Does this sound like Private Line?

This forum is for discussions regarding System Infrastructure and Related Equipment. This includes but is not limited to repeaters, base stations, consoles, voters, Voice over IP, system design and implementation, and other related topics.

Moderator: Queue Moderator

Post Reply
User avatar
Hoseman292
Posts: 224
Joined: Wed Jul 02, 2003 1:37 pm
What radios do you own?: too many

Does this sound like Private Line?

Post by Hoseman292 »

Gents,

I managed to find a tape of our fire department dispatch center circa 1980 and created a wav file that can be found here as a zip file:

http://www.thewatchdesk.com/forum/attac ... ntid=23036

What I'm puzzled with is the pronounced "hum" sound that is heard in between the paging tones. I recall hearing this hum during those days and always wondered what could be causing it on their radio system. At the time they used a Motorola Centracom console (model with the red green and white buttons for selecting transmitter sites and PTT) and Quik Call for paging. The dispatchers wore Starset headsets and the PL was 5A or 156.7 hertz.


Thanks,
Tim - N3EKG
Silver Spring, Maryland
Batboard $upporter
________________________________________
[email protected]
Will
Posts: 6823
Joined: Tue Sep 04, 2001 4:00 pm

Post by Will »

Sounds like the Console compressor gain goes way up picking up any hum arround. Like a ground loop from the encoder, ect;.

60hz hummmmmmm!
User avatar
d119
Posts: 3538
Joined: Tue Mar 19, 2002 4:00 pm

Post by d119 »

Wow... That's freakin awesome... CLASSIC!

That's definitely 60Hz hum. I agree with will - the gain on the recodrding device picks up bigtime during the periods of silence... Almost like an AGC type thing.

Plectron tones too! NEAT!

Are there any standalone plectron encoders that do the dual-tone (not Quik-Call, I mean the dual-tone dual-tone) Plectron paging these days? I'd love to get one...
Birken Vogt
Posts: 262
Joined: Thu Nov 10, 2005 7:53 pm

Post by Birken Vogt »

FWIW there is still one department I am aware of in the next county that uses the "chord tone" style tone and I think there might be another as well but it doesn't get sent very frequently. CDF has a few of them left too but they converted all their local stations and crew buggies to DTMF recently :cry:

Birken
Post Reply

Return to “Base Stations, Repeaters, General Infrastructure”