Updated 28-april-2001
I used a "Stereo" rx system listening to signals when I worked EME. This means I had 2 separate RX lines all the way using common LOs. How to do this? Here is a small description of my setup.
The FT1000MP is moded with the external BPF-1, band pass filter unit. In the older FT1000D the optional BPF filter can be installed internally. Further mods I have in my FT1000MP: 70MHz IF-mod from Inrad and vfo-tracking, by pressing a switch I have the sub rx vfo running as a slave to the main rx vfo. That´s it! RX opacute;s it! RX operation is very simple, I just tune the band with the main VFO. The human brain mixes the H and V pol so I get all polarisation. According to some people I lost 1dB by listening like this instead of the best pol in both ears. But I felt comfortable with it. It gave me a minimum of relays and stuff that always malfunctions when trying to work the rare ones!
I used the Collins mechanical 500Hz cw filter in both RXs on the FT1000MP. Either external DSPs (two required!) or homebrewed audio filters of some sort or a dsp software that runs stereo RX.
When moding the FT1000MP the op of the rig handles like this: when switching off the external BPF unit it runs exact as a original FT1000MP. When activating the BPF unit I got 2 diff antenna jacks for each antenna. The rx paths is identical except for one thing: the rf amp only works on the main RX. This means I get lower signal levels in the sub rx. In the following wavs I have compensated this with the balance control of the sound blaster wav recorder, not the best way to do it. In the future I will straighten this out by: adding more RX gain on 2m. Then I can switch off the rf amp in the main rx. Now I have to much IF gain in the main rx, but this the main rx, but this is fairly simple to correct.
Note: The wavs were recorded with the sound blaster 16 wave recorder, in stereo 11025Hz and 8 bits. Signals in the ref/dubus contest was weaker than normal because of bad wx/degraded RX. The files are zipped so you have to download and then play them local on your machine. Pay attention left channel is horisontal and right channel is vertical polarisation. Recording in full 44kHz and convert them into MP3 would be better.
Here is VE7BQH in qso with W3SZ.
Here is RU1A calling cq.
Here is IK3MAC calling qrz.
Here is W5UN calling KE7NS .
One ham told me he can not hear anything else but noise. If so pse
use hi-fi headphones, the pitch of my cw-rx is very low.