Just received a brand FT-991 and the transmitted AM audio is horrible. I noted a couple of other posts with the same issue, but did not note if anyone has found a fix.

SSB mode seems to be fine.

Is there a fix or is it what it is?

Thanks,
N4RCC, Richard

In article ,
N4RCC - Richard wrote:

Just received a brand FT-991 and the transmitted AM audio is horrible. I
noted a couple of other posts with the same issue, but did not note if anyone
has found a fix.

SSB mode seems to be fine.

Is there a fix or is it what it is?

Richard-

I've had my FT-991 for nearly a year. That includes a trip back to
Yaesu to repair damage caused by a transmitter lockup that was
discovered an hour later.

At the 2015 Orlando Hamfest, I talked with a Yaesu manager and provided
a list of the many problems I had found. I exchanged subsequent E-mail
messages with him. Yaesu is well aware that there is a problem with AM
transmission!

There have been several Firmware Updates that have solved most of the
problems. They changed ALC meter action during AM modulation, but did
not make any other improvement that I can detect. As I understand it,
you adjust audio gain so there is just an occasional downward power
kick, and that is the best you can do. That appears to produce about
ten percent modulation. Any higher audio gain only increases distortion.

I think Yaesu has failed to fix AM operation with firmware, and are not
willing to recall the radio for a hardware modification. Perhaps a new
FT-991A will be introduced with the needed modification.

AM operation is not the only problem the radio has. There are
occasional situations that may require a power cycling to correct.
Sometimes a change in a setting, followed by changing it back will fix a
problem. It is unfortunate, since the FT-991 is an impressive radio
most of the time!

73,
Fred
K4DII

On Monday, December 28, 2015 at 12:08:27 PM UTC-6, Fred McKenzie wrote:
In article ,
N4RCC - Richard wrote:

Just received a brand FT-991 and the transmitted AM audio is horrible. I
noted a couple of other posts with the same issue, but did not note if anyone
has found a fix.

SSB mode seems to be fine.

Is there a fix or is it what it is?

Richard-

I've had my FT-991 for nearly a year. That includes a trip back to
Yaesu to repair damage caused by a transmitter lockup that was
discovered an hour later.

At the 2015 Orlando Hamfest, I talked with a Yaesu manager and provided
a list of the many problems I had found. I exchanged subsequent E-mail
messages with him. Yaesu is well aware that there is a problem with AM
transmission!

There have been several Firmware Updates that have solved most of the
problems. They changed ALC meter action during AM modulation, but did
not make any other improvement that I can detect. As I understand it,
you adjust audio gain so there is just an occasional downward power
kick, and that is the best you can do. That appears to produce about
ten percent modulation. Any higher audio gain only increases distortion.

I think Yaesu has failed to fix AM operation with firmware, and are not
willing to recall the radio for a hardware modification. Perhaps a new
FT-991A will be introduced with the needed modification.

AM operation is not the only problem the radio has. There are
occasional situations that may require a power cycling to correct.
Sometimes a change in a setting, followed by changing it back will fix a
problem. It is unfortunate, since the FT-991 is an impressive radio
most of the time!

73,
Fred
K4DII

Thanks for the post Fred. However, I must admit is sounds pretty ominous. Sounds like the best thing I can do is try to send it back to the dealer for a refund..

In article ,
N4RCC - Richard wrote:

Sounds like the best thing I can do is try to send it back to the dealer for
a refund..

Richard-

I think the FT-991 has "redeeming qualities" that make it worthwhile to
keep. For Yaesu's Fusion, it is more expensive than the FTM-100/400 or
FT-1, but they can not be used on Ten or Six Meters*, and do not have
SSB or CW capability. Recent FT-991 firmware updates have added some
new features including the ability to control a WIRES-X node.

*Yaesu's Fusion digital system has too wide a bandwidth for legal
operation below 29 MHz. Frequencies of 29.460 and 51.160 are often used
for simplex Fusion contacts when the bands are open.

But if AM operation is that important to you, returning it now may be
your best recourse. Before you do, you might call Yaesu and ask them
directly if the AM operation will be fixed soon. Try (800) 253-1498 for
Technical Support or (800) 426-7983 for Customer Service. They are on
the West Coast, so call 7:00 AM to 5:00 PM Pacific time.

73,
Fred
K4DII

On Sunday, December 27, 2015 at 10:54:00 PM UTC-5, N4RCC - Richard wrote:
Just received a brand FT-991 and the transmitted AM audio is horrible. I noted a couple of other posts with the same issue, but did not note if anyone has found a fix.

SSB mode seems to be fine.

Is there a fix or is it what it is?

Thanks,
N4RCC, Richard

Richard
I have same problem with my 991,I use it on 6M AM.I left an inquiry on the yaesu website but have had no reply.
I have noticed that when transmitting the alc level is full scale no matter what the carrier level is or mic gain is set at.
Hopefully when enough users report this problem maybe Yaesu will look in to it.
On HF the alc works properly the way it should but i have have found no one to check my audio.10 is fairly dead more so on 29.0
73 Bob WA9M