[Amps] Amps] Vacuum relay

[jim.thom jim.thom@telus.net]

Date: Thu, 15 Dec 2022 12:25:09 -0600
From: Robert W5AJ <woodr90 at gmail.com>
To: Amps group <amps at contesting.com>
Subject: [Amps] Vacuum relay

https://mgs4u.com/product/gigavac-gh-1/

<About to order couple of GH-1 vacuum relays for switching RF at amp output

<Any CONS to the GH-1 design?

<12VDC option here

<73 Robert

##The gigavac  GH-1 is a superb relay.  Note the threaded base is metric. A
9/16"
hole is ideal in the chassis.  A  5/8" will also work, with a tiny bit more
play / slop.  A  1/2"
hole is too small.  If a 5/8" hole is used, and relay centered in the hole,
ordinary 3/4" garden hose washers can be used on each side, for a totally
dead quiet relay.

## The 12 vdc coil is field replaceable, and either a 12 vdc coil or a 26.5
vdc coil
can be used.

## Rich Measures used to buy them  100 at a time. He hi-pot tested them to
slightly over 7.5 KV.... which is excellent..and 2.5 kv higher than their
stated 5 kv hi pot test ratings. They still hi-pot test to > 7.5 kv.

## what you want to avoid is the greenstone version, and also the
talyor brand version.
Val at Acom sez they have a whopping 30% failure rate, BEFORE they install
them into any Acom  SS / tube amp.  And of the ones that do work, and
installed in Acom products,
there is a high failure rate out in the field. Jay Terleski at Array
solutions still repairs Acom amplifiers, and told me 3 weeks ago, that the
greenstone vac relay is a major pita..and always gets replaced with the
Gigavac  GH-1.

##  I use the bigger gigavac G2 relay, and it too is superb.... ( same as a
jennings RJ2B.).
The big advantage of the G2 is, it has the option of threaded contacts,
inside the 3 x cylinders, so terminating with strap or lugs is very easy.
It also has a choice of a flange base, or threaded base.  Coils in 12 vdc,
26.5 vdc or 115 vdc.   They are easily sped up for QSK use. They can also
be paralleled to quadruple the power rating on any freq.

##  Jennings is now out of business...and the Kilovac HC-1 is stupid
expensive. (HC-1 is Kilovac's version of a GH-1).   The SS amp made in the
UK uses a HC-1.

Jim   VE7RF