[FedCom] Help programming search ranges for Federal / Military users

[Larry Van Horn, N5FPW]

>I am looking at the new Grove Monitoring Times /
> Airshow guide and also Tom Kneitel's "Top Secret
> Registry of US Governement Frequencies"

Keep in mind that there have been tons of changes in the fed spectrum since 
the last edition of Tom's book. It's use as a reference is greatly reduced. 
In its day it was pretty cool. But it is over 22 years since the IRAC files 
were closed and the fed and mil bands have been overhauled since then. Use 
the Tomcat's pub with great care.

> #1. I know that Civil Air tops out at 137.000, and
> according to the MT Article, they suggest a search
> range of 138-144MHz.  Kneitel suggests 137-144MHz.
> What is in the range of 137-138MHz?

It is a satellite band primary assignment. There has been some sporadic 
milair traffic reported here over the last 10 years (abt four instances), 
but they aren't suppose to be here and no sense in adding another 40 
channels to the mix when the chances are nil you will hear anything here but 
telemetry downlinks that will stop your scan or search.


> #2. Tom Kneitel splits up the Federal UHF VHF band as
> 162.000-173.200 and 173.400-174.00.  What is between
> 173.200 and 173.400?

>From my Federal Frequency Directory (which is a current resource)

173.2000 [Spectrum Hole]
173.2125 [Spectrum Hole]
173.2250 Civilian Assignment: Video Production/Press Relay (Newspapers)
173.2375 [Spectrum Hole]
173.2500 Civilian Assignment: Power and Water Utilities
173.2625 Army
173.2750 Civilian Assignment: Video Production/Press Relay (Newspapers)
173.2875 [Spectrum Hole]
173.3000 Energy Department and Civilian Assignment: Power and Water 
Utilities
173.3125 [Spectrum Hole]
173.3250 Civilian Assignment: Video Production/Press Relay (Newspapers)
173.3375 Forest Service (NC)
173.3500 Civilian Assignment: Power and Water Utilities
173.4000 Experimental Testing

> One other question, if 137-144MHz is a mixed mode
> band (e.g. AM & FM), which mode would be more useful
> to search at an airshow where both modes may be
> used?  AM or FM?

Well that will depend on what you are fishing for. Aero (aircraft) ops will 
use AM. Ground ops will use FM. You will have to determine what is important 
to you to monitor at the show. Personally I doubt you will hear any base 
unit air ops (accept the show performers) so I would go for looking for 
ground (LMR) targets so I would be programming the FM mode.

Have fun and 73

Larry

Larry Van Horn, N5FPW
ATC (AW)      USN (Ret)
MT Milcom/Help Desk Columnist
Assistant Editor Monitoring Times
Founding Father Milcom/Fedcom/Trunkcom