Sine System and phone line not working well with each other at times

[midatlanticengineer]

I have noticed a situation at a few sites that use the Sine System. Every two or three weeks when you go and dial into the r/c [Sine System], I'll get a busy signal. Then that requires a drive to the transmitter site to unplug the phone line and Sine System. At that point, you can dial in and everything is normal, then out of the blue in a few weeks the same busy phone line deal occurs again. ???

Anyone ever have this problem and find a fix for it?

 

[Andy_Brown]

Not familiar with the system, but am familiar with the problem.

Is this a POTS line?

Check for noise/hum levels or have the phone company do same.

I've had noise on a phone line do screwy things to remote controls ... raise power, lower power, reset xmtr when it wasn't even off, etc. etc. Caused by strong harmonics of 60 Hz hum.

 

[midatlanticengineer]

It is a POTS line but the POTS lines are clean. The problem does not have a pattern persay as resetting the system today might result in it working normally for 2 days or two weeks before the problem rears its ugly head again.

 

[rew]

I had a problem like that last year. When the remote would call out it would not release the phone line. disconnecting power would reset it. I found the transistor that drives the phone line relay (ry1 I think) leaky. I replaced that transistor and no problem since . IT would be odd to be having this problem on more than one site. The sine has a timer that will hang up the line if it has not received a command after a set time. Check its setting. I think it is address 1000.
Good luck and let us know what you find.

 

[kenhawk1160]

The sine has a timer that will hang up the line if it has not received a command after a set time. Check its setting. I think it is address 1000. Good luck and let us know what you find.

Interesting...is this is a first or second generation Sine unit?

 

[Andy_Brown]

It is a POTS line but the POTS lines are clean. The problem does not have a pattern persay as resetting the system today might result in it working normally for 2 days or two weeks before the problem rears its ugly head again.

I've also had problems like this being caused by other RF systems nearby. Is your transmitter all by itself or are there other services nearby? In the case I'm remembering, a military SSB repeater with a loose filter in its output was causing the RC to act squirrely (ignoring commands). Took months to figure it out ... one day when I was at the transmitter the jock called and said "See, it's doing it again." Got talking with the maintenance guy for the military rig who happened to be up there at the same time, and together we traced it to his new filter on the output of the offending rig.

 

[ChiefEngineer]

It is a POTS line but the POTS lines are clean. The problem does not have a pattern persay as resetting the system today might result in it working normally for 2 days or two weeks before the problem rears its ugly head again.

Andy,

Had this problem at a site with 2 Class B stations at lower height. Months and months worked on it.

The sine units are circuit boards with no enclosure. No rf shielding. I have never had an am station create this problem where you normally expect rf.

The site is rural and the telco is a rural carrier. Sine indicated the problem was rf after I sent the unit back twice. We also had lightning involved which made this more complex. There WAS noise on both lines I don't see with an SBC install.

There are settings for ring detect that helped. What really helped were torroid filters designed to filter fm rf. wrapped phone lines, lines to transmitters, and wall wart lines through them. Presented new grounds to the remote in multiple locations. This ultimately resolved the problem.

Not just an "equipment rack ground"...ran a ground line to the master halo ground. One resolution of the many does not work by itself. I can remove ground, filter, etc, and find that any of the changes will cause problems.