IMD is not the only issue, but hey the impact of any  amplifier with bad IMD performance affects all ham operators. Do you want the ham bands to sound like the CB band thats full of splatter?

The importance of the IMD issue is also this. There is little point in buying a state of the art transceiver with high performance when a bad IMD amplifier makes performance numbers largely irrelevant. Do  hams actually understand this
point or are we just brain dead CB operators who cant understand this simple point.

While I might be  ranting and raving continuously on this issue, its a point in radio physics thats important  for maintaining  the excellent weak signal performance of the ham bands. Look at the ham bands in suburban areas
its almost  a  waste of time using HF in many suburban locations because of noise pollution. What leg do hams have to stand on when they cant even keep their own act clean? So we going to turn the bands into splattered filled bands full of IMD and splatter from poor amplifiers such as CB amplifiers  that cause excessive  splatter.  We have a duty of care to pass on  to the next generation of hams a set of standards that  define how we enjoyed the ham bands in the past, operating on bands free of QRM caused from operators and other man made sources..

Anyhow hams who argue against IMD performance I am sorry to say are dummies and simply dont get  it.. They rush out bragging about their wonderful transceivers with sky high receiver numbers and cant even understand
that these radios are useless unless transmitters are clean. Its even more importance on the VHF bands. But hey   I can understand when people dont have the brains to understand a simple issue like IMD and splatter and carry  on like dumb CB'ers with all knobs to the right splattering everyone with  bad equipment choices. A not very ham friendly spirit that preserves the excellent resource called the HF bands in a pristine condition free of crud. Hams who cause excessive  splatter due to poor operating practices and  poor equipment choices are no better than a dumb CB'er who gives no thought to what they are doing nor care too understand the impact of what they doing.

So  you can throw all the mud in my direction, I dont mind. At the end of the its only  you who looks bad because you so ignorantly  dont fully  understand  the importance of the issue. There are a great  number of hams who have technical expertise who understand this issue and say nothing. Its only the loud mouth know nothings who make the same old lame attacks about no callsign or other trivial  rubbish. Why dont  you address the issue of IMD and  show us your genius and explain why amplifiers with poor IMD  has no impact on hams and the ham bands. I would be interested in your arguments.  I am sure so would many hams would also be interested in another view rather prattling on about nothing. Nobody else can produce a counter argument as to why a crap IMD CB amplifier  or any crap amplifier for that matter is good for the ham bands. The floor is yours SIR! 

When the ITU considers these standards necessary for professional HF users, I cant take comfort that I am on the right side of the argument. How confident are you in your argument against the best possible IMD standards?




AD9DX,
Thank you , thank you, I also have become very tired of Mr. (I have no callsign), (one tune) Zenki.  To him IMD is the ONLY thing that matters, and his one man campaign of criticizing almost every amplifier made today for IMD is getting real old. Zenki, you have made your point HUNDREDS of times, give it a rest. 

John  W5JON  -  V47JA 
[/quote]

I wonder when the HOA is going to start telling people what color and of brand car they can drive. Next will come how you should dress and finally they will tell you when you should die so you can make room for someone who wants your house. Dont worry its coming to a place near you, just give it time. The HOA will soon tell you that they dont like the look of your wife and that you should get rid of her. Like sheeple to the slaughter!

Meanwhile they let  all the crap equipment from China onto the market that causes vast amount of interference.

Nobody has faith in any of the government bodies like the FCC anymore anywhere in the world. They dont have the high moral technical ground anymore.
The quicker government departments like the FCC dies and blows away  out of our lives the better off we will all be.

Government is disease like cancer that has no cure. If somebody can make money out of getting away with high levels of RF exposure they will let them do it.  Just look at how the bent the rules on BPL and  made the ARRL look like fools by changing the goal posts. They then prance around like they have some moral and technical competence. When lawyer engineers try and fool real engineers they lose all respect.  Its even worst when these government bodies sole
existence is to accommodate their political masters.

