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Allison,

Yes, most of what I had in my last post was gleaned from your older posts.
I posted in response to Henning's warnng about using a better 45mhz transistor:
? ? "Using e.g. BFR106 instead could worsen the spur problem."

Here's Warren's plot for 15m:
? ??/g/BITX20/photo/65861/2
There's a fair bit of dirt showing that's lower in freq than the 15m fundamental.
Is that stuff real, or an artifact of the test setup?

Warren used a 1mhz RBW and 1mhz VBW, are the results accurate enough for our purposes?
I'm still chewing on this from your post? ?56613,
would be less ambiguous if I knew something about spectrum analyzers.


"FYI: if you run video bandwidth down far enough you can get a 10db?
error and also clean up the baseline, save for it will be wrong.??
Anything less than 30khz (for 3-30mhz span) on the Rigol and a less?
than 1:3 radio of RBW and VBW will yield low readings.? With the?
HP8568B less than 10khz and 1:3 give errors.? Also sweep rates less?
than 300mS give sampling errors.

The test in my case was radio, Bird model 43 wattmeter, NArda 30db attenuator,?
Telonics step attenuator, Spectrum analyzer.? ?With 10W indicated on the Bird
BOTH machines of known calibration will read low if set up wrong.? For the?
Rigol I could not get an accurate 10W (40DBM) indication with 3khz RBW
and 1Khz VBW (is was short by 11db) at 311mS sweep and 3-30mhz span.
If I lowered the span to 10mhz it was off by 3db.? At 1mhz the indication?
was under 1db of correct.? ?For the setup you used I add 10db.? If I make the?
VBW 30khz it gets better but its still off."

Jerry