CW Operation of IC 718

[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

[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

[johnnpierce]

That is not to encouraging. I think I will ask the same question of ICOM support and see what they have to say.

[kc0uws]

Thats a GREAT idea! If they have a fix, be sure to post it!

[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.

[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