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Author Topic: RM Italy Amplifiers  (Read 91217 times)
AD6KA
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Posts: 2243




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« Reply #15 on: November 10, 2011, 12:15:50 PM »

Quote
North America has one of the lowest passport holders per head of population in the western world, this reflects some comments made here, very inward looking.

Perhaps, it's a good point, and I can see why you might think that.

I think the bigger factor is the economy, and folks
travelling overseas less.

Besides, there's so many great travel destinations within the U.S.A. .
Here in Southern California in the Winter I can go downhill
skiing, ride my motorcycle in the desert, and go surfing,
all in one day.

Next time you're in California look me up Rex.
I'll give you a tour and show you why we don't
have to spend thousands to travel overseas
to see anything new or have a wonderful vacation.

73 & God Bless, Ken  AD6KA
« Last Edit: November 10, 2011, 12:17:41 PM by AD6KA » Logged
W8JX
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Posts: 13268




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« Reply #16 on: November 10, 2011, 01:18:55 PM »


I think the bigger factor is the economy, and folks
travelling overseas less.



Well also if you live overseas you need a passport to go anywhere far as many countries over there are small or size of some states here. I talked to guy in nothern Maine other day on 17 how lived right on border with Canada. He told me how it is still easy to go to Canada but a hassle to come back even though day guy at border is his neighbor and KNOWS he is a citizen his hand are tied with bureaucracy.
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--------------------------------------
Ham since 1969....  Old School 20wpm REAL Extra Class..
WY3X
Member

Posts: 768




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« Reply #17 on: November 10, 2011, 04:36:00 PM »

Quote
North America has one of the lowest passport holders per head of population in the western world, this reflects some comments made here, very inward looking.

I'll give you a tour and show you why we don't
have to spend thousands to travel overseas
to see anything new or have a wonderful vacation.
73 & God Bless, Ken  AD6KA

This is precisely his point- which I am well aware of, having been a world traveler myself. I've visited ten foreign countries, each one with very unique things to see NOT available in the U.S. Of course you can find something to do and/or see in the U.S., that's not the point. The point is that other countries have things that the U.S. doesn't have, and unless you visit them, you live a very sheltered life.

I was thrilled with the cleanliness and views in Germany.

I thoroughly enjoyed the quaintness of France.

I got stuck in an airport for 8 hours in England, and had a blast listening to Londoners speak. (I hope to go there for a visit.)

The Canadian view of Niagara Falls beats the U.S. view hands down.

The people of Thailand earn their title "the land of 1000 smiles" with friendliness beyond anything you'd ever expect.
And I had a blast at the open air market in Bangkok! There are some ex-pats living in northern Thailand that I had
the opportunity to speak with while operating from the HS0AC club station. I fell in love with the beauty of Chiang Mai
and wanted to move there!

Vietnam feels like the U.S. did in the 1950's. I imagine Cuba isn't much different. I loved it! Yeah, the communist
propaganda exists, but you don't have to pay it much attention. I'm about as far right-wing anti-communist as
you can get. I found it curiously interesting. We took a tour of Buddhist temples that was worth every penny!

Cambodia was so poor in some areas, it made me appreciate being home in the U.S., but
the views of Angkor Wat were spectacular, and Siam Reap was very special. And our guide
was hilarious! I highly suggest seeing the "city in the lake".

South Korea is a little slice of heaven, and no Korean food in the U.S. can match it! The
architecture of the ancient areas is spectacular!

Italy was a lot of fun too, but a tad more expensive than I prepared for. The one thing that
hit me in the gut was having to pay to sit down at almost all restaurant tables. You can stand
up and eat for no charge, but if you sit in a chair, you've likely just spent 5 euros! And Italian
food is better here in the U.S. except for a chain of small restaurants called "Gnam" (I think that
was the name) that serve sausage sandwiches. YUMMY!

Out of all the countries I've visited, I'd love to go back to each and every one of them! I only
wish they weren't so far away. And I also wish some of the vaccinations and pills you have to
take weren't so expensive! Oh well- I've had about all the vaccinations anyone could get at this
point.

I've visited about 35 of the 50 states, and I do agree with you, there's always something to see or
do, but not the things you would see or do in a foreign country. Every country I've visited holds a
special place in my heart. You should try visiting a foreign country sometime! I hope some day to
get invited to participate in a major DXpedition.

