[TowerTalk] Help need Vacuum Relay Isolation 1.8 to 30 MHz

Tom Rauch w8ji at contesting.com
Wed Jan 5 00:26:57 EST 2005


> I am planing to construct an antenna switch for a Multi-2
operation. Each
> antenna will be shared with two stations. Using two single
pole normally
> open vacuum relays on series. The center connection going
to the antenna.
> The open ends of each vacuum relay going to a station.

As long as you use a single-armature relay  and as long as
you make sure no failure in voltage or switching can dump
one rig into another it will be OK! NEVER use a reed style
vacuum relay. NEVER.

> At the 1500 watt power level will the single open vacuum
relay provide
> enough isolation?

Sure. If it is a typical vacuum relay. I use them all the
time even in 25 kW and higher systems.

> How much isolation can I expect?

60 dB or more if you do a good layout.



More information about the TowerTalk mailing list