[MRCA] R1155 Receiver Project

[Ray Fantini]

With all respect to K4CHE(Old Max) It is not lost on me that you were rebuilding and restoring radios before I had any idea how to use a soldering iron, and that perhaps there is no aspect of the craft that you have not done before me and often better.

I still have to say those stupid British triple cans are blight in the world of radio restoration, and in no way add to the character of the radio!

This is the third R1155 I have had the opportunity to play around with and on every one all of the triple headed monsters are bad. Not in any way you would expect because if you use a modern capacitor tester the capacity is just fine, but use a real capacitor tester and you quickly discover they all leak worse then the Titanic. Just about each one is leaking at least 1 Ma @ 250 volts, when you consider that there are around a dozen just in the IF chain you can be dissipating around 20 Ma just there, not to mention that they are on each screen and after a series limiting plate resistor so the plates and screens are run at reduced voltages. Then there is the wax, what in the Hell did they use for filling those things with? It’s like ear wax and of course when they leak they get warm and all that wax runs out the bottom of the can all over the wires and everything else around the can. And last but not least the wires themselves are some form of primitive PVC covering that maybe because of the wax or they just don’t age well falls apart when you touch it. The parts that don’t fall off and short out to the center tube of can have the wonderful habit of melting and falling off when you are soldering them to there contact point.

After removing the cans including there attachment nut that not metric or SAE , its mound of dissolved melted wax and Octopus cluster of red wires there is plenty of space to install modern 0.1 400 volt Mylar capacitors from the IF wafers and tube sockets to ground.

All I can say is that anyone who has cleaned out those cans, would deal with the ear wax and installed new wires just to somehow keep a all original appearance on the inside of the radio that has no affect on operation beyond aesthetics must have the patience of Job and is a better man then I am.

Perhaps I am not up to the challenge of stuffing capacitors, but those little triple headed bastards don’t deserve to live!



Ray F/KA3EKH

________________________________
From: mrca-bounces at mailman.qth.net <mrca-bounces at mailman.qth.net> on behalf of B. Smith <smithab11 at comcast.net>
Sent: Wednesday, January 11, 2023 6:36 PM
To: Military Radio Collectors Association <mrca at mailman.qth.net>
Subject: [MRCA] R1155 Receiver Project


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One of the interesting challenges when restoring a R1155 is rebuilding the many tubular capacitors that are mounted vertically on top of the chassis - -  Often they are ripped from the chassis and substitute  caps are installed underneath but this results in complete alternation of the appearance of the receiver and thus you lose a lot of the original personality.   [cid:part1.9W0Dc74t.6iOIBZtF at comcast.net]     In addition it is very crowed underneath the chassis.
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[cid:part2.tsOALwd4.6qHJ0dSM at comcast.net]
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