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Author Topic: I finished this QRP project  (Read 1770 times)

Offline ve3lyx

  • Commodore
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  • Posts: 159
  • Country: ca
I finished this QRP project
« on: January 22, 2014, 15:38:44 UTC »
I finished this QRP project I started some years ago. The transmitter is a three transistor model I built from circuit in a book. It has a NTE128 final and makes decent but not big power. It is very good on CW and I just added AM phone with a absorption loop which works very well. The receiver I designed and built a couple of weeks ago and just finished the final refinements Monday. It is a three transistor regen with a FET regen detector and a two stage audio amp. The receiver uses no variable capacitors or vcap diodes but uses a fixed cap (220pf) across a ceramic slug tuned coil. Result is no hand effect , no vernier required, as tuning is at a very comfortable rate and it is rock solid. The regen control also uses an absorption loop to pull excessive feedback from the tickler. Once set I can tune across the 80M band both CW and SSB signals with no further trimming required.  Best SSB receiver I have here. Set is 12v powered (cigar lighter socket or portable 12v gel battery etc.

Offline KI6J

  • Petty Officer
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  • Posts: 13
  • Country: us
Re: I finished this QRP project
« Reply #1 on: January 24, 2014, 00:19:01 UTC »
Neat rig, Don.  I like the slug-tuned coil. Is it commercial or did you homebrew the hardware?  I've made a few homebrew PTOs with just a brass screw and no slug, and I like the results.

We' going to need a homebrew forum.