[amsat-bb] Icom 706 FM Narrow

K & R Yoksh yokshs at sbcglobal.net
Tue Jun 3 20:37:54 PDT 2008


I discovered something last night while working AO-51 and wanted to share it 
with the group. Thanks
for the many short QSOs on AO-51 last night, BTW.

I use two Icom 706Mk2g radios as my satellite station. Although I've read 
through the manual for my
radio many times, I wasn't aware that Icom included a wide and narrow FM 
capability in this radio. This is
not to be confused with WFM receive (which this radio can also do), for 
commercial radio and TV audio

After checking out page 23 of the manual, I can better understand this, but 
honestly, it might have been a
good idea for Icom to spell this out a little better!

When selected, the narrow filter is active in both transmit and receive. 
According to Google, the wide FM
setting has a maximum of 4.8 KHz deviation, and the narrow FM setting has a 
maximum of 2.4 KHz deviation.

The standard AM/FM filter (FL-23) is 15 KHz wide, and the narrow filter 
(FL-94) is 8 KHz wide.

Armed with this new piece of information, I experimented with using the 
narrow filter on my receive radio
last night on AO-51 with very noticeable results! The filter eliminated much 
of the background noise, and
I also noted that the S meter reading displayed typically 2 S-units higher 
with the narrow filter
enabled, FWIW.

If you use a 706 on the birds, you might want to check out menu M3, and 
select FIL while in FM mode.


Kyle Yoksh
Olathe, Kansas

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