The are likely “wet” electrolytics, which seem to last almost indefinitely.
The grey colored military “extended life” electrolytics are also surprisingly long lived. Probably due to excellent sealing.
I for one am not an advocate of wholesale component replacement, but I have waxed on the subject in the past, so I’ll refrain.
I replace “on condition”, or as the USAF/USN say “IRAN”- Inspect and Repair As Necessary.
Scott W7SVJ
From: mrca-bounces@mailman.qth.net <mrca-bounces@mailman.qth.net> On Behalf Of Ray Fantini via MRCA
Sent: Friday, February 28, 2025 09:32
To: mrca@mailman.qth.net; MMRCG@groups.io
Subject: Re: [MRCA] SCR-284 - BC-654 progress 3.11
Addendum to 3.1, Last night removed the connections to C19 and 23 and checked them and as I suspected after eighty years, they are still good. Don’t know why but those old early large electrolytic capacitors somehow hold up well. On the other hand, there are two Sprague wire would resistors that somehow deteriorated to a point where the leads broke right off when touched. Now will need to replace them before anything else gets done. Do not see any signs of water damage or other corrosion anywhere else in the radios but cannot explain the deterioration of the two Sprague wire would resistors. Anyone else seen this?
Ray F/KA3EKH