A shame  some company cant produce a radio like the ADAT transceiver  for the mass amateur radio market. Unfortunately there does not appear to be  a ham radio company with the engineering expertise of ADAT that produce such a radio. I dont really know why the ADAT company has kept such a low marketing profile especially in such an important market like the USA. Its really too understand why  are not very active marketing their product. Once you use  an ADAT radio you soon appreciate the virtues of putting a SDR radio into a stand alone box. If a company like Icom produced a radio  like the ADAT transceiver it would be a runaway success.

The ham radio transceiver manufacturers are very bad at doing  basic market research, they are not very proactive at exploiting the hot button issues in the ham radio market for new products. All we seem to get is  same old crap.
Every year the  release  of more radio models with useless features that nobody needs, the  performance deficit is glaringly obvious.

There is so much more  that could be offered  if they tried. The feeling that I get  is that the ham radio business is at the end of its product life cycle. Its about too die and blow away  because of technology obsolescence. The new
affordable SDR market is making life difficult for manufacturers. However if they grabbed the bull by the horns and start delivering advanced technology features hams will buy these new products rather than the stale bread  that they offer year after year.

And the Flex 6000 will also be discontinued because despite having some excellent features. Its not the radio that most hams want. You make money by producing a box with knobs on it.
Flexradio should have built a Flex6000  as standalone box with knobs on it and a TFT touch screen.  For the price the Flex 6000 represents poor value.  If most hams had a choice between a Flex6000 and say a Kenwood TS990S
the Kenwood would be the radio of choice. Lets face it how many people can listen to more than 2 bands at once so, whats the real point of  such a feature packed radio? Now if you could use those receiver slices to do some beam forming or direction finding it might be another matter. So unfortunately most of the potential of the Flex 6000 will be  wasted on the average ham.

The Flex5000 failed for all of the above reasons.

I would buy the Flex6000 as precision test instrument radio  if  Flex delivered decent spectrum analyzer software features and a radio with a clean 200 watt FET PA with adaptive predistortion. I am not going to pay such a huge amount of money for features I can get in a 500 dollar radio and then buying a decent SDR radio like those from RFSPACE and  the HPSDR group. I can buy  a Rigol spectrum analyzer, a HPSDR Hermes,  build a 200 watt FET PA and then buy a high performance SDR receiver that accomplish what the Flex6000 will do for a lot less money.

SO like the Flex5000 the Flex6000 is doomed to the technology graveyard of opportunity squandered because  Flexradio is not delivering anything is  useable in the real world of everyday ham radio. There would be far more interest
in the Flex6000 if they could deliver  features like transmitter monitoring, pre-distortion PA, beam forming, direction finding and a full working VNA. I dont need to receive all ham bands  at once. I only have one mouth and 2 ears for 1 QSO.

I do, but I will believe it when I see a  practical working example. At the moment its all hot air. I am however optimistic that pre-distortion delivered and will be  of great benefit to the ham radio service. At the moment however we hear all these radios on the air splattering  with  cheap CB PA designs. I have heard more Anans on the air with cheap RM italy amplifiers causing havoc,  the kit producers dont even aspire towards producing a decent higher voltage FET amp. This clearly shows how  the priority is for producing a amplifier design with superior IMD performance. Heck a pair  of MRF150s can produce -40db 3rd products without trying so why  go for a cheap bipolar design in such a high performance radio. Some in the HPSDR group needs to reset their design priorities. The Flex6700 will be in the same boat, excellent receiver and opportunity to produce world class transmitter squandered. For the price that they are charging I would have expected a PA design with at least -40db 3rd order performance. Homebrewers  are doing this now, why cant a manufactured  radio that costs 6000 dollar achieve this performance? The answer is simple because hams dont really understand the importance of the issues and the designers of radios like the Flex60000 are maximizing their profits. Look at the Kenwood TS990S. A 8000 dollar radio with -24db 3rd IMD performance on the higher bands. Thats a disgrace for a 8000 dollar radio.