73, -Web (WY3X)
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AD6KA
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Posts: 2243




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« Reply #18 on: November 10, 2011, 08:22:32 PM »

W3YX:
Quote
You should try visiting a foreign country sometime!
I'm not as well travelled as you, Web, but yes, I
have been off the continent several times.
To both modern and poor, and poverty stricken countries.
There's beauty in both, both in the the landscape and people.

GL & 73, Ken  AD6KA , 5R8GQ
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KA5ROW
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Posts: 579


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« Reply #19 on: November 10, 2011, 08:38:00 PM »

Would it not be better for RM Italy to make and meet FCC requirements and be approved? Then they could legally enter the amateur market. 
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AD6KA
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Posts: 2243




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« Reply #20 on: November 10, 2011, 09:42:27 PM »

Would it not be better for RM Italy to make and meet FCC requirements and be approved? Then they could legally enter the amateur market. 

One would think so.
Maybe they are "inward thinkers".  Roll Eyes

Ooops! We have to say:
"Legally enter the U.S. amateur market".
No inward thinking allowed on this thread!  Grin
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G3RZP
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Posts: 1225




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« Reply #21 on: November 11, 2011, 12:15:10 AM »

They may have a big enough market without the US, and the costs of an approval. If you have a smallish operation that is busy, you may well need a significant increase in sales to justify the extra costs involved in expansion. In Europe, they can self certify.
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W1BR
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Posts: 4179




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« Reply #22 on: November 11, 2011, 06:59:59 AM »

They'd have to do a redesign to get FCC certification. Just being RF keyed (easy change) makes them
illegal in the USA. I'm sure there is a lot more.

Pete
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K6AER
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Posts: 5693




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« Reply #23 on: November 11, 2011, 01:41:33 PM »

The last three leagle limit amplifiers I did the FCC certification on, here in the US, ran an average of 22-29 thousand dollars and took up to three months on the harder ones units. I some cases metal work had to be changes and shilding added. This was not much of a problem when the manafacturing was only 50 miles away from the test facility but it would be a pain in the ass for RM Italy.

In addition, the amplifier that performs above 21.45 MHz now require case harmonics to be the same as conducted harmonics. This makes no since for you are connecting the amplifier to an antenna on your roof. This is what happens at the FCC when lawyers are in charge instead of engineers.
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ZENKI
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Posts: 1621




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« Reply #24 on: November 12, 2011, 03:57:56 PM »

We really require the FCC now to incorporate the same Type Acceptance rules as those for marine HF radios. Part 80 for marine HF marine SSB radios require all the radios to pass a IMD mask test. Such a test if applied to the amateur service would really be  the beginning of cleaning up our own act and remove the rubbish like RM Italy products from the ham bands. where they dont belong.

This test should be applied to all  transceivers and amplifiers. The standard should be set to the old FCC marine Part 80 rules, which were rules developed by real engineers who understood HF and amplifiers. If these IMD rules were adopted junk equipment that causes a lot of splatter would not make  its way onto the market. Of course the idiot hams from the CB service will continue to use their favorite CB toys causing a lot of interference.

What was so good about the old FCC Part 80 mask was that it specified minimums for both the 3rd order as well as the  higher order products.  These higher order products are the ones that  cause the typical CB like splatter interference that we hear both on the ham bands  and on the CB bands.

The OLD  FCC Part 80 rules set the  3rd order IMD level at -36 below PEP, 5th order at about -42 db below pep and the most important part of that old rule said that all higher order products greater than the 11th order should be suppressed by greater than 75 db below one of two tones.  If you applied these rules to RM Italy amplifiers you would instantly understand why these products cause so much splatter and interference, this is even before we talk about spurious  and harmonic products.

While QST makes no comments about poor IMD from radios like the Ten Tec Eagle and Flex 1500 who amongst many ham radios have very poor TX IMD suppression nothing is going to be done about this issue. It really requires the FCC to  act and introduce mandated IMD standards for the ham service. There is absolutely no need for the poor IMD standards that we see coming from ham manufacturers. Considering the pricing point of ham equipment has long passed the price of commercial HF SSB equipment why are we paying such a high price for equipment with such low IMD standards? This comments applies to radios from cheapest radio right upto to the 10.000 dollar radios. I would not  be please buying a FTDX9000 and Icom 7800 whose TX IMD is not much better than the cheapest CB radio, when are we going to be technical hams and wake up to this nonsense from manufacturers?

