Interesting article... One little warning to note with some (if not all)
Uniden Bearcat portable scanners, and maybe others... The earphone jack is
directly fed full power audio, and is then reduced via a resistor place on
the ground line of the earphone jack. Using this item, wired as indicated,
would bypass the resistor (audio grounding would go through the unrestricted
antenna ground) allowing full power audio out of the earphone jack once
again. Audio output would be quite a bit higher than you would normally be
used to! Be careful as to not damage your hearing because of this!

That little trick (jumpering the audio ground to the antenna connector) is
commonly used by those that hook up small external speaker(s) to the
headphone jack...

PH


"Lars Janqqvist" wrote in message
...
I recall a few weeks ago someone here was asking about building a
stealth / undercover scanner antenna.

I happened to see just the thing while reading through an old
issue of Popular Electronics (Aug 96.)

Scanned it in and put it up at

http://spammedaddy.home.netcom.com/S...a/antenna.html

It's pretty much as folks here said. The earphone wire
capactively coupled to the antenna input on the scanner.

My guess is that a plain wire connected to the center of a BNC
plug and run down the inside of your pants leg would have worked
just as well. Perhaps not as practical, depending on the
circumstances.

Frightening the yaks, PowerHouse Communications just had to say:

Interesting article... One little warning to note with some (if not all)
Uniden Bearcat portable scanners, and maybe others... The earphone jack is
directly fed full power audio, and is then reduced via a resistor place on
the ground line of the earphone jack. Using this item, wired as indicated,
would bypass the resistor (audio grounding would go through the unrestricted
antenna ground) allowing full power audio out of the earphone jack once
again. Audio output would be quite a bit higher than you would normally be
used to! Be careful as to not damage your hearing because of this!

That little trick (jumpering the audio ground to the antenna connector) is
commonly used by those that hook up small external speaker(s) to the
headphone jack...

If that turned out to be the case, the project might work just as
well with the connection to the antenna ground omitted.
Depending on the RF impedance of the earphone, the whole thing is
close to ground potential anyway. The audio limiting resistor
inside the unit could only help lift that level.



--
To reply, DO NOT remove spam from the return address!

***************************
This calls for a careful blend of
clever psychology and extreme violence.
***************************