Re: No Signal on uBit-x #ubitx-help


On Sun, Sep 23, 2018 at 09:53 AM, KM4TRT wrote:
) I get about 90 mv @ 45 MHZ just before the crystal filter with the amount of hash you'd expect to see after a mixer
4) Nothing out of the crystal filter. or out of the second amp.
Yes I did check voltages on all the concerned transistors
Can I use any of the cheap bandpass filters from Ebay as long as they are +/- 7.5 Khz pass
The second amp is at ~12mhz.  if the LO to the second mixer is not correct then nothing works.
The second LO is in either 33 or 57 mhz (check the docs).

The chain from antenna in is 14.0mhz upconverted to 44.985ish mhz and then down converted to 12mhz.
If any of the oscillators are wrong you miss the 45mhz pass band or the 12mhz filter pass band
(11.995 to about 12mhz) you get nothing as in deaf.

Those 45mhz filters are not likely to fail, bad joints are possible. Any  45mhz filter should work 7.5 or the
wider 15Khz.   

I'd insure that the calibration went well and the 3 digital oscillators are indeed where they should be.
IF they are not its  going to be a deaf rock.


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