Yaesu FT-990 AM Sounds bad on tx

[W2EBR]

Hi,
I have a Yaesu FT-990 and it has worked great over the years. I never really use the am mode for tx but I have tried using it and on tx it sounds aweful to say the least. I have spoke to other 990 owners and they say the same exact thing. I am using a Yaesu MD-100 Mic with it and it sounds great in all other modes. Has anyone ever come across this and what did they do to improve this. I would like to use it on am no and then.
Other than this the radio works and rx/tx perfectly.
Thanks,
Rich

[WA2ZDY]

Get the manual out and you MUST adjust it exactly as they suggest. That might still not make it ideal but AM on modern riceboxes was an afterthought and to make it work at all requires careful adjustment. Carrier level and audio have to be right. That rig is a 100w PEP output rig so you can only run about 25% of that as carrier and still hope to get decent modulation.

Good luck.

[W0LPQ]

Drats Chris, you can't run 100W AM ... darn... yes the manuals do state to cut the power back ... but .... but ...

Bill, W0LPQ

[W2EBR]

Hi,
I did go through the manual and tried the recommended adjustments.
It wasn't any help. On AM it does about 40w pep and I tried cutting it back to
see it it would help but it didn't. The folks that I spoke to that have the smae rigs with the
same problems have tried this also with no help. I am stumped for now.

[W2EBR]

So,
Any ideas or solutions that were found on this problem?
Thanks,
Rich

[WA2ZDY]

The possibility is high that the rig just isn't destined to sound good on AM. Like I said, AM is an afterthought on many of these new rigs and it doesn't work well.

Good luck OM.