I need to connect PC Modem to wireless analog telephone :(
I need to connect PC Modem to wireless analog telephone :(
(OP)
so I need to establish wirelles connection beetwen pc modem and telephone line using analog wireless telephone. I tried to connect mic and headphone from wirelles telephone to line of modem, modems start recognizing, but can't establishing connection . I think problem is mic and headphone from wirellesphone is in same circuit and come like microphonia efect. So can someone help me how to do this.
This is circuit which I used. Please I need realy help for this...

This is circuit which I used. Please I need realy help for this...






RE: I need to connect PC Modem to wireless analog telephone :(
I hope this helps a little.
RE: I need to connect PC Modem to wireless analog telephone :(
and thats what you said is matter for waiting dial tone or maybe not while i senfd to modem phone line sound and modem start dialing.
Second! i established connection but with 1200 bps :(
on one other forum one user told me that modems 24000 bps and higher don't use just frekvency modulation , but also phase of sound changing, and this is problem.PHone can't work with this type of sound
So i need now how to work with this phase change of sound signal. Something must be possibile to make to resolve this problem , What to do with phse changing before send signal to phone?.
And Lewish one thing I established connection without ampliefer, did you know whats voltage out from phone?-very small and modem recognize it and work.
Maybe Im in wrong, than tell me whats however.
Please can anybody help me?
RE: I need to connect PC Modem to wireless analog telephone :(
One thing your ckt probably needs is a hybrid connection between your send/receive ckts and the modem line. The modem already HAS a hybrid internally to separate its send/receive. The hybrid allows the two connections to a single bi-directional line while isolating the two from each other. Without a hybrid it is difficult to avoid oscillation.
The BEST solution would be to find the hybrid coil on the modem and bypass it, connecting each path separately to the modem in/out circuits from your mic/spkr ckts.
RE: I need to connect PC Modem to wireless analog telephone :(
RE: I need to connect PC Modem to wireless analog telephone :(
RE: I need to connect PC Modem to wireless analog telephone :(
I seriously doubt, however, that you are going to get to 28Kbaud. If you do, publish it, others will want to know how.
RE: I need to connect PC Modem to wireless analog telephone :(
http://www.hut.fi/Misc/Electronics/circuits/teleinterface.html
Just below the middle of that long page, are some op amp interface circuits that might be of interest.
Your wireless link COULD have a wider audio bandwidth than the telephone system, and the clever modems might use it to help compensate for any extra noise and distortion if the app is a stand alone modem-to-modem arangement. But, if the link will connect to the telephone lines, that advantage will be lost and the wireless link noise will just add to the existing noise.
So, getting 28K or even better might be possible with just the wireless link, probably a tough target, though, if used in combination with a telco connection. Go for it.
RE: I need to connect PC Modem to wireless analog telephone :(
"telco"
RE: I need to connect PC Modem to wireless analog telephone :(
Sorry, just meant the telephone company - jargon.
If the modem path is through the wireless link, then through the telephone system to a remotely located modem, both systems will add noise, distortion and bandwidth limitation of their own. The sum of these will determine what the modem sees and limit connection speed.
So, as a thought, breaking that path into two separate links could, in theory, give a higher throughput. ( device modem to wireless link to local modem - back-to-back modem data connection - second modem to the telephone line )
RE: I need to connect PC Modem to wireless analog telephone :(
I have US Robotics Sportster Voice 33.6K
RE: I need to connect PC Modem to wireless analog telephone :(