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Author Topic: Nice Amplifier  (Read 20821 times)
W5JON
Member

Posts: 161




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« Reply #90 on: June 07, 2013, 09:54:05 PM »

Zenki,

The point that I, and others have tried to make, and one that you continuously choose to ignore is, PETITION THE FCC.

For years you have been on this anonymous rant on IMD, but have chosen not to PETITION THE FCC, to change the IMD standard.  When an amp discussed on Eham meets or exceeds FCC requirements, they have MET the current FCC standards. If you want companies to do better, PETITION THE FCC to change the standard(s), to meet what YOU perceive a "acceptable".  

On almost every amplifier topic, here comes Zenki with a comment, on how this, or that amplifier does not meet YOUR IMD requirements.  You have made your point HUNDREDS of times. We get the message, IMD is bad, and you are the savior, so PETITION THE FCC to change their standards. That is how a "Standards" CHANGE WORKS, not years of ranting on Eham.

Sorry, but I just realized, the FCC does not accept anonymous petitions, but maybe you can Petition them to change that also.
......
John W5JON    





« Last Edit: June 07, 2013, 10:26:43 PM by W5JON » Logged
K2GWK
Member

Posts: 374


WWW

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« Reply #91 on: June 08, 2013, 12:19:23 PM »

Zenki,

The point that I, and others have tried to make, and one that you continuously choose to ignore is, PETITION THE FCC.

For years you have been on this anonymous rant on IMD, but have chosen not to PETITION THE FCC, to change the IMD standard.  When an amp discussed on Eham meets or exceeds FCC requirements, they have MET the current FCC standards. If you want companies to do better, PETITION THE FCC to change the standard(s), to meet what YOU perceive a "acceptable".  

On almost every amplifier topic, here comes Zenki with a comment, on how this, or that amplifier does not meet YOUR IMD requirements.  You have made your point HUNDREDS of times. We get the message, IMD is bad, and you are the savior, so PETITION THE FCC to change their standards. That is how a "Standards" CHANGE WORKS, not years of ranting on Eham.

Sorry, but I just realized, the FCC does not accept anonymous petitions, but maybe you can Petition them to change that also.
......
John W5JON    







I am heading downstairs to throw my keyboard in the dishwasher because I just spit my coffee all over it after reading your post.
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K2GWK Website

Stupidity for Dummies (http://stupidityfordummies.com/)

…because sometimes, you just can’t dumb it down enough…
KW6LA
Member

Posts: 91




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« Reply #92 on: June 08, 2013, 05:28:17 PM »

Just wondering how many Hams have found these dirty CB Amps in operation ? I am very active on HF and can’t remember when I heard a 20 meter SSB signal  on 10 meters. Zenki  seems to think it’s one big problem.
I for one, have not found his argument to be true ? Guess I don’t troll the airways looking for that stuff either.
 Cry
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WD5GWY
Member

Posts: 390




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« Reply #93 on: June 09, 2013, 09:13:02 AM »

Just wondering how many Hams have found these dirty CB Amps in operation ? I am very active on HF and can’t remember when I heard a 20 meter SSB signal  on 10 meters. Zenki  seems to think it’s one big problem.
I for one, have not found his argument to be true ? Guess I don’t troll the airways looking for that stuff either.
 Cry
And I doubt you will find a 20 meter SSB signal on 10 meters. IMD splatter is usually found
within the band you are operating in, and not scattered up and down the HF spectrum. (although
it can happen) What Zenki is talking about is interference above and below a transmitted signal.
When you can hear a signal that sounds like someone talking into a sock 10KC or more away from the actual signal, and you have to keep tuning till you finally find the actual signal, that is one form
of IMD.  Some of the noise we hear on HF is associated with splatter from a dirty amp or transmitter. If you were to look at some of the signals on HF with a spectrum analyzer you can see
where the splatter is occurring from a given signal. What I think has happened over time, is people have become used to the interference from a transmitter and/or amplifier, that they either no longer notice it or just think it is a normal condition of HF. A LOT of the problem, in my opinion, is
improper setup of a person's radio. Over modulation etc. can create IMD problems itself. And coupled to a transmitter or amplifier with problems, it only makes matters worse.
While Zenki seems to be or to some is, over the top about his feelings about IMD and it's causes
and even it's cures, he does have some very valid points. And given the attention that most manufacturer's pay to receivers, and little to no attention paid to transmitters, I can understand
his rants on the subject. Radios today are not cheap at all. Especially the high end radios. And for them to not preform any better than they do, IMD wise, it really is a shame.
  There is not, in my opinion, any easy answer to the problem. The Amateur radio community is not that large compared to the big 3's main customers and for that reason, they will not focus on the problems that poor transmitter design are causing. And, when there are functions within most
modern receivers to limit the effects of IMD on the receive end, then they have little incentive to do so. Voting with our wallets might help, but, I'm inclined to believe that it really won't make a difference.
james
WD5GWY
   
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N4KC
Member

Posts: 286


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« Reply #94 on: June 09, 2013, 10:09:19 AM »

And I agree with you, James.  Maybe if Rob Sherwood made transmit IMD figures as prominent as his receiver numbers it would help.  My disagreement is about the level of the response to what is, to me, not really a huge problem...yet

Frankly, I don't see how any more type acceptance standards than already exist for transmitters and amplifiers would make much difference in the interference you and Zenki reference.  Guys would still run their mic gain hot, crank up the audio processing, and drive their amps out of linearity.

