On Tue, 22 Sep 2009 08:20:14 -0700, Joerg
wrote:

It's the comm from handset to base that drops out, base to handset never
drops out. The next cell tower is about a mile away though but we are on
top of a knoll.

The means the base receiver might be getting clobbered by a cell site.
Move the base away from the window and put something substantial (like
a wall) in between it and the cell site. Experiments with reflectors.

I would assume the base could also be fooled by a signal from a cell
phone itself if close enough.

Probably not. DECT 6.0 phones operate on 1920-1930MHz.
US PCS cellular base to mobile is at 1930-1990Mhz.
US PCS cellular mobile to base is at 1850-1910MHz.

The handset is at least 20 Mhz away from the PCS receiver, which is
sufficiently far away so that a cheap SAW or ceramic filter would
work. That's in contrast to the PCS base, which is literally adjacent
to the DECT 6.0 frequencies.

Why did they screw up the chip sets so
badly?

The chipsets are fine. It's the lack of RF filtering that's the
problem. I haven't looked inside the phone, but my guess is that the
RF filtering is fairly minimal.

I mean, I can stand right next to a guy with another cell phone
at the airport or even inside the metal fuselage of an airplane (after
landing) and nothing interferes. Did the DECT guys screw it up?

Actually, it does interfere. For GSM, the cell site synchronizes
frequencies and TDMA slot times so that they don't directly interfere.
With CDMA (spread spectrum), it's not so nice as additional handsets
raise the base line noise level. With sufficient noise generated by
other handsets, a marginal signal could cause a session disconnect.
The good news is that you won't hear any beat notes, intermod,
crosstalk, or garble. All that will happen is a dropped call.


--
Jeff Liebermann
150 Felker St #D http://www.LearnByDestroying.com
Santa Cruz CA 95060 http://802.11junk.com
Skype: JeffLiebermann AE6KS 831-336-2558