[Amps] HV rectifier strings - to bypass or not?

[Fuqua, Bill L]

The broadband noise is not due to the current thru the rectifieres but the shot noise the transmitting tube. If the tube is not biased off during receive and you are using an electronic switch or the receiver is not entirely decoupled from the output of the transmitter you will get broad band noise generated by the random arrival of electrons on the plate of the tube.     I once had this problem with my EF Johnson Challenger transmitter when I was using  separte transmitting and receiving antenns. It had not solid state diiodes in it at all. Took a while to figure it out, I was only a teenager at the time.
73
Bill wa4lav

________________________________________
From: amps-bounces at contesting.com [amps-bounces at contesting.com] On Behalf Of Jim Barber [audioguy at charter.net]
Sent: Saturday, October 30, 2010 4:32 PM
To: AMPS
Subject: [Amps] HV rectifier strings - to bypass or not?

I'm getting ready to lay out the HV rectifier board for my YC156
project, and it occurs to me to wonder if anyone has ever really heard
HV rectifier "white noise" in the receiver? It would be simpler to
forget about the per-diode bypass caps and just bypass the output as it
leaves the board. The supply will be housed in a separate cabinet from
the RF deck, but connected of course with bypassed leads for HV, (SHV
connectors) 110VAC and control signals.

My current intent is to use 8 6A10 diodes per leg. The transformer is a
3KV, 2A CCS Peter Dahl and the filter is 32uF by means of two new 16uF
7500V oil-filled caps from Henry Radio via eBay.

Opinions?

Thanks,
Jim N7CXI

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