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Author Topic: A Chinese Amp  (Read 32414 times)
NK2F
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Posts: 35




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« Reply #75 on: January 24, 2013, 10:34:29 AM »

You have to credit them on a nice quality build even though it is a clone. MFJ would not manufacture something this nice.

While the original Chinese amp, two years ago, was indeed a clone, not much is known about the improvements that have resulted in the current design.  According to one of the designers, they have sold over 200 amps and have identified several design flaws (in OM Power, that is) that have been corrected since then. This amp is not an example of blindly copying an existing product.

In general, having a healthy competition in the ham amp space is good for us hams as it pushes innovation and drives prices down. To that end, you may also want to take a look at Alpin, a Bulgarian company, that makes a well priced GU74-based HF and HF+6m amps:

http://www.alpinamplifier.com/

The amp has been reviewed by the German and UK ham publications, receiving very high marks.
« Last Edit: January 24, 2013, 11:27:17 AM by NK2F » Logged
KO4NX
Member

Posts: 179




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« Reply #76 on: January 24, 2013, 03:34:10 PM »

You have to credit them on a nice quality build even though it is a clone. MFJ would not manufacture something this nice.

This is true, even if they did, I would not want to pay what they would ask for it!

Rich
« Last Edit: January 24, 2013, 03:44:27 PM by KO4NX » Logged
W9KDX
Member

Posts: 778




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« Reply #77 on: January 25, 2013, 02:57:24 PM »



In general, having a healthy competition in the ham amp space is good for us hams as it pushes innovation and drives prices down. To that end, you may also want to take a look at Alpin, a Bulgarian company, that makes a well priced GU74-based HF and HF+6m amps:

http://www.alpinamplifier.com/

The amp has been reviewed by the German and UK ham publications, receiving very high marks.

I would love to see some competition in amps over on this side of the pond.  The gap between Ameritron and anything else is just to wide.  Some quality mid-priced alternatives might wake the quality control people at MFJ up a bit.  I no longer care where products are made; if MFJ stands for what "Made in America" means these days.....
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Sam
W9KDX
K0IZ
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Posts: 809




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« Reply #78 on: January 25, 2013, 03:19:11 PM »

Many more hams coming along in China, so their domestic market will grow a bunch.  The craftsmanship on this amp looks really good, would cost quite a bit here in the US.  Due to distance and questions of support, however, not sure how much market in US.  Would take one of the US major distributors to make it go here.

I don't own any MFJ amps, never have, but I think they do a good job of building to a specific price target.  That's why their amps are popular, and good value.
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KO4NX
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Posts: 179




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« Reply #79 on: January 25, 2013, 03:26:42 PM »

Many more hams coming along in China, so their domestic market will grow a bunch.  The craftsmanship on this amp looks really good, would cost quite a bit here in the US.  Due to distance and questions of support, however, not sure how much market in US.  Would take one of the US major distributors to make it go here.

I don't own any MFJ amps, never have, but I think they do a good job of building to a specific price target.  That's why their amps are popular, and good value.

I think the reason MFJ/Ameritron was brought up here is the fact the amplifier in question provides way more features, and by all appearances better workmanship for just a little more than you would pay for the top of the line Ameritron.

When they finish the TFT version with the new LOGO that does not look like OM Power, I think I am going to take a gamble on one of these. It's become more of a matter of curiosity than anything!


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NK2F
Member

Posts: 35




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« Reply #80 on: January 25, 2013, 04:34:59 PM »

Many more hams coming along in China, so their domestic market will grow a bunch.  The craftsmanship on this amp looks really good, would cost quite a bit here in the US.

I don't own any MFJ amps, never have, but I think they do a good job of building to a specific price target.  That's why their amps are popular, and good value.

The Chinese amp sells for $2,000 for the manual and $3,000 for the automatic, plus shipping. Note that these prices are for the previous model, the OM Power clone, and not for the prototype shown on the site. The RF deck and power supply, however, are identical. This is a steal!
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BG1FPX
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Posts: 7




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« Reply #81 on: April 09, 2013, 10:42:01 PM »

From March, Guan (BG7JAA) uses a new interface to avoid possible patent/copyright dispute.

http://amp.co.nf/8.jpg
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K6AER
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Posts: 3649




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« Reply #82 on: April 10, 2013, 05:22:06 PM »

What are the design flaws with the OM Power amplifiers?
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K6UJ
Member

Posts: 595




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« Reply #83 on: April 05, 2015, 09:19:49 PM »

Is it coincidence that
Chinese amps are  priced virtually identical to the OMPOWER pricing. They making a absolute killing. Last time I looked the Emtron Amplifiers from Australia were selling for a cheaper price than these Chinese Amps.



