[BC] dtmf tone filter solutions

[Thomas G. Osenkowsky]

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

> If you thought you could signal something to happen
> in the studio by pressing a telephone keypad button
> without anybody knowing about it, you need to
> rethink your idea. You use sub-audible tones for
> that, not DTMF!