Yaesu FT-991 AM transmission defective
 

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

Yaesu FT-991 AM transmission defective
 

In article ,
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?

WA7KGX-

I have the same problem with my FT-991, with the Po Meter kicking
downward with modulation. The manual’s procedure for setting AM
Microphone gain does not work. They instruct you to adjust so ALC does
not deflect when speaking. If you do that, there is no modulation. The
ALC meter has a static level that kicks upward with modulation.

It might help if we compared notes on other problems. From what I can
tell, both the hardware and firmware have bugs. Here are some other
problems I've found:

1. On several occasions the radio has locked-up, stopped receiving or
refused to transmit. Recycling power cleared up the problem.

2. On 14, 50 and 430 MHz SSB, the ALC Meter reading is missing,
depending on antenna SWR. On 14 and 50 it only works if SWR is high, on
430 if it is low.

3. If you look at the left side of the display, you may see IPO, AMP1
or AMP2 listed. It depends on the IPO setting on HF. AMP1 and AMP2 do
not apply to VHF or UHF. They may appear there as well, and can only be
changed by re-programming the frequency. If you select an HF frequency
in VFO mode, you can turn the AMPs on and off. Whatever state they are
in, remains if you then select BAND - ENT and enter a VHF or UHF
frequency.

4. The 5/10 Hz setting is stuck on 5 Hz for AM, FM, C4FM and DATA-FM
modes. Main-dial frequency step is 100Hz, but CLARifier is 5 Hz.

5. In order to use a program like CHIRP to program the radio, it is
necessary to start up the radio in Clone mode The manual is missing
information on CAT and Cloning. FT-817/857/897 Clone setup does not
work with the FT-991, which is missing the two Mode buttons.

I would be interested in knowing if you have observed any of these
problems in your FT-991.

Fred
K4DII

Yaesu FT-991 AM transmission defective
 

On Mon, 02 Feb 2015 18:34:02 -0500, Fred McKenzie wrote:

In article ,
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?

WA7KGX-

I have the same problem with my FT-991, with the Po Meter kicking
downward with modulation. The manual’s procedure for setting AM
Microphone gain does not work. They instruct you to adjust so ALC does
not deflect when speaking. If you do that, there is no modulation. The
ALC meter has a static level that kicks upward with modulation.

It might help if we compared notes on other problems. From what I can
tell, both the hardware and firmware have bugs. Here are some other
problems I've found:

1. On several occasions the radio has locked-up, stopped receiving or
refused to transmit. Recycling power cleared up the problem.

2. On 14, 50 and 430 MHz SSB, the ALC Meter reading is missing,
depending on antenna SWR. On 14 and 50 it only works if SWR is high, on
430 if it is low.

3. If you look at the left side of the display, you may see IPO, AMP1
or AMP2 listed. It depends on the IPO setting on HF. AMP1 and AMP2 do
not apply to VHF or UHF. They may appear there as well, and can only be
changed by re-programming the frequency. If you select an HF frequency
in VFO mode, you can turn the AMPs on and off. Whatever state they are
in, remains if you then select BAND - ENT and enter a VHF or UHF
frequency.

4. The 5/10 Hz setting is stuck on 5 Hz for AM, FM, C4FM and DATA-FM
modes. Main-dial frequency step is 100Hz, but CLARifier is 5 Hz.

5. In order to use a program like CHIRP to program the radio, it is
necessary to start up the radio in Clone mode The manual is missing
information on CAT and Cloning. FT-817/857/897 Clone setup does not
work with the FT-991, which is missing the two Mode buttons.

I would be interested in knowing if you have observed any of these
problems in your FT-991.

Fred K4DII

Based on previous experience reviewing the Yaesu Spirit ham/aviation
handheld for Aviation Consumer and W7WAA's commenta on the Yaesu
FTDX-1200, I decided not to wait for a miracle to happen soon at Yaesu
and took the FT-991 back to HRO and insisted on getting my money back.
The radio does not meet its advertised description.

Yaesu FT-991 AM transmission defective
 

The air checks are available at http:www.omen.com/waykgx/ham.html

For some reason I couldn't post the sound files to the newsgroup with PAN.

Yaesu FT-991 AM transmission defective
 

In article ,
wa7kgx wrote:

The air checks are available at http:www.omen.com/waykgx/ham.html

For some reason I couldn't post the sound files to the newsgroup with PAN.

