Yaesu FT-991 Detailed Review

This is going to be an informative and technical review of the Yaesu FT 991. It comes from a love/hate relationship with the radio.

First to let you know my bias – I am a Yaesu Fan boy. Over the past 34 years I have owned a Yaesu FT 102 and use it on a daily basis. I have found that to be a remarkable performer and my everyday radio under all conditions. In addition I have repaired over 800 of these units over that time and I am widely known thru the amateur community and the internet for my efforts in that regard. Because of that endeavor I have a lot of precision equipment and know how to use them.

Now to the radio under the love relationship column. A friend two weeks ago lent his 991 to me to play with for a week. I thoroughly put it thru its paces with the exception of digital FM and AM. I avoided these functions as there have been reports of PA final failures when people were using these modes and this was not my own radio (see below in the prior reviews).

The radio is absolutely lovely. The size for this “shack in a box and do everything radio” is just right to fit under a shelf. It is approximately 3 x 9 x 10. The received audio is smooth and non-fatiguing to copy when adjusted properly to your liking in the menus. The TFT touch screen works easily and is quite intuitive to use. The functions work exceedingly well including the very sharp and deep receive interference rejection functions.

I tested the receiver’s sensitivity on 40 meters and I get 0.125 uV for 10dB S+N/N with RF amp 2 on and using a 1kc tone. That is quite sensitive.

The notch filter, available from the touch screen, has a narrow and wide setting. In toggling the narrow function notch on and off, with the touch of a finger, I cannot hear any difference in the voices of folks on the air. It is exceedingly deep and narrow and seemingly does not affect speech. If I am listening to a weak station on my inverted V on 40 meters and place a 20 over 9 carrier in his passband at 2kc (accomplished by using my 8640B to place a signal transmitted via a zip wire inserted into the SO 239 of the generator and looping this wire near the radio to get the desired signal level) enables me to test the notch function. In this way I can control the level and frequency of the interference which comes from the pure signal source of high quality precision generator. When the notch filter is off, the box on the touch screen shows the word off. When touched it is turned on and shows audio the frequency of the notch, which is adjustable in 10 cycle steps. Looking at the S meter I can see that the 20 over 9 signal is eliminated and can judge the depth and width of the notch. Suppression of 60 dB is easily accomplished and there is no audio trace of the tone or the interference. Then I can tune the notch either side of that interfering carrier and see how many clicks (10 cycle steps) it takes before the signal from the heterodyne rises to close to full level on the S meter. That takes 30 cycles (each side) from the maximum depth before the signal is almost back up to its unnotched level. That is very narrow and deep. So back to the weak fellow that I was listening to – without the notch I cannot understand the fellow and most times cannot even hear that he is talking. With the notch on and placed properly I cannot tell that a carrier was present and his voice is easily copyable and without coloration. It sounds the same as the same signal with the interference and notch turned off. I did not test the wide function.

This is a pre-detection filter and so takes the signal out of the IF circuitry which generates the AGC feedback function to the front end. When the interfering signal is in the IF path, (with the notch off), the front end is suppressed by the AGC, and when the notch takes it out the AGC does not reduce the sensitivity of the front end because there no longer is a strong signal there. The AGC then works same as when there is no interference and permits the front end to stay open for full sensitivity for easy copy.

Another touch box enables the auto notch. This is a post detection function and works on the final audio signal only. It is not as good as an IF notch. It takes the tone from the above setup and notches it out as well, but the S meter still shows a 20 over interfering signal although you cannot hear it from the speaker. When you the listen to the audio, the signal that you want to hear is now way down because the front end sensitivity is turned down by the continuation of the strong signal in the IF chain where the AGC is developed.

So both functions work splendidly but with the auto notch (audio notch, post detection notch) you will have to strain to hear your wanted signal.

