"From Crystal Sets to Sideband" -- A Great Book about Homebrew Radio by Frank Harris K0IYE (FREE!)

I first came across the above picture of K0IYE's inspirational, completely homebrew station many years ago in the pages of "World Radio" magazine. I have already linked to Frank's book many times over the years, but it is so good that I regularly feel compelled to write about it again. Frank updates the book. Just check out the introduction to his website. Frank even has a Spanish language version of his book. All for free. Thank you Frank.

The introduction to Frank's web site:

Over the last century amateur radio has evolved into numerous different

hobbies. Some hams enjoy weekend contests in which they try to

contact as many stations as possible. Others talk to as many of the

world's 341 call areas as possible and collect QSL cards to prove it. Other

hams just like to ragchew with friends. Still others communicate over

long distances at UHF frequencies using satellites, meteorites, aurora and

other substitutes for a sunspot-charged ionosphere. Some hams provide

communications for their communities during emergencies.

Many of us have returned to the early days of radio by building our own

equipment from scratch. Most home builders start by building QRP (low

power) transmitters. If this doesn't satisfy your urge to build something,

you can move on to build the entire station. That is what this website is about.

https://www.qsl.net/k0iye/

Mike WU2D on VFOs (with additional Tribal Knowledge from Frank Harris K0IYE)

Great stuff from Mike and from Frank Harris K0IYE.   But when I put the VFO in a box, I usually try to put the frequency determining components (the coil and most of the caps) in the box, with the powered components (transistor, Zener,  voltage dropping resistors) outside the box.  If I put these powered components in the box, I find there is some drift as these components slowly heat up the interior of the box. 

Dean KK4DAS and he VWS Builders have just stated building analog VFOs, so Mike's video is very timely for them. 

Looking at the Galaxy's Spiral Arms with a Dongle, a Raspberry Pi,and a Homebrew Antenna

I told Farhan that the world NEEDS a homebrew Raspberry Pi observatory at Lamakaan in Hyderabad. They are on it.  

This looks very do-able.  And fun.  And UHF.  And SDR. And Raspberry Pi. 

I'd like to build one too.  I was encouraged by the video demo -- it was done in Alexandria, Virginia, very close to where I live. 

A while back I was lamenting to Dean that I reluctantly threw away a DISH or DIRECT TV  satellite TV antenna.  I worried that I had discarded something that would have been useful for radio astronomy.  Turns out I didn't need it.   This video and the associated .pdf shows how to look at the galaxy with a simple homebrew (Home Depot!) horn.  

https://www.gb.nrao.edu/~glangsto/aas2020/Langston2020AasTelescopeWebinar.mp4

https://drive.google.com/file/d/1ssS_zBQWDEXMENc2_aqqPGxGkEEU5Ea3/view

Thanks to Thomas K4SWL of the SWLing Post for alerting us to this. 

Exorcism Not Quite Complete -- Thinking of Other Options

As often happens, I may have jumped the gun in declaring the exorcism of my 17 meter transmitter to be a success. As readers of this blog will recall, my problem was that when trying to "net" my separate 17 MHz receiver and transmitter, at around 18.116 MHz I could hear more than one tone as I tried to get to zero beat.  The 8th harmonic of my 5.176 MHz carrier oscillator was mixing with the 23 MHz VXO signal and producing a spur.  I could probably knock the level of this spur down below FCC limits, but -- and here is the problem -- I probably could never knock it down to the point that it would not be audible in the sensitive receiver that sits right next to the transmitter.  So this is really a netting problem, not really a spur problem. 

I don't want to try another filter frequency -- I have VXO crystals that really work only with a filter at 5.176 MHz.

So here is my current idea:  Build a receiver board and turn this thing into a transceiver.  Switch with relays the input and output of the 5.176 MHz filter, and use relays to switch to the receiver board the VXO and carrier oscillator signals. 

Making this thing a transceiver would eliminate the need for netting.  This should solve my problem. 

What do you folks think? 

73  Bill 

Roy Lewallen W7EL Gives Us All EZNEC for FREE! Thanks Roy! (Video)

Free download here: https://www.eznec.com/

Thanks to Roy Lewallen W7EL for this great gift to the amateur radio community.  

And thanks to G-QRP for the excellent video (above) of Roy talking about antenna modeling.