WA7KGX-

Some news servers do not accept files.

I saw your comments on the eHam net forum.

I have a list of several problems with my FT-991, including the
defective AM. There are some things I like about the radio, so I prefer
to get it repaired rather than getting a refund.

The reason AM power is set to 25 Watts, is that the radio is only
capable of 100 Watts. One hundred Watts is the peak power of a 100
percent modulated 25 Watt AM signal. The FT-991 Po meter should kick
from 25 Watts to nearly 100 watts on voice peaks. Mine kicks downward
instead.

If you can not get a refund, I suggest you also take the "repair"
approach. There is no reason the radio should not produce an acceptable
AM signal. It almost certainly is misaligned, and can be corrected. If
Yaesu can not correct the problem by alignment, then they should replace
the defective module.

With regard to your other comment about listening to a repeater's input
frequency, you can easily do that with the REV function. You will
notice that it changes the memory contents, so you must press the REV a
second time to return to normal frequencies.

That is one of my minor gripes about the radio, that some functions
directly affect memory, rather than a "working copy" of the memory.

73,
Fred
K4DII

Yaesu FT-991 AM transmission defective
 

On Fri, 13 Feb 2015 01:30:16 -0500, Fred McKenzie wrote:

In article ,
wa7kgx wrote:

The air checks are available at http:www.omen.com/waykgx/ham.html

For some reason I couldn't post the sound files to the newsgroup with
PAN.

WA7KGX-

Some news servers do not accept files.

I saw your comments on the eHam net forum.

I have a list of several problems with my FT-991, including the
defective AM. There are some things I like about the radio, so I prefer
to get it repaired rather than getting a refund.

The reason AM power is set to 25 Watts, is that the radio is only
capable of 100 Watts. One hundred Watts is the peak power of a 100
percent modulated 25 Watt AM signal. The FT-991 Po meter should kick
from 25 Watts to nearly 100 watts on voice peaks. Mine kicks downward
instead.

If you can not get a refund, I suggest you also take the "repair"
approach. There is no reason the radio should not produce an acceptable
AM signal. It almost certainly is misaligned, and can be corrected. If
Yaesu can not correct the problem by alignment, then they should replace
the defective module.

With regard to your other comment about listening to a repeater's input
frequency, you can easily do that with the REV function. You will
notice that it changes the memory contents, so you must press the REV a
second time to return to normal frequencies.

That is one of my minor gripes about the radio, that some functions
directly affect memory, rather than a "working copy" of the memory.

73,
Fred K4DII

First time I tried using REV: set fm repeater 145.29 rpt - offset.
REV made a sound but did nothing.

Did a full processor reset, same result.
Then on a hunch I set repeater offset to + and voila! REV works.

This is one buggy radio.

Yaesu FT-991 AM transmission defective
 

On Fri, 13 Feb 2015 02:30:57 -0600, wa7kgx wrote:

On Fri, 13 Feb 2015 01:30:16 -0500, Fred McKenzie wrote:

In article ,
wa7kgx wrote:

The air checks are available at http:www.omen.com/waykgx/ham.html

For some reason I couldn't post the sound files to the newsgroup with
PAN.

WA7KGX-

Some news servers do not accept files.

I saw your comments on the eHam net forum.

I have a list of several problems with my FT-991, including the
defective AM. There are some things I like about the radio, so I
prefer to get it repaired rather than getting a refund.

The reason AM power is set to 25 Watts, is that the radio is only
capable of 100 Watts. One hundred Watts is the peak power of a 100
percent modulated 25 Watt AM signal. The FT-991 Po meter should kick
from 25 Watts to nearly 100 watts on voice peaks. Mine kicks downward
instead.

If you can not get a refund, I suggest you also take the "repair"
approach. There is no reason the radio should not produce an
acceptable AM signal. It almost certainly is misaligned, and can be
corrected. If Yaesu can not correct the problem by alignment, then
they should replace the defective module.

With regard to your other comment about listening to a repeater's input
frequency, you can easily do that with the REV function. You will
notice that it changes the memory contents, so you must press the REV a
second time to return to normal frequencies.

That is one of my minor gripes about the radio, that some functions
directly affect memory, rather than a "working copy" of the memory.

73,
Fred K4DII

First time I tried using REV: set fm repeater 145.29 rpt - offset.
REV made a sound but did nothing.

