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Digital data over telephone line

Is there any available product that could encode [digitalize analog
signal] and transmit digital signal over telephone line? (except for
modems of course) I don't really need to estabilish a connection -- I
can deal with data loss.

thanks,

Oscar
 
T

Tim Shoppa

Is there any available product that could encode [digitalize analog
signal] and transmit digital signal over telephone line? (except for
modems of course) I don't really need to estabilish a connection -- I
can deal with data loss.

Call it what you want, but you are specifically asking about modulating
at the transmitter end and demodulating at the receiver end. Modem
stands for "modulator and demodulator" so you're stuck here.

Now to do this, you do not need computer-and-RS-232 modems (although
since you seem to be insisting on "digitalizing" this could be the wise
course.)

For many purposes, a FM-modulated carrier at the transmitter and a
simple demodulator at the receiver will do just fine for many
applications. Could just be a 4046 and some shaping/conditioning at
each end.

Tim.
 
T

Tim Shoppa

Is there any available product that could encode [digitalize analog
signal] and transmit digital signal over telephone line? (except for
modems of course) I don't really need to estabilish a connection -- I
can deal with data loss.

Get one of those talking digital voltmeters :).

(Although technically that IS a MODULATOR, just with a really
complicated but easy for human to decipher modulation.)

Tim.
 
J

J.A. Legris

Is there any available product that could encode [digitalize analog
signal] and transmit digital signal over telephone line? (except for
modems of course) I don't really need to estabilish a connection -- I
can deal with data loss.

How about a DTMF decoder? You literally punch in digits at one end and
recover digits at the other end.
 
D

Don Bowey

Is there any available product that could encode [digitalize analog
signal] and transmit digital signal over telephone line? (except for
modems of course) I don't really need to estabilish a connection -- I
can deal with data loss.

thanks,

Oscar

If you mean an ordinary POTS telephone line, then no. The public interface
to the telephone network is strictly analog unless you have an ISDN line
with a Terminal Adapter. You must use a modem.

There are "digital data" units (a Channel Service Unit and a Data Service
Unit, which may be in one box) that are used to connect data signals to
Private Line (Leased Line) networks, at rates up to 64 kb/s. They tend to a
bit expensive.

What is it you are trying to do?

Don
 
P

Paul Hovnanian P.E.

Tim said:
Is there any available product that could encode [digitalize analog
signal] and transmit digital signal over telephone line? (except for
modems of course) I don't really need to estabilish a connection -- I
can deal with data loss.

Get one of those talking digital voltmeters :).

(Although technically that IS a MODULATOR, just with a really
complicated but easy for human to decipher modulation.)

He said that he didn't want a 'modem', but what you describe could be
called a 'mo'.

Larry and Curly can't be far behind.

;-)
 
M

Michael A. Terrell

Paul Hovnanian P.E. said:
Tim said:
Is there any available product that could encode [digitalize analog
signal] and transmit digital signal over telephone line? (except for
modems of course) I don't really need to estabilish a connection -- I
can deal with data loss.

Get one of those talking digital voltmeters :).

(Although technically that IS a MODULATOR, just with a really
complicated but easy for human to decipher modulation.)

He said that he didn't want a 'modem', but what you describe could be
called a 'mo'.

Larry and Curly can't be far behind.

;-)


No, they are too busy posting in the "New Book of Rules" thread. :(


--
Service to my country? Been there, Done that, and I've got my DD214 to
prove it.
Member of DAV #85.

Michael A. Terrell
Central Florida
 
J.A. Legris said:
How about a DTMF decoder? You literally punch in digits at one end and
recover digits at the other end.

Why do I imagine this randomly dialing "interesting" numbers if the
line momentarily goes on hook and then back off without the device's
awareness?
 
M

Michael A. Terrell

Phil said:
Pick two fingers!


Why, I otta! ;-)


BTW, I have a VERY irritating Three Stooges screen saver if you
really, REALLY want to bug someone. It is 2.8 MB, but I could put it on
the web for you. It does work on XP.


--
Service to my country? Been there, Done that, and I've got my DD214 to
prove it.
Member of DAV #85.

Michael A. Terrell
Central Florida
 
M

Michael A. Terrell

Why do I imagine this randomly dialing "interesting" numbers if the
line momentarily goes on hook and then back off without the device's
awareness?


Never heard of a dial tone detector?


--
Service to my country? Been there, Done that, and I've got my DD214 to
prove it.
Member of DAV #85.