There is no legitimate place on the ham bands for these cheap 12 volt CB amplifiers from Italy on the ham bands. Every ham that I hear using once typically splatters 20khz to a level that causes interference. Why would any sensible ham want to use this garbage on the air? Its really easy identifying stations  using these rubbish CB amps on the air. Their splatter has such a unique signature that even the worst IMD performing ham radios dont sound as bad. Now considering how bad these poor ham radios are in TX IMd performance,the CB amps are plain horrible in performance. The raspy  fast buck shot that these amps  typically send up the band is a recipe for disaster for hams bands like 10 meters which has such superb low noise floor. Why anyone wants to crap in their own ham nest with these garbage amps is beyond understanding, its plain moronic.




The last three leagle limit amplifiers I did the FCC certification on, here in the US, ran an average of 22-29 thousand dollars and took up to three months on the harder ones units. I some cases metal work had to be changes and shilding added. This was not much of a problem when the manafacturing was only 50 miles away from the test facility but it would be a pain in the ass for RM Italy.

In addition, the amplifier that performs above 21.45 MHz now require case harmonics to be the same as conducted harmonics. This makes no since for you are connecting the amplifier to an antenna on your roof. This is what happens at the FCC when lawyers are in charge instead of engineers.
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WB2WIK
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Posts: 21836




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« Reply #25 on: November 12, 2011, 06:17:06 PM »

Except ZENKI isn't a callsign so I have no idea why you'd be here commenting on anything. Cheesy
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G3RZP
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Posts: 1225




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« Reply #26 on: November 13, 2011, 04:44:27 AM »

FCC rules do actually mandate the level of higher order products to be no greater than -43dB rel PEP, although to meet international requirements for Unwanted Emissions in the Spurious Domain, it should be -43 + 10 log P, not exceeding -50dB. That's for HF: for bands above 30MHz, the requirements are -43 +10logP not exceeding -70dB. (ITU-R Rec. SM.329-11). The Unwanted Emissions in the Out of Band domain aren't limited, although for a 3 KHz wide SSB signal, the -43 +10 log P applies at +/- 7.5kHz from the centre frequency of the emission. So between 1.5 and 7.5 kHz from the centre frequency, intermodulation and spurious components need to fall from -20dB rel PEP to -43dB rel PEP in the US and -43 + 10 log P elsewhere. Only Part 97 doesn't spell this out explicitly, but it's what the Radio Regulations effectively require.

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M0HCN
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Posts: 566




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« Reply #27 on: November 13, 2011, 05:01:41 AM »

But even -43 ref PEP is only -37 ref one tone (The way everyone except amateur manufacturers measures it), and that is not great even for third order products that fall in channel, never mind the wider stuff.

Collins managed better then that with a bottle based radio years ago, so it should be a walk in the park with modern parts, instead some modern radios have positively embarrassing transmit IMD performance numbers (-19dB ref one tone (-25 ref PEP) from one major US manufacturer for example).

I don't know who ZENKI is, but in this matter he has a point.

Regards, Dan.
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G3RZP
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« Reply #28 on: November 13, 2011, 05:30:56 AM »

>The way everyone except amateur manufacturers measures it<

ITU, CEPT and ETSI all specify relative to PEP. So did the old MPT and TSC maritime specifications of the UK, as well as the manufacturers such as Racal, STC and marconi. See the IEE 1963 HF Conference Proceedings.

-36dB rel PEP was the limit for ISB transmitters, usually using 2 SSB voice channels in one 6 kHz or so sideband and the other 6 kHz sideband filled with MCVFT (Multi Channel Voice Frequency Telegraph)
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M0HCN
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« Reply #29 on: November 13, 2011, 05:48:28 AM »

All the broadcast transmitters I have seen have specified ref one tone, but I will admit to generalizing from that specific use case, apparently in error.

I retract the comment about everyone else specifying ref one tone.

The interesting thought is that with the advent of narrow band digital modes being transmitted using SSB rigs with audio injection (PSK31 and friends), this whole issue becomes more important as the 'nominal' bandwidth of the signal drops to much less then the audio bandwidth of the transmitter.
Once you are using the audio IO as in effect the final IF, then the distortion in the audio chain becomes a potential source of close in spurs, particularly as the filters in the first radio frequency IF will be so much wider then the actual required bandwidth.

For something like PSK31, do you view the channel bandwidth as being ~50Hz, or 2.4Khz?

Regards, Dan.
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