Rx Freq is Extremely Sensitive, no AFC

[K9EQ]

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

[W1MSG]

It would be much better if it was possible to connect to the Wires X network with out using an RF bridge. This would eliminate many of the issues that happen when using an RF bridge. However the Wires X network is a closed network dependent upon proprietary hardware ( HRI Box ) to connect so an RF bridge is all thats available to those who want to use Wires X and YSF together.

As to the high BER rate, users should always make sure to adjust the RXOffset for the best BER for the mode being used.

[K9EQ]

The issue here is that the 7021 appears to be managed in such a way that frequency is extremely critical. I would think you'd want your hotspot to work better.

Your suggestion would not work. Garbage generated by the hotspot would still be garbage when it hit WiRES-X.

Your comment is off-topic as this is about the extreme frequency sensitivity of the radio.

73,
Chris, K9EQ

[W1MSG]

Like I said it is the end users responsibility to adjust the offsets for the lowest BER rates.

[MW0MWZ]

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

Chris, very interesting, it may well be worth reaching out to Andy (CA6JAU) with your feedback, I am sure he would be interested.
The ZUMSpot firmware is not something I look after, at least not outside of helping to make upgrading the firmware simple, maybe start with raising an issue here: https://github.com/juribeparada/MMDVM_HS/issues or reaching out to Andy directly.