Vintage PACO C-25 Cap Checker Resto

Discussion in 'Amp Tech Center' started by Luthier Vandros, Mar 24, 2020 at 4:08 PM.

  1. Luthier Vandros

    Luthier Vandros Tele-Holic

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    Well, no. It's not quite a tube amp, but it sure makes troubleshooting them easier. PLUS, it's got two tubes in there! NO rectifier! This is my first venture into RF tools and it's very exciting.

    She came in sassy n' nasty. Full of dust, sticky controls, stiff A/U coax, flimsy power cord, you name it.
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    Let's crack her open. Hey, is that a Bugle Boy EM84? Yep!! A nice Euro eye tube.
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    ...and check out this GE 6C4.
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    There's that sticky power switch. No problem.
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    Here's the old RG62 A/U (49 ohm). This unit uses precisely 40" of it to form a precise 1/4 wavelength of the 40MHz test frequency. Not only is the original cable too short, it was haphazardly repaired, so off it goes.
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    The old .1uf cap in the background has a severed lead. I didn't realize this at the time I took the pic, but his time is coming,
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    Old, dried grommets! I forgot to mention those prior. There are 2 x 3/8" grommets on this unit. One for the test leads and the other for the power cord. Both grommets have been replaced, along with the addition of a grounded cord.
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    The new guy.
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    Seshual shocklate. I need to find a little leather handle for the thing. Waiting on the coax and silicon test lead cables to arrive.
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    Opposite the cathode within the envelope is a rectangular fluorescent target. The voltage on the grid directs the angle and size of the electron stream that strikes it, causing it to glow green/blue over various portions of the fluorescent material's length.
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    Once the new coax/test leads are attached, I can align this thing and put it to use. Update soon.
     
    Wayne Liska, dan40 and Jon Snell like this.
  2. Jon Snell

    Jon Snell Tele-Meister

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    Nice little bridge with the 'magic eye' as an indicator. All the rage in the 50's. Originally sold in kit form.
    Here's a schematic.
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    Luthier Vandros likes this.
  3. Luthier Vandros

    Luthier Vandros Tele-Holic

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    Yah, the cat who assembled it originally did a pretty fair job of it.
     
  4. dan40

    dan40 Tele-Afflicted

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    I have a very similar Paco bridge that I had restored a few years back. I still enjoy pulling it out from time to to time to check old caps for leakage.
     
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  5. Luthier Vandros

    Luthier Vandros Tele-Holic

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    Found a good use for this old pilot lamp I’ve been hanging onto.
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    corliss1 likes this.
  6. Luthier Vandros

    Luthier Vandros Tele-Holic

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    COMPLETEDDDDDDDDdddddd.....d
    Requires a precise 40" coax/test lead to create a 1/4 wavelength stub.

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    Added top handle and rear cable wrap. Well, that's a handle, too.
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    Last edited: Mar 26, 2020 at 4:28 PM
  7. Luthier Vandros

    Luthier Vandros Tele-Holic

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    The NOS 6C4 arrived yesterday. It's been installed and the unit is now realigned and ready for service. What a fun tool!

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  8. Texas Special

    Texas Special Tele-Meister

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    That's very cool. Limited use of course. But, well done in keeping a wonderful piece of equipment going that you can actually use.
     
    Luthier Vandros likes this.
  9. Luthier Vandros

    Luthier Vandros Tele-Holic

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    C2 is supposed to be 100pf btw. Or micromicro haha.
     
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