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Reviews For: 572B Tubes- China Manu.

Category: Electron Tubes

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Review Summary For : 572B Tubes- China Manu.
Reviews: 27MSRP: $35
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# last 180 days Avg. Rating last 180 days Total reviews Avg. overall rating
00273.4
VK3BL Rating: 2016-09-23
OEM Tubes, may arc Time Owned: 0 to 3 months.
I recently managed to get a brand new set of 4 572B Shu Guang tubes off ebay for $280 usd delivered, straight from China. The tubes took about a month to arrive, and were well packed with lots of bubble wrap.

Inspecting the tubes, they are the new design as advertised - a slightly different glass envelope to the old shu guangs, and a different (more cetron looking) plate. Basically, there is no gap showing the support rods anymore. The plates themselves are also noticeably thicker / bigger.

Upon installation and power up in my AL-572, one of the 4 tubes had a very minor flash over - it was not serious enough to damage anything. After the brief flash over, that tube and the rest were stable at full power.

I have noticed the filaments are not all the same brightness, for what that is worth. However, as a general rule the filaments emit less light than the previous set of 572Bs I had in use.

The new set of tubes easily puts out the full rated power on the AL-572. I am pretty happy with the purchase, but would probably recommend those in NA, or those not comfortable replacing a component if an arc causes issues stick with well known NA suppliers.

RF Parts has a good name, as does K5SVC who sells Machlett tubes.

All in all, the 'new design' 572B tubes appear to be a better product than previous Chinese generations. It probably pays to pay the 'tested tax' if you are in NA, however.

Alternatively, be sure to bring the tubes up at 1/3rd and 2/3rd plate voltage first and burn them in a bit as per W8JI's instructions.
K7QXG Rating: 2014-09-22
Not available in USA Time Owned: 6 to 12 months.
Using AL811HD which comes with four 572B tubes. At 10 months operation, tubes would not produce power. A check of the four by experienced engineer on high quality tester showed two were weak and one was very weak. Unable to obtain replacements in USA. Phone calls to RF Parts, Penta, etc revealed that they have none and won't obtain more until the Chinese mfr.does something about the poor quality. So here I am with a good amp and no 572B replacements available, except from the mfr plant in China - and I won't order from them! So, I replaced the 572Bs with 811As and the amp runs fine... it just falls short on power output (400 watts instead of 550 watts on CW). Ameritron should be ashamed of themselves for still selling the AL 811HD since replacement 572B tubes are no longer available.
MM0IMC Rating: 2014-05-21
Okay for the price... Time Owned: 3 to 6 months.
I use them in my Ameritron AL-811HXCE amplifier and they require about 1 minute or more to warm up. Not a great issue. ;)

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Earlier 2-star review posted by MM0IMC on 2014-01-31

I sent two of these Chinese 572B's (Shuguang) to a friend to test in his Yaesu FL-2100Z amplifier, into a dummy load.

His Russian valves (tubes) easily produced 700W+ into the dummy load. The Chinese 572B's (Shuguang) struggled to reach 520W on the lower bands. :(

I guess they are okay if you've nothing else to run in your amp, but not as good as the real McCoy.
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Earlier 2-star review posted by MM0IMC on 2014-01-25

The replacement 572B that I received from China seems to have a loose anode cap, that needed resoldering.
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Earlier 3-star review posted by MM0IMC on 2014-01-20

I finally got a replacement for the duff valve (tube) from China, but the heater filament seemed to be somewhat dimmer than the other three.

After a couple of hours in the amplifier, this seems to have settled things done and there appears to be no problems with it.

They seems to be slightly down on output as compared to my 811A's, about 10% down. Otherwise they are fine...
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Earlier 3-star review posted by MM0IMC on 2013-12-13

I bought four of these from China for use with my Ameritron 811H. Three worked and one had to be returned because of a filament-grid short which caused the Grid Current meter to peg backwards and also blew one of the fuses.
K5RCR Rating: 2014-01-29
Tale of two suppliers Time Owned: 0 to 3 months.
Lets cut to the chase. I ordered three matched 572b's from a Chinese vendor via eBay. These are for my AL811. They were matched all right. ALL THREE and shorts from filament to grid.

I sent the tubes back three weeks ago and have yet to have the money refunded to paypal. I think it is safe to assume that it will not happen. So, while some of these guys are honest businessmen, others are clearly not.

Now, on a brighter note, I still needed tubes, so I ordered a set of "811H's" from RF Parts. These tubes are also Chinese, but were actually tested by RF Parts. They are not much more expensive than the tubes sold by the Chinese bandit. These 811H tubes are 572b's derated to 1900 volts...fine for the AL811 but not other amps running in the neighborhood of 2500. After about 20-30 hours of "burn in" [as suggested by RF Parts that they would require] the tubes are producing full rated power plus a little and don't show any sign of red anodes like the 811a's do.

Lesson: While you can't avoid Chinese tubes, you can avoid Chinese vendors.
M0HDX Rating: 2013-12-30
Matched pair...Really Time Owned: 0 to 3 months.
I purchased a matched pair of 572b valves from the seller Shuguangs off ebay and only one worked out of the pair.

One valve had getter silver/grey coating on the glass of the tube and worked fine but the defective valve which did not light up had a white getter colour.The only time the getter colour will indicate a problem is when it turns white. A tube with a white getter will not function and cannot be used. This happens when air leaks into the tube.

