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Lars Janqqvist
November 18th 04, 07:14 PM
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/StealthAntenna/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.



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PowerHouse Communications
November 18th 04, 11:09 PM
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/StealthAntenna/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.
>

M.S.
November 19th 04, 07:04 AM
That's the little beggar! Thanks!

M

"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/StealthAntenna/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.
>
>
>
> --
> To reply, DO NOT remove spam from the return address!
>
> ***************************
> This calls for a careful blend of
> clever psychology and extreme violence.
> ***************************

Lars Janqqvist
November 19th 04, 09:56 AM
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.
***************************

Tony VE6MVP
November 25th 04, 05:19 AM
On Thu, 18 Nov 2004 18:14:43 GMT, Lars Janqqvist
> wrote:

>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.

Or on my suspenders for full body coverage. <smile> Hmm, do they
make elasticized wires? <bigger smile>

Tony

Lars Janqqvist
November 25th 04, 08:50 AM
Frightening the yaks, Tony VE6MVP just had to say:

>On Thu, 18 Nov 2004 18:14:43 GMT, Lars Janqqvist
> wrote:
>
>>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.
>
>Or on my suspenders for full body coverage. <smile> Hmm, do they
>make elasticized wires? <bigger smile>

Well, if you're going with the suspenders, you could hide a whole
folded dipole in there.



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

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

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