I've tried benching up a Minicircuits POS-900W VCO module.

With a Spectrum Analyzer (RBW 1 kHz, VBW 1kHz, peak hold, 100kHz span) I've
been hoping to see a clean waveform that drops to -75dBc at 1,000Hz away, as
specified in the Minicircuits spec. Instead, I have something that looks
like a triangle spreading for MHz!

I've got in such a mess, my brain is now totally confused (not difficult!).
I just don't understand why the trace doesn't look good, compared to my own
discrete design(lower frequency) VCOs. Even with the POS-900W out of circuit
(ie. no PLL), well grounded, and run from batteries, the waveform is still
more-or-less a triangle!

What could I be doing wrong? (My other POS-900W's do the same).
Incidenatlly, I have a screenshot (23Kb) of the display which I can e-mail.

Al.
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mail[underscore]me[at]freenet[dot]co[dot]uk