Anyway pre-distortion and the cartesian loop systems is the way forward. Maybe Icoms new radio will adopt this new technology. However I am skeptical because look at the IC7800 they spend more effort making the S-meter look pretty and dancing correctly rather than calibrating the S-meter. With these poor priorities I dont expect any ham  equipment manufacturer to produce a clean transmitter.  The sad part about this is that I can buy 1500 dollar marine transmitter that has better dynamic IMD performance that meets ITU standards  and one that runs on 12 volts. I wonder why Icom can produce  marine transmitters that can meet ITU standards and then sell 10,000 garbage radio models to the ham radio service. Hams have to stand up and complain that these crap transmitter designs  need to be removed from the market place. I know you understand this issue, its a shame more hams dont get it. We starting to buy radios like CB'ers if it has knobs and a cool name it must be good regardless of the performance!

Without a high performance transmitter your receiver performance hardly matters. The IMD performance of most ham rigs are so bad you can never possibly realize the full receiver potential. Everybody only talks about receiver numbers.

The most important issue today is the quality of transmitters. Its safe to say that all current ham transceivers have transmitters that are dismal in performance. Unless someone does something about this sad state of affairs
you only kidding yourself about the importance of receiver numbers.

Look at the TS990S 8000 dollar radio and the radio has like -24db 3rd order IMD on the higher bands. Thats poor, and with a radio operating nextdoor to your frequency you will never realize the excellent dynamic range of radios like the K3 and others. The K3 could have been the best all round radio if its transmitter IMD performance was better.   Talking about transmitter performance seems not to be a cool subject and matter and it seems bragging about
receiver numbers is a better PR and marketing exercise for manufacturers. Hams really need to wake up to this point and should asking the manufacturers why their transmitters are so filthy.  $8000 dollar radio with poor IMD  transmitters and uncalibrated S-meters what a joke.

So blah blah blah about this rig versus that rig. It does not matter while most hams spew out garbage from the  expensive receivers/cheap transmitter radios. The smart guys are the ones who are buying the Icom 718 and such radios, because they missing nothing in the real world of dirty signals. NASA's million dollar optical telescopes and radio astronomy systems cant look or hear through the garbage such light and other RF pollution. Having a million dollar super receiver will not help the average ham because of the pollution  from hams transmitters. Maybe some day hams will wake up and get it, at the moment  they not thinking all that well ranting and raving about receiver numbers and this radio versus that radio. Its an exercise in futility because of the laws of physics.

Nobody mentions how important  the issue of spectral cleanliness of amplifiers. Tubes and solid state amplifiers with poor IMD performance should really be placed at the bottom of your list.

You cant rely on the ARRL reviews to tell  you how clean the amp is. The ARRL simply ignores the issues and does not care if the AMP Is dirty. Every piece of crap spewing out IMD garbage is OK by them if they review it.
 An example is  the review of the Acom 1500 amp in this months QST. -27db 3rd order  and -49db 9th order. Rather unspectacular figures yet they say nothing about such amplifiers. A 8877 as comparison has superior IMD performance. The current batch of solid state amplifiers are also rather poor performers but the ARRL just keeps on reviewing like everything is well. Hear no evil see no Evil!

If I was shopping for a decent tube or solid state amp I would by the model that produces the cleanest signal. Clean means no tetrode amplifiers, poorly designed solid state and CB amplifiers. Manufacturers like Tokyo High Power and other are stuffing industrial RF fets into their amplifier designs. These FETS are not linear RF devices meant for linear SSB service. The outcome is a dirty amplifier designs  that have poor IMD performance that is  no better than a crap CB amplifier.

Yeah very expensive and another SDR radio with a junk transmitter with poor IMD performance.
Regardless of the ham transmitter manufacturer, its the same  old same old lousy TX performance.

Its is very easy too design and build a SDR transmitter that produces  very little splatter or IMD. Its also very easy too design a low power PA that is clean.
But this is typical what QRP companies do, they build the worlds worst PA in their QRP transmitters.

If they took leaf out of military radio producers and copied what they did they would get some respect for being innovative. Most of the low military transmitters  run class A and they are very clean.
Once you have a clean QRP driver it then becomes a good foundation for either building a super clean tube or FET PA.

