[Amps] Kilovac relay in MFJ 2020 catalog

[Jim Thomson]

Date: Wed, 19 Feb 2020 09:28:37 -0600
From: Jim <jimw7ry at gmail.com>
To: amps at contesting.com
Subject: Re: [Amps] Kilovac relay in MFJ 2020 catalog

<Depends on how fast the relay is. Just because its vacuum, doesn't mean 
<its fast!

<I use solid state relays for cathode switching now days. Works great.

<73
<Jim W7RY

##  an  opto isolator  works,  along  with  its 4  kv  isolation.  Problem  is,  I  typ
use  60-120  vdc  OCV  for  the  sped  up  26.5  vdc  vac TR relays....  +  drop
resistor..+  small  cap  across  drop  resistor.   Kilovac  told  me  years ago,  that
if  voltage  limited,,  like  only  24 –27 vdc  available,  use vac  relays  with 12 vdc  coils.

##  Buddy  and  I  managed   to  speed  up a gigavac G2.....same  as a jennings RJ2B.
Rated  for  15 msecs   operate...and  9  msecs  release.   Sped  up,  with  80  vdc
and a .5uf  cap  across   drop  resistor,   they  become   2.5 msecs  operate..and  rls.
2nd  G2  was  2.7  msecs  operate  and  rls.   26.5 vdc  rated coils.

##  Both  G2s  were  individually tested on  bench.  Then  installed  in  GG  triode  amp,
on  output  side,  with  all  contacts in  parallel.   Fast  enough  for  QSK,  and  good  for
20A  CCS  at  32 mhz.

## Ameritron  sez their  kilovac relay can be used  in  QSK.   Dunno  how u can  do  that
with a DPST relay.  Normally a DPDT  is  used...  or a SPDT  on   both input +  output. 

##  I  might  buy one....just  to  test on  the  bench....since  they  are  cheap.

Jim  VE7RF