Friday, November 8, 2024

Video Update on the Mythbuster II 20 meter SSB Transceiver


I have added the transmit circuitry. I described building practices. We listen to the receiver again. I talk about plans for transmit/receive switching. After this I will build another CCI 100 watt RF amplifier for use in the Dominican Republic.

For the first look at this rig see:
https://soldersmoke.blogspot.com/2024/10/bill-n2cqr-builds-yet-another.html

 We will discuss this further in an upcoming Ham Radio Workbench Podcast, and in SolderSmoke Podcast #254 (mid-November 2024) 

5 comments:

  1. The SBL-1 can also get burned out :) I took the metal cover off a broken one thinking it might be repairable and it was potted with some kind of white rubber - yuck.

    I wonder if the receiver quiet might be due to the lack of AGC and preamp ? People seem to enjoy being able to report that a signal is XX db over 9 but then they will often complain about the noise - maybe it's all that gain from the preamp and AGC ?

    Best Regards,
    Chuck, WB9KZY

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  2. Chuck: There is no RF amplifier ahead of the mixer. On receive it is jus the antenna to the LP filter then to the BP filter and then the mixer. This helps. Also no OLEDs or Clocks or other noise generators. It does sound good. And it is good on TX. I just worked South Africa with it, using 3 W QRP. It is still on the bench! 73 Bill

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  3. Great walk-through of a cool project. Now I feel better about using a Drake VFO assembly on my next homebrew project instead of reworking my past Franklin VFO project. I may still rework the Franklin anyway just because it looks like a good technical challenge.

    Wes
    W4JYK

    ReplyDelete
  4. Wes: FB. But I think there is a reason why the Franklin never caught on: Why do with two transistors what you can do with just one? 73 Bill

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    Replies
    1. There are other LC oscillators that use two transistors, recently learned of this one, the Peltz oscillator:

      https://wiki.analog.com/university/courses/electronics/comms-lab-peltz-osc

      more transistors but possibly fewer parts overall.

      Best Regards,
      Chuck, WB9KZY

      Delete