Batboard

Is it possible to record audio from a wireline?

I'm having issues with a MTR2000 that is remotely controlled from another location. I want to have a recording of what audio is being sent to the transmitter.

Also, does the RSS have a log that records all events (tx,rx,...)

I'm sure it's possible. There are two common wireline configurations: DC control and tone control. Whatever you do, you don't want to upset the signals already on the line, or prevent its proper operation.

You could probably connect a tape recorder to the line through at least one or two capacitors, or maybe a capacitor and a transformer. The caps would keep the DC load off the line, and the transformer would isolate your equipment even further. I'd rather put a high impedance pickup across the line, but this might be hard to come up with. I don't know if there's already a commercial piece of equipment that will do this for you. As an experimenter, I'd measure the voltage on the line and use the appropriate components, and probably use a battery-operated tape recorder to further isolate stuff.

Depending on the type of circuit, the phone company might not put all the remote control points on the same line, so monitoring one console from another location might not work. They'd all have to meet up at the controlled equipment, so that might be the best location to monitor all the consoles. Of course, you'd also hear anything coming from the equipment that might be feeding the consoles too.

Bob M.

wow; that was my 500th post!

I'll look into the high impedance pickup; someone here mentioned that a while ago. My goal would be to have some sort of interface to show on paper exactly what time the transmitter is being utilized with a corresponding audio recording. I noticed in the RSS it shows when the transmitter or receiver are being used in one of the menus.

It might be a bit more difficult to determine which transmitter or frequency is being used. Perhaps a spare control receiver could do the work, otherwise you'd need to figure that out yourself based on the tones or DC levels that were sent down the line at the time.

A high impedance, ungrounded, capacitor-isolated tap should work fine. I just don't know if someone already makes such a device. Same with figuring out the frequency/transmitter being used. Getting a paper record could be trickier. It might be easier to setup several receivers and record those, as it would definitely not interfere with the existing consoles and equipment, you could use almost any tape recorder, and a carrier indication could be easily derived.

There might already be a commercially available (i.e. expensive) solution out there.

Bob M.

Hmm...I'll have to check and see if I can just buy a used tone remote and hook it into the system properly. I see them on ebay for like $30 all the time. Then record the audio from that. I still would like to also have some sort of corresponding information if the transmitter is transmitting. I know the RSS has realtime info; maybe I can write a program that will just pull that data down and log it along with the recording.

As for just monitoring the line, a DC remote will also hear everything on a tone controlled line. It also will not filter out the guard tone. Just don't key it up!

If it is trouble shooting you are doing, a line level meter may be more helpful.

Nand.