[Heathkit] HD-1481 Coax Antenna Switch - Odd Behavior?

[jack m]

I recently procurred an HD-1481 4-pole remote antenna switch at a hamfest.  When put in service, the remote unit switches across all 4 antennae in a perceived "normal" manner as monitored in the receiver.  However, when a low-SWR 100 watt transmitter signal is applied through the control box SO-239's, the remote unit seems to "lose" the signal (regardless of the 4-position selection number) on the receiver upon release of the PTT mic switch, but it can be "recovered" by simply switching the antenna from another antenna selection position, then back.  This occurs on 80, 40, 20 and dummy loads, although I tested the dummy position by moving an antenna to that position.

 

Before I start tearing into the 2 units, has anyone else experienced this problem?  Can anyone offer suggestions for what may be happening here?  The fact that the behavior is the same for any relay position seems to rule out the +DC, -DC and 22 VAC control voltages for the actual remote unit relays.  The relays have good mechanical operation and adequate armature springs in place.

 

Thanks Jack
 		 	   		  
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