Did a full processor reset, same result.
Then on a hunch I set repeater offset to + and voila! REV works.

This is one buggy radio.
Yaesu have posted firmware updates to the FT-991 as well as the CAT codes.

Yaesu FT-991 AM transmission defective
 

In article ,
wa7kgx wrote:

Yaesu have posted firmware updates to the FT-991 as well as the CAT codes.

I updated my FT-991 yesterday and spent most of today re-entering
channel data lost in the reset.

There are two separate updates, one called "Main" and one called "DSP".
Each has its own updater program. The Main update went smoothly but the
DSP updater needed some help.

It seems that Yaesu's "enhanced" USB driver installed as COM14 on my
computer, but the DSP updater can only handle COM ports 1 through 10.
It took some research to learn how to change COM14 to COM1. After
making that change, the DSP update went smoothly.

I do not know what all was changed, but did notice that the AM mode is
working differently. Instead of kicking downward during modulation, the
Po meter barely wiggles. It does kick downward slightly with the
microphone gain turned up high. I hear some distortion on a local
receiver, but it may be due to overload. Looking at a PEP wattmeter, I
would guess that modulation percentage might be around 70 or 80 percent.
A scope might tell a different story.

73,
Fred
K4DII

Yaesu FT-991 AM transmission defective
 

On Friday, February 27, 2015 at 7:09:51 PM UTC-5, Fred McKenzie wrote:
In article ,
wa7kgx wrote:

Yaesu have posted firmware updates to the FT-991 as well as the CAT codes.

I updated my FT-991 yesterday and spent most of today re-entering
channel data lost in the reset.

There are two separate updates, one called "Main" and one called "DSP".
Each has its own updater program. The Main update went smoothly but the
DSP updater needed some help.

It seems that Yaesu's "enhanced" USB driver installed as COM14 on my
computer, but the DSP updater can only handle COM ports 1 through 10.
It took some research to learn how to change COM14 to COM1. After
making that change, the DSP update went smoothly.

I do not know what all was changed, but did notice that the AM mode is
working differently. Instead of kicking downward during modulation, the
Po meter barely wiggles. It does kick downward slightly with the
microphone gain turned up high. I hear some distortion on a local
receiver, but it may be due to overload. Looking at a PEP wattmeter, I
would guess that modulation percentage might be around 70 or 80 percent.
A scope might tell a different story.

73,
Fred
K4DII

hey dave on am do you know what the power output should be mine only does 20 watts on am

Yaesu FT-991 AM transmission defective
 

If the 991 is like other Yaesu rigs, you will need to inject a voltage into the ALC port on the back using a battery and a pot. See W8JI's excellent page on this very topic at http://www.w8ji.com/amplitude_modulation.htm

You may also have to set the carrier in that mode using a menu item in a manner simlilarly as the 897.

It seems a LOT of solid state rigs do this (ie downward modulate).

GOTO to the Foxtango Group on Yahoo for more inflammation.

Philip KA4KOE

Yaesu FT-991 AM transmission defective
 

In article ,
wrote:

On Friday, February 27, 2015 at 7:09:51 PM UTC-5, Fred McKenzie wrote:
In article ,
wa7kgx wrote:

Yaesu have posted firmware updates to the FT-991 as well as the CAT
codes.

I updated my FT-991 yesterday and spent most of today re-entering
channel data lost in the reset.

There are two separate updates, one called "Main" and one called "DSP".
Each has its own updater program. The Main update went smoothly but the
DSP updater needed some help.

It seems that Yaesu's "enhanced" USB driver installed as COM14 on my
computer, but the DSP updater can only handle COM ports 1 through 10.
It took some research to learn how to change COM14 to COM1. After
making that change, the DSP update went smoothly.

I do not know what all was changed, but did notice that the AM mode is
working differently. Instead of kicking downward during modulation, the
Po meter barely wiggles. It does kick downward slightly with the
microphone gain turned up high. I hear some distortion on a local
receiver, but it may be due to overload. Looking at a PEP wattmeter, I
would guess that modulation percentage might be around 70 or 80 percent.
A scope might tell a different story.

73,
Fred
K4DII

hey dave on am do you know what the power output should be mine only does 20
watts on am

W2MGF and Philip-

The above is either a mis-quote or a mis-statement on my part. I do not
recall posting that the FT-991 AM modulation was that high. I think it
is around 10 percent at most, but my Icom radio has 70 or 80 percent AM
modulation by comparison.

