On Sunday, December 27, 2015 at 10:48:46 PM UTC-5, N4RCC - Richard wrote:
On Friday, January 30, 2015 at 2:30:06 AM UTC-6, wa7kgx wrote:
My initial testing on an FT-991 I bought Tuesday indictaes AM
transmission is severely distorted. I tried everything in the manual
that seemed relevant to AM transmission without any improvement.

Transmitting into a Cobra Senior perfectly matched with a Nye Viking MBII
on 3885 showed pronounced downward modulation even on a peak reading
MFJ 870 meter. Normally a peak reading watt meter will show strong upward
movement as the peak power is 4 times carrier power.

I called Yaesu tech support. The tech was not aware of any prolbems with
AM on the 991. He suggested I reset the processor.

After the processor reset returned the 991 to its factory defaults, the
3885 morning crowd confirmed the transmitted signal was still terrible.

I have been able to get good results transmitting AM with many oher
radios including IC706mkiiG, 756Pro, and FlexRadio 5000a.

A quick check on 2 meters showed the same profound downward modulation
on the FT-991.

Anyone having better luck with AM on the FT-991?

-de WA7KGX

I just got the FT-991, and have the same poor audio on transmission in AM mode. Has there been any luck in finding a fix?
Thanks,
N4RCC, Richard

I have same problem with my 991 bought in June 15.it sound a little better when I use MD100 desk mic on hi emphasis
Bob Meyer WA9M