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Re: 2.4 gHzCordless Phones



Roy,

This is something that I have been interested in also.  I took the step of
buying
a 2.4 GHz telephone for myself.  I thought it would be a good way to learn
what
the problems might be ahead of time.  Before my neighbors started interfering.

I was also curious to see if the spread spectrum mode would suppress the
interference.

The model I bought was a Panasonic KX-TG2570B.  It was rather expensive
and comes with lots of features.  From the telephone users point of view it
performs rather well.  It has a very long range.  I have used it up to a mile
away
from the base.  The base of this model has two antennas.  One for transmit and

one for receive.  They are both on swivels.  If you set them parallel the
phone
desenses itself badly. The phone operates in the 2406.16 - 2477.84 MHz range
so its not technically on the satellite frequency.
The FCC ID is ACJ96NKK-TG2550

Now for the bad news:  It completely wipes out the AO-40 satellite when in
use.
I have moved the phone into the shack so I can control when it is in use.  The

spread spectrum mode does not keep me from listening in to my own calls
either.
If I tune in AO-40 and open the radio speaker while I have the phone off the
hook I get instant feed back.  I can easily understand what is being said on
the
phone by listening to the 2.4 GHz radio using FM mode.  The problem is only
present when I have the 2.4 GHz pre-amp on.  This is due to the pre-amp being
overloaded and generating cross modulation products neat 2.401318 GHz.
So far I have not heard any neighbors on the band.  I do not know if any of
them
have 2.4 GHz phones yet.  I'm not going to ask because of the perception they
might get about me listening.  They won't understand that I'm concerned about
not hearing them!

I have been concerned about unlicensed devices using our frequencies for
quite a while.  I found another one recently.  Its a remote wireless outdoor
thermometer sold at Radio Shack.  It uses 433.92 MHz and carries type
type approval, FCC ID: AAO6301026R.  I can hear a couple of these in my
neighborhood.

By the way you can look up FCC ID's at:
http://gullfoss2.fcc.gov/cgi-bin/ws.exe/prod/oet/forms/reports/Search_Form.hts

73's de Rich @ WC8J

----

Roy Welch wrote:

> I am interested in whether or not anyone here has experienced interference
> to your AO-40 reception from nearby 2.4 gHz cordless phones.  Associated
> with that, how about from your microwave ovens.  I have associated
> interference to a 2.4gHz phone from a microwave.  Just curious as to the
> interference from the 2.4gHz to the AO-40 reception.
>
> --
> 73, Roy -- W0SL
>
> Internet: w0sl@amsat.org
> Home Page: http://home.swbell.net/rdwelch
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