Rx Freq is Extremely Sensitive, no AFC
Posted: Thu Jan 17, 2019 3:07 am
The BER using YSF on a ZumSpot is extremely sensitive to frequency. Changing RXOffset by a few hundred Hz can make the difference between low BER and very high BER (or no Rx) on Rx.
The DV4mini uses the same ADI7021 chip and is very insensitive to frequency error. It is possible to vary the frequency by +/- 500 Hz with very little change in BER. 100% of the YSF users never have to fool around with receiver offsets.
The OpenSpot also uses the ADI7021 and is also insensitive to changes in frequency.
AFC appears to be disabled in 1.4.14. In addition, the AFC parameters (if AFC were to be turned on) do not appear to be optimal.
This frequency sensitivity is causing "hell on earth" for network operators, such as myself. The high BER coming from hotspots bridged to WiRES-X rooms is causing system components to behave improperly or shut down. The hotspots should not emit packets onto the network that contain bad FICH information or are malformed.
(I bought a Zumspot so I could figure out why so many Pistar users were causing problems with the network. This had not been an issue prior to the popularity of the Zumspot on Ham Radio Outlet.)
So please put some effort into reducing the high BER resulting from small differences in frequency. This will go a long way to helping the problem and I think a lot of Pistar users will be happier as a result.
73,
Chris, K9EQ
The DV4mini uses the same ADI7021 chip and is very insensitive to frequency error. It is possible to vary the frequency by +/- 500 Hz with very little change in BER. 100% of the YSF users never have to fool around with receiver offsets.
The OpenSpot also uses the ADI7021 and is also insensitive to changes in frequency.
AFC appears to be disabled in 1.4.14. In addition, the AFC parameters (if AFC were to be turned on) do not appear to be optimal.
This frequency sensitivity is causing "hell on earth" for network operators, such as myself. The high BER coming from hotspots bridged to WiRES-X rooms is causing system components to behave improperly or shut down. The hotspots should not emit packets onto the network that contain bad FICH information or are malformed.
(I bought a Zumspot so I could figure out why so many Pistar users were causing problems with the network. This had not been an issue prior to the popularity of the Zumspot on Ham Radio Outlet.)
So please put some effort into reducing the high BER resulting from small differences in frequency. This will go a long way to helping the problem and I think a lot of Pistar users will be happier as a result.
73,
Chris, K9EQ