We seek to understand and document all radio transmissions, legal and otherwise, as part of the radio listening hobby. We do not encourage any radio operations contrary to regulations. Always consult with the appropriate authorities if you have questions concerning what is permissable in your locale.

Author Topic: GU-50 Project finished  (Read 219 times)

Offline stationqrp

  • Newbie
  • *
  • Posts: 7
    • View Profile
    • Station QRP
    • Email
GU-50 Project finished
« on: April 20, 2021, 0938 UTC »
After about a year of working on GU-50 shortwave tube transmitter project, I finally finished! Download it, build it, enjoy it as much as I enjoyed it.


Twitter: @StationQRP

Offline Charlie_Dont_Surf

  • Full Member
  • ***
  • Posts: 117
  • Charlie's Point, California
    • View Profile
Re: GU-50 Project finished
« Reply #1 on: April 21, 2021, 2127 UTC »
I haven't read it all yet but thanks for the nice write up. I have had a lot of experience with tube (valve) equipment a long time ago and I love the feeling and light in a room full of warm, glowing filaments but my professional experience is strictly in transistors and I appreciate the compact efficiency of them. I probably won't go back. To each his or her own.

Just to be sure the No. 2 ‘scope probe was transferred to the input of the power amplifier and all  was  perfect  there  at  any  volume  level.  So  it  appears  that  these  amplifiers  do  not  like  to  power into the nasty reactive load of a modulation transformer, only a loudspeaker!

I have had similar experiences. I've had more problems at low frequencies where the impedance of the transformer changes the most but I guess you could have probelms at any frequency depending upon the model. It's good to do frequency sweeps and look for unexpected things.
"such a TW*T". "Just ignore...." - Stretchyman

Every minute Charlie squats in the bush, his signal gets stronger...