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

[B52hbuff]

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

I have some questions about the various search 
ranges...

#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?

#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?

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?