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32s-3 VFO no output

Discussion in 'Ham Radio Discussions' started by KA4LBI, Oct 14, 2021.

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  1. KA4LBI

    KA4LBI Ham Member QRZ Page

    Hello all, this my first go-round with this forum so bear with me.... I am attempting a repair on a 32s-3 transmitter and moving trough the block diagram and the schematic, I got to the first mixer V4a and at pin 2 and pin 7 of the 12at7 in transmit mode, all I have is 455 khz. and no VFO input resulting in no 3.155 to 2.995 Mhz out put to T1. I tried to trace the output of the VFO V301 but the tube socket pins are not available for testing. the multiconductor cable that come from the 70K-2 assembly has coaxial line that goes to the device behind the Frequency Control Selector Switch. when I select the Transmitter VFO selection where is the best place to measure the output of the VFO? Respectfully, Brooks Barnes KA4LBI
     
  2. W0FS

    W0FS Ham Member QRZ Page

    if you want to see voltage or waveforms at the tube pins, get a test adapter for the (7 pin?) socket. There is a name for it that escapes me. Adapter plugs into tube socket, tube plugs into adapter. Terminal for each pin outside adapter.
     
  3. KA4DPO

    KA4DPO Platinum Subscriber Platinum Subscriber QRZ Page

    Try replacing the 6AU6 tube first. They tend to get gassy, and they do fail over time.
     
  4. WB2WIK

    WB2WIK Platinum Subscriber Platinum Subscriber QRZ Page

    I'd post this on the Collins reflector, run by the CCA. Those guys know everything!
     
    N8ZL likes this.
  5. KA4LBI

    KA4LBI Ham Member QRZ Page

    Thank you sir .....I ordered one today...Brooks
     
  6. KA4LBI

    KA4LBI Ham Member QRZ Page

    I replace the 6au6 with a new one .... still no input at the first mixer from the VFO
     
  7. KA4LBI

    KA4LBI Ham Member QRZ Page

    Thank you I will post on the reflector now....Brooks
     
  8. KA4LBI

    KA4LBI Ham Member QRZ Page

    I found the problem .... the VFO had no B+..... R17 was open.... replaced R17 .....now ok.....Brooks
     
    KA4DPO and KP4SX like this.

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