OK my brain may be playing tricks, but if you vary only your transmit frequency such that you always hear yourself on the same downlink frequency, isn't it true that the other station may not necessarily be hearing you on the same downlink frequency and is chasing you anyway? Your doppler is +5kHz (for example) on the receive, the bird is just about to pass overhead of me though so my receive ferquency goes rapidly from +2kHz to -5kHz, your transmit tuning has no relation at all to what frequency I am listening on. Then the bird goes past you and you suddenly switch down 5kHz, so I have to follow you on my receive.
Or am I nuts? (Quite possible, come see where I work and you will understand!)
Jerry NØJY
I always varied the transmit.
This way the person I'm talking to as well as any other listeners are all on the same freq listening.