DNR is - dynamic noise reduction - function. Again touching the box on the touch screen turns it on and off. Then turning the multi knob will yield the numbers 1 to 15 in the lower part of the touch screen box. Initially, I thought this was a level adjustment for the function but the manual clearly states that there are 15 different algorhythms employable and those are set up for different types of noise. So the noise reduction functionally is actually 15 different animals. That is incredible and the noise reduction is spectacular. However and in truth, I find all noise reduction systems (except noise blankers) to be only a cosmetic function in that they all reduce the noise but in addition also reduce the sibilant bandwidth of the speech to a similar degree so there is no real gain in intelligibility. That is my feeling for signals that are close to the noise but it is terrific for signals that are louder than the noise where they only cosmetically perk up the signal. There is no need or advantage gained for intelligibility of speech. In truth noise reduction might prevent a lot of headaches and fatigue when listening for long periods. Anyway the final like or dislike can only be judged by the individual user.

The contour control was my favorite. It is a receive parametric equalizer. You can adjust the depth/height and width of the equalizer in the menus and then the placement of it by its frequency after touching its box on the screen and turning the multi knob. It can be adjusted from 100 cycles to well over your maximum frequency that you are listening to. I thought it went as high as 4K. I liked to place the max frequency at 2400 cycles and gave it a boost – so it acted like a treble boost with a wide base (not bass). I placed this with its broad base and relatively gentle effect so the sibilants on folks with lackluster audio could be perked up with a light touch of the display control. It was very effective and completely adjustable in all three parameters width, max frequency, and level (either positive or cut.) It makes for easier and non fatiguing copy of received mushy audio.

The width control is similar. The box says off under the label until you touch it. Then it will give you adjustable bandwidth in receive. Its maximum shows band width to to 3200 cycles. I usually kept it at 3,000 cycles. It has a noticeable effect when employed and turning the multi knob can yield very restrictive audio to full almost hi-fi audio. In effect it cuts bass and treble to the same degree simultaneously. 

The shift function is similar. It will say off or 0. After touching the screen box and adjust the multi knob, it can be set to just about anywhere even to negative 3k where you will hear almost nothing or to +3K where the audio will sound very squeaky. You can place it anywhere however +400 will eliminate low frequency intrusion and –400 will sound mellow and soft and eliminate high freq squeaking from interference. The range for + to – 400 cycles will sound exceptionally good regarding intelligibility of the incoming signal. Again this control makes for less fatiguing and easier copy.

Those are just a few of the receive functions. Lets get to some of the transmit functions. The three parametric eqs cover the entire audio range from the mic input. They are adjustable for frequency of maximum effect, width of the effect, and level at 10 dB positive thru 20 dB negative. These as well as the separate processor parametric equalizers are set up in the menu. To test them I placed a sweepable leveled audio signal directly into the mic connector. I found the levels and widths were appropriately adjusted with the menu settings while looking at the power output on a bird meter. The ability to set the frequency and place the effect exactly where you want is a far better functionality than a set equalizer where you only have discrete non moveable frequencies. Unfortunately I did not have time to test the processor or its eq. settings but have no reason to believe that there would be problems with them. The mic EQ when used on the supplied hand mic worked pretty well according to listeners.

The continuous power output into a Bird 43 meter with a known accurate bird slug and into a bird dry dummy load was between 108 and 115 watts on every HF band from 1.8 to 30 Mhz. 50 and above were not tested as I don’t have the slugs. However the output meter on the 991 showed 48 watts on 2 meters.

For a real treat I listened to aircraft frequencies and there was exceptional reception. Going to the band menu and touching the box labeled “AIR” and you are there. Same is true with any of the bands and modes of operation. You can also get weather channels as well by touching the box labeled “144” and turning the main frequency dial appropriately to the frequency of interest.

The touch screen is tremendously functional and simple and quick to use. You can turn functions on and off quicker than you can toggle a switch by hand. The scope and waterfall functions were interesting and helpful.

All the automatic repeater offsets are present on 2 and 440 and you can set that yourself as well to anything that you like. CTCSS tones etc. are also there and you can set them by touching the appropriate box and turning the multi control. The scan functions seemed to work well.

I cannot go into every detail as this review would turn into an encyclopedia given how wordy I am. Suffice to say that everything, and I mean everything worked easily and as it should and was easily adjustable.

