FDIM Interview with Farhan VU2ESE

I didn't realize that our correspondent in Dayton/Xenia had interviewed Farhan.  There was a typo in the audio file name and I was wondering who this UV2ESE guy was.  A Ukrainian QRPer?   I was really pleased to find out that it was Farhan.  

In Bob's interview you will hear Farhan discuss the capabilities of his new Antuino (pictured above).  Pete's Antuino is in the mail, going transcontinental.  It should arrive in the Newbury Park Laboratory later this week.  

As for the spectrum analyzer that Farhan got me last year, I am waiting for retirement (soon!) to get that one going.  But there is a danger that the Antuino will leave little room for the older tech... 

In the interview you will hear Farhan talk about the Antuino circuitry, and about the roots of the three main devices in the Antuino box.  Very cool.  

Thanks again Farhan. And thanks Bob. 

Here is the interview:

http://soldersmoke.com/VU2ESE FDIM 2019.m4a

Farhan's Antuino page: 

http://www.hfsignals.com/index.php/antuino/

FDIM Interview -- NM0S on John Reinartz W1QP K6BJ -- Scandal on an Arctic Expedition?

John Reinartz, 1QP, at the operating position of WNP aboard the Bowdoin

Bob Crane W8SX interviewed Dave Cripe NM0S about his FDIM presenation on radio pioneer John Reinartz 1QP and later K6BJ. Listen to the interview here: 

http://soldersmoke.com/NM0S FDIM 2019.m4a

Here is Reinartz's obit in the New York Times: 

https://www.nytimes.com/1964/10/07/john-l-reinartz-pioneer-in-radio.html

Here is some background info on Reinartz: 

http://k6bj.org/Club_History/WhoWasK6BJ.htm

Dave Cripe's interview left me wondering what the north pole scandal was all about.   I found this passage from a book that seems to partially explain what happened.  Can anyone else shed more light on this unfortunate event?  

Antuino: Farhan's Compact RF Lab In-a-Box

I now have Farhan's latest invention, the Antuino.  Pete will have his shortly.  Very cool.  SWR meter and antenna analyzer, power meter and scalar network analyzer all in one box. I put an old-school knob on the rotary encoder -- it seemed like the right thing to do.  Soon I will be able to find out if my rigs have spurs or are somehow non-compliant.   I'm sure Farhan's "RF Lab in a box" will be an important addition to my test gear arsenal. We will be talking about this in upcoming podcast episodes. 

Mike N2HTT did a nice write up of the new device: 

https://n2htt.radio/2019/05/26/hello-antuino/

And here is the info from the htsigs.com page: 

http://www.hfsignals.com/index.php/antuino/

Thanks Farhan! 

KG7SSB -- Homebrew SSB in Tuscon -- Learning from the BITX40 Module

On Sun, May 26, 2019 at 1:45 PM William R Meara wrote:

Dale: 

  I was talking to Jim W9UD on 20 SSB today.  When I told him I was running a homebrew transceiver he mentioned that he talked to another guy who is on the air with homebrew SSB gear -- you! 

There are so few of us Dale.  I felt compelled to send you an e-mail.  

What are you running?  

After several years on DSB, I started building separate SSB receivers and transmitters, mostly for 17.  Lately I am running versions of the Indian BITX transceiver. 

Please send info on your homebrew SSB projects. 

Thanks,  

Bill N2CQR

Hi Bill, 

I have two radios that are completed to date. I started out building the BITX 40 transceiver from scratch and also a companion 60 watt solid state linear rf amplifier. Then I decided to construct the second transceiver for 20 meter using some of the BITX design concepts and mixed with the UBITX design for additional rf amplification. It too is amplified to about 25 watts output. The 20 meter rig is my favorite radio at this time but I am going to go a different direction on my next build. It's presently just in the design stage but I'm thinking about using the MC1350 integrated circuits for the IF amplification and for the front end I may try using a FET rf amplifier. The beauty of the bitx design is the use of wide band amplifiers that don't have a tendency to oscillate. But, the new design I'm working on will have more shielding between critical circuits and I will use a small amount of negative feedback in the high gain circuits. The reason for changing the radio to a higher impedance design is to simplify the design build. I will basically build a receiver that I can reverse the signal direction over to transmit using the same amplifiers and filters. This will cut in half the amount of circuit building however it will increase the switching circuit complication associated with this new design. 

Today I'm beginning the build of a 100 watt rf linear amplifier design using the kit parts from China (minipa 70) amps. This provides the transformer components and circuit boards. I purchased two kits of parts and I have a large heatsink to build it on. I'm working on a current sensing circuit for protecting the final FETS.  It  will run 4 IRF530's tied together with a splitter and combiner for the input and output matching transformers. It should produce at least 100 watts at 75/80 meters and maybe a little less on 40 meters but 20 meters it will drop off to about 60 or so watts. 

I'm just having as much fun as a guy can have playing around with the homebrew radio's and like you say there's not many doing it these days. I love operating a radio that I built vs. running a factory made radio. I have two commercial rigs on my bench and a couple of Collins radios but the homebrew takes the lead. 

Jim W9UD has become one of my ham friends this year. We end up talking every week or so on the air and keeping touch with local weather conditions.

