## Alpha, back years ago, used a RJ1A. They later switched to the
Kilovac HC-1...which has more robust insides..esp for QSK CW...lasts
a lot longer.
The gigavac GH1 is superb..and consistently Hi-pot tests to > 7.5
kv. The GH1 is the best of the 3. All 3 look identical .
## Kilovac told me the speed up circuits with the overvoltage,
with or without the cap across the drop resistor will not degrade
the relay life.
## Buddy uses 3 x gigavac GH1s on his 2 x GS35B 6M monoband amp.
Input, output, and cutoff bias. Handles 4.7 kw just fine for
the last 8 years.
## The sped up gigavac G2s ended up with 2-3 bounces.. but still
were 2.5 to 2.7 msecs.....including bounces. Used on a YC-156
amp..and also a 3x6 amp.
The YC-156 80-10 amp gets the QSK work out on a regular basis.
Jim VE7RF
-----Original Message-----
From: Jim Garland
Sent: Thursday, February 20, 2020 4:27 PM
To: 'Jim Thomson' ; amps@contesting.com
Subject: RE: [Amps] Kilovac relay in MFJ 2020 catalog
I've long wondered whether these speed-up circuits that pulse vacuum relay
coils with an overvoltage also exacerbate contact bounce and possibly
shorten the relay life. Intuitively that seems reasonable, though I've not
taken any data to check out the possibility. A few years ago, I wrote up my
personal QSK design and some of the accompanying relay data for QST (June
2015, and http://www.w8zr.net/QSK/). and at the time looked at the switching
characteristics of numerous vacuum relays. I found a wide variation in the
amount of contact bounce. The Gigavac G41C, used in the Alpha 9500,
typically had a half dozen or more bounces before the contacts settled down.
That was a particularly noisy relay, with an audible twang when the movable
contact slammed into its mating contact. The best relay, bounce-wise, was
the Jennings RJ1A, which switched in about 2 msec, was nearly silent, and
showed no bounce. There are various clones of the Jennings design, but I
didn't check any of them. On the basis of the data, I chose the RJ1A for my
"contest-rated" 160/80m duoband amplifier, and it's been great. (It's
probably not hefty enough for the upper HF bands in that kind of
application.)
73,
Jim W8ZR
-----Original Message-----
From: Amps [mailto:amps-bounces@contesting.com] On Behalf Of Jim Thomson
Sent: Thursday, February 20, 2020 08:51 AM
To: amps@contesting.com
Subject: [Amps] Kilovac relay in MFJ 2020 catalog
Date: Wed, 19 Feb 2020 09:28:37 -0600
From: Jim <jimw7ry@gmail.com>
To: amps@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
_______________________________________________
Amps mailing list
Amps@contesting.com
http://lists.contesting.com/mailman/listinfo/amps
_______________________________________________
Amps mailing list
Amps@contesting.com
http://lists.contesting.com/mailman/listinfo/amps
|