Pocsag decode 1200 intermittent

[kevtheskin]

Hello all, Can anyone tell me why the pocsag decoder is so intermittent. I have a very strong signal here and only some times decodes? Also does the settings in the pocsag Tx effect the rx set up.

Thanks Kev

[jboone]

I would try reducing your gain to see if that helps. Too strong a signal will distort and become unreadable. Are you certain all the transmissions you're seeing are POCSAG and not some other pager flavor? I know that trips me up frequently -- I see signals in the frequency range I expect for pagers, but they turn out to be FLEX pagers or some other signal. I don't know for sure if this is done in practice, but perhaps two different modulations are being used on the same frequency?

[kevtheskin]

Thanks Jared, Its Scottish Kev here. The frequency I am using is Pocsag only 512,1200,2400 . All signals can be decoded with Pdw and sdr# have tried various gain settings on PP and only decodes some times. Its a pity the rssi indicator didnt show a good level marking. Or if you could hear the signal to see if its clean. Any more hints please. Cheers and hope your well. Kev

[furrtek]

You can hear it and record it in the analog audio app in NFM mode.

[kevtheskin]

Thanks furrtek. I think the issue is that it's picking up a nearby flex system on an adjacent which possibly confusing the decode. Are you planning any new goodies to add to the firmware. Cheers Kev

[kevtheskin]

Hello all , Is anyone managing to decode pocsag. I only manage to decode every now and again. Signals are good its is definately pocsag1200 and Pdw which is running with my rtl sdr is decoding constanly. Please any help would be much appreciated. Thanks Kev

[furrtek]

Hey. I'm able to decode almost all pocsag transmissions here in France, I've let it run for an hour and missed 2 messages out of about 70. Could you please record audio in NFM mode with 16k BW on your frequency and share the .wav file ? Seeing the waveform you receive would help a lot.

[kevtheskin]

Will try thanks

[kevtheskin]

Hello furrtek, Here is a captured file from Edinburgh Uk. AUD_0001.zip Hope this helps. Gain settings 32 32 16k 153.350

[furrtek]

Thanks, taking a look at it right now.

[kevtheskin]

Hi furrtek, What colour should the rssi bar be when rx signal. It shows red with me?

[furrtek]

You should have some blue when the transmission is active.

[kevtheskin]

Hello again, Not seeing much blue on the pocsag rx mode can see it on the same frequency in audio mode? Furrtek what is your name or do you just use furrtek. Cheers Kev

[kevtheskin]

FAO Furrtek, Hello there, I think I know why the decoding of the pocsag is so intermittent. I ran the unit in hackrf mode on pc and tried decoding with Pdw and Sdr#. I noticed that when you apply any gain which I do require at my locality I see lots of mirroring of the signal either side of the spot frequency which seems to stop the decode . I compared it to my Rtl sdr and sdrplay which was ok at 100% decode. I also tried my spare hackrf and it displayed the same mirroring. Would it be possible to add a filter to help reject the residual noise. Cheers Kev

[kevtheskin]

Sorry for double posting

Cheers Kev