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Author Topic: TC-300, HF amplifier 150W  (Read 58057 times)
AA4HA
Member

Posts: 2100




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« Reply #15 on: November 12, 2013, 07:42:12 AM »

...
A ham can put the biggest piece of home brew crap on the air and it is legal.  Yet when someone buys something made off shore without the FCC acceptance label the sky is falling down.
...
The spectral purity of your signal is the responsibility of the operator.  No amount of harmonic filtering will cure signal IMD distortion from over driving an amplifier.
...
Here is an idea…Why not put one into operation and measure the two tone IMD and harmonic content. Look at the 1 dB compression point. Then if the amplifier needs a harmonic filter build one for the specific band of operation. Post the results and describe the project in the article section. Find out at what voltage the amplifier is most linear. Play with the bias to improve the amplifier IMD performance.
...
I look at this as a examination of human nature. If you have the talents to homebrew an amplifier then you probably have some basic understanding of amplifier design, operation and performance. These amateurs will usually be more capable of following best practices, in recognizing the different designs and limitations and in making the changes to get an amplifier working in a proper manner.

Conversely if you are buying a ready-made, off the shelf product you may have no real idea of what to test or how to test an amplifier. There are many amateurs who do not even own a voltmeter or wattmeter, much less a spectrum analyzer or how to measure IMD. They will probably never crack the case open on the amplifier and really just want a box that puts out power.

There is a big skills gap between an engineer-tech and an appliance operator. To be honest, maybe there should not be one rule that applies to everyone. We can either say that only triple-tested, CE and FCC stamped amplifiers (and radios) with >60 dB down should be certified and sold, with sealed chassis (no user serviceable parts inside) or we require that every amateur who buys a radio have at least an associates degree in electronics and a test bench full of gear.

That is the reality of the situation, very few amateurs who want a radio or an amp are going to have the skills or means to qualify that the device meets emission standards. That is why they ask questions here, to find out from "experts" if a device is appropriate.

I can go anywhere to hear a libertarian answer to "do what thou will" or parsing the letter of the law. Yes, sure, in theory that is all just great; you are indeed responsible for making sure that your station operates in accordance with rules & regs and best practices. How do we make that happen for all amateurs?
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Ms. Tisha Hayes, AA4HA
Lookout Mountain, Alabama
Free space loss (dB) = 32.4 + 20 × log10d + 20 × log10 f
G3RZP
Member

Posts: 7387




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« Reply #16 on: November 12, 2013, 02:31:58 PM »

Well said, Tisha.

But there are those amateurs who are quite willing to ignore regulatory requirements. Firstly, the chance of being caught causing 'undue interference' is not that high, secondly, the authorities are pretty lax on enforcement on the amateur bands and thirdly, many of these products are low cost enough to throw away if the necessity arises.

When you have an amplifier with no output low pass filtering, you must remember that with a trapped beam, the second harmonic of 20m gets radiated well: with a 40m dipole, the 3rd harmonic of 40 gets radiated well....

So if you don't have an FCC or CE approved (genuinely approved, not just sticker applied!) amp and you don't have the technical ability or equipment to evaluate such a non-approved amp, what's the best thing to do? PASS BY and leave well alone!
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K2OWK
Member

Posts: 1199




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« Reply #17 on: November 12, 2013, 02:37:30 PM »


can go anywhere to hear a libertarian answer to "do what thou will" or parsing the letter of the law. Yes, sure, in theory that is all just great; you are indeed responsible for making sure that your station operates in accordance with rules & regs and best practices. How do we make that happen for all amateurs?
 

 
                                                                                               
 
That's easy, The FCC needs to enforce its rules and regulations. Some big fines for non compliance will straighten things out quick.

73s

K2OWK
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G3RZP
Member

Posts: 7387




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« Reply #18 on: November 12, 2013, 02:54:19 PM »

Except that resources for enforcement in the FCC, as in probably every other administration, are cut to the bone and then deep into it. So it tends to be cases of interference to primarily safety services that comes first, then to commercial users and from illegal broadcasters. In most countries,  amateur interference gets (unless it's to a safety or commercial user) little response - once described as 'you guys are sucking on the hind teat'.

That's the problem of not paying for a licence. That is why here, they made the ham licence free - no pay, no claim. I think the majority of UK hams would have been more than happy with a $75 annual licence fee that provided 3 or 4 dedicated guys to cover the country to fix RFI complaints - to and from amateurs - and even better representation at CEPT and ITU. But it would have needed a change in the law so domestic stuff such as plasma TVs and LED lighting had not to cause interference, and that would never have been politically acceptable.

