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Old 5th Dec 2017, 10:21 am   #48
PsychMan
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Join Date: Jun 2013
Location: Fleet, Hampshire, UK
Posts: 1,764
Default Re: AR88 Low HT

I've removed the 3 remaining bathtub units and gave them a test for capacitance and leakage using the reform/leakage tester described on this site. Nothing too shocking in terms of capacitance, some values were up to 25% higher than stated. The tub containing C76, C56, C93 tested pretty poorly. With C76 showing 15ma leakage at 350 volts, others 6ma and 3ma. Other 2 tub units tested fine for leakage with all showing well under 0.6ma.

As they were removed I gutted them anyway cutting the backs off as before. Unfortunately my nitrile gloves did manage to split during the process and I got some oil on my finger which I quickly washed off - not ideal. In terms of risk I've had a pretty negligible exposure, but all the same its a reminder to be cautious If doing any rough work with light duty gloves on! Que Sera.....

I'm in the process of fitting new caps into the tubs and hope to get them installed on the weekend. I read somewhere that while these are non polarised caps, it might be better to install them so that the outer foil is connected to the earth end. I cut one open to check this and will install this way for these units - too late for the others. I'm using those yellow polypropylene "TSE" capacitors on this receiver as I've found them to be pretty decent and have loads of them.

I found the electrically leaky tub unit, had a fair bit less oil than the others did. I'd imagine this contributed to the spillage on the case. PCB or not its horrible stuff and I will be glad to be rid of it completely!

Last edited by PsychMan; 5th Dec 2017 at 10:33 am.
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