[Boatanchors] 2013 myth

Sun Jul 7 13:29:22 EDT 2013

What would be worthwhile, IMO, would be to take the removed capa and:L

Discard any that are split, leaking, etc.

Measure and record the leakage current for the remaining ones at 1/2 and
full rated DC voltages. Reversing the supply is also worth boing.

If a leaky one is found, it would be interesting to apply voltage, such
that the leakage current is small (maybe 100 uA) and record tye current
every few hours for several days, to see if thyere are changes.

There seems little point in shipping them.

-John

================

> Would a package of randomly removed, un-tested, sent to you serve as a
> *valid* sample?
>
> I have Hallicrafters SX-101MkIII and HT-32 that haven't had them removed
> NOR tested.
>
> I'd be glad to remove them and provide a *sample*.
>
> Quite frankly, I just plain remove them. I have yet to bother to test
> them.
>
> It is like the HRO 50T-1 that I brought home yesterday. Simply removing
> the bottom cover tells a simple FACT.
>
> The melted wax on the bottom cover, along with several bubbly wax coated
> electrolytics, would be what I would call a significant CLUE that there
> ARE bad caps. I'd also be willing to wager that especially those above
> the wax that had puddled on the bottom cover, AND those that look like
> the wax on them boiled, what I call bubbly, ARE indeed bad.
>
> How much evidence does it take?
>
> Try joining the R-390 list. They have a long history of "Black
> Beauties", "Bumble Bees", "Brown Beauties", and "Tiny Chiefs". They also
> have played with testing these simply by lifting one leg and testing them.
>
> Leakage? Good grief yes. Way off value, same comment.
>
> Why is it that to restore an old R-390A we replace a significant number
> of capacitors?
>
> We have developed a list.
>
> A SK used to sell a whole package as a replacement kit.
>
> Here it is, AND NO I do not make these kits up NOR provide them!
>
>
> The entire list of the old kit is as follows:
>
> R390A capacitor kit.
>   > I have put together a ReCap kit for the R390A.
>   > It consists of:
>   >
>   > (13) 0.1 ufd
>   > C256, C309, C504, C505, C517, C521, C528, C531,
>   > C536, C538, C543, C547, C548
>   >
>   > (7) 0,033 ufd
>   > C275, C529, C533, C534, C541, C545, C602
>   >
>   > (7) 0.01 ufd
>   > C549, C553, C601, C604, C605, C607, C608
>   >
>   > ( The above are Orange Drops or equivelent. )
>   >
>   > (3) 30 ufd 300 v electrolytic C603A, C603B, C603C
>   > (2) 47 ufd 300 v electrolytic C606A, C606B
>   >
>   > ( The above electrolytics have axial leads. You can wire them under
> the
>   > chassis and leave the originals in place to retain stock appearance.
> Or you
>   > can order capacitors small enough to fit inside the cans of C603 &
> C606.
> Just
>   > remember you will have to deal with the Dreaded Black Ukkumpucky to
> get
> the
>   > guts out of the cans of C603 & C606. If you do not specify at time of
> your
>   > order, the under the chassis capacitors will be shipped.)
>   >
>   > Finally, one each of :
>   >
>   > 0.047 ufd 100v C227
>   > 8 ufd 30v tantalum electrolytic C609
>   > 50 ufd 50 v electrolytic C103
>   > 0.22 ufd 100 v C101
>   >
>   > I cannot find a source for:
>   > 2 ufd 500v C551 oil filled paper
>   >
>   > so, I will include a very high quality poly cap. I have installed one
> of
>   > these in one of my R390A's and I can say I cannot hear any difference.
>   > They work great. This is the AGC capacitor.
>
>
>
>
> Bob - N0DGN
>
> On 7/7/2013 9:42 AM, J. Forster wrote:
>> I would actually like to see some data on BB's. And I do not mean
>> measuring those that have been removed because they have failed, which
>> will obviously badly skew the stats.
>>
>> Do they, in fact, fail more than other similar caps of the same vintage?
>>
>> -John
>>
>> ===========
>>
>>
>>
>>
>>> On 7/7/2013 8:13 AM, Bill Cromwell wrote:
>>>> On 07/07/2013 05:49 AM, David Knepper wrote:
>>>>> This “hysteria” concerning replacing the so-called “black beauties”,
>>>>> etc. frankly is like the man who washes his car every day so as to
>>>>> believe that somehow this will increase gas mileage!
>>>>>
>>>>>
>>>>> David Knepper - W3CRA/W3ST
>>>>> Collins Radio Association
>>>>> www.collinsra.com
>>>>> Join the CRA today
>>>>>
>>>> David,
>>>>
>>>> You are implying that you have "black Beauty" caps that test good. Are
>>>> you actually saying that?
>>>>
>>>> 73,
>>>>
>>>> Bill KU8H
>>> Morning,
>>>
>>> Still consuming my morning coffee.
>>>
>>> However, "Black Beauties", "Bumble Bees", "Brown Beauties", and "Tiny
>>> Chiefs", ALL fall into the same category!
>>>
>>> There is NO myth. Just "junk" that either leaks like a sieve or just
>>> plain shorts!
>>>
>>> Is David now an Audiophool? I can send him those I remove so that he
>>> can
>>> keep his Collins gear in "original" condition.
>>>
>>> Bob - N0DGN
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>>
>>
>
>