The Cliperton-L is a neat amp. 160 to 10 meter coverage. The xmfr has a hi
and lo tap so you can select either around 640vac or around 900 vac if my
memory is still working (been a while since I had one n the bench). This
turns out to be 1728 vdc and 2430 vdc if you figure the secondary voltage of
the xmfr times 2.7 in a E doubler which is what Denny used in all his amps.
Svetlana rates the 811A maximum dc plate voltage at 1250 vdc CCS or 1500vdc
ICAS. The Svetlana 572B max. dc plate voltage is 2750vdc.
By running the 811A at the normal 572B plate voltage of 2450 vdc you will be
exceeding the manufactures recommended Ep by around 1000volts. That is a lot
for the 811A.
Dave I agree with Carl. Before you go making tube swaps you better make sure
that you are not exceeding the parameters of the tube. This includes Ig and
Ip also although I have yet to find recommended values for Ig in both tubes.
Even if you run the Clip-L on the low voltage setting (CW) the plate voltage
will be exceeding the manufactures recommended Ep by around 250 volts.
I'd stick with the 572Bs. Four of the Svetlana's in that amp will give you
around 1400 out no problem (the power supply becomes the limiting factor in
this amp) and should last a LOOONNNGGG time. Keep you drive at 100 watts and
they should never need replaced.
Save your 811As for the Ameritron AL811 series amps or the 30L1.
GL and 73s
Lane Zeitler
KM3G
San Diego
-----Original Message-----
From: david wintheiser <w0opw@yahoo.com>
To: amps@contesting.com <amps@contesting.com>
To: <amps@contesting.com>
Date: Tuesday, October 06, 1998 10:02 AM
Subject: Re: [AMPS] Clipperton L & Bad tubes
>
> Here's why I made that suggestion. I have a Dentron 160-10L, the
>older brother to the clipperton. It has a 2200 volt plate transformer
>and was designed for 4 811a's . The rather crude owners manual
>advises the user to replace the 811a's with 572b's for mucho power/Qrm
>!. I'm converting it for 2 572b's.
> Info on the Web(AG6K ?) states that 811a's and 572b's are swappable.
>I think the newer manufactured 811a's handle the higher voltages just
>fine.
> - Pat W0OPW
>
>
>
>
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