halle1@houxz.UUCP (09/26/83)
I don't think changing things will help. You probably need an RF filter. I have exactly the same problem with my modem. If I turn it on (and this has happened with two entirely different modems) I get the pattern you describe on channel 5, with nominal interference on 4 and a little on 6. I tried shielding with foil without luck. The interference seems to be carried on the electrical lines. I haven't tried filtering yet. Since modems and base phones are different, the answer must lie elsewhere. I think the problem must lie within the common electronics. Perhaps some memory or a transformer or such?
shacklet@ittral.UUCP (Cliff Shackelton) (09/27/83)
The present crop of cordless phones use the AC line for transmitting the voiceath to the handset at a frequency of around 1.7 Mhz. If the output of the RF driver is not tuned properly, or some heavily inductive item is on the same circuit ALL KINDS of crazy harmonics are produced. The kicker is that the FCC doesn't specify a particular amount of power that can be applied to th AC line but only a field stregnth at 3 meters from an arbitrary line. Most cordless phones pump in excess of !! 1 watt !! at 1.7 Mhz into the AC line. If you play around with the fine tuner on your tv you can get the audio for the phone. BUT** don't fret! a tune up on your phone by the factory or someone who knows what the're doing will cure your problem. This reason is why th FCC is changing the requirement for cordless phones to 49 & 46 Mhz at 100Mw power input, and may require some sort of voice scrambling and line access security. Look for the new wave of cordless phones from all manufacturers after next june that will have these features. Cliff (I know we makem) Shackelton ITT Telecom