[time-nuts] puzzling level and harmonics partially solved
walter shawlee 2
walter2 at sphere.bc.ca
Wed Jan 27 18:14:18 UTC 2016
thanks to all that sent me info on this issue. it proved very helpful.
digging into the smd chinese add-on board tied to the oscilloquartz
ovenized oscillator, I discovered something unexpected.
the 2 outputs are in fact just tied together though a forest of series
inductors and shunt caps and then tied right to the to the oscillator output.
so, the reason the level is so low, and the harmonics so high is that both
outputs are
in parallel through very lossy networks. I am not sure what the intent was, but
the result was to over-load the 50 ohm output of the oscillator, and then
dissipate most of the signal. maybe this was some kind of 10Mhz bandpass filter,
but now I need to dig right back to the oscillator and see if it is even needed.
I will see if this can be patched to at least work properly with a single
output. all the circuitry on the underside is actually just a fantastically
complicated (to no good end) 12V power supply, and bias for the efc pin. sigh...
I got a second unit at the same time off ebay, it does not work at all, if you
plug into the power jack, it kills the power. I was able to tease it into
operation, and it has the exact same problems. clearly QA is not the strongest
feature with this vendor (amoj1010).
all the best,
walter
--
Walter Shawlee 2, President
Sphere Research Corporation
3394 Sunnyside Rd., West Kelowna, BC
V1Z 2V4 CANADA Phone: (250) 769-1834
walter2 at sphere.bc.ca
WS2: We're all in one boat, no matter how it looks to you.
Love is all you need. (John Lennon)
But, that doesn't mean other things don't come in handy. (WS2)
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