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.
“When i measured the HLA300 not with 2 tones using white noise loading using a IC706 and HLA300 the IMD was disaster at fully output. The IC706 was putting out between 20 and 25 watts for about 300 to 400 watts across all the bands. Thats about the manufacturers ratings and where most hams would be running them not at 200 watts. Why would spend money on a 400 watt amplifier and run it at 200 watts? No normal ham would do this. Its a nice feel good argument for hams who buy this CB splatter garbage and then run the amp at full power. Everyday on the ham bands we hear these crap boxes spewing out splatter and occupying 20 khz of bandwidth with splatter when they drive to the full rated output.”
The HLA-300 uses 4 SD1446 80 watt transistors. Why would you try to get 300-400 watts out of an amplifier that is in compression at 300 watts out?
What was your Amplifier Vcc voltage during the test?
What was the occupied bandwidth from the driving transceiver?
How did you mesure that bandwidth?
What instrument did you measure the bandwidth with?
I still don’t see any hard numbers.