Where are you getting your pricing from?  The advertised price for these amplifiers is far less than OM Power, and Alpha.  At the current exchange rate it appears as though the subject amplifier is $3700.00 USD for the Automatic, and $2580.00 for the manual version. I have not looked at EMTRON pricing, thus I cannot comment if EMTRON is in fact less expensive or on par with the above mentioned prices.

73

Rich

Another ZENKI discrepancy is his statement that 2KW solid state amps will the norm in 2 years.  They have been saying that for years.  ZENKI generates a prolific amount of unreliable information and hides  behind his "ZENKI" alias so we won't discover who he is.  He probably is disguising the fact that he is not a ham.  Roll Eyes

Bob
K6UJ

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W1QJ
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Posts: 1813




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« Reply #84 on: April 05, 2015, 10:05:39 PM »

http://s118.photobucket.com/user/gudguyham/media/IMG_20150330_170228_396_zpskgeicqmq.jpg.html?sort=3&o=0

Hey guys, have a look at this photo of the burned contacts and let me know if you think RF did that in a couple of minutes with no warning to the op or if B+ was on the switch and cooking away while the amp was just turned on.
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KH6DC
Member

Posts: 755




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« Reply #85 on: April 05, 2015, 10:25:04 PM »

I'll stick with the known brands like SPE Expert, Alpha, OM Power, ACOM, Emtron, Elecraft and even Ameritron.  Cheesy
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73 and Aloha,
de Delwyn, KH6DC
KK5DR
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Posts: 395


WWW

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« Reply #86 on: April 06, 2015, 03:22:11 AM »

It's amazing what dirt cheap labor will get you.
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N3QE
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Posts: 3025




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« Reply #87 on: April 06, 2015, 03:53:10 AM »

http://s118.photobucket.com/user/gudguyham/media/IMG_20150330_170228_396_zpskgeicqmq.jpg.html?sort=3&o=0

Hey guys, have a look at this photo of the burned contacts and let me know if you think RF did that in a couple of minutes with no warning to the op or if B+ was on the switch and cooking away while the amp was just turned on.

Is that the 10M contact that burned away? That's almost always the one I find bad in amps.

I've seen American and EU-made amps, where the amp had apparently made thousands of QSO's on 10M yet the band switch didn't actually close the contact (and the amp still apparently worked fine on 10M). Surprised. There was certainly a lot of arcing going on from black marks around that area, but at 3K plate impedance, it's nothing to bridge a 1mm gap. There was indeed a glow from the bandswitch while operating but no obvious sounds or smell.
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W1QJ
Member

Posts: 1813




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« Reply #88 on: April 06, 2015, 04:21:43 AM »

http://s118.photobucket.com/user/gudguyham/media/IMG_20150330_170228_396_zpskgeicqmq.jpg.html?sort=3&o=0

Hey guys, have a look at this photo of the burned contacts and let me know if you think RF did that in a couple of minutes with no warning to the op or if B+ was on the switch and cooking away while the amp was just turned on.

Is that the 10M contact that burned away? That's almost always the one I find bad in amps.

I've seen American and EU-made amps, where the amp had apparently made thousands of QSO's on 10M yet the band switch didn't actually close the contact (and the amp still apparently worked fine on 10M). Surprised. There was certainly a lot of arcing going on from black marks around that area, but at 3K plate impedance, it's nothing to bridge a 1mm gap. There was indeed a glow from the bandswitch while operating but no obvious sounds or smell.

QE, no, in fact it is the 160 meter position.  In that position the padding caps are switched in.  Do you see how the whole contact is burned away right level with the ceramic?  This damage could not have been caused by RF in a matter of minutes of transmitting.  I stick by my gut and say it is B+ on the band switch.  If anyone is curious about this, look up the schematic for the OM-2500 and study it VERY VERY carefully and you will see some rather unconventional circuitry with the plate choke and blocking system.  The plate choke is actually center tapped.  Well seeing is believing. Check it out.  If you can't find the schematic I will try to upload the PDF I have which has it, but if you google images of OM-2500 you will see all the schematics and manual pages come up in an image search.  Amplifier geeks will love to look at the circuit involved here.  Perhaps a better choice might have been to use the Ameritrion type plate choke.  But maybe at 3KW it would not hold up?
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W1QJ
Member

Posts: 1813




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« Reply #89 on: April 06, 2015, 04:28:15 AM »

One more thing, while you are googling images of the OM-2500 tank circuit, then go ahead and look at images of the Alpha 8410 tank circuit and then see if you can find images of the Chinese HF-2013.  HUH?  Who is copying who? You tell me.
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