Yeah, send me free transmitters too.
With reference to my previous point (which has been ignored) made about the necessity of testing multiple examples of each transmitter, particularly those that come in kit form and the provenance is unknown or at least questionable...
The Jerry Gaulle NOUO is still being discussed in other Forums. The originator of the Transmitter Challenge is questioning that particular NOUO and the field strength readings generated from the FCC Inspector. He has offered publicly (as of today) that he will be testing his FOUR (yes, you read that correctly) Talking House transmitters in similar installations to see if he can duplicate the readings obtained.
I guess he feels it's OK to question testing a single transmitter as long as he wasn't the one doing the testing.
I can't say for sure, but I'm fairly sure I read in this thread or on another forum at least a mention of your idea of testing multiple transmitters of the same kinds, but we've heard about what an uphill struggle it was to do the testing that was done, so I'm thinking that the obstacle of arranging multi-transmitters might have seemed overwhelming.
I also feel ignored because I declared the challenge a success on promotional grounds, and was in no way joking. It created a great stir for part 15 on several forums. After all, we're still talking about it.
What's the difference of a couple microwatts among friends? My neighbor can hear me. That's all it's intended for anyway..
In politics and business it is common practice to install spies, moles, plants, and operatives to disturb the peace and cause disruption.
No less than four forums, perhaps more, have been used to discredit the AMT5000, as if spreading the truth about its "false claims" is a godly mission.
When attempts were made to attack the AMT5000 here at part15.us we arose in protest and wouldn't allow it. The instigator slinked over to another forum and set up shop for continued attacks.
By my count there are at least three individuals dedicated to bashing the AMT5000. Here's how you can tell they are plants:
They talk about nothing else. The only subject they push is that "the amt5000 is not truly class e." In other words they attack its strength.
None of them own an AMT5000, but are somehow magically knowledgeable about its "shortcomings."
They have an un-authorized copy of the manual (copyright by sstran) that "someone else disposed of."
They contradict themselves. They claim that the "class e mode of operation cannot possibly be achieved without a scope." So, then, the AMT5000 is capable of Class-E afterall, but only by smart rich people.
When all else fails they kick the transmitter for not returning e-mails.
By knowing how the plants and moles and operatives operate, we can be assured that the AMT5000 is a serious contender in the Part 15 transmitter line up and has enemies who want it stopped.
The AMT5000 from sstran.com reaches 96% efficiency. Proven.
The AMT5000 from sstran.com reaches 96% efficiency. Proven.
Hopefully I will not be added to the group described above by Carl.
For the sake of clarity it should be noted that the "96% efficiency" figure applies to the r-f output power from the final r-f amplifier, with respect to its d-c input power.
If that efficiency truly is 96% (and I have no reason to believe this is not possible), then for 100 mW d-c input power, the r-f power applied to the input of the internal loading coil in the AMT-5000 could be 96 mW.
However that internal loading coil has r-f losses which will dissipate some of the power from the final r-f stage. The r-f power at the output connector of that transmitter will not be 96 mW.
If at the high end of the broadcast band the coil loss is 15 ohms, then even if a 3-meter, base-driven monopole was mounted at the surface of a perfect, infinite, ground plane, that system using the AMT5000 would radiate only about 0.7 mW, when Z-matched at the operating frequency.
So the system efficiency from the r-f at the output connector of the transmitter to the amount of r-f radiated by a matched, 3-m antenna driven against a perfect ground plane would only be about 0.0075, or 0.75%.
Even given the signal losses between the coil and the stick, the exceptional output efficiency of the RF circuit puts the AMT5000 in a top contender class compared to transmitters of less or unspecified output efficiencies.
It is this superiority that the haters strive to smear.
All transmitters are subject to the same energy losses in the loading-coil/antenna/ground pathway.
But, it is such an elegant way to degrade the performance of a device that performs better than others.
Does anyone know what Class the output circuit is for the Rangemaster?
But I don't know who it is.
Maybe K. H. ?
So - my amt5k was awesome. My only issue with it was that I didn't have the patience to become proficient at tuning it properly. Phil answered all of my questions, people on this forum helped me out a LOT. I was able to get it going, and it worked great. It just was not for me. I am not technical enough in this regard to make this thing work at maximum efficiency - honestly, if I had the skill/technical knowledge, or the time to gain it, or a friend nearby who did - then I would have a bunch of them. As it is, I would rather put my time and efforts towards what I know how to do. I think this is an awesome transmitter, and when I did manage to get it working - it outperformed most of the others I have tested.. both in richness of sound and in range.
Not only balanced input from mir's AMT5000 experience, but did you know that the AMT5000 has the included option of a balanced audio input?
This is a rare gift since other transmitters require a costly extra component for balanced input.
What I hope someday to hear, is PhilB's story of how he went about inventing the AMT5000! Imagine the steps involved in designing and bringing such a sophisticated product to market! This is a story for "Front Line" on PBS.
I have mlr's AMT5000, but haven't used it yet, so I can't personally comment on its performance. I look forward to trying it out alongside the Rangemaster, ProCaster & Talking House.
But in response to Carl's post about multiple transmitters, surely the most difficult aspect of the testing was to secure the testing arena, install the ground, and to ensure that the testing instrument was accurate (he claimed he spent $1800 on calibration of that alone) etc. Virtually anyone, even those without 15,286 years of broadcast engineering experience, can procur a transmitter or two.
If you're going to do the testing, you should do it right, with multiple examples of each transmitter to eliminate potential errors. And as I reported previously, the driver of the Transmitter Challenge wants to do just that with Talking Houses for the Jerry Gaulle case (but, of course, we all know that's different than the Challenge).
But he failed to state the date when the FIM was calibrated, having had the thing for several years.