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Author Topic: RM Italy FCC Approved  (Read 24463 times)
KC4MOP
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Posts: 960




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« on: March 17, 2016, 06:12:35 AM »

RM Italy Model HLA-305V is approved by the FCC for Ham Radio use. 160-10M

For yous guys that buy flea power QRP rigs and now you want to boost power.

5- 10 Watts drive and 200-250W out.

$700

This month's QST pg 51.

Sorry for double posting...eHam will not allow me to delete.
« Last Edit: March 17, 2016, 08:38:36 AM by KC4MOP » Logged
W1BR
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Posts: 4179




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« Reply #1 on: March 17, 2016, 09:49:49 AM »

As an earlier poster noted:

The ARRl review shows the 14 MHz, 200 watt 3rd order IMD to be -40 dBc in the low power mode. In the high power mode running 250 watts the 3rd order IMD is -29 dBc. 


Low power looks decent, but the 250 watt IMD is pretty terrible... and I'd be the higher odd orders are not that great. What were the ARRL figures for 5th, 7th, etc. products?

Pete
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KD0REQ
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« Reply #2 on: March 17, 2016, 10:23:41 AM »

they did not print the chart, pretty much a text-only review
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K6AER
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« Reply #3 on: March 17, 2016, 03:16:25 PM »

I wander what the IMD on the SB-200 is?
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KK5DR
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« Reply #4 on: March 17, 2016, 04:03:44 PM »

I wander what the IMD on the SB-200 is?

The IMD of most well designed tube type class AB2 amplifier will be much better than the broad banded solid state amps using 12vdc.
An SS amp running devices at 50 or 100vdc can meet or surpass the tube amp as for low IMD.
The regulation of the DC psu running the SS amp must be better than 0.5%, or fluctuations in that supply voltage will contribute to the IMD, and incidental FM induced by wide voltage swings of the DC source. 
Voltage fluctuations in an HV DC supply in a tube type amp, is of concern as well. Regulation better than 10% is acceptable. Regulated of the HV supply that fall below 25% is unacceptable, and will cause a dramatic increase in output IMD.
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G3RZP
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« Reply #5 on: March 18, 2016, 03:31:50 AM »

haven't got figures on the SB200: the SB221 - which was an SB220 without 10 metres - at 1100 watts had 3rd order at -29dB rel tone (-35 dB rel PEP) 5th order at -44dB rel tone (-50dB rel PEP) and 7th order at -55dB rel tone (-61dB re PEP)

So about 6 to 10 dB better, which seems typical of tube amplifiers.
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K6AER
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« Reply #6 on: March 18, 2016, 11:03:08 AM »

I wander what the IMD on the SB-200 is?

The IMD of most well designed tube type class AB2 amplifier will be much better than the broad banded solid state amps using 12vdc.
An SS amp running devices at 50 or 100vdc can meet or surpass the tube amp as for low IMD.
The regulation of the DC psu running the SS amp must be better than 0.5%, or fluctuations in that supply voltage will contribute to the IMD, and incidental FM induced by wide voltage swings of the DC source. 
Voltage fluctuations in an HV DC supply in a tube type amp, is of concern as well. Regulation better than 10% is acceptable. Regulated of the HV supply that fall below 25% is unacceptable, and will cause a dramatic increase in output IMD.

I understand all of that but the question is...what is the measured IMD of a SB-200?
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G3RZP
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« Reply #7 on: March 18, 2016, 02:43:47 PM »

See if you can find a review. It maybe that there is an RSGB review of a 2 times 572B amplifier: QST doesn't list one. My suspicion is that a 2 times 572B won't be much different to the SB221. If you can't find a review, the you need to measure one.
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W1BR
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« Reply #8 on: March 18, 2016, 09:23:26 PM »

I'd also suspect that those solid state amps have horrid odd order products that go one forever.  They probably do far more damage than their 3rd order IMD.
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KW6LA
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Posts: 128




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« Reply #9 on: March 19, 2016, 01:10:41 AM »

< RM Italy Model HLA-305V is approved by the FCC for Ham Radio use. 160-10M >   Wow.. is it that hard to get over it… now approved for hams to use on the air.

G3RZP --    Mike, K6AER      Know this amp 200 only too well and trying to make a point.  It’s been on the air for decades and no one gets worked up about IMD’s
It may sound like a echo in the room, but any amp over driven / miss-tuned will have some bad products. It is up to you Mr. Ham /me to make sure THAT does not
happen. Yes it is a cheap amp that will pinch out about 200 watts. Perfect for the QRP guys that want to kick it up a notch.
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W1BR
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« Reply #10 on: March 20, 2016, 09:25:42 AM »

An amp that is sold as 200 watt amp should produce acceptable odd order IMD products at 200 watts... 3rd order is important, but   higher order IMF products are much more important. That is where most cheap amps fail apart spec wise. Even many ham rigs have poor higher order responses.

So what if the FCC approved it?  Does that mean one can trash a band, and feel smug because the FCC has issued a type acceptance?

Pete
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ND6M
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« Reply #11 on: March 20, 2016, 09:49:18 AM »

Gee, the only FCC info I can find on the FCC website is an FCC I.D. number (2ACTRHLA305V), which is NOT an FCC CERTIFICATION number.


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G3RZP
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Posts: 1225




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« Reply #12 on: March 20, 2016, 10:40:37 AM »

Quote
Even many ham rigs have poor higher order responses.

I think that should read:

"Even many most ham rigs have very poor higher order responses."

But Pete is perhaps trying not to be too controversial!

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KD8MJR
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Posts: 5536




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« Reply #13 on: March 20, 2016, 11:22:12 AM »

Even if I put aside the IMD issues, the problem with RM Italy amps are that they blow out the finals too easily.   The protection circuitry is not good at all.


73s
Rob
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“A lie can travel half way around the world while the truth is putting on its shoes.”  (Mark Twain)
N4ATS
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Posts: 1297




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« Reply #14 on: March 20, 2016, 05:40:10 PM »

Oh for crying out loud people..

It is a good bang for the buck , and if you do not know how to use one , you should not be in the market for one.

Good Lord
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