[Test-Equipment] spectrum analyzer as radio receiver

[Allan Henry Kaplan]

Using  spectrum analyzer as a radio receiver is not really wacky, but
they fall far short of being a communications receiver because of their
lousy sensitivity (HP141 noise fgure > 25 dB!).  It drives home the idea
that sometimes a "lousy" receiver can be useful (or entertaining)!  My
former managers would decry that as "inefficient use of resources" or
worse, but I left the rat-race a few years back!

Yes, Gil, you WERE demodulating FM broadcast stations near 100 MHz!  You
were using the  time-honored technique of Slope Detection, tuning in the
signal so that it substantially falls on the sloping response of the
analyzer's resolution filter.  This generally results in some distortion
of the recovered ausio compared to a good linear discriminator, but
again it makes the point that sometimes mediocre performance is
acceptable!

The "broadcast-like" signals near  550 MHz were almost certainly UHF TV
audio (FM subcrrier). 

I have nearly the same boat-anchor spectrum analyzer as yours, but my
tracking generator (8443) and 8554L both need some repair.  I believe
the TG will give you a fair frequency readout, but I cannot prove it.

Hope this helps...
73, Allan Kaplan, W1AEL since 1954.