[Collins] Advice please: 516F-2

[Gerald]

On Mon, 2005-08-08 at 12:10 -0700, wb6orz wrote:
>     A 516F-2 here, which was reworked by the late, fine gentleman Harry Kaklikian (SK) has me somewhat puzzled, and I have no documentation.
>     Regarding one of the mods, wherein a relay was inserted in order to take current load off the power switch of the KWM-2 and 32S-x, a choke (L3) was removed---one of two in the low voltage supply. My concern is that with one removed, I might have compromised filtering and high AC ripple, causing hum to get into the Mic amp stages. 
>     The voltages are OK, but we have not yet looked for any AC ripple in the output under load. 
>     Opinions? Experiences with this mod?
>     Thanks in advance.
>     (((((73)))))
>     Les
>     ---===WB6ORZ===---

Loss of choke should raise ripple and loaded voltage. Most of the time
extra voltage on the low voltage supply makes for a bit wilder final
where the off resonance plate current runs high.

If the filter capacitors were increased in value they could take up most
of the ripple filtering, but can also lead to higher loaded voltage and
depending on the exact value to poorer voltage regulation than the choke
filtered supply.

Going solid state rectifiers raises the voltage more. Going with large
capacitors, especially and input capacitor in the vacuum tube rectifier
can lead to shortened tube life from the higher peak currents
characteristic of large filter capacitors.

-- 
73, Jerry, K0CQ, Technical Advisor to the CRA
All content copyright Dr. Gerald N. Johnson, electrical engineer