The 1 st law of ham radio physics is that excellent receiver performance is wasted when you have substandard transmitter performances. Unfortunately all ham transmitters are sub standard.
The fools are the hams who continue on the road of enlightenment demanding better receiver performance and say nothing about the poor transmitter performance. Idiocy at its best I am sorry too say.

A lot of hams dont get the joke that is being played on them by all the receiver number propagandist. While  the objective  of the argument was a legitimate one   a decade ago, the argument holds no weight now
while  manufacturers are still selling radios with poor keying sidebands and IMD. Even worst is the terrible ALC designs that by their nature cause excessive splatter. Who is listening ? Unfortunately nobody because hams dont understand the issues all that well and just say nothing and continue to buy the crap.

And both radios have such lousy transmitter IMD specifications that in the real world would  making having such excellent receivers of waste of good technology in the real world.
Both manufacturers simply dont get it! They build receivers  that perform well yet put cheap 12 volt  poor IMD amplifiers in the box. Its plain technical stupidity.

Despite the admirable aims of the HPSDR group, they too are the leaders in producing lousy PA designs that causes excessive IMD or splatter. These days how hard is it really
too design a high voltage FET PA in place of a lousy  12 volt crap amplifier design that is no better than the average CB radio in IMD performance.

Everyone who buys and owns these radios will wax lyrically about the amazing receiver technology and say nothing about the stone age transmitter amplifier, that affects how all
other receiver perform in the real world regardless of price. The IMD performance is  slipping down a greasy slope to the abyss and yet the ARRL and others dont give a damn. The ARRL continues
too heap ton of praise on radios with lousy transmitters in their ARRL reviews. Its clear that people like the ARRL and the RSGB amongst others are becoming convenient marketing tools for companies
that produce poor transmitting equipment. These bodies are supposed to uphold technical standards and promote technical excellence rather than trying too promote cheap equipment that at the end of the day
is making the ham bands sound like the CB band that is full of splatter.

FLEXRADIO 0 Stars for a crap transmitter design
ANAN 0 Stars for another crap PA in   radio that should of  had a  world class PA.

What gets me is that most ham radio models now exceed the price of commercial marine, military and aeronautical HF equipment yet ham equipment could not even meet these basic ITU standards for commercial products.
We getting ripped off by the manufacturers  who are selling substandard equipment. Really they all need to get their cheap eye blinkers off and forget about receiver performance and employ real RF engineers who know how too design a proper PA with decent IMD performance. Hams need to  wake up and get a reality check and start demanding better transmitters performance, while we still carrying on about receiver performance numbers the manufacturers will definetly know that we a bunch of idiots when  we make no mention of the transmitter performance that will never let any ham realize  their  high performance receivers potential. A huge waste of money and you might as well buy a IC718 because you cant realize any more performance BECAUSE OF THE CRAP TRANSMITTERS LIKE THE FLEXRADIO AND ANAN.

Oh Another SDR radio blah blah blah, same crap transmitter from yesteryear!

5 watts is adequate  for QRP CW
20 to 25 watts is adequate for  SSB QRP. If you use anything less than this on SSB you are really asking for frustration.

Its ridiculous that contest rules set the QRP power limit for CW and SSB at the same level considering the advantage that CW has over SSB. The contest SSB power level should be at least 25 watts.
I call this power level minimum necessary  communication power.  Minimum necessary power on CW is 5 watts and on SSB its 20 watts. Just arbitrarily setting the power level  in contesting  rules is
a flawed concept. Contesting was supposed to be about testing the effectiveness of antennas and modes of operation. Without applying some kind of weighting to the advantage of one mode over the other
shows how ridiculous the whole QRP operating bandwagon is. The objective should be to use the lowest effective power that allows communication, not just selecting a power level in some arbitrary manner.
Just like moon bounce requires a minimum ERP that depends on TX power and antenna gain, HF is no different. You require a certain level of power based upon mode and SNR to complete the hf circuit.

