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Tram D201 Multi-section Caps

Discussion in 'General CB Services Discussion' started by Wildcat444, Sep 19, 2020.

  1. Wildcat444

    Wildcat444 Yea, that's right.

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    I am doing the restoration on a 1976 Tram D201 (2nd version). I will replace all electrolytic caps and high power resistors.



    What are people using to replace the original Tram D201 Multi-section Caps?

    I see that Mike's Radio Repair and some others appear to be using new JJ brand caps to replace the original multi-section caps. From the values that I see available, it looks like I could use the 40/20/20/20, and a 50/50, then use an additional 20uf... this would be 4X20uf for the 4x10uf in the schematic, a 40uf from the 40/20/20/20 for one of the 40uf on the schematic, and finally the dual 50/50 for the other two 40uf on the schematic in parallel.

    So I could basically get all sections of the to original multi section caps taken care of with two new ones plus one single. I also read however that you one of these JJ caps could be a dual 100uf because the 40uf in parellel would effectively be 80uf and 100uf is close. But then I would have an unused 100uf which seems high to use for one of the other positions. What are you experienced techs using or what have the techs you sent your radios to using?

    Thanks!
     

  2. BJ radionut

    BJ radionut Supporting Member and 6m addict

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  3. nomadradio

    nomadradio Analog Retentive

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    The two-section 500-Volt caps are perfect for the D201. LCR brand, F&T or JJ all seem to hold up just fine. A cap rated at only 450 Volts gets stressed while the tubes are cold when first powered up. Voltage on the 3-section cap can jump to nearly 500 Volts, and then falls to the normal 405 to 410 when the tubes warm up and draw current. Using a 450-Volt cap for this can cause a shortened service life.

    We have been using 10uf 450 Volt radial caps to replace the four-section 'can' and the two axial caps in that vicinity. For three of the four sections, you can follow the single wire soldered to each of those three lugs, and put a radial cap onto the circuit board edge where the other end of each wire was connected. This leaves the one section with two 7-Watt resistors on it. We put a single tie point there to support the resistors and the radial cap.

    Snapped some pics of this recently. With any luck, I can get some of them posted before long.

    73
     
  4. DoctorAudio

    DoctorAudio Active Member

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  5. Wildcat444

    Wildcat444 Yea, that's right.

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    Thanks guys, this really helped a lot! What a fun project. Well, I have chosen to use a dual 100uf / 500v in place of the three section 40-40-40uf, and a dual 50uf / 500v along with two additional 50uf 500v single caps in place of the 10-10-10-10.

    It seems someone did a sloppy job with an attempt at recapping these multi-sections a few decades ago. Nomadradio, if you are able to provide those photos, that would be VERY helpful!! It's difficult to tell what was moved/changed exactly with just the schematic.
     
  6. guitar_199

    guitar_199 Well-Known Member

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    Wildcat444 and tecnicoloco like this.

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