My LK-500ZC was purchased new and still has the original caps. It has
also been beat as hard as possible in about 12 years of intensive
contesting as well as general DX chasing since new.
Id suspect the replacement caps are lower quality than the originals.
Ameritron sells PS caps that are supposedly pre screened for ESR as well
as matched.
Carl
KM1H
----- Original Message -----
From: "Russ Williams" <hrd998cc@yahoo.com>
To: <amps@contesting.com>; "Larry K4AB" <larry.k4ab@gmail.com>
Sent: Monday, December 01, 2008 11:27 PM
Subject: Re: [Amps] LK-500 Blows Filter Cap
>
> My .02: Heat can be a factor, and lacking enough voltage headroom
> with respect to the capacitor voltage rating can definitely be a
> factor. Suggest using caps rated for 105 degree C and increasing the
> headroom to say at least 25% over peak voltage A step start is nice
> as well; I use the Harbach Electronics kits for convenience. The
> Drake L-$B power transformer no longer growls with a BONNNNNNNG on
> closing the ON switch. The switch and the 3-500z filaments must love
> it too.
>
> So... did your capacitors hiss and spew out goo or just POP!? ;-)
>
> 73.
>
> Russ
> W6OHM
>
>
>
> --- On Mon, 12/1/08, Larry K4AB <larry.k4ab@gmail.com> wrote:
>
>> From: Larry K4AB <larry.k4ab@gmail.com>
>> Subject: [Amps] LK-500 Blows Filter Cap
>> To: amps@contesting.com
>> Date: Monday, December 1, 2008, 7:13 PM
>> "I love the smell of smoke in the morning..."
>>
>> Lost a filter cap in my old LK-500ZC this weekend. The
>> thing is, the caps
>> were replaced
>> only 3 years ago. Some folks say that this is common
>> problem, due to lack
>> of surge suppression
>> in this amp. Then again, some people say it's
>> unnecessary.
>>
>> What's the group's thoughts?
>>
>> Is this the reason the amp blows caps higher than others?
>> I push it
>> hard...hours of non-stop contesting.
>> Therefore, the heat really builds up. Could poor cooling
>> really be the
>> problem?
>>
>> Right now, I'm thinking of addressing both issues....a
>> step-start solution,
>> AND doing something to
>> improve the cooling. Is there anything else I should be
>> doing?
>>
>> By the way, the smell of blown caps is awful!
>>
>> 73,
>> Larry K4AB
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>
>
>
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