Michael A. Terrell
Central Florida
 
R

Robert Baer

Don said:
Is there any available product that could encode [digitalize analog
signal] and transmit digital signal over telephone line? (except for
modems of course) I don't really need to estabilish a connection -- I
can deal with data loss.

thanks,

Oscar


If you mean an ordinary POTS telephone line, then no. The public interface
to the telephone network is strictly analog unless you have an ISDN line
with a Terminal Adapter. You must use a modem.

There are "digital data" units (a Channel Service Unit and a Data Service
Unit, which may be in one box) that are used to connect data signals to
Private Line (Leased Line) networks, at rates up to 64 kb/s. They tend to a
bit expensive.

What is it you are trying to do?

Don
You mean the old Bell Blue Steak guys are still in business?
 
J

J.A. Legris

Michael said:
Never heard of a dial tone detector?

Also, no mention was made of the desired data rate. I figured he might
do the A/D conversion in his head or with pencil and paper and then
just key in the results ;-)
 
M

Michael A. Terrell

J.A. Legris said:
Also, no mention was made of the desired data rate. I figured he might
do the A/D conversion in his head or with pencil and paper and then
just key in the results ;-)


He could use a "Code Practice Oscillator" and send slow Morse Code,
too. ;-)


--
Service to my country? Been there, Done that, and I've got my DD214 to
prove it.
Member of DAV #85.

Michael A. Terrell
Central Florida
 
M

Michael Black

Michael A. Terrell" ([email protected]) said:
He could use a "Code Practice Oscillator" and send slow Morse Code,
too. ;-)
You guys are amateurs. The obvious solution is pulsing the line, just
as old dial phones (including the one I still use today) worked.

If the DC variants are too much for the poster, then he can use
the dial pulses to modulate an oscillator and count those at the other
end. I can't even recall why this was done, but I know for some radio
work they used similar schemes, though touch-tone was already in operation
at that point.

Michael
 
J

J.A. Legris

Michael said:
You guys are amateurs. The obvious solution is pulsing the line, just
as old dial phones (including the one I still use today) worked.

If the DC variants are too much for the poster, then he can use
the dial pulses to modulate an oscillator and count those at the other
end. I can't even recall why this was done, but I know for some radio
work they used similar schemes, though touch-tone was already in operation
at that point.

Michael

Dammit, you're right. How quickly we forget.

Are they ever going to phase it out?

Ha! My uncle refuses to pay the phony surcharge for DTMF service and
now he's having one hell of a time finding phones with pulse/tone
switches. He needs the tones for telephone banking :)
 
R

Rich Grise

Dammit, you're right. How quickly we forget.

Are they ever going to phase it out?

Ha! My uncle refuses to pay the phony surcharge for DTMF service and now
he's having one hell of a time finding phones with pulse/tone switches.
He needs the tones for telephone banking :)

Once, I had just moved into a new apartment, and the phone didn't work.
This was in the old days, when the phone and everything came from Ma Bell.
Well, they tell you to call repair service, but I couldn't dial out,
because the phone wouldn't dial. I got dial tone, but no touch-tones
from my phone.

So I flashed the hookswitch. Ten pulses for "0". The operater answered.
She transferred me to repair service, and they said, "Oh, Polarity!" and
the guy was there on his next call and fixed it in a few seconds. :)

Cheers!
Rich
 
R

Robert Baer

Rich said:
Once, I had just moved into a new apartment, and the phone didn't work.
This was in the old days, when the phone and everything came from Ma Bell.
Well, they tell you to call repair service, but I couldn't dial out,
because the phone wouldn't dial. I got dial tone, but no touch-tones
from my phone.

So I flashed the hookswitch. Ten pulses for "0". The operater answered.
She transferred me to repair service, and they said, "Oh, Polarity!" and
the guy was there on his next call and fixed it in a few seconds. :)

Cheers!
Rich
When i moved into a new home in Olympia WA, i had ordered two phone
lines; was given two numbers, but..
The "primary" number was on the secondary line and the "secondary"
number was on the primary line.
Also....they had the polarity ass-backwards on one of them (forgot
which one).
I called to complain of the shoddy workmanship (Quest, well after the
Bell breakup) and told them that i could have done better blindfolded,
and would fix it myself and bill them $120 per hour with a one-half hour
minimum (*their* rates then) if they did not get it fixed in 24 hours.
That got them so flustered that they actually sent someone to the
house to fix it (very simple re-wiring job).
 
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