But there is one more point. The manual is lovely and printed on good paper. It is easy to read and about 3/8 inch thick. This as opposed to”go to the internet, download it, and print it out yourself” as is now regretfully becoming the norm. If you are spending over a grand on any radio, at least the manufacturers can do, is give a printed manual. Downloading and printing would double the thickness for a lot of people (only one side printing for a lot of folks), be costly as there are a lot of pages, time consuming, have to be professionally bound, and put a lot of effort and wear and tear on our home non-pro machines. I like having a properly bound manual to read at my leisure – even if in the ceramic defecatorium. Kudos to Yaesu for that!

So why the hate part of the relationship? In looking at the past 9 reviews from Jan 4 to today (1-24-16), 4 owners had the final transistors fail and needed to send the unit back. And in this – the tenth review this month, also had the finals fail and needed factory repair (so now at five out of ten here this month). 

In checking the reposts after repair for all the units reviewed here at Eham, a significant number of people said the radio was not quite right and had to send it in again. This is an unheard of failure rate and less than stellar factory repair work. And PA failures are noted in other areas of the internet for the 991. 

Yaesu repairs the radios questionably but even as important they have not changed the design - as the newest and most current radios are still grossly affected. The radio that I am reviewing was purchased in late July of 2015 and failed and was repaired by Yaesu – they did do a good job on this one..

It is not just that the PA fails but that Yaesu has not corrected the problem in manufacture. When people get the radios, like in my case, they are avoiding the AM usage and the digital FM features out of fear of losing the finals. 

Personally I believe that Yaesu should have a recall and make these radios right as they are clearly not made properly. There is a one year guaranty, but I am sure people who only use the radio on HF may not have any failures now but in several years they might try the digital modes or AM only to find they have a radio with no power output and absolutely no value for resale. They are then up the creek when out of the 1 year warranty period. And someone might want to sell this radio in the future and only be offered a pittance for it or not offered anything because of its dismal failure rate and reputation. 

The other alternative is for Yaesu to offer a ten year warranty on the finals if they fail, excepting lightening strikes and user abuse. Still that would inconvenience a lot of people as the radio should not fail in that fashion and at that rate. It should be reworked and made right at the manufacturing level. In time we will see if Yaesu is responsive to the people and does the right things for those hams who support them and give them life with our business and hard earned dollars.

The only solid state radio that I can remember that had a PA failure of note was the Kenwood 930. Apparently, the sil pads under the PA transistors were defective and caused the failures. I believe Kenwood also took care of the failures after the warranty period was up.

So is there a reason to explain why this is happening? Some sites have made mention that the final PA transistors were being made in China. I cannot personally confirm this. Most of us know the reliability of the cheap products made in China. But for Yaesu to skimp here and place us in jeopardy is unconscionable and then to not recall the units and repair them properly or redesign them is just as unconscionable. Several people have replaced the finals themselves and you can find that on the internet. They purchased the high quality final devices and so far I have not read where those are failing again but you need to look for those things yourself.

And lastly, QST labs rated the radio and found the transmit IMD distortion level to be -22 dBM. That parameter is how broad or how much splatter the radio causes on SSB. In the 35 years that I have been following QST lab reports that is the absolute worst report ever by a wide margin. For comparison the best radios do –40 dBM. The 991 is about 100 times dirtier than those best radios if the reports are true. From the FCC regulations the radio is probably not legal for use in the US.. This poor a reported value probably reflects back on the PA final failures as something (like the bias) is probably not correctly set or they are using inferior semiconductors and that could explain both problems.

So do I love the radio - well I truly do. It is an absolute pleasure to use it and an admirable performer. I would get up early just to use and play with it. Would I purchase the radio? I might after psychiatric evaluation. In my opinion it seems like it could be a 1300 dollar flush down the toilet unless Yaesu can stand by us.

Finally, I would just like to point out that the majority of failures of the finals are very likely to appear on this forum and the internet, while 991s that work flawlessly are not mentioned to the same degree and are likely in the vast majority. However, the presence of 5 out of 10 reviews this month so far (Jan 2016) with failures of the finals seems quite excessive.

Yaesu FT-991(A) Users Group (groups.io)
https://groups.io/g/Yaesu-FT-991