atcomsystems.ca/forum Forums Wiring - Telecom Carriers - Trunks & Services Telecom Service & Providers Calls on radio station request line drop when put on hold on air

Here's one I need help figuring out.
There is a radio station that has had an "fx"line as one of its request lines for years. This is a line from a different city that "appears" as a local call at the radio station. A Qwest tech has told me there are no facilities for this in the originating city, so it must be some sort of call forwarding to another co in the other town. The Qwest tech told me that it is a "designed circuit".
At the radio station demarc, the 3 request lines are paralleled, one leg to the phone system, and the other leg to the "phone board" that puts the call "on air" on the radio. This has worked fine on the same equipment for years. Now a problem has cropped up... When a call is answered on the fx request line on the phone system and placed on hold and retrieved again on the phone system all is ok. But.... when the call is answered on air and put on hold via the "phone board" the call is dropped. The other request lines are regular local pots lines and have no trouble. When the fx line is swapped with a regular pots line on the phone board, the problem follows the fx line....A second phone board has the same symptoms.....

I'm going to guess all vendors are going to stand in a circle and point to the right saying its the other guys fault! Any ideas? Loop current maybe? The customer says nothing has changed and the problem just started last week.

Thanks for any input.
Z102.9

Polarity reversed? Quest will deny responsibility, but any cable rehab going on in the area is the culprit.

The fact that it is happening on both phone boards that were working fine leads me to believe that you have a low line voltage problem.

I think that this circuit has changed from being a physical metallic one to one that is being derived by some form of pair-gain or even (gasp) IP. The original phone boards were designed around the 1A2 environment where precise line voltages and currents were required for everything to operate in harmony.

I'll bet that the tip/ring voltage on this FX circuit is far outside of the industry standard of +/- 48 volts. I'll go a bit further and bet that you'll probably find it to be more in the area of +/- 32 volts.

Technically, the service providers are required to deliver service at certain levels as mandated by the FCC. The key is in getting through to someone who understands what you are requesting. It seems as if most front-line service provider people go blank if you ask for anything other than caller ID.

At the time when the change happened on the FX line, has there been any OTHER symptoms crop up? A noticeably lower signal level? More echo/talk-back/sidetone?

Like John and Ed, I assuming there was a change too to how the service is delivered, but without knowing exactly what changed on the telco side it can only be a guess, but I’m guessing switch to a pair-gain system but the FX service was not properly redesigned.

Bryan or Ed, as lots of radio/TV call in lines are on a "choke exchange" would that have anything to do with ictelco's problem?

I understand those exchanges are designed to something different with the incoming calls.

Seriously doubt it, but a good question to ask... Anything is possible when a cause is known.

If there was odd call routing or blocking issues I would suspect how the translations was set up the choke exchange as a culprit right away but it really seems like the issue is past the switch.

I'm sure of two things:

You want to get this fixed the right way.

You want to get this fixed quickly, so your customer doesn't suffer.

If you want it fixed so that the provider is supplying the proper voltage and current, you can pretty much go buy a lottery ticket, and you'll have the same statistical success.

It will take lots of time to do measurements, and to arrange "vendor meets" and at the end of the day, you'll still have the problem.

To get the customer working again in a half-hour, do this:

Get a used, small, cheap, key system. Program the suspect incoming line onto a trunk port, and program a single-line station port as the input to your customer's systems. If you can get a key system that uses close to 48 volts on its SLT's all the better.

An incoming call will now get passed to the SLT port, and perhaps the customer's system will react favorably with it. Perhaps not, but it's worth a shot.

Now I know I've been retired to long, what the "H" is a "choke exchange"?

Funny question, Jim but a very legitimate one!

In many major markets, the LEC will set up mass-calling exchanges at the toll level instead of at the end office. This prevents 10,000 callers from crippling a local CO when the whole town is trying to win concert tickets. By off-loading this traffic in the toll offices, the impact of a huge inrush is minimized.

Since toll offices are engineered for 100% throughput, as in "trunk in, trunk out", they can handle huge influxes just fine. Local end offices are (were) designed around more casual dialing, so the allocation of receivers, etc. could be relaxed. It wasn't often that everyone in town picked up the phone at the same time to dial. I'm sure you remember crossbar offices where the absence of available receivers resulted in delayed dial tone. Even I remember that!

In the DC area, the 202-432 code was used for radio and TV call-in lines. New York City used 212-955. Now that CO equipment has become more sophisticated, there isn't the need for exchange-based routing between offices. In the day, these stations paid for circuits directly from the nearest toll switch to handle the incoming traffic, thus bypassing their local end office. This reduced or eliminated the proverbial "choke" points.

Most of these have been abandoned now, but ours still resides in a DMS-200 just in case. Many stations just use a toll-free number, which routes calls through toll switches by default.

Our city's choke (204-780) is running on a dedicated DMS-100.

Until tonight I never thought to look up on telcodata what switch platform it was running on.

If I am not mistaken in the late 60's when I was a little kid my uncle told me about a few exchanges locking up with "Santa" being on a call in show here in Winnipeg.