🚀 go-pugleaf

In article <Pine.A32.3.95.981026213500.66965A-100000@freenet2.afn.org>,
Todd L. Sherman <afn09444@AFN.ORG> wrote:
>   Anyone know where to get ahold of that program that IDs signal footprints?

Try KB8RLN (Sinclair Lock and Safe) http://www.axom.com/kb8rln/ 
 click on Xmit ID icon.  
 And also read the Legal page, the conditions are ok but you need to read it.

> sort with micro-wattage -- noone can hear him at a distance even with beams,
> yet he gets into the repeater just fine, and sometimes even overrides local
> mobiles) 

If he's winning DFQ with mobiles running 25+W, he'd have to be very
close to the repeater.  Another possiblity is he's using a beam tipped
Up, so that the repeater can hear him but no terrestrial station
can.  Does your part of florida have any hills you can look down
from?

> to confirm that what instrument(s) we find were indeed used to cause the
> malicious IF.  The sig footprint ID software might help towards that end.

Sounds useful in building case.  I trust you've contacted the OO's and are
documenting carefully.

>   Can anyone explain how it is used, too?

I haven't (had to) use it yet, just working off theory here.

Basically it's a digital storage osciliscope connected to the
discriminator of the repeater receiver or some other receiver that
can hear the jammer.  (Better be at the repeater in your case, maybe
tapping into the receiver's feed-line after the cans, or modding the
receiver itself.)  It records the transients at key-down, which is
quite distinctive among brands of radio and some say unique to a
specific unit.  

When any transceiver goes from receive to transmit at keydown (except
possibly on SSB!) the VFO has to shift by the offset (800Hz for CW,
600kHz for 2m FM, 1 or 5 MHz for other bands).  While key down but
until the PLL (or other frequency control feedback loop) locks, the
transmitted frequency is all fluttery. The design of the specific VFO
chain determines this partly, as do the specific part-values (within
tolerance bands) of the individual unit, accoding to some.
(Whether you really see a difference between different IC-W32A's or
not is debated.  It certainly differentiates brand/model and I'd
guess also slope of his antenna response, but whether it's really a
fingerprint for model number or for serial number has been a matter
for debate. I don't recall a definitive answer, so YMMV.)

So you just bring the raw demodulated receive out from the
discriminator, capture it with a DSP unit, and archive the leading
edges of all transmissions with timestamps.  Compare naughty
transmission fingerprints to signed fingerprints, and if your
naughty boy every uses the same radio "as himself", he signs his
confession.  (Probably not a good idea to announce you've installed
it, if he's got more than one radio or could get another.)

XMIT_ID requires (quoting KB8RLN's web page):
     a modified receiver or 9600 baud packet ready radio 
     a 386 or better computer 
     DOS 5.0-6.22 (Win95 maybe, see web)
     VGA monitor 
     1 meg of memory 
     Sound card (A real 8 bit Sound Blaster works the best) 

73
BILL N1VUX
-- 
Bill Ricker  N1VUX  wdr@world.std.com  "The freedom of the press belongs 
http://world.std.com/~wdr               to those who own one."--A.J.Liebling