When I hear such, I often tell the station what is happening, remind him/her that such practices not only interfere with other stations but also decrease intelligibility and rob them of precious power that could better be concentrated on the frequency on which they transmit.  Such practices are counterproductive in a contest or while trying to work DX, where a lot of such malfeasance takes place.

With the proliferation of band scopes, I suspect more and more offenders will be called out...on the air or in DX spots...and that is the best way to handle it, in my opinion.  Called out in a polite and positive way, because often the op does not realize what he is doing or what a negative effect it is having on his contest score or DX results.  In my opinion, if the problem is no worse than it is now, we are better served by doing it ourselves, not by asking the FCC to tighten standards on ham gear or to step up enforcement (which is unlikely to happen anyway).

Don N4KC
www.n4kc.com
www.donkeith.com
(Author of the new book RIDING THE SHORTWAVES:
EXPLORING THE MAGIC OF AMATEUR RADIO, now in
all print and e-book formats)
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WD5GWY
Member

Posts: 390




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« Reply #95 on: June 09, 2013, 12:22:02 PM »

Very nice post Don. I think that you are correct about getting the FCC involved would not really
help. Or for that matter, make much of a difference. Self-policing can help, if done in a positive
manner. I have mentioned to other hams in the past about problems I could see and hear from
their signals and most of the time, but not always, it has been received well and it actually helped the other person to adjust their radio properly and get the most out of their equipment.
But, I have also ran into people that turned completely nasty about it as well. But, that is not always the norm. (thankfully) And like you the problem really rears it's ugly head during a contest or
a lot of people trying to work a rare DX station. In the case of working rare DX, (especially if they
are working a huge split) it can really get out of hand, making it hard for someone with limited power and antenna (me in lots of cases! Cheesy ) to be heard or to hear when the DX station comes back to them.
  I have mentioned this before and I'll say it again, local ham clubs could also help with the problem by offering either classes or just having guest speakers who give talks on proper set up of radios and amplifiers. There are a lot of well intentioned new hams, that have no real idea on how to properly set up their equipment for best results. And it does show. I have helped new hams with setup and most seem grateful for the help. I know that I appreciate it when someone tells me when I have a problem that I do not notice. Besides all that, I need to concentrate as much power into what little signal I have as it is!!!
james
WD5GWY
 
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K1ZJH
Member

Posts: 898




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« Reply #96 on: June 09, 2013, 12:37:46 PM »

IMD is one spec... but many of the cheap broadband amps are also lacking individual low pass filters for each of the ham bands. It is entirely possible for the second harmonic of a CB grade amp being used on 14 MHz to be heard on 28 MHz as well. IF there aren't individual lowpass filters for each ham band.

Pete
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WD5GWY
Member

Posts: 390




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« Reply #97 on: June 09, 2013, 03:30:49 PM »

IMD is one spec... but many of the cheap broadband amps are also lacking individual low pass filters for each of the ham bands. It is entirely possible for the second harmonic of a CB grade amp being used on 14 MHz to be heard on 28 MHz as well. IF there aren't individual lowpass filters for each ham band.

Pete
You are correct. But, the amp mentioned in this thread , HLA-300, from RM Italy does have low pass filtering. And they also make amps, that are just as you describe. But, it is rare to hear someone using one of the cheap CB amps on the Amateur bands. All of the manufacturer's of CB amps all claim that their amps are for Amateur use. But, that is to get around the restriction by the FCC for them being sold to their real intended users, CB operators. Very few hams use CB amps such as the cheap RM Italy amps or even amps like the Texas Star, which is advertised as an Amateur amplifier, but, is really intended for the CB crowd. Little to no filtering in those amps at all.
james
WD5GWY
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WV4I
Member

Posts: 136




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« Reply #98 on: June 10, 2013, 02:38:00 AM »

I own both the HLA150V and HLA300V amps. Looking at their output on a SDR display or even my old Yaesu YO-101 scope, they look fine, at least at 150 and 300 watts PEP, respectively. At least as good as the exciter.

As an aside, some may care to read 97.315 (b) (3) re amplifiers that need "certification".

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W5JON
Member

Posts: 161




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« Reply #99 on: June 10, 2013, 05:55:54 AM »

Hi,

Excellent presentation by Rob Sherwood, at Dayton Contest University 2013.

http://www.youtube.com/watch?v=SOf2OOGeGi8

73,

John W5JON
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K4RVN
Member

Posts: 758




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« Reply #100 on: June 24, 2013, 11:49:17 AM »

If anyone knows where I can buy this amp new please post and I will see if it works OK by buying one to run about 300 watts SSB.

Frank
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K6AER
Member

Posts: 3476




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« Reply #101 on: June 24, 2013, 02:20:51 PM »


They generally have stock at $475.

http://www.rmitaly.us/index.php?main_page=product_info&cPath=1&products_id=1

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N4ATS
Member

Posts: 798




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« Reply #102 on: June 24, 2013, 02:47:50 PM »

I got mine on Amazon.com a while ago.
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W8JX
Member

Posts: 5441




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« Reply #103 on: June 24, 2013, 03:03:34 PM »

I got mine on Amazon.com a while ago.

How is it?
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K4RVN
Member

Posts: 758




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« Reply #104 on: June 24, 2013, 07:59:24 PM »

Thanks for replies, but both out of stock. Amazon does not know when they will have any more.

Frank
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