[Amps] 811H pops fuses / reliable electrolytics

Leigh Turner invertech at frontierisp.net.au
Mon Jan 20 21:22:33 EST 2014

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.


-----Original Message-----
From: Amps [mailto:amps-bounces at 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.


----- Original Message ----- 
From: "Alek Petkovic" <vk6apk at bigpond.com>
To: "Tom Osborne" <w7why at frontier.com>
Cc: "Amps" <amps at 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

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.
> 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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