[SCCC] 756 PRO III with AL-80B RX antenna

[rick darwicki]

Hi all,

I just built a small rotatable RX antenna similar to 1/2 a K9YA. It is plugged into my 756 and works fine on 160 and 80 meters.

Today I was listening to the 9X on 40 and he was considerably better copy on the loop.

However, the AL-80B keys funny if at all when I transmit with the RX antenna selected on the 756.
The AL-80 Output Meter is indicating 500 watts of power, but the Grid and Plate current isn't moving.

This is only happening on 40 meters. If I don't transmit on the 40 meter vertical, IE use a dummy load or beam, it is fine. If I disconnect the RX antenna or put the 160 preamp in line it is fine.

I can hear a relay flip in the AL-80 and it appears too much RF is getting into the system on the RX antenna, possibly keeping the QSK circuit in the AL-80 from keying.

Anyone had a similar problem? I'm thinking a pair of back to back diodes on the RX antenna might fix it.

TNX, Rick N6PE