[Elecraft] [K3] FM and AM Bandwidth

[Ken Kopp]

Lyle, others ...

I'm a career two-way radio tech.  I've been in the midst of
amateur radio VHF/UHF FM since (almost) the beginning.
The first 2M repeater in Florida was built in my shop.  I've
been Montana's frequency coordinator for 30+ years.  In
short, I think I'm qualified to enter into the FM deviation
discussion.

The industry's deviation standard is 4.5 kHz for today's 15 
kHz channel spaced radios.  Yes, there is a move to 12.5 
kHz channel spacing in some services, but these (mostly) use 
"digital" techniques, and I don't for see this impacting any K3 
users.  Please consider this (+/- 4.5 kHz deviation) standard 
for the K3's FM mode. 

FWIW, when measured on Motorola's latest / greatest service 
monitor, my K3's (S/N 56 with a KFL3B FM filter and Ver. 
2.80) transmitter deviates +/- 5.0 kHz on 52.525 with a menu 
setting of 4.0 kHz deviation.  This is while using a "robust", 
sustained "F-o-u-r". (:-))  I didn't measure it on 10M FM.

I won't enter into any discussion about ESSB, except to say 
most view a (transmitted) AM or SSB bandwith signal over 
4.0 kHz wide to be excessive, discourteous and "not in good 
amateur practice".

73! Ken Kopp - K0PP