Philip's link to W8JI's AM report seems to describe the FT-991's AM
operation exactly. The problem with his solution is that the FT-991
does not allow you to run the AM power level up beyond about 40 Watts,
so applying a DC level to the ALC terminal would not buy you much. You
could try setting the power level to its maximum and use the ALC to
reduce power to a quarter of that. You might then have a rather low
power but well modulated AM signal!

I recently updated the FT-991 firmware to the July 24, 2015, version.
The update fixed some minor problems, but did not affect AM operation as
far as I can tell.

Fred
K4DII

Yaesu FT-991 AM transmission defective
 

In article ,
Fred McKenzie wrote:

I recently updated the FT-991 firmware to the July 24, 2015, version.
The update fixed some minor problems, but did not affect AM operation as
far as I can tell.

A new update to the FT-991 "Main" firmware was posted on August 17. The
only obvious improvement was the addition of another GPS option. I can
not tell any difference in AM operation.

One thing I did notice, was an occasional event where the radio stops
responding to its controls. One way to correct it is to cycle power.
Another is to keep trying different controls until you find one that
does something. Afterward, the others seem to start working again. I
suspect the problem may be time related, and it would start working
again if I just waited a minute or two!

Fred
K4DII

Yaesu FT-991 AM transmission defective
 

On Thu, 20 Aug 2015 23:32:58 -0400, Fred McKenzie wrote:

A new update to the FT-991 "Main" firmware was posted on August 17. The
only obvious improvement was the addition of another GPS option. I can
not tell any difference in AM operation.

One thing I did notice, was an occasional event where the radio stops
responding to its controls. One way to correct it is to cycle power.
Another is to keep trying different controls until you find one that
does something. Afterward, the others seem to start working again. I
suspect the problem may be time related, and it would start working
again if I just waited a minute or two!

Yikes!! *Not A Good Thing* (tm) for a contesting rig.

Jonesy
--
Marvin L Jones | W3DHJ | W3DHJ | http://W3DHJ.net/
Pueblo, Colorado | @ | Jonesy | __
38.238N 104.547W | jonz.net | DM78rf | 73 SK

Yaesu FT-991 AM transmission defective
 

In article ,
Fred McKenzie wrote:

In article ,
Fred McKenzie wrote:

I recently updated the FT-991 firmware to the July 24, 2015, version.
The update fixed some minor problems, but did not affect AM operation as
far as I can tell.

A new update to the FT-991 "Main" firmware was posted on August 17. The
only obvious improvement was the addition of another GPS option. I can
not tell any difference in AM operation.

One thing I did notice, was an occasional event where the radio stops
responding to its controls. One way to correct it is to cycle power.
Another is to keep trying different controls until you find one that
does something. Afterward, the others seem to start working again. I
suspect the problem may be time related, and it would start working
again if I just waited a minute or two!

Another "Main" Firmware Update was released August 25. I installed it
today. The only response problem was when I first fired it up after the
update. So far, it seems to be working OK.

I have not tried to check AM operation yet.

Fred
K4DII

Yaesu FT-991 AM transmission defective
 

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

Yaesu FT-991 AM transmission defective
 

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

Yaesu FT-991 AM transmission defective
 

Dr OM,

It's likeley that the AM carrier level in the service menu is set wrong. Maybe interesting to read: http://www.amateurtele.com/index.php...el=168&id=#752 This is an article about the FT-991 and how to adjust the AM carrier level.

73 de PE2CJ.

Yaesu FT-991 AM transmission defective
 

On Monday, February 8, 2016 at 3:13:48 PM UTC-5, wrote:
Dr OM,

It's likeley that the AM carrier level in the service menu is set wrong. Maybe interesting to read: http://www.amateurtele.com/index.php...el=168&id=#752 This is an article about the FT-991 and how to adjust the AM carrier level.

73 de PE2CJ.

GM OM
With my 991 I cannot set the alc level it is at max no matter where the carrier level or mic gain is set on 6m.On hf bands it seems to work properly u can set the alc level.I have not been able to get audio rpts on 10 AM yet.
I am wondering if there are enough complaints to Yaesu if they will look in to problem.Probably maybe a recall would be in order,that would invole sending radios back to factory.
I have been on website and left a email,but have had no reply.I think a phone call from 991 owners might alert them to the problem.

73 Bob WA9M