Continuing this series of observations, using very simple antennas indoors with my FT-817:
I worked on a eastward 5 deg. max elevation pass of XI-V, or CO-58, this evening. This cubesat has a nominal output of 80mW. Its periodic transmission makes it less ideal than CO-55 for this sort of experimentation, but the break between transmissions is not as long as LO-19's: in my experience with this low pass it never doppler-shifted out of the 500 Hz filter while silent. I had to have only the exterior wall between me and the bird for it to be reliably heard.
If I've done the math right, this is a free-space path loss of about 153 dB on a, roughly, +20 dBm signal, meaning that the receiver can hear down to at least -133 dBm at 500 Hz bandwidth (since we haven't factored in the losses due to the indoor reception).
A dipole mounted directly on a BNC copied VO-52's 2m downlink quite well for a couple of minutes, both from the second storey of our home and from the first. By the time I found my video camera, there was apparently no activity. Possibly the dipole's pattern got in the way of reception.
I would be very interested to hear if anyone else has had success with similar minimal equipment. I hope to take this setup to a more urban environment and see if it will still work, say, outdoors.
73, Bruce VE9QRP