[Amps] reed relay /vac relay

[Jim Thomson]

Date: Thu, 11 Mar 2010 09:01:17 -0500
From: "Rex Lint" <rex at lint.mv.com>
Subject: Re: [Amps] Amps] Solenoid polarity on DC reed relays
To: "'Bill VanAlstyne W5WVO'" <w5wvo at cybermesa.net>, <n8cc at mei.net>,
Bill,

I'm doing a similar project with my SB-220, but the HF version.  I got the
reed relay from Richard Measures.  He also has things to say about snubbing
diodes and resistors.  See 
"High Speed Switching / QSK for the TL-922 and SB-220..." at
http://www.somis.org/QSK922.html, and his order page at
http://www.somis.org/Price-Info.html.  I haven't done the mods yet...

    -Rex-

##  measures uses a reed relay on the input.. and  a transistor for switching the bias. 
##  come glitch time, don't be surprised when the bias switching doesn't work.

## the drawback to using a reed relay on the input is.. the amp will not handle more than 100w 
on bypass !     OK to use a reed relay for the bias though.. as long as contacts are up to the job. 

## In my case.. the L4B has a built in wattmeter, and the only way to calibrate it is to apply 1 kw  from
a 2nd amp.. via  a calibrated wattmter,.. to the input of the L4B  [ with L4B in bypass mode] 

## In bills case..  he's using vac relays on both input and output. Either use  a new reed relay
for the bias.. or  a vac relay...esp for qsk  

##  If the surplus relay in question , is only good  for 100 k operations... and no doubt it's used
it probably does not have a lot of life left in it..esp  for qsk use.  

Later... Jim  VE7RF