Jumping to adjacent channel

Discussions about the Ryde "Set-top Box" Style Digital ATV Receiver. See https://wiki.batc.org.uk/Ryde_Receiver
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G6GZH
Posts: 16
Joined: Thu Jun 11, 2020 12:27 pm

Jumping to adjacent channel

Post by G6GZH » Sun Jan 16, 2022 8:11 pm

I wasn't sure where to raise an issue for this but hopefully the relevant person(s) will see it here.

Last May the scan width was reduced to prevent an adjacent channel signal capturing the receiver between transmissions but I recently observed that this was happening again.

I had a quick look at my current installation and it seems that Longmynd now provides a command line option (-S) to override a default value of 1.5 but as far as I can see Ryde does not use this option to set it to 0.6 as had been hard coded in the earlier fix.

Thanks,

David

G8GKQ
Site Admin
Posts: 2397
Joined: Sun Mar 22, 2009 1:21 pm

Re: Jumping to adjacent channel

Post by G8GKQ » Mon Jan 17, 2022 11:54 am

Hi David

I have not seen this behaviour recently with my Ryde receivers but I am not able to do any tests for a few weeeks. The one thing to check is that your LNB offset is set to match your LNB. If you are listening "between channels" that might cause this to happen.

73

Dave

G6GZH
Posts: 16
Joined: Thu Jun 11, 2020 12:27 pm

Re: Jumping to adjacent channel

Post by G6GZH » Tue Jan 18, 2022 11:15 am

Hi Dave

Thanks for the reply.

I've confirmed the LNB offset is correct. The LNB is GPS locked and I leave the MiniTiouner on all the time, so it's as stable as possible.

It's not something that happens a lot; the change which I suspect is the cause was a while ago and I only just noticed it happening.

Enjoy your break.

David

dc1op
Posts: 21
Joined: Sat Jul 27, 2019 3:35 pm

Re: Jumping to adjacent channel

Post by dc1op » Tue Feb 01, 2022 11:24 am

Hi,

just updated the Ryde (controled from Quick Tune) with the actual update and found something like the "jumping effect" too (LNB offset is ok). The following will give more details:
Say, a signal (A) ist received on ..497.25 (333Ks) and another signal (B) is appearing on ..496.75 (333Ks) and i click this signal, the Ryde will go red, opens the service ID window and shows ID of signal (A) and its A+V. Then clicking at signal (A) again it appears with service ID and A+V.
The workaround to go to signal (B): go from signal (A) to to e.g. the beacon and from there to signal (B) = ok. From there clicking signal (A) it will appear.
Alternative trial: using the IR RC and input frequency and symbol rate shows the same behaviour as above.

Did not observe this behaviour in an earlier version that I had used before. How is that to be cured?

dc1op, Hubertus

g0mjw
Posts: 1852
Joined: Sat Sep 20, 2014 9:15 am

Re: Jumping to adjacent channel

Post by g0mjw » Tue Feb 01, 2022 12:43 pm

G6GZH wrote:
Tue Jan 18, 2022 11:15 am
Hi Dave

Thanks for the reply.

I've confirmed the LNB offset is correct. The LNB is GPS locked and I leave the MiniTiouner on all the time, so it's as stable as possible.

It's not something that happens a lot; the change which I suspect is the cause was a while ago and I only just noticed it happening.

Enjoy your break.

David
The LNB is not the only item that drifts, so does the tuner. Perhaps it has moved just enough now as it has aged. I would measure the offset against the beacon with Minitioune on a PC and recalibrate the LNB offset to compensate. I expect the same data (i.e. tuned frequency vs commended frequency) is available in the Longmynd software that underpins Ryde, but not sure how to find it.

Mike

G8GKQ
Site Admin
Posts: 2397
Joined: Sun Mar 22, 2009 1:21 pm

Re: Jumping to adjacent channel

Post by G8GKQ » Wed Feb 23, 2022 4:20 pm

Thanks for all the reports on this. My configuration control failed and I lost an earlier amendment which had cured the problem.

The latest release (202202230) has the signal search width correctly set to about +/- 0.5 SR, so if you perform a software update, this problem should be cured.

Dave, G8GKQ

G6GZH
Posts: 16
Joined: Thu Jun 11, 2020 12:27 pm

Re: Jumping to adjacent channel

Post by G6GZH » Fri Feb 25, 2022 9:59 am

Thanks Dave, I can confirm it is fixed here.

David

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