I have owned an HC4 relay for a number of years. I just checked it on my 9kv
hi pot tester and it shows only 2 microaamps leakage at 9kv. That is as low
as the best of my other vac relays and better than good transmitting tubes
show. Mine has silastic rubber potting around the glass relay and over the
hv contacts. My catalog says they are suitable for RF to 30mhz. The contacts
are molybdenum and tungsten with 0.020 ohms resistance max. Operate time is
6ms max. I have been told that they are built for use in HV medical
equipment. I would think that the capacitance between terminals would be
higher than non encapsulated version like HC1 which is a possible negative.
73, Dan, N5AR
----- Original Message -----
From: "Roger Parsons" <ve3zi@yahoo.com>
To: "Amps" <amps@contesting.com>
Sent: Saturday, March 07, 2009 5:48 PM
Subject: Re: [Amps] KiloVac HC4 Relays
>
> I have received a private email strongly disagreeing with my conclusions
> on these relays :-)
>
> I still believe I am correct about the use of tungsten contacts in rf
> vacuum relays and that, based on manufacturers' information, the HC4 is
> suitable for use in an amateur linear.
>
> I should not have put the paragraph about gas filled relays into the
> message - although at least one of the manufacturers does indeed say that
> rf can ionise the gas, they are apparently commonly used in some high
> power rf systems.
>
> 73 Roger
> VE3ZI
>
>
>
>
>
> _______________________________________________
> Amps mailing list
> Amps@contesting.com
> http://lists.contesting.com/mailman/listinfo/amps
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