Transverter - ran too much power to it, now what?

Discussion in 'Radio Circuits, Repair & Performance' started by K9OO, Feb 11, 2018.

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  1. K9OO

    K9OO Ham Member QRZ Page

    I bought a transverters store 146 to 10m transverter with attenuator board for Christmas. After moving the shack around, I forgot to swap the antenna output on the rig. Which means I accidentally ran 60w into it while it was powered off. The max is supposed to be 5w.

    It still receives fine, bit doesn't transmit. The transmit light comes on, it sounds like a relay comes on, but no output. I pulled it apart, but there is no visible damage. I pulled the mosfet and that tests out ok. Any idea where I should start looking?

    Tldr: ran too much power to transverter, what is broken?
     
  2. VE1IC

    VE1IC Ham Member QRZ Page

    check the drivers and finals on the PA
     
  3. WB2WIK

    WB2WIK Premium Subscriber QRZ Page

    I'm unfamiliar with the "transverter store" unit. Is there a schematic diagram for it on line anywhere?

    I'd think if you transmit into a transverter with an attenuator to reduce drive power installed, the first thing to fail from excessive power applied would be either the attenuator itself or the mixer stage that follows it.

    The "driver and PA" should be pretty far down the line from that (not near the 28 MHz input area, but at the output/antenna area of the circuit) and would have tuned circuitry for 2m that strongly rejects RF at 28 MHz.

    I'd look first at the TX mixer and also at the attenuator.
     
  4. W9GB

    W9GB Ham Member QRZ Page

    146/28 MHZ TRANSVERTER BOARD : $35 USD
    Designed and sold by Serge, UT5JCW
    http://transverters-store.com/146mhz.htm
    7776FD13-0B08-4ECF-8132-6413A33FA42B.jpeg 4CF7B037-43A8-4293-A547-1669F77FBA03.jpeg
    F5DQK comments about transverter design not meeting stated specifications.
    http://www.eham.net/ehamforum/smf/index.php?topic=118187.0

    146/28 Transverter Manual and Schematic
    http://transverters-store.com/144mhz/TR-146 Manual.pdf

    Transverters Store
    Company is based in Ukraine
    E-mail: transverters@usa.com
    Phone: +380-505768707

    http://transverters-store.com/

    Repair?
    Start with schematic, parts list ... and Electronics Knowledge / Bench Tools.
    7EBFB537-565F-48C7-9800-8F8E3688078F.jpeg
     
    Last edited: Feb 11, 2018
    KB4QAA likes this.
  5. K6CLS

    K6CLS Ham Member QRZ Page

    While it's interesting and educational to debug and fix it, for $35 I'd order another one (or two ;). So I could continue operating while I work on the borken one.
     
    K3RW and K9OO like this.
  6. VE1IC

    VE1IC Ham Member QRZ Page

    Oy, didn' t see that is is a transverter PA. Yeah, there is probably something either open or shorted on that lil transverter board.
     
    K9OO likes this.
  7. K9OO

    K9OO Ham Member QRZ Page

    In reading the info page, if the device is turned off, it is supposed to divert to the HF antenna port. Unfortunatly, this port was empty for me. I may have blown that relay? I stopped testing and ordered new boards for the box - $33+shipping. I can rewire it all again and have my transverter back.
     
  8. WB2WIK

    WB2WIK Premium Subscriber QRZ Page

    What would have been taken out instantly would be Q5.

    Possibly also RV1, L14-L15 and maybe C43-44-45 and the input swamping resistor (I can't read its designation on this screen but looks like 180 Ohms across the 28 MHz input just prior to the low-pass input filter).
     
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  9. K9OO

    K9OO Ham Member QRZ Page

    AWESOME! I wish I could understand this better. I can swap parts, but understanding it eludes me. Make it a gas motor and I can get it troublshoot quickly enough :)

    Q5 is also what the manufacturer suggested would be bad. I will check it out when I get some shack time in about 3 days.
     
    K3RW likes this.
  10. K3RW

    K3RW Ham Member QRZ Page

    I've noticed these transverters seem to have all sorts of problems. But puts me in a bind because $85 for 222mhz is a lot better than the $500 lot from Q5 (the new DEMI supplier for UHF/VHF but not SHF) or take chances with a several hundred dollar used unit.

    W1GHZ has plans and parts (no prices) but I'm a shaky solderer. Microwave Modules went away years ago and most that I've seen are untested, missing power cables, etc. And the Kuhne ones are $$.

    Is there another source for these? SG Labs in Bulgaria does only 902, 1296 and 2.2. High quality units at about $200.

    But I'm finding nothing sub-$200 for 222mhz,and zilch under $500 for 5 or 10ghz. I'm using a drone transmitter at the moment for 5ghz.

    Am I missing a great source out there?

    Yep, wish I had a 736R but if I could afford that I wouldn't need a transverter!

    I'm tempted to build a mixer or multiplier and run it for 222mhz but I am way over my head there.
     

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