:
From: R L Measures <r@somis.org>
Date: July 18, 2006 6:31:07 PM PDT
To: "Phil Clements" <philc@texascellnet.com>
Subject: Re: [Amps] FW: RF Chokes
On Jul 18, 2006, at 1:53 PM, Phil Clements wrote:
>
>
>
> Subject: RE: [Amps] RF Chokes
>
> This is not as bad as many Internet suggested mods are,
> since the additional C at the bottom of the choke won't
> hurt.
1000pF bypassing the typical 1.5A-rms of 160m current in the HV-RFC
allows over 100V-rms of 1.8MHz energy to enter the HV-PS. Is this
good engineering practice in your opinion, Tom?
> Unfortunately some mods on Websites actually hurt
> reliability, but this suggestion is benign. The bad ones
> include resistor grid fuses,
Since Fall, 1988, no one who has installed the frangible grid-fusing
resistors that comes with our low VHF-Q suppressor retrofit kits has
reported having a 3-500Z grid-filament short or a 572B or 811A
shatter its filament.
> increasing power supply capacitance,
Good point, Tom. Increasing power supply stored J requires
increasing the J-capability of the glitch R.
> and removing caps across diodes,
What function do such caps serve at 50 - 60 Hertz?
> and increasing resistance across electrolytics.
In the Sprague electrolytic cap data sheets, there is no formula for
calculating the resistance of the equalizing resistors. As I see it,
if the voltages measured across the caps during use are within a few
percent, and the caps bleed down in approximately the time needed to
drink a Becks, the R is right.
>
> Food for thought...
Indeed, Tom, indeed.
>
> 73 Tom
>
R L MEASURES, AG6K. 805-386-3734
r@somis.org
R L MEASURES, AG6K. 805-386-3734
r@somis.org
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