On Fri, 10 Oct 2014 11:13:14 -0700
Paul Baldock <pbaldock@frontier.com> wrote:
One solution to the receiving problem when using high
current relays may be to have dc current (eg 100mA) pass
through the contact in RX.
1. In all my antenna systems I always use some wetting
current. I feed from 24 V about 2 mA of DC wetting current
via a 1 mH choke and a 4k7 resistor at each end. I used to
have receive problems with all kinds of relays, including
vacuum relays, before I added the wetting current. Since
then, all relays have been working perfectly in RX (via
the normally closed contacts).
2. For TX above 500 W I use vacuum relays. Where the SWR
is low I use RJ1A (HC-1) or RF1D ((K45C) or similar types
and where the SWR could be high I use RJ4 (KC-2, KC8 or
H-8) types. Overkill? Maybe. But...
73,
George
AA7JV
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