Topband: RX antenna switching

[K9AY]

> If I want to switch a topband RX antenna among three radios, can I just 
> use an ordinary rotary switch, without special attention to maintaining 
> impedance, etc.
>
> 73, Pete N4ZR

Pete,

If you are using each antenna on one radio at a time, then you are correct. 
Special attention would be needed for...

1. Sharing the same antenna on two or more radios for diversity reception, 
or for a SO2R or multi-op contest setup. Then you want a splitter that 
isolates the radios from one another, and maintains approx. the same 
impedance as you switch among antennas and radios. This will minimize signal 
level changes. You may need to make up splitter losses with a preamp.

2. Two-direction Beverages with both directions available in the shack (two 
feedlines). The switch must provide a termination for the unused directions 
to maintain the antennas' directivity.

73, Gary
K9AY