Not sure how these could of been tested and sold as a matched pair.

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Earlier 3-star review posted by M0HDX on 2006-11-25

Tube factories in china.

shuguang factory produce many valves which are frequently REBRANDED BY IMPORTERS AND OEM,s,such transmitting types are often branded with old American/European brands and sold without notification that they are chinese made as are the audio types.

liuzhou factory make many types of valves which are marketed abroad.pm components,a british firm,has golden dragon.

sino factory...there are other tube factories in china,most keep a very low profile.some of these lesser known factories specialize in transmitting tubes such as the 811A,812A,813,3-500Z,4-400,100TH,833 and others.

chances are the tubes in your amp branded with RF parts for example or whatever name they have on them are from the same chinese manufacturer as your friends who have the same tubes in there amp but a different brand name.

I use chinese 811A,s (no brand name)in my ameritron al811 and up to now no problems,good pwr output but i would feel alot better if the tube had been branded cetron,penta labs,rf parts,taylor or amperex,I might of even got a few extra watts with a brand name stamped on the tube.


TAKE A TOUR OF THE SHUGUANG FACTORY IN CHINA.
makes you realize how important tweezers really are.
http://www.ks-hifi.com/artical/shuguang/shuguang.htm

jim,M0HDX

VE1FG Rating: 2013-12-01
new chineese tubes Time Owned: 0 to 3 months.
hi my name is mike my call is ve1fg I bought a mached pair of these tubes about 3 months ago and installed them in my old heathkit sb-200.after removing a old set of cetron 572b,s that were just about dead .after doing so the amp went from about 200 watts with the old cetrons to 550 watts on 80 m so far so good I have been running them everyday now and haven't found any trouble with them as of yet well here,s hoping they will cont to give me good service first time ever to buy them.best 73 from Canada da dit da.
KD7ZYZ Rating: 2013-03-22
Not worth your time Time Owned: 0 to 3 months.
I bought a matched set of three shuguang 572b tubes
from a seller on ebay. After burn in I apply power
600 watts ok that looked good but shortly after my receive on my Ft-950 began to get very load pulsating noise . One of the tubes had broken into oscillation.Replaced by seller next while loading on 75 meters the swr went whacky and in ssb there was a carrier. Put My 811a's back in my Ameritron
amp and all was well. Would not buy another China tube if it was the last one in the world total dodo.
N9BTU Rating: 2012-01-10
Quality has finally come! Time Owned: 0 to 3 months.
I needed a new Quad set for my Clipperton L. The tubes that were in the amp were two "Chinese" and two Taylors which I presume now to be Chinese as well. Maximum output on 40 meters was 1300 watts-pretty decent for this amp. Was there any more there? I ordered from Ebay seller Qmall who has best price and best warranty. He has 30 day return (for any reason) and 1 year warranty from manufacturer Shuguang. Tubes take about 3 weeks for matched quad set to arrive. I broke them in by powering up-low power and then 8 hours at full 2600 VDC. Results? 1600 watts OUT with 110 watts drive. Was 1300 before with 100 watts drive. For $29.95 a piece plus $34.95 shipping (for four) I was pleasantly surprised as I was for the warranty. Qmall handles the replacement so you don't end up arguing with the maker. Looks like we have a good alternative once again. Seller also has 99.6% pos. feedback, so doubt he would have this high a rating if DUDS were floating around. I give them a 2012 thumbs up. Only sold on Ebay by Qmall at this price and warranty.
K4FLH Rating: 2010-11-12
Pretty Damn Good Time Owned: more than 12 months.
I've bought and used Chinese tubes both generic and some branded,such as Taylor. I've used them in my amps,Yaesu and Heatkit, and have got them for friends. Out of the dozen or so I've purchased I have had only one go bad in an unacceptable time,two days after I installed it. I contacted the vendor about it and two days later I received a new tube, no hassel. I didn't even have to return the bad one.
I ALWAYS let the new tubes idle for a few hours before pouring the juice to them. Then when I tune the amp I key down at 40-50 watts input and only for the max of 10-15 seconds then let them cool for the same time. Maybe that's why I haven't any of the problem others here have had.
I will continue to buy Chinese 572B's as long as I keep getting the service I've been getting from them.
VE3FDT Rating: 2009-10-31
QC sucks! Time Owned: 0 to 3 months.
I have bought a matched quad (4 tubes) from an eBay seller in Hong Kong. The price was more than reasonable, the delivery cost and time was good. The quality sucked big time.

Out of 4 tubes all had very nice gold metallic stickers on them saying "QC Passed", beyond that one had a direct grid short causing my amplifier to blow a fuse on applying HV (this required replacing blown grid resistors) and another tube had a loose pin (while this is not an outright failure it causes a plate current spike on applying HV / closing the relay and makes me wonder how much longer this tube is going to survive).

The Chinese vendor agreed to replace the shorted tube, but the one with loose pin is apparently OK for him / her. Only that it has been almost a month now and the replacement tube has not been shipped yet. The concept of QC and standing behind the product you sell seems to be entirely foreign to those guys.

In my personal experience the Chinese 572Bs are about 60% of the price of the other such tubes readily available, the problem is that their failure rate is 50% which makes them more expensive in real terms than other 572Bs offered for sale nowadays. Nobody behind the product either.