[Amps] Speeding up vac relays.

[Jim Thomson]

Date: Sun, 21 Feb 2010 20:37:06 -0800
From: James Colville <jimw7ry at gmail.com>
Subject: Re: [Amps] hotswitching 30s1

There is no reason to speed up a vacuum relay. 1.8 mS is more than enough
time.  Please see:


http://home.earthlink.net/~wd7s/updates.htm

73
Jim W7RY

## I saw that too, years ago. I think he has something amiss in his test procedure.
Nobody else gets  1.8 msec  with just 26.5 vdc applied to a 26.5 vdc coil, on 
either a Jennings's RJ-1A, nor a gigavac GH-1   nor the kilovac  eq of a RJ1-A 

## I had the Kilovac engineer's  perform some timing tests for me a few yrs back.
They indicated that just by doubling the coil voltage [ and using a correct size 
drop resistor]  that the op time was WAY faster.   They also tripled the coil voltage,
and got even more speed out of it.  Quadruple, and a bit more.  Placing a small cap,
50uf or less, across the  drop R, will speed it up even more. [ RC hot shot]

## be aware that applying an overvoltage only speeds up the Op time,  and 
does nothing for the RLS time. 

##  Not all vac relays are fast, like the RJ-1A.    I use the Gigavac G2  vac relay,
which is only 15 msec OP... and 9 msec  RLS.  [ the GH-1 is 6 op / 6 rls] 

##  The Jennings  eq of the G2 is a RJ2-B/C  and is  18 msec op / 9 msec rls.

##  these  slow vac relays need to be sped up.   I apply  +120 vdc to em, and
drop the Op time down to 6-8 msec.   Still no qsk,  but faster vox  cw/ssb.  
Any plane jane open frame mech relay can also be sped up with an over-voltage.

later... Jim VE7RF