Can you re-stuff a Collins vintage tube receiver plug in Filter Cap? Military 51J4 R388

Comments · 30

• DE

  @Delatsch · 2 months ago

  You can take a thin drill bit and drill through the pins and pull the leads of new capacitors through.

  8

• DH

  @dhpbear2 · 2 months ago (edited)

  <a href="https://www.youtube.com/watch?v=RNbIF_rcAv4&amp;t=283">4:43</a> - Maybe that resistor represented the actual amount of ESR in the capacitor! :)

  3

• KR

  @kraftconspiracies8480 · 2 months ago (edited)

  I have rebuilt two of those and also used a tubing cutter. I had to heat up the can a bit with a torch to losing the inards enough to be able to pull it out. Then I drilled holes for the new capacitor leads and soldered them to the pins. The pins on my caps were nickle plated brass, so I had to file away the nickle.I just closed mine up with scotch tape, since the cap is held in place with a clamp on top. Works very well and keeps the original build too.

  1

• WA

  @wa4aos · 2 months ago (edited)

  I took the old cap outside with a propane torch, carefully removed the the stuff attached to all 4 pins, tapped &nbsp;small brass screws to the holes, 4-40, I think, maybe smaller, to the 4 holes, then soldered a small copper wire, just long enough, to attach the cap leads. Worked great. Similar on the R390A receivers with plug in caps.

  4

• DH

  @dhpbear2 · 2 months ago

  I always thought <b>attaching copper to aluminum was a no-no.</b> remember stories of mobile homes burning down when someone would add a copper outlet to the existing aluminum wiring.

  3

• DE

  @derstrom8 · 2 months ago

  I use a Dremel and cut the can right at the top of the &quot;bulge&quot;. Then I pull out the old capacitor, cut off the leads, drill out small holes in the &quot;base&quot; right near the terminals, and feed the new capacitor leads through. Then I solder the capacitor leads to the terminals, and reattach the can to the base using 5-minute epoxy. Since I cut it right where the can meets the bulge, the seam is nearly invisible

  2

• KE

  @kenchilton · 2 months ago

  Three techniques are common aside from the mechanical suggestions made (tapping and installing a screw). <br><br>First is using a transition metal. Aluminum can be nickel, tin, silver, or gold plated. Those platings can be soldered. Electroless Nickel followed by Silver or Tin plating would likely be the most successful connection. &nbsp;I suggest coating the finished joint in an epoxy to waterproof the galvanic transitions. &nbsp;<br><br>Second is spin welding. Leave the flat aluminum surfaces in place, chuck that pin in the tail stick, and spin a copper wire in the lathe, pushing the tailstock to create friction. If you have a high speed lathe, or a friend with one, this is an easy way to get to a solderable copper connection.<br><br>Battery packs often have to join copper to aluminum, and they use ultrasonic welding for that, so there is a third way. &nbsp;If you check with your friends who may dabble in making batteries, they might have such a welder. They only cost about $500, so a dedicated hobbyist might have one. Another option is the capacitive discharge spot welders. They might also work well for this.

  1

• BL

  @Bleats_Sinodai · 1 month ago (edited)

  The trick for soldering to aluminum is buffing the surface, immediately putting beeswax or paraffin on it (it&apos;ll work like argon for welding, keeps surface from oxidizing, and also as a sort of solder flux), and a lotta heat (Snozeramous type heat). In this case, I believe the pins will melt through the base before you can get any solder to stick.

  1

• MI

  @michaelmiller641 · 2 months ago

  i just leave the old caps in place, disconnect them underneath, and wire the new caps underneath, it still looks vintage!

  1

• JE

  @jeremiahlyleseditor437 · 2 months ago

  Terry, drilling a hole for a #2-56 × 1/8 in, or smaller in those posts then attaching the capacitor leads to that internally, might have worked. <br>Might be an idea for the future just to save you some time and money.

  1

• DA

  @davidthomas3859 · 8 days ago

  I use a metal lathe and trim the swayed part only then glue the can back on. You can’t tell.

• EU

  @eugenepohjola258 · 2 months ago

  Howdy.<br>Snozzeramus and Cutteramus are a powerful duo alright ...<br>Cheers.