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CW Operation of IC 718
Posted: Thu Dec 14, 2006 3:47 am
by johnnpierce
When I am on 40cw with an S8 noise level and a signal greater than s9 is received, why does the audio have a pumping sound caused by the cw signal. I was using an IC706 for a while and do not remember that problem. When i am on 20mtrs and the noise level is very low, everything sounds the way I expected it to sound.
John
Posted: Thu Dec 14, 2006 7:13 am
by kc0uws
I think it's a common thing with the 718. I also have one and noticed the EXACT same type of problem on 40m CW.
73 de KC0UWS
Posted: Thu Dec 14, 2006 1:03 pm
by johnnpierce
That is not to encouraging. I think I will ask the same question of ICOM support and see what they have to say.
Posted: Fri Dec 15, 2006 1:27 am
by kc0uws
Thats a GREAT idea! If they have a fix, be sure to post it!
Why IC 718 pumps on CW
Posted: Tue Dec 19, 2006 10:27 pm
by johnnpierce
I have found out what the issue is, although not from ICOM. I suspected it and it happens to be a very fast ACG circuit. On the ICOM 706 series, there is an AGC option. When you choose F-AGC the 706 has the same action. So it appears that the IC-718 does not offers an AGC speed option. That's a bummer.
I am checking out Radio Mods to see if there is a fix to the ACG speed. However, its pretty hard to re-engineer the current Surface Mount constuction of any rig.
Posted: Thu Dec 21, 2006 1:41 pm
by johnnpierce
For the AGC issue, I just found and downloaded a modification which should help. I have not tried it yet but probably will between Christmas and New Years.
John, AD2F