Can anyone suggest a decent inexpensive spectrum analyzer, that I can look
for used on ebay, that would be suitable for evaluating SSB transmitter
output for spurs, harmonics, etc.?

A few years ago I picked up an HP 8557 analyzer plugin, in a 181T (I
think) display mainframe, at a local hamfest. It's simple, and its
bandwidth range isn't super-wide by today's standards (it's rated for
..01 MHz to 350 MHz), and it isn't the most precisely tuneable or
rock-stable analyzer around, but it has been extremely useful over the
past few years. It's plenty good enough to look at the HF spectrum
and at the basic performance of a 2-meter radio (although it won't
tune up far enough to see the third harmonic of 2-meters or to be
directly useful on 440).

The tuning dial is analog, and tends to require a tweak to the
calibration-zero when you move more than a few MHz away from your
previous location. Having a decent crystal calibrator or comb generator
isn't a bad idea (I built one using a 10 MHz oscillator can, a 10:1
decade divider, and a MMIC amplifier chain deliberately driven into
saturation... works great).

The newer 8557A has a digital frequency display - I don't know whether
it's fundamentally any more stable or precise than the analog tuning
and indicator dial on the older 8557.

I've used the 8557 to help identify some local QRM problems. Hooked
to a directional 2-meter antenna it let us track down the source of a
drifty "buzz on the squelch-tail" signal which had been plaguing
several local repeaters (turned out to be a bad Ethernet switch,
"singing" loudly enough to be heard for miles!).

More expensive, wide-bandwidth spectrum analyzers might not work as
well, in your application. A lot of the wideband ones don't work at
all below 10 MHz (one of their IF frequencies, I suspect).

My repeater group was recently gifted with a used Tek 491... a
wide-band model. It turns out to have a very interesting and
significant quirk - the 10-to-200-MHz band uses a non-balanced mixer,
and input signals can "blow through" right into the 150-to-250-MHz
first IF. This creates some *huge* non-tunable spurs in the display.
As a result, I *dis*recommend this model if you have any thought of
hooking it up to an antenna and looking at your ambient RF
environment... pager and public-safety-band transmissions will show up
as non-tunable spurs which can exceed the signal you're looking for!

--
Dave Platt AE6EO
Friends of Jade Warrior home page: http://www.radagast.org/jade-warrior
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