[AMRadio] Boat Anchor Receiver

[Brett Gazdzinski]

I think you can also do L-C coupling if you do not need the IF transformers to do the bandwidth.
My receivers are very simple, link coupled antenna input tuned with a cap (preselector) right into a simple mixer, simple LO circuit using no tricky coils, then into the IF filter, into 3 stages of IF amp, low distortion detector.
Add on ckts for S meter and a 455 KHz xtal bfo for zero beating signals.
The digital display just has a pickup wire around the LO tube, and automatically compensates for any drift.
You need no sort of RF amp up to 20 meters.

The first receiver was very experimental, and I even did things like mount the IF transformers on octal tube bases and used sockets to plug them into. That way all I needed was a round hole and could try different setups.
I did try different IF amp tubes, some types had too much gain and were unstable.
I also tried all sorts of LO setups, and having a spectrum analyzer helps a lot in seeing how the LO worked, its range and amplitude and drift.
I used a high end piece of equipment, but an sdr-iq  would be even better.
I found the LO would work down to as low as 10 volts on the plate, and VR tube regulated it at 90 volts.
The highest voltage in the receiver is 125 I think, and the simple line up and lack of high voltage high gain stages equals a VERY low noise level.

Eddy, your receiver looks great.
Another advantage of building your own is you can style it how you like.
Mine match the rest of my homebrew stuff, others that have built my receiver used vintage cabinets for a 1960's look, and even put everything on separate small circuit boards in sections, and it looks much better then how mine turned out.

Receivers are very fun projects and you learn a LOT when you build one.
No big expensive parts to find, and you can likely get a lot of stuff out of any old tube table top radio.

I have homebrew transmitters, receivers, antenna's, and thought it would be cool to make a microphone to complete the station.

Brett
N2DTS
  ----- Original Message ----- 
  From: Eddy Swynar 
  To: Brett Gazdzinski ; Discussion of AM Radio in the Amateur Service 
  Sent: Sunday, December 25, 2011 8:27 AM
  Subject: Re: [AMRadio] Boat Anchor Receiver







  Hi Brett,


  I, too, have built no less than THREE receivers here in my 40 year tenure as a Ham. Allow me to share my experiences along these lines with you & the group:


  (1) A regenerative receiver may look easy to be build, but it can drive you to drink very quickly making it work right!


  (2) IF transformers CAN be homebrewed---I have seen at least two links on-line with information on exactly how this can be done. Google it.


  (3) A hand-wound enamel wire coil on a plastic pill container sealed with clear fingernail polish works just as well as a piece of B&W coil stock.


  (4) Do NOT start "BIG" & overly ambitious in the making of a receiver---you'll quickly become overwhelmed, & disillusioned. Start small first, & learn from your mistakes (a good beginner's project this way is "A MATE FOR THE MIGHTY MIDGET", ref. 1969 ARRL HANDBOOK, & April 1966 QST).


  (5) THERE IS NO FEELING OF ACCOMPLISHMENT IN HAM RADIO AS THE JOY & SATISFACTION THAT YOU'LL DERIVE WHEN YOU MAKE TWO-WAY COMMUNICATIONS WIITH YOUR FELLOW HAMS USING A STATION THAT WAS 100% CRAFTED BY YOUR OWN HANDS!!!


  Don't be intimidated to start, don't give up---remember, THE LONGEST JOURNEY BEGINS WITH THE FIRST SMALL STEP...!


  ~73~ de Eddy VE3CUI - VE3XZ


  PS: My last HB receiver creation: http://www.superhets.info/page9.html