Especially with all the 'green' crap we have these days - cut energy consumption but pollute the radio spectrum so low energy consumption is achieved cheaply....
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VK3ADU
Member

Posts: 1




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« Reply #19 on: February 06, 2014, 08:09:04 PM »

The TC 300 amp from China is the same product as the KL300 amp from RM in Italy.
The Chinese company appears to be a Motorola accredited vendor and have a very well equipped Lab. See their web site  http://www.hysct.com/
They use a West coast US company to do their certification testing. 
The cost of a TC300 is about $80.00 plus postage.

You can also go to the RM web site for a manual of the KL300.


 
73s
VK3PD
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YO9IRF
Member

Posts: 40


WWW

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« Reply #20 on: February 06, 2014, 10:33:49 PM »

Please ignore the CB type ratings, they're pretty much fantasy. That is about 1/3 of a linear amplifier, that would be good for about 100W in the end. You still NEED:

- idle current circuitry;
- switched low pass filtering;
- SWR and thermal protection;
- a heatsink, or at least a fan over it's case;
- remote PTT.

On CB, the small mobile resonant antennas make take the role of the low pass filters and they mostly use FM, wich is why no idle current is necessary. The SSB switch just adds a delay to the carrier operated relay, but it still remains in class C. The power transistors are rated at 70W each (140W max for the pair), but you will need to drop that to about 90-100 to keep the IMD within decent limits, and you will also loose a few watts (mostly the odd harmonics energy) in the low pass filters. The case (wich acts as a heatsink) is VERY undersized, after 10 minutes of normal operation it will be HOT; if you add a fan it will take longer to get to those high temperatures, maybe 45-60 minutes.
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AF4RK
Member

Posts: 60




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« Reply #21 on: February 12, 2014, 10:07:44 AM »

There is a fellow who tested the HLA 150 and found that it is clean below 100 watts. 150 watts is advertising. I used mine with a Flex 1500 and worked fine. I even looked at the output on a scope. It's got SWR fault protection and band filtering. There are RM amps that are CB quality. This is not one of them.
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G3RZP
Member

Posts: 7387




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« Reply #22 on: February 12, 2014, 12:24:13 PM »

How do you define 'clean'? What numbers for 3rd, 5th, 7th and 9th order IMD and harmonics on all bands?
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KW5B
Member

Posts: 22




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« Reply #23 on: September 17, 2015, 09:57:17 PM »

I realize this is an old post and maybe no one will read this.

There is no such thing as a certification for any Ham Radio equipment.  If there were it would not be possible for a Ham to design and build their own equipment.  The individual ham is responsible for making sure their equipment meets accepted standards. 

Those Chinese amplifiers are NOT illegal for a Ham to use.  But the Ham must make sure that spurious emissions are below an acceptable limit.  Actually they are illegal for a CBer to use.   In the case of the Chinese amps filters of a design that has been proven to reduce the emissions to an acceptable limit on other equipment are usually sufficient.

Perfectly ok to buy one of those amps, but it should be treated like a homebuilt amp with the appropriate tests done. 

Furthermore even with equipment properly designed and built for Ham Radio use, the individual Ham is the one responsible to make sure their equipment meets acceptable specs.  Even if a Ham is using a Henry amp, that Ham is still the one responsible for proper use and acceptable emissions, not Henry.

This business about Amateur Radio Certified equipment is BS.  So called type acceptance is a guide only for Hams.  Type acceptance is only the law for commercial or CB.  That's why Hams take a theory test. 
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JS6TMW
Member

Posts: 854




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« Reply #24 on: September 18, 2015, 07:23:56 AM »

Good common sense here about so-called type acceptance. They are actually stricter in Japan than in the USA (but if your gear doesn't have a TC here you can just pay about $35 and the problem goes away.)

The KL300/TC300 is a compact building block for a linear amplifier that would be hard to replicate for the money. It is a standard "Motorola" pushpull power amp design. No way you can duplicate the PCB, input and output transformers, controls, power transistors, keying circuitry, and case for under $100. All the stuff that has to be added has been correctly identified. With the added goodies it is possible to get a reasonably clean (uh-oh, there you go again, to quote the second worst President in history) 150-200 watts PEP and you would still be way under $200 cost.

