[R-390] Capacitor tester...

[Pete Lancashire]

and everyone remember save those black/brown Beauties and sell them on
the E. They are selling
for up to $20 each used, I've even seen cracked ones sell for over $5.

-pete

On Wed, Mar 7, 2012 at 2:37 PM, David Wise <David_Wise at phoenix.com> wrote:
> I'd add that they should be checked when hot.  Leakage goes
> up fast with increasing temperature.  It may look okay cold.
>
> After I got my 390A, I decided to replace all of the Prokars
> (Brown Beauties) that were (a) highly charged, or (b) at
> high-impedance points.  I left the cathode bypasses alone.
> Just for fun, I hooked the IF deck to a current-limited power
> supply (B+ only), put it in the oven on low, and left it overnight.
> Next morning I found two shorted caps, and I was a believer.
>
> Dave Wise
>
>>-----Original Message-----
>>From: r-390-bounces at mailman.qth.net
>>[mailto:r-390-bounces at mailman.qth.net] On Behalf Of chacuff
>>Sent: Tuesday, March 06, 2012 5:59 PM
>>To: John Saxon; r-390 at mailman.qth.net
>>Subject: Re: [R-390] Capacitor tester...
>>
>>Hi John and group...
>>
>>John I'm a firm believer in using a cap analyzer in tube radio
>>work.  The
>>cap really needs to be tested at its rated voltage for leakage
>>current.  I
>>have been using the Sencore products for years.  The LC-53, LC-73 and
>>currently the LC-102.  They work great.  A bit pricey at times
>>but if you
>>wait and watch you can usually pick one up priced right.
>>
>>It can be as simple as using a megar type device with the
>>crank on the side.
>>Works for fishing too if you don't get caught...:-)
>>
>>The important part is to check the caps at rated voltage.  I
>>can't say I
>>have ever found a Black Beauty or Brown Beauty that tested
>>good....all had
>>excessive leakage.  As a result I usually do a mass paper cap
>>replacement
>>but that is a personal thing.  Many only replace a few in the
>>radio in key
>>spots like the DC blocking cap that can cook your Mechanical
>>filters in the
>>"A" models and let the rest of the rock on...
>>
>>Be sure to check out the Pearls of Wisdom documents and the
>>nicely done
>>Y2KR390 manual....(may have that name wrong)  Both are must have
>>resources....
>>
>>Good luck and drop questions on us anytime...someone will
>>always know the
>>answer!
>>
>>Cecil Acuff
>>K5DL
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