[BC] dtmf tone filter solutions

[RichardBJohnson at comcast.net]

...and the 110 volt ringing frequency is?

http://telecom.tbi.net/phone.htm

Of course sub-audible signals pass over
phone lines. It's done all the while. It may
be that some scum-sucking accountant
that took over some broadcast operation
got away with punching holes in program
material to use DTMF, but it doesn't mean
that one is supposed to use it that way.

In fact, when I was in Radio, CBS was
sued because they used some audible
high-frequency squitter to signal over
the network. Since it was within the
normal program audio band, the
FCC disallowed its use and CBS
had to replace their queuing boxes
with ones that used sub-audible
tones.

--
Cheers,
Richard B. Johnson
Read about my book
http://www.LymanSchool.org


 -------------- Original message ----------------------
From: "Thomas G. Osenkowsky" <tosenkowsky at prodigy.net>
> Sub-audible tones will NOT pass through a
> standard POTS line. That is why DTMF is
> used. Business Radio Network (BRN) used 
> a model 4C-MTD 4 relay muted audio box
> for cueing at sone time. I have one for sale.
> I haven't opened it, however, as I recall it
> was effective. They used the DTMF over
> satellite feed.
> 
> Tom Osenkowsky, CPBE
>