If the objective is to put yourself  through as much frustration by communicating with the lowest possible power and you enjoy doing so, thats another argument. Then why pick 5 watts  why not just set the power level down to say 1 milliwatt and  be a real QRP hero? We dont do this because that makes it too  hard, that will be the argument. So if it 1 milliwatt is  ineffective or too hard why not set the power on SSB or any mode for that matter to something that produces results. On SSB the QRP power level should be set at 20 to 25 watts not  something ridiculous like 5 watts  which assume 5 watts on SSB is as effective as CW. The 5 watt QRP argument is  flawed the moment you change the mode. What about digital and models like WSPR and PSK?  WSPR can achieve communications with  milliwatts   so 5 watts is excessive power for that mode.

We need to move into modern era of HF communication planning and adjust our ham radio notions, rules and pragmatism  about effective communications power  and not be stubborn  5 watt zealots trying to be supermen. The argument  that also is forgotten is that signal to noise ratio is getting worst and worst and worst in modern cities. The romantic image of  a ham or SWL listener running a end fed wire through the wooden house window frame and pulling in DX signals from all over the world is long lost. If you do this today in a modern house or city, all you will ever hear is S9  of noise. The same goes for  areas like the tropics. The low bands are covered with S9 static year round and we have some arrogant NA or European QRP purist that will tell you  that 5 watts is enough for SSB based on only what they know, not on the  real reality of  getting the message through to any place on the earth. I am not  a QRP hater. I enjoy QRP operations as well, but  anything  that I do I want to be effective at.  If this means  selecting the appropriate power level so be it. I consider power levels up to the power level of 25 watts to be QRP in this modern day and age when you consider all factors.   We all remember bygone sunspot cycles where you could work DX on 10 meters 24 hours a day with 5 watts, they gone and today we dealing with many challenges. We should change with the times  and be pragmatic. If i hear anyone with 25 watts or less saying they are QRP, I dont give them lectures about how QRP only starts at  5 watts. Same goes for HF mobile operators on the low bands. They are dealing with antenna efficiencies of less than 2 % with 100 watts of power they are QRP operators, do we give them a pat on the back say good job you doing amazingly well?  Most hams dont! The NTIA rules on  5mhz about effective radiated power and transmitter power is how we should determine power levels for all band for so called QRP operation. This is how professionals work out effective communications power  based on the requirements of the HF circuit and antenna gain. For hams  setting a limit like 25 watts is simple way of achieving this based  on what the average ham uses for antennas both mobile, portable and from a home station.

 The Military guys have known  for years that 20 to 30 watts on HF is all that you need even when using short tactical whips on HF manpack radios.  If  the military could have used 5 watts and make more battery space or light radios they would  have have done so a long time ago. They experts at what they do and 20 watts today is  considered effective communications power even when special forces operators have to get the message from 1 continent to the other. When the Falklands war was happening I could hear military HF clansman manpack communications all day and all night  long . If they were running 5 watts  I would have never have heard them from another continent.

5 watts Booooooooooo!

All good questions Mike.  I can  answer all of them.

 Your original contention was that the amp was "clean" at 200 watts. Maybe in your hands only! You have technical ability others dont.  My point was that the typical ham does not run this amp anywhere near 200 watts from a mobile or home station. They always drive these amps to the limit because they looking for a cheap amp with high output. I can  almost guarantee that every ham using one of these amps is driving this amp to a power output level of between 300 and 400 watts. They will even describe their RM power output on their QRZ profile. In Europe this is the output power that most hams are running these amps for mobile or home station use. Every  time I hear splatter and query the stations who use these amps this is the power they running the unit at. Saturation, do you think  anyone who buys this amp can actually measure  and drive this amp  below the saturation point? I dont think so. Its nice for you and me with test equipment. The only piece of test equipment that most hams have is a SWR/wattmeter, especially those who buy a CB amp! You being way too optimistic about ham skill levels.

