Hi guys
my RYDE rx has been working fine until recently.
The sympton is the lock signal will from time to time go high for a short while probably less than 100mS other than that it works perfectly.
It show this glitch every few minutes or so - normally this wouldn't be a problem but as it's likely to be used in a repeater it will cause unwanted beacon transmissions.
I could filter out these glitches post Ryde but ideally would like to get to the root cause as I've not had this problem in the past.
Question - is the Ryde lock detect logic bullet proof and if so what might be causing this problem ?
FYI I don't have any transmitters operating in the shack which might be triggering it.
Regards Tim
Random lock signal
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radiogareth
- Posts: 1384
- Joined: Wed Jan 06, 2016 9:46 am
Re: Random lock signal
Have you gained local 4G or some other local strong RF recently? SAW or tight filters might be worth a play along with a look at Bandviewer to see if there is anything. Could there be a new mixer product upsetting things? (4G exp.)
Gareth
Gareth
Re: Random lock signal
Hi Tim,
I had a conversation about this with Tim MW0RUD and the later with Dave G8GKQ and Noel G8GTZ
The Ryde I have at GB3EN does this occasionally but what was a bigger issue was that if I transmitted an analogue signal on 23cm to GB3EN the Ryde would always react to it, this was a problem because the Ryde would display its red screen briefly and then the repeater would go back beacon mode, so effectively killing off any analogue reception.
I made a work around that when analogue is received a defeat signal is sent to the switcher so that valid signal from the Ryde is ignored, this works well, however in conversation with Dave and Noel they thought that the Ryde shouldn't react like that to an analogue signal.
Duncan G7VVF
I had a conversation about this with Tim MW0RUD and the later with Dave G8GKQ and Noel G8GTZ
The Ryde I have at GB3EN does this occasionally but what was a bigger issue was that if I transmitted an analogue signal on 23cm to GB3EN the Ryde would always react to it, this was a problem because the Ryde would display its red screen briefly and then the repeater would go back beacon mode, so effectively killing off any analogue reception.
I made a work around that when analogue is received a defeat signal is sent to the switcher so that valid signal from the Ryde is ignored, this works well, however in conversation with Dave and Noel they thought that the Ryde shouldn't react like that to an analogue signal.
Duncan G7VVF
Re: Random lock signal
Hi guys,
just to clarify the random lock happens with no antenna connected and previously the same hardware never showed this behavoir - momentary signal indication.
I'm thinking the simplest solution would be to 'de bounce' the signal before use - a bit of a bodge until I can get to the bottom of what has changed / happened.
73 Tim
just to clarify the random lock happens with no antenna connected and previously the same hardware never showed this behavoir - momentary signal indication.
I'm thinking the simplest solution would be to 'de bounce' the signal before use - a bit of a bodge until I can get to the bottom of what has changed / happened.
73 Tim
Re: Random lock signal
I've determined that the rogue lock signals last for between 400 and 800mS so I'm writing a bit of code which waits for the lock signal to be true for more than 1000mS before it is used.
Not ideal as it adds directly to system response time but better than triggering the tx on noise.
Not ideal as it adds directly to system response time but better than triggering the tx on noise.
Re: Random lock signal
I encountered a similar issue on GB3EY's Ryde on 1275MHz. It was intermittent and only showed whilst the transmitter was on when it did deem to occur.
EY uses a single antenna with a duplexer, so initially I thought it might be desnse. It turned out to be a combination of propagation enhancing the radar signal from Great Dun Fell, on the other side of the Pennines, and having the Ryde capable of receiving 1000kS/s symbol rate.
By restricting EY's Ryde to receive 250, 333 and 500kS/s the problem has been eliminated.
A similar issue on an audio repeater I was responsible 45 years ago for was fixed with a 555 timer and a PNP transistor forming a pulse swallowing circuit. Short duration pulses continually reset the timer, but a long valid pulse allowed the timer to complete so that the output changed state.
Clive
EY uses a single antenna with a duplexer, so initially I thought it might be desnse. It turned out to be a combination of propagation enhancing the radar signal from Great Dun Fell, on the other side of the Pennines, and having the Ryde capable of receiving 1000kS/s symbol rate.
By restricting EY's Ryde to receive 250, 333 and 500kS/s the problem has been eliminated.
A similar issue on an audio repeater I was responsible 45 years ago for was fixed with a 555 timer and a PNP transistor forming a pulse swallowing circuit. Short duration pulses continually reset the timer, but a long valid pulse allowed the timer to complete so that the output changed state.
Clive
Re: Random lock signal
Thanks Clive
so from what you describe the lock detect is not bullet proof.
I have my Ryde set to detect only 250, 333 and 500ks but yet with no antenna connected it still generates a lock signal every 30 seconds or so.
It never used to do this so I'm writing a bit of code to pulse swallow much as your 555 time did.
Regards Tim
so from what you describe the lock detect is not bullet proof.
I have my Ryde set to detect only 250, 333 and 500ks but yet with no antenna connected it still generates a lock signal every 30 seconds or so.
It never used to do this so I'm writing a bit of code to pulse swallow much as your 555 time did.
Regards Tim
Re: Random lock signal
I've found that the spurious lock signals can be as long as 2 seconds so my code filters them out - the downside being that it directly to system response time.
Out of interest I built an new RPI Ryde from the ground up and the problem wasn't there, so I integrated it into my system and all was good for about 1/2 hour with no spurious lock signals.
However as the shack was quite warm and the RPI started to heat up the spurious locks returned.
I've added an extra cooling fan just for the RPI which seems to be helping - but not yet totally convinced it's a heat problem.
Out of interest I built an new RPI Ryde from the ground up and the problem wasn't there, so I integrated it into my system and all was good for about 1/2 hour with no spurious lock signals.
However as the shack was quite warm and the RPI started to heat up the spurious locks returned.
I've added an extra cooling fan just for the RPI which seems to be helping - but not yet totally convinced it's a heat problem.