Topband: Relay types-Tx and Rx

George Cutsogeorge w2vjn at
Thu Mar 23 11:43:23 EST 2006

At Top Ten Devices we have been using the same relays in our antenna 
switching products for about 15 years now.  They are the Aromat JW1FSN-DC12V 
types.  They are sealed with 10 amp contacts and have high voltage 
insulation.  Aromat has become Panasonic Electric Works.  These relays are 
available from many sources and are shown in the Digi-Key catalog at $2.67. 
Many thousands of these relays are out there in our products and they don't 
come back.  Note that in all cases the designs use the normally closed 
contacts for grounding and the normally open contacts to pass the tx power 
and the rx signals.  i.e. We don't use the normally closed contacts for 
passing signals.  It may take extra relays to design like this, but there 
are never any receive signal failures.

In my own SO2R station there are 47 of these relays in use and there has 
never been a failure in the 12 years since I started building in Oregon.

George, W2VJN 

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