Here is a link and review of this amplifier. It even mentions your callsign in the review of this amp. Even here you recommend 300 to 400 watts not 200 watts of output.

http://pa0fri.home.xs4all.nl/Lineairs/HLA300/hla300eng.htm

Again here you can see how users want to use their favorite little amp not at 200 watts but at 300 to 400 watts of output power. When these amps are driven as per this review the splatter is  horrendous just like
you hear on the CB band. You can also get an excited idiotic  mobile ham who thinks that cranking up the mic gain a bit helps, and   by golly the band is awash with crud. I hear these Turkeys every day doing this.

The typical ham who buys  this kind of amp is not considered and measured like  yourself. They will not even consider, supply voltage, saturation, ALC overshoot etc etc. They will drive the amp and look at the wattmeter, smile and say all is well. This is unfortunately how most users of these amps operate. They dont check to see if the amp is saturating. They dont use a second receiver or SDR to actually check the quality of their signals etc etc. The end result
is  that other users have to put up with the splatter collateral damage because of ignorance.

This kind of splatter does not happen if they use was using an Ameritron AL811, FL2100Z or any other good tube amplifier. When there are so many good cheap ham amps available that dont cause such high levels of splatter why even bother to use this CB junk? There are so many hams who cant even tell if a signal is dirty or splattering, or simply dont want to offend their QSO partners. While there are a few hams who stick their necks out and inform stations that they are splattering most hams dont bother these days because of the attacks that they suffer from offending stations, Attacks about your poor receiver, your ears, your NB, your wife, you a idiot etc etc.

 If I got a splatter report on my signal. I simply ask the reporting station what my signal strength was on their receiver, their radio brand/model and thank them for the report. I would then go off air connect my SDR or second good receiver and check my signal. This  what most hams should do rather than acting tough because they ignorant, dont want to know or like acting like the tough big mouth on the air. New hams especially those from the CB band seem to have a Pitt bull attitude on the ham bands, that is that their attitude is to destroy or humiliate any ham who criticizes  their operating practices. In this climate its difficult trying
to help stations reduce mic gain or drive for a clean signal. I would  gladly recommend any piece of commercial equipment if hams  had a better attitude and  a technical approach towards using this equipment. If  hams who use this equipment cant understand what splatter and IMD is,  and then want to  launch  personal attack   because of their ignorance then the best bet is for most hams to not use this kind of equipment.

 My view is  ham radio is no longer a technical fraternity  that fosters and cares for fellow amateurs, its  just become of hobby of selfish people buying equipment and selfishly doing whatever they want  with very little regard of how they are behaving.  I get this argument  time and time again I spend 10,000 dollar on  brand X and I dont splatter. I would have  preferred to hear I spent 10,000 dollars on a spectrum analyzer and I see no splatter or IMD. The ignorance around the use of CB amplifiers is indication of the poor standards that have infiltrated  the ham service from the CB band.

 I am not against  CB'ers or new hams. I know many CB'ers who have become great hams. However when people use ignorance and poor technical skills as a defense argument  and that they think that they have every  right to use  operating practices that causes harm to other users of the band this  I dont agree with. This includes criticizing selecting equipment that is poor like CB amps.

Hams should have the right  to criticize any ham who operates a CB solid state amp or any amp for that matter like they do on the CB bands by driving the crap out of the unit and taking out 20khz. Unfortunately their many CB hams who think that obtaining a ham licenses gives them the right to tell old hams how they did it on the CB band and that  they are expert radio operators  with 30 years experience  on radio. If I had 1 years of radio experience  I would expect that I can operate my station in a clean manner.  What good is 30 years of experience on radio if all you ever learned is how to drive the crap out of equipment and use equipment that has poor technical standards?

