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1997-01-16 - Re: Newt’s phone calls

Header Data

From: Dale Thorn <dthorn@gte.net>
To: Eric Blossom <eb@comsec.com>
Message Hash: 26fec3b2f26f94fb3d143bd83e60a1678106a3f04c22b3f5fec2c991e15a7a77
Message ID: <32DDA26D.1D39@gte.net>
Reply To: <199701150204.SAA25917@comsec.com>
UTC Datetime: 1997-01-16 04:03:14 UTC
Raw Date: Wed, 15 Jan 1997 20:03:14 -0800 (PST)

Raw message

From: Dale Thorn <dthorn@gte.net>
Date: Wed, 15 Jan 1997 20:03:14 -0800 (PST)
To: Eric Blossom <eb@comsec.com>
Subject: Re: Newt's phone calls
In-Reply-To: <199701150204.SAA25917@comsec.com>
Message-ID: <32DDA26D.1D39@gte.net>
MIME-Version: 1.0
Content-Type: text/plain


Eric Blossom wrote:
> > Exactly. So how come mom&pop with a scanner were able to record
> > BOTH sides of the conversation without interruption? This seems
> > pretty suspicious to me.

> You typically only need to tune into either the forward or reverse
> channel.  You can usually hear both sides (one may be down a few dB).
> This is probably a result of acoustic coupling from the speaker into
> the microphone on one or both ends (could also be near-end hybrid
> echo).  You see the same situation on both cellular and the 49 MHz
> cordless phones.

Actually:
1. 49 mhz is the handset frequency, which doesn't carry both sides,
   or doesn't very well. 46 mhz is the base, and carries both sides
   pretty well.  I don't know how it works on 900 mhz non-digital.

2. My experience on cellular has been that the further the
   mobile phone is from the scanner (on average), the fainter the
   mobile person's voice is going to be, and it is often virtually
   inaudible. There are two 25-mhz cellular ranges, upper and lower,
   and I think 2600 or 411 mag. has detailed which carries what
   info.  Someone with a scanner may be tuning in the upper range
   when they really want the lower, or vice-versa.

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