The AM Forum
March 28, 2024, 09:16:44 AM *
Welcome, Guest. Please login or register.

Login with username, password and session length
 
   Home   Help Calendar Links Staff List Gallery Login Register  
Pages: [1]   Go Down
  Print  
Author Topic: Kill-the-Kilovac!! Vacuum Relay  (Read 3442 times)
0 Members and 1 Guest are viewing this topic.
WBear2GCR
Member

Offline Offline

Posts: 4135


Brrrr- it's cold in the shack! Fire up the BIG RIG


WWW
« on: April 19, 2017, 07:16:19 PM »



How to not mount a glass vacuum relay.

Anyone have specs on a Kilovac H-12 relay? (not the one in the pic, that one is done broke)
Or a copy of a ~1980 Kilovac catalog?

This relay is not made now, and I found zilch on the interwebbie...

Pulled this relay from some HB gear I just picked up. Perhaps this is why the unit stopped working?

             _-_-bear


* KILL A KILOVAC.jpg (300.09 KB, 2048x1385 - viewed 437 times.)
Logged

_-_- bear WB2GCR                   http://www.bearlabs.com
W7TFO
WTF-OVER in 7 land Dennis
Contributing
Member
*
Offline Offline

Posts: 2521


IN A TRIODE NO ONE CAN HEAR YOUR SCREEN


WWW
« Reply #1 on: April 19, 2017, 09:11:17 PM »

There be very nice ones from Russia on eBay.  Cheap, too, by comparison.

73DG
Logged

Just pacing the Farady cage...
WBear2GCR
Member

Offline Offline

Posts: 4135


Brrrr- it's cold in the shack! Fire up the BIG RIG


WWW
« Reply #2 on: April 19, 2017, 11:50:37 PM »

Dennis, based on your experience what are the minimum ratings for (A) antenna relay and (B) B+ relay in a
rig with 5-6kv on the plate... (I'm assuming headroom over a 4.5kv nominal B+). I guess there are two cases
here too, linear vs. plate modulated?

And, do you know what the difference is between "RF" rated vacuum relays and not??

I've looked at the ruskie relays. Bought American,  got a NOS military H-12 Kilovac coming... it's 12kv rated, but beyond that
I only know that it is higher rated than the H-8 that was in there (the broken one).

Surprised at the minimal info online. Kilovac does not return calls, no one picks up the phone. Sad
Logged

_-_- bear WB2GCR                   http://www.bearlabs.com
W7TFO
WTF-OVER in 7 land Dennis
Contributing
Member
*
Offline Offline

Posts: 2521


IN A TRIODE NO ONE CAN HEAR YOUR SCREEN


WWW
« Reply #3 on: April 20, 2017, 08:50:03 AM »

The various Russki jobs have listed specs, and with vac relays the operating freq. range is no big deal.

KiloVac is most likely a CIA front op, you'll get a replacement on a 'need to know' basis Wink

73DG
Logged

Just pacing the Farady cage...
w4bfs
W4 Beans For Supper
Contributing
Member
*
Offline Offline

Posts: 1433


more inpoot often yields more outpoot


« Reply #4 on: April 21, 2017, 04:48:24 PM »

same warning for glass relays as for vacuum tubes .... no lateral pressure to the pins .... only straight in line with the pins .... best to use something flexible, if possible
Logged

Beefus

O would some power the gift give us
to see ourselves as others see us.
It would from many blunders free us.         Robert Burns
K1JJ
Contributing
Member
*
Offline Offline

Posts: 8893


"Let's go kayaking, Tommy!" - Yaz


« Reply #5 on: April 21, 2017, 05:36:07 PM »

 Grin  Yikes -  I've made that exact mistake with the same vacuum relay about 25 years ago.  It usually happens when we try to torque down the screw fastener without terminal support. Even if the lead is flexible, the screwdriver torque can take out the glass seal.

Just so nobody else makes the same mistake:   The best way to torque the screw is to hold the floating / resting relay by its terminal (with needle nose pliers) while carefully torqueing the screw. This will keep all stress away from the glass. Any stress at all into the glass is a bad thang. And yes, flexible leads are the only way to go. Even a soldering iron can heat up a solid lead enough to mechanically expand it and crack the glass. Or, the lead heats the glass enough to make the seal fail - no vacuum, kaput!

A vac relay may be the most fragile part in any amplifier.... being made of thin glass and holding a vacuum.  Except for old buzzard glass tubes with plate caps and grid leads on the side, at least most tubes have sockets to eliminate direct connection failures.

T
Logged

Use an "AM Courtesy Filter" to limit transmit audio bandwidth  +-4.5 KHz, +-6.0 KHz or +-8.0 KHz when needed.  Easily done in DSP.

Wise Words : "I'm as old as I've ever been... and I'm as young as I'll ever be."

There's nothing like an old dog.
KD6VXI
Contributing
Member
*
Offline Offline

Posts: 2648


Making AM GREAT Again!


« Reply #6 on: April 21, 2017, 08:57:29 PM »

I'll vouch for the communist relays.  Just as good as the capitalistic pig sourced kilo/jenning/gigavac sourced stuff where I've used it.

I can't remember which company was the split off by hams, but either gigavac or kilovac is very helpful when called and you identify as an amateur op.  The prices are even better to 'us'.

Since commie stuff is so cheap, it's been a no Brainerd on which brands to use.....  And the drop in American stuffs price sure reflects the competition of ebay.

--Shane
KD6VXI
Logged
flintstone mop
Contributing
Member
*
Offline Offline

Posts: 5055


« Reply #7 on: April 24, 2017, 11:23:54 AM »

ahhhh such a shame..Usually hard to kill those things; but glass is fragile
Logged

Fred KC4MOP
Pages: [1]   Go Up
  Print  
 
Jump to:  

AMfone - Dedicated to Amplitude Modulation on the Amateur Radio Bands
 AMfone © 2001-2015
Powered by SMF 1.1.21 | SMF © 2015, Simple Machines
Page created in 0.075 seconds with 19 queries.