In the past  years in ham radio when equipment building was routine, and there was a lot of splatter around like the old AM days, hams expected signal quality reports. Splatter reports were routinely done and nobody took offense
at any ham who criticized or gave a signal quality report that was bad. Hams appreciated splatter reports. The attitude today is  much difference, because  telling a ham that his equipment is splattering means telling a ham that his equipment that he has bought is crap and that he has no idea what he or she is doing. In the case of someone causing splatter, they  dont really know what they are doing this is the sad reality. Even radios with relatively poor IMD performance can be used on the air with  little harm to other users. This is before we even start with operating practices like ESSB which causes excessive splatter regardless of the skill level of the operator. If your signal is not brick wall on a SDR receiver you are splattering  and this splatter is easy to see on any SDR. We have tools  that are readily available unfortunately most hams dont want to acknowledge that technology has moved ahead and that splatter reports are not personal attacks.

I tested the amp  and radio using  several methods.

1. Installed in the car with the amp in the car with second battery. Nominal voltage 13.8 in all cases. Voltage drop was minimal.
2. Installed in the car with the amp on the second battery  and a Voltage boost regulator on the IC706 which maintained the voltage  on the  IC706 at 13.9 volts. I did not have a regulator big enough for the amp.
3. Tested on the work bench with  a 200 amp DC telecommunications  for both the amp and the radio. The figures that I quoted above was on the DC supply not even on the mobile. I am sure that in the mobile
the figures would have been far worst. 
4. I used 2 X R&S  spectrum analyzer one was a real spectrum analyzer one with  a onscreen dynamic range of more than 100db. My main analyzer is a R&S FSU All these analyzers have ITU compliant
pass fail IMD mask software suites. I believe in dynamic IMD measurements not 2 tone figures which are are a static indicative test that  has little relevance to how a ham transmitter works in the real world.

The average ham who installed a mobile radio and a RM italy amp is not going  to go through all the motions of testing for saturation, IMD at various drive levels, IMD versus voltage levels etc etc. Asking hams to do
all this before getting on the air is just never going to happen. We should just accept the fact that  ham radio today is a clas service no different to other HF users who buy and operate radio equipment without technical skills. We
should have  Type acceptance standards that are written into law. These type acceptance standards should define the IMD standard based on the ERP of the ham station just like the ITU and FCC standards require by law for commercial users.  Its just unfortunate that hams dont have the skills nor the equipment to drive a poor piece of equipment like the RM300 within acceptable limits. Thats why I dont agree with recommending  such equipment for the ham service where we have to be vigilant  and considerate of other users of the ham bands.

Produce a 25  watt PA  and LIPO battery pack for  the whole combination and you will have a winner. If  you also have a  MANPACK frame that includes the radio, amp and tuner you will  have winner.

If you wanted to take the radio to the next level. You can make a ready to go HF station by combining  2 X 25 watt PA's, antenna tuner, DC to DC converter 10 to 50 volts, AC power pack 90 to 260 volts as  portable radio setup.
50 watts is enough for portable/maritime/holiday/pedestrian mobile and casual operation. Pedestrian mobile is becoming very popular. The ham companies do very little market research and most of their designers dont actually use
the equipment that they design. The end result is you end up with useless equipment that is far from flexible.

5 watts output on SSB is almost close to useless with simple portable antennas. Portable SSB starts to wakeup at about 25 watts of power. On CW  5 watts is effective.

Bottom line is  that if you design  flexible equipment that can be configured for many styles of operation you will have  a sales winner. Your transceiver design looks like a winner for building a good portable HF station platform.
The military have been optimizing their HF portable radios for decades,  the result is the HF manpack the most practical portable radio you can find. All ham designers can come up with is useless cutesy radios that are not effective
at doing what they supposed to be doing, that is communicating because they so poorly designed or largely impractical for operating from any other place besides being a near a car or picnic table. The HF pedestrian mobile pioneers from the UK like G4AKC shows the kind of design expertise and lateral thinking thats needed.

Aliasing  is known to cause spurious signals, however you cant generalize because there are so many variables hardware and software.

I would recommend the K3 with  the P3 and second receiver.

I would also recommend the K2 which is an excellent weak signal CW radio. There is just something about the K2's receiver on weak signal CW that makes  signals just jump out at you.

A K3 will almost be a waste of a good radio on CW only, therefore the TS590S would be a  happy all round compromise.