(full disclosure - I had a bum output transistor in mine but this was a bit of bad luck that can happen with any product.)

Steve JS6TRW
« Last Edit: September 18, 2015, 07:27:55 AM by EXW6BMZ » Logged
KM1H
Member

Posts: 1277




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« Reply #25 on: September 20, 2015, 06:15:13 PM »

It would make a nice IPA for a real amp with a tuned input, think Henry 8K, pair or more of 8877's, YC-156, 3CX6000, etc.
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G3RZP
Member

Posts: 7387




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« Reply #26 on: September 25, 2015, 04:41:46 AM »

KW5B

Quote
There is no such thing as a certification for any Ham Radio equipment.

Not quite true in a global context. In Europe, there are requirements under the Radio Equipment Directive (which supersedes the Radio and Telecommunications Terminals Directive), but home brew, modified and pre-used amateur radio gear that pre-dates the introduction of the Directives is exempted. Commercially available amateur radio equipment needs certification, but this may be done by the manufacturer/distributor if a suitable QC system is in place and the technical file is complete.

Additionally, there are requirements under the international Radio Regulations on unwanted emissions from ALL amateur stations after 1/1/12, which have in practice been ignored by the authorities - just as well, in many cases.
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SM0AOM
Member

Posts: 135




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« Reply #27 on: September 25, 2015, 11:00:12 AM »

As radio amateurs, we are expected to have sufficient competence to "self-certify" our transmitters.
The EU directives contain specific exemptions based on this perceived competence.

We have never been able to justify "lousy signals" on the grounds that we "only are amateurs";
the Radio Regulations put exactly the same burden of responsibility on our shoulders as on other transmitter users.
In the 1947 Regulations this was put in these terms:

"§ 5. (1) All the general rules of the Convention and of the present Regulations shall apply to amateur stations. In particular, the transmitting frequency must be as constant and as free from harmonics as the state of technical development for stations of this nature permits"

Without this competence, we only become CB:ers in the eyes of the regulators. 

73/
Karl-Arne
SM0AOM
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KA4WJA
Member

Posts: 877




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« Reply #28 on: September 26, 2015, 11:40:34 AM »

Larry,
I'm confused here?
You resurrected an almost 2 year old thread to post some wrong / inaccurate information??

In addition to reading the very first reply to this thread, by AF6WL, on Nov 9, 2013....you may wish to read the FCC rules and regs (both Part 97 and part 15), and you'll see that there actually is such a thing as FCC type certification for amateur radio service, for RF power amplifiers...  
There is no such thing as a certification for any Ham Radio equipment.  If there were it would not be possible for a Ham to design and build their own equipment.  The individual ham is responsible for making sure their equipment meets accepted standards.
Regarding transmit IMD / spectral purity, there is no transmit IMD spec / regulation....as it is the ham operator themselves who is responsible for keeping their signal within their authorized band / band segment, maintaining a clean signal, and not causing interference to others...  
But, there is a Part 97 FCC certification for external RF power amplifiers!!





Here, you (and others who have posted here earlier), are correct that these "Chinese" amps (as well as Italian-made, etc. amps), are not illegal for a ham to use (under US FCC Regs). assuming the operator maintains the spurious/out-of-band / harmonic radiation is within the FCC spec...AND, the operator follows the other rules regarding not causing interference to other stations (as well as using the minimum power needed for maintaining communications, using good amateur practice, etc.)
Those Chinese amplifiers are NOT illegal for a Ham to use.  But the Ham must make sure that spurious emissions are below an acceptable limit.
And, THIS is the gist of the discussion here....since most hams these days do not have the equipment, nor expertise, to test / evaluate / modify / adjust their transmitters/amps to maintain good IMD performance / spectral purity (and sadly many actually have no idea what these numbers/specs mean)....
Others have pointed out the difficulty for most in making these amps work with good transmit IMD...



And, much of this was elegantly written about by Tisha, AA4HA, just 3 days into this discussion....almost two years ago...
I look at this as a examination of human nature. If you have the talents to homebrew an amplifier then you probably have some basic understanding of amplifier design, operation and performance. These amateurs will usually be more capable of following best practices, in recognizing the different designs and limitations and in making the changes to get an amplifier working in a proper manner.

Conversely if you are buying a ready-made, off the shelf product you may have no real idea of what to test or how to test an amplifier. There are many amateurs who do not even own a voltmeter or wattmeter, much less a spectrum analyzer or how to measure IMD. They will probably never crack the case open on the amplifier and really just want a box that puts out power.

