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Ameco PT preamp

Discussion in '"Boat Anchor" & Classic Equipment' started by KJ4UO, Aug 13, 2018.

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  1. KJ4UO

    KJ4UO Ham Member QRZ Page

    Hello from KJ4UO in Navarre Florida.
    I have been working on an Ameco PT preamp. I found that the transformer had high side open and replaced it with another from another preamp. Then the diode and caps for the power supply were shorted, this must have taken out the transformer.

    I need to get a schematic, it has one tube which is a 6EH7. There are alot of Ameco preamp schematics out there but none of them are of this old unit. Can't tell if the problem is the tube or the circuit. It's simple circuit and all elements check. There a a few different ways to connect the preamp and I may just need the owner manual.

  2. WA2CWA

    WA2CWA Ham Member QRZ Page

    I have the complete manual available.
  3. WA7PRC

    WA7PRC Ham Member QRZ Page

  4. KJ4UO

    KJ4UO Ham Member QRZ Page

    Thanks Pete and Bryan.
    The manual and schematic just what I needed.
    Crazy that google never hit on this one for me.
    I did check bama but the site was off line this weekend.

    de KJ4UO
    WA7PRC likes this.
  5. KJ4UO

    KJ4UO Ham Member QRZ Page

    Replaced the power supply diode and filter caps plus the tube and now it back to working.
    Ordered 2 tubes off ebay for $7. Zenith brand, appeared to be unused and brand new.
    This preamp only needs one tube, so the other is back up. The tube is 6EH7
    WA7PRC likes this.

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