intermodulation. I don’t have a good test bench for that but I can tell you that I noticed some unwanted interference from transmitters that were not close to my location.

How Many dB’s Is That?

So let’s summarize the dB situation.

5W HT with standard rubber duck antenna       0 dB
5W HT with 1/2-wave antenna                  +8 dB
3-element Yagi antenna (Arrow or similar)    +6 dB
25W transceiver (vs 5W output)               +7 dB

Total improvement (25W with yagi vs HT)     +21 dB

Wow, I can improve my signal strength by over 20 dB be making these improvements! I should point out that the antenna improvements help on both transmit and receive, while the increased transmit power only improves your stations transmitted signal.

73, Bob K0NR

The post More Power For VHF SOTA appeared first on The KØNR Radio Site.


Bob Witte, KØNR, is a regular contributor to AmateurRadio.com and writes from Colorado, USA. Contact him at [email protected].

AmateurLogic 110: MFJ’s 45th Anniversary


AmateurLogic.TV Episode 110 is now available for download.

It’s MFJ Enterprises 45th Anniversary.
Join us in this bonus episode of ALTV for Interesting interviews, tours and fun.
1:45:42

Download
YouTube


George Thomas, W5JDX, is co-host of AmateurLogic.TV, an original amateur radio video program hosted by George Thomas (W5JDX), Tommy Martin (N5ZNO), Peter Berrett (VK3PB), and Emile Diodene (KE5QKR). Contact him at [email protected].

Autumn Antenna Adventures Again….

…with Arduino.

I’m not well versed in mechanics. Motors, gears, bearings….not my forte. I know how to work with wood, but not with metal. However, as a ham you should posses some mechanical skills, right? How else will you get these antennas built, up in the air on a tower, with a rotor to move them?

So, for tuning my loop I decided to learn something new and use a stepper motor to turn the variable capacitor. Amazing things, these stepper motors! There was a lot to read about them, like the types (unipolar or bipolar), stepcount, gearing and wiring.

In the Arduino beginners kit I bought for my son there was a small stepper motor, the 28BYJ-48. It’s a 5 Volt motor, so a perfect fit for an Arduino.

I “salvaged” it from my son’s room and hooked it up. Here is a web page about it with all the specs. There is also a code sample on that page and it shows that controlling a stepper motor is not difficult at all. But the code uses a lot of switch statements and that gets unwieldy very quickly.

In such cases a library will help out. A library is just that: a place to look up code to use in your own code. This is usually done by referencing to it and as long as your library is included in your IDE you are good to go. To understand more about how libraries work and how to write one yourself I found this tutorial on the web. I followed it and indeed ended up with my own library to control the stepper motor.

But don’t worry, you don’t have to write every library you need. For almost any input or output device there is a library available and the most basic ones are included in the Arduino IDE. If not, a quick search on the web will yield one you can use, but then you will have to install it yourself (not difficult if you use the Arduino IDE).

With the library installed code looks like this….

The first of the three block of the code has two lines:

#include StepperMotor.h
StepperMotor myMotor(8,9,10,11);

The first line doesn’t need explaning, except that libraries usually end in “.h”. In this case my library is simply called StepperMotor.h.

Now I might have more than one stepper motor hooked up to my Arduino, so I have to make it clear which motor I’m using. Here I use only one motor, so my code reads:

StepperMotor myMotor(8,9,10,11);

In plain English this says that in my code any mention of “myMotor” will reference to the StepperMotor library and it will use the motor connected to pin 8 through 11. If I would have used two motors my code it would have been…

StepperMotor myMotorOne(8,9,10,11);
StepperMotor myMotorTwo(4,5,6,7);

In the setup I add this:

myMotor.setStepDuration(1);

In the library there is a function to set the duration of one step. By simply referencing to is and adding a value between the brackets it has been set. I don’t have to worry about the code that sets the step duration, because the library takes care of it all. Ease and simplicity at its finest.

Now I can control my stepper motor in the loop block:

myMotor.step(4800);
delay(2000);
myMotor.step(-4800);
delay(2000);

myMotor.step() looks up the library function to move the motor and then moves it 4800 steps. After a delay of 2 seconds it moves the motor back 4800 steps. Another 2 second delay and the process repeats itself.

Fine and dandy, but this code might only be useful for moving an advertisement sign, not much else. In my case I needed to control a variable capacitor, so mounted everything on a piece of plexi glass, added a few push buttons and the result looks like this…..


In the end there was a lot more that needed to be added to get it working perfectly. Preventing button bounce was one thing, limit switches were another. Physical limit switches were not an option, so I devised a software solution. To go from maximum capacity (500pF) to minimum capacity (9pF) the stepper motor needs 11000 steps. In my code I therefore added a counter and as long as this counter stays between 100 and 10900 the stepper will work. Now I don’t have to worry about stressing the stepper motor when it reaches either end of the capacitor. By putting the counter’s value in the Arduino’s Eprom I can switch the loop off without losing its settings.

With this part of the project done it’s time to put everything together and box it up.


Hans "Fong" van den Boogert, BX2ABT, is a regular contributor to AmateurRadio.com and writes from Taiwan. Contact him at [email protected].

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