I have started for the first time my Digithin this morning.
- Pidatv image 1.2.1
- raspberry model B
it seems to modulate well, but I have a big carrier remaining.
input is 437MHz . I try between -10 and -20 dBm, it changes nothing.
Have you an idea to fix this?
Looks like the digithin isn't actually getting the right data stream from the Rpi. With an LO of -20 DBm the output when correctly modulated should be 0dBm.
What's the LED doing? It should be flashing every second - if it's not that's the problem and you need to check you're running 333Ks and if you are playing a TS file it is recorded at right bit rate...
led flash every second.
All seems to work, but there is that high LO signal that remain..
I suppose I must check the level of IQ that go in the modulator, perhaps they are too low?
The levels should be about 120mv pk-pk.
Hopefully it's something simple. I have also seen that pattern if the modulator is faulty. If it's the one I gave you in Portsmouth, I think that came from the Ebay batch from Israel.
Even that would not explain the very low level of the modulation, so it must be something else causing it.
Now this problem is fixed. when I receive on 437Mhz, max MER is 27dB. using R21=390 ohms, 120mV I have now 29dB MER