[MilCom] A new milcom frequency search strategy

[Dan Wanchic]

Like most other milcom listeners I'm always on the
prowl for new frequencies. In the UHF end of the
spectrum this is a particularly daunting task since 
there are approximately 7000 potential channels.
Attempting to scan from 225 MHz through 400 MHz in 
25 KHz steps takes about 70 seconds with my scanner
and is not practical in my opinion.

There are several solutions - faster scanners, more
scanners or a smarter search strategy. 

The other day, I read a couple of posts on the Radio
Reference website related to reshuffling of UHF milcom
frequencies in Europe. As I looked at the lists, I
noticed that they seemed to have larger useage of 
XXX.X25 and XXX.X75 channel assignments. 

That got me wondering how the distribution is
stateside because my experience told me that we tend
to use 100 KHz channel frequencies more i.e XXX.100,
XXX.200 etc (neglecting ATC). I began to wonder if I
could develop a new search strategy based upon trends
in channel useage. 

I did a brief analysis using a few magazine articles
and by looking at the frequenices that I have loaded
into my scanners. I thought I'd share with a few
milcom groups. 

Data:

Composite from the August 2002 Monitoring Times and
a few others:

376 channels
283 100 KHz channels - 76.3%
061  50 KHz channels - 16.2%
032  25 KHz channels -  8.5%

>From my own BC785D Scanner channels

300 NORAD/AWACS/JSTARS channels
221 100 KHz channels - 73.7%
052  50 KHz channels - 17.3%
027  25 KHz channels -  9.0%

Broken down as - 

204 NORAD channels 
195 100 KHz channels - 95.6%
007  50 KHz channels -  3.4%
002  25 KHz channels -  1.0%

033 AWACS channels
018 100 KHz channels - 54.5%
009  50 KHz channels - 27.3%
006  25 KHz channels - 18.2%

007 AWACS/JSTARS joint use channels
001 100 KHz channel 
004  50 KHz channels
002  25 KHz channels

056 JSTARS channels
007 100 KHz channels - 12.5%
032  50 KHz channels - 57.1%
017  25 KHz channels - 30.4%

097 Refueling channels
084 100 KHz channels - 86.6%
008  50 KHz channels -  8.3%
005  25 KHz channels -  5.2%

127 UHF OPs/Cmd Post/Tactical channels

089 100 KHz channels - 70.1%
025  50 KHz channels - 28.1%
013  25 KHz channels - 10.2%

New strategy:

The VHF range is small enough that I can scan
through in 25 KHz steps pretty easily. So I have all 
of the VHF channels assignments loaded as memory
channels of one scanner. I skip all of the known Army
NFM assignments. 

In the same scanner I load all of the UHF assignments
that I have identified, either by my intercepts or
validated intercepts by others into banks by function
i.e NORAD, refueling etc. I tend to have about 7-8
banks operational at any one time. 

My data analysis shows that 100 KHz channel
assignments are used significantly more often with
JSTARS/AWACS assignments being the exception. I solve
this by loading all the known NORAD/AWACS/JSTARS
channels into 3 banks in the first scanner.

Use my second scanner to continue to scan ARTCC 
channels within approx 300 nmi of my location.  

Use my third scanner (yet to be acquired) to step
through the UHF spectrum in 100 KHz steps. This will
allow me to step through 1750 channels in 17.5
seconds. Although I will only be looking at 25% of the
available channel assignments, those appear to be in
more common use. The frequency of use for 50 KHz is
low and 25 KHz channels is so low that the chances of
getting intercepts is low.  

Anyways, that's my new plan - just have to come up
with another BC785D. Comments or suggestions are
welcome.

Dan
Apple Valley, MN 













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