There is a big skills gap between an engineer-tech and an appliance operator. To be honest, maybe there should not be one rule that applies to everyone. We can either say that only triple-tested, CE and FCC stamped amplifiers (and radios) with >60 dB down should be certified and sold, with sealed chassis (no user serviceable parts inside) or we require that every amateur who buys a radio have at least an associates degree in electronics and a test bench full of gear.

That is the reality of the situation, very few amateurs who want a radio or an amp are going to have the skills or means to qualify that the device meets emission standards. That is why they ask questions here, to find out from "experts" if a device is appropriate.

...., sure, in theory that is all just great; you are indeed responsible for making sure that your station operates in accordance with rules & regs and best practices. How do we make that happen for all amateurs?

Now, to answer Tisha's question of "How do we make that happen for all amateurs?"....I've had a few ideas....and have been mentioning them for years...

a)  Seriously increase the technical standards / theory of amateur radio exams....and make a passing grade 90%!!

b)  Meld some of our international / foreign nation amateur radio rules and regs, with our own "incentive licensing" from the late 1960's....  
Having lower class licensees limited to lower power outputs, and only allowing those that can actually show the technical knowledge / proficiency, by passing the stringent exams for the highest grade licenses to actually operate at higher power!

c)  Encourage the ARRL to mention transmit IMD / spectral purity more than in passing....and actually issue a "failing" grade to rigs / amps that don't measure up...

d)  Encourage our equipment manufacturers to actually design / manufacture rigs and amps that meet much more stringent standards...and boycott those that don't comply!

e)  Encourage the ARRL to get behind the campaign to institute all 4 of the above ideas...


{Some here also believe that petitioning the FCC to actually institute transmit IMD / spectral purity standards for the amateur radio service, is a good idea...and while in utopia, some think this might work....but, in the real world, it's a pipe dream!  
We'd still have all the existing gear which would be "grandfathered-in", as well as all the home-brewed gear, etc....
So, in my opinion, the 4 or 5 ideas, above, that I've been promoting for years, would give us a better chance of improving things!}



And, lest we forget...
Mike, K6AER, is pretty close with his point about the mic gain control and overdriven amps, being the biggest cause of splatter on-the-air these days....
But, promoting the use of poor IMD rigs and amps, doesn't help either!!




Finally, you may find these to be useful / helpful...

RE: What HF Amp Has The Best Intermod Figures ?
http://www.eham.net/ehamforum/smf/index.php/topic,104518.msg866891.html#msg866891


Over-Driving Amps, increases IMD / splatter, looking at device specs/data sheets
http://www.eham.net/ehamforum/smf/index.php/topic,101398.msg821031.html#msg821031


Tube vs. SS / Amplifier IMD Tests / Tirode vs. Tetrode vs. Solid-State
http://www.eham.net/ehamforum/smf/index.php/topic,100600.0.html


Ham Xcvrs' and Amps', Transmit Spectral Purity, IMD Products, vs. comm/maritime
http://www.eham.net/ehamforum/smf/index.php/topic,97093.0.html


And, another post from this...RE: What HF Amp Has The Best Intermod Figures ?
http://www.eham.net/ehamforum/smf/index.php/topic,104518.msg866058.html#msg866058


And, regarding the Italian amp...read this test report, and LOOK at the spectral scans!!!
http://www.w8ji.com/rm_hla-150_test.htm
Here's just a short quote...
Quote
The HLA-150 is a 90-watt PEP amplifier at best, and if operated that way will be acceptable for many uses. It is not as good as it could be for the very wide bandwidth distortion at higher power, but it is comparable to worse-case IMD for a common radio like the FT1000MP when it is at 90-watts PEP output.

And, when you combine these poor IMD amps with the IMD specs of the Flex-1500 (–22/–38/–48/–48 dB)....we can end up with a mess on-the-air!!!




I hope this helps!

73,
John,  KA4WJA
« Last Edit: September 26, 2015, 11:52:42 AM by KA4WJA » Logged
VK6YAE
Member

Posts: 7




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« Reply #29 on: September 29, 2015, 02:40:26 AM »

I have this amplifier. It is terrible. Max output is 160w PEP but it is not very linear and gets very hot. It is not well biased if biased at all. Distorts even at low drive levels.
Not as good as the similar RM product.
Not worth the money sorry to say.
There is always a good reason why things are cheap.
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