For just a small number of extra dollars one can readily find reputable
brand and quality built Cornell Dubilier / CDE high-voltage /low ESR / high
ripple current rated 105 deg C electrolytic surplus NOS capacitors on eBay.
These caps will eliminate risk of dodgy provenance and virtually last a
lifetime in HV power supply service.
The key with facilitating a long service life MTBF with any electrolytic cap
is to keep them cool with adequate air flow and well away from any heat
source within the equipment.
Leigh
VK5KLT
-----Original Message-----
From: Amps [mailto:amps-bounces@contesting.com] On Behalf Of Carl
Sent: Tuesday, 21 January 2014 12:07 PM
To: Alek Petkovic; Tom Osborne
Cc: Amps
Subject: Re: [Amps] 811H pops fuses
Guaranteed Chinese, that fraud has been discussed elsewhere.
Carl
KM1H
----- Original Message -----
From: "Alek Petkovic" <vk6apk@bigpond.com>
To: "Tom Osborne" <w7why@frontier.com>
Cc: "Amps" <amps@contesting.com>
Sent: Monday, January 20, 2014 5:51 PM
Subject: Re: [Amps] 811H pops fuses
Found the caps I bought.
See Ebay item number 190875604650
73, Alek
VK6APK
On 21/01/2014 6:38 AM, Alek Petkovic wrote:
> Yeah, that's right Tom.
>
> Its the same with the AL-1500 model. More caps, higher voltage but they
> are still right on or over the limit of 450V per cap.
>
> I changed mine for higher value, 500V jobs. I was able to fit 16 caps in
> the space where the 8 originals were. They are arranged as a string of 8 x
> 2 x 330uF/105°C caps in parallel. That's 8 x 660uF in series to give me
> 82.5uF at 4000V.
>
> There was nothing wrong with the 8 x 220uF caps. I just got nervous
> running them that high.
>
> I bought them from the US, on the bay. They are probably cheap charlie
> ones but they do the job really well.
>
> 73, Alek.
> VK6APK
>
> On 21/01/2014 12:53 AM, Tom Osborne wrote:
>> Vic said:
>>
>>> Ameritron's prices are reasonable and they have shipped within a day
>>> every time I've ordered parts from them.
>>
>> The problem is - the Ameritron ones are rated at 450 volts. That seems
>> like they are operating at pretty much their max. This one has about
>> 1800-1900 plate voltage. Four of the Ameritrons are 1800 volts rating
>> (unless they have a built-in safety factor). 73
>> Tom W7WHY
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