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Reviews For: CHINESE 572B TUBES

Category: Electron Tubes

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Review Summary For : CHINESE 572B TUBES
Reviews: 16MSRP: varies in price.
Description:
High-mu power triode for use in Class AB2, Class B, Class C RF, and audio amplifiers. The chinese 572B is virtually an exact copy of the original 572B/T160L tube and normally rebranded.

Product is in production
More Info: http://www.tomstubes.com/572b.htm
# last 180 days Avg. Rating last 180 days Total reviews Avg. overall rating
00163.5
N1CKX Rating: 2010-09-28
Working Fine Time Owned: 0 to 3 months.
Ordered 4 Shuguang 572b tubes from E-bay/China to back up the tubes in my MFJ/Ameritron AL-572 amp, as I had a bad one in the Amp from the factory (another story).

Arrived in a week, well packaged. Gave them a careful inspection under high magnification for bent/distorted elements, and then checked them for shorts.

Installed them in the amp and have been running them for over a month with no issues.

Carefully measured the output with a calibrated dummy load and a 200mHz scope and output is around 1380 watts PEP. Pretty darn close to legal limit. Not bad for less than $150.00 for four tubes.

My original tubes are (a month later) still at MFJ/Ameritron. Way to go MFJ/Ameritron.
I would have an $1800.00 paperweight if I had not purchased backups.

I suspect the tubes that short are going into old Heathkit Amps that mount the tubes horizontally.
These tubes are rated for vertical mounting. Elements can sag when horizontal and short out.

The original tubes in those amps were special construction for Horizontal mounting.

I’m holding my breath, but will give them a 5/5 for now.
PA1ZP Rating: 2010-08-11
Service OK Time Owned: N.A.
Hi All

I bought 18 572 tubes at factory in China.
Delivery was perfect packaging perfect, price perfect.

Only one tube was not 100%, it rattled loose anode in glass envelope.

17 tubes were OK.
In use now fer 6 month, no problem at all.

You can complain abt the one defective tube , but with my Ameritron on delivery came a tube with the same defect.

It was only after arrival of 18 the chinese tubes that I found out what was the problem with the original set of tubes.
One was defective from day one (not causing serious touble but just strange noises from vibrating anode against glass envelope)
Noises are gone with new set of tubes installed

Original Chinese set of Ameritron was in service for 3 yrs and completely warn.
(they had a hard life with 1KW key down in CW and I tend to TX for more then 20 minutes at a time without pause), they had to work full pull 70% of my QSO's, 100 watt in and 1KW(+) out fer 1 hour or more every day.

I couldn't get over 800 watts key down anymore and SWR at input was becoming higher.
Anode current would not pass 575 mA no more, even with 100W input.
But after 3 yrs Anode top resistor and coils 100% and grid resitors 100% like new.

New set was Ok from day one.
No more strange noises.

I know that the 572B and the AL572B amp are not the best in town but 4 tubes cost me 120 Euro's now, if they last another 3 yrs I am quite happy.
You have to be realistic AMP is cheap tubes are cheap don't compare the 572B with a 3CX1500 or 8877m, though our chinese friends at High Hope International deliver up to 3CX50000.
3-500 3cx1500 3cx800 etc. all produced by them in China.
VE3FDT Rating: 2009-10-31
QC sucks! Time Owned: N.A.
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.
KX5JT Rating: 2009-03-31
Strange! Time Owned: 0 to 3 months.
So I put that matched pair back into the SB-200 after a while and the plates DO NOT turn very red at all now. I have NO IDEA what happened. Same settings on the amp, same loading.... maybe the getters weren't complete and the red plates finished them? At anyrate, they are working FB now! Mysterious but I'm happy!

KX5JT

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Earlier 2-star review posted by KX5JT on 2009-03-11

Hello everyone. This is a warning to stay away from Shuguang 572B tubes as direct replacements for amps designed for 572B's. I own a Heathkit SB-200 and decided to try a matched pair. After ordering direct from Hong Kong from that JCCsomething fella on Ebay, they arrived at my home well packed and timely. No problems there. The problem is when you put 2400 volts of plate voltage on them as the original 572Bs are specified for and as many of the amps that use 572Bs utilize. The plates will glow a BRIGHT CHERRY RED in less than a minute of talking with ssb. RTTY will have them glowing RED HOT in less than half a minute. Graphite anodes should just barely blush a deep red not a bright red hot cherry red. I found out the reason too. See here....

http://www.analogmetric.com/forum/viewthread.php?tid=223

Check the specs on those Shuguang 572Bs... they are only rated for 1250volts on the plates. THAT IS less than HALF of the voltage rating of original 572Bs... .unless you are designing your own amplifier/transmitter with this low plate voltage, this is useless for replacing 572Bs. Real 572B's should be able to take 2750 volts on the plate in intermittent amateur service. My Sylvania Made in the USA 572B's barely blush when I run AM continuous carrier or heavy duty RTTY or SSTV. You have been forwarned! Svetlana 572B's from the 1990s maybe a better choice. I understand the newer Svetlana 572B's were designed with audio in mind and they may not be a good choice. Anyway, I am in the process of putting a matched pair of NOS Svetlana 572B's through a burn in and will report on my findings with them in the near future. *Sigh*

Caveat Emptor

John KX5JT
N3OQD Rating: 2008-05-12
brief overview Time Owned: 6 to 12 months.
I put a set in my Ameritron AL-811. In this application they serve me quite well. With the larger graphite anode of the 572B in the stead of the 811a's tin steel type, these are more forgiving and more durable. Even Ameritron recommends this upgrade with no hesitation. 40w drive gives me about 400w out SSB consistantly. Have a set in the wings but I may never need them. $75 plus shipping for the three from China on e-bay
K4SPS Rating: 2007-06-27
Have had great luck with these. Thank God for the Chinese, Ha! Time Owned: 0 to 3 months.
I ordered, directly from China, a matched set of four 572B's for my 'new' Collins 30L amplifier. They arrived in perfect shape and tuned up with no problems. They run cool and efficiently in this classic amp. Will probably buy a spare set to have a lifetime supply of valves. I highly recommend them; hopefully, you will have similarly good luck! K4SPS