Side Note:

I wanted to build a SSB radio since I was a young lad with a technician license in the early 60's. SSB came into the picture many years after I was first licensed.  Then move forward to 2015 my ham license had long ago expired during my time in the Vietnam war. I spent several weeks studying the tech, general and finally the extra class exam information and passed on through that adventure. So I decided it's time to build my own radio from scratch. So I started to look online and in books and I still didn't have the confidence to begin building. Then I ran across Farhams BITX 40 and I thought why not buy this radio and just use it as a model of how sideband circuits work. So I did just that and I got it working fine I took the radio and placed it on the test bench and began circuit analysis and signal level evaluation until it all made perfect sense. This is accomplished while transmitting so the levels can be seen on the oscilloscope. Just kill the voltage on the final stage of the bitx. I put a 1khz signal on the mic input. That was just about the only thing I used the bitx 40 rig for and I still keep it handy when I need information. 

Good hearing from you I hope I haven't over done this reply but I really enjoy talking about this subject.

73's Bill.... keep up the building and good luck on your next radio. 

Dale KG7SSB

-----------------------

And of course, Pete N6QW knows Dale and has been talking about SSB with him for some time... 

Workshop Tour -- Good use of older test gear (video)

This fellow is making good use of older test gear.  Very nice.  

https://www.youtube.com/watch?v=2LPcLAkhdFE

http://gokarters.com/smf/index.php?topic=2549.0

DIY Waterfall -- A Quick and Easy Panadaptor Using a Sig Gen and O'scope (video)

I've been getting waterfall envy.  The panoramic frequency display is the one thing that could lure me to the dark side (SDR).   Heck, they now have 3D waterfalls!  What next?  Holographic waterfalls? Virtual reality waterfalls?  This is almost too much. 

Anyway, in an effort to counteract all of this waterfall seduction and to show that us analog HDR guys can go panoramic too, I decided to try to create my own panoramic display without resort to SDR.  

Of course, this is a very old technique.  It was invented in the 1930s by Marcel Wallace, F3HM.  He was the inventor of the Panadaptor which was the forerunner of today's waterfall.  Panoramic reception was used by the armed forces during WWII.  In 1946 Hallicrafters marketed a Panadaptor for its ham radio receivers (see below). 

In figuring out how to do this, I thought back to my use of my Feeltech signal generator to scan the response of a crystal filter.  The Feeltech has a very handy sweep feature.  

In this case I set up the Feeltech to sweep from 4.85 MHz to 4.75 MHz in one second.   With the 12 MHz IF of the BITX40 module, this would result in a sweep from 7.150 to 7.250 MHz. 

The sweeping Feeltech just replaced the VFO on my BITX.   I hooked up the Rigol oscilloscope to the audio output of the BITX.  I set the horizontal scan rate at 100 ms per cm.  This would have the trace go across the whole screen in 1.2 seconds. 

After a bit of fiddling, I could see signals on the 40 meter phone band.  But my display would kind of drift along the screen making it hard to know the frequency of the signals I was seeing. 

Alan Wolke W2AEW provided the solution.   He advised me to put a big stable signal at 7.150 MHz near the input of the BITX, then use this strong signal to trigger the 'scope scan.  The HP8640B signal generator that Steve Silverman gave me (and that Dave W2DAB picked up for me in NYC) provided the triggering signal.  

I put a piece of tape across the bottom of the scope display to calibrate the display.  See video above. 

It works!   It is not as cool as the SDR waterfalls, and it does not convey nearly as much information, but it was a fun project. 

More here: https://en.wikipedia.org/wiki/Radio_spectrum_scope

http://www.astrosurf.com/luxorion/qsl-ham-history7.htm

KJ5VW's Cool uBITX Mods (Video)

Beautiful work Gary, and great to see that you are putting ideas from Pete and from Don Cantrell in your rig.  

Gary wrote:

Don and Pete,

I thought you would be interested in the QRP station accessory I added to my version 3 microbitx transceiver.  In addition to using Don's AGC and Reverse/Forward Power and SWR  circuits, I developed another board using a separate Nano and TFT display to show day, date, time, temperature and humidity as well as showing the relative audio strength in three separate bands centered on 400 Hz, 1000 Hz and 2500 Hz.  In addition, when I put the transmitter in a 'tune' mode the power out and SWR will show on the TFT display as well.  The date, time, temperature and humidity information is updated once every minute, the audio is displayed continuously during receive and the power/swr is only displayed when the transmitter is activated.

The audio frequency analyzer is based on the MSGEQ7 microchip and it actually picks up the audio strength in 7 bands covering 63 hz to 16,000 hz.  I just display the three most likely to show up in a SSB transmission.  You can see a 'live' example near the end of the video showing a 20 meter QSO and how the audio strength by audio frequency varies over time.

This project falls into that 'frivolous but fun' category that was a challenge to design but I doubt many other hams would want to replicate it. I learned a lot and wanted to thank both of you for arduino scripts, useful circuits and lots of inspiration for getting started.  I have long admired the work both of you contribute to our hobby.

Here's the link to the YouTube video. 

https://youtu.be/v84TUqsVtTg

73,  Gary KJ5VW