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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
Description:
Watch Limited Warranty!
Product is in production
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# last 180 days Avg. Rating last 180 days Total reviews Avg. overall rating
00273.4
K6HJM Rating: 2004-12-25
Great and so is Penta Labs Time Owned: 0 to 3 months.
Just got a matched quad set of 572Bs and very pleased. Arrived in perfect condition (well packed and 4 tubes taped together so assured matched set). Graphite anode looked serious unlike the thin metal of previous 811As. Easy drop-in installation into my 811H amp with bit more power at same drive.

The best part..great service from Penta Labs. Easy to order and shipped same day I ordered. Seem like nice folks too! By the way, $160 for 4 plus postage.
K0IZ Rating: 2004-04-13
Penta Labs good prices Time Owned: 0 to 3 months.
For drop-in replacement of 811A's the Chinese made 572b's are the way to go. The Russian version have different cut-off bias requirements. RF Parts sells matched quad Chinese 572b's for $200 (with "Taylor" branding). Penta Labs sells SAME chinese tubes, matched quad for $140. Good deal.

Also, for best life on RF power tubes, at least a one hour burn-in is highly recommended (up to 10 hours even better) before applying drive.
WD9CMD Rating: 2004-01-24
Not an ouce of trouble Time Owned: 3 to 6 months.
Installed a matched set of 3 China manufacture 572b's in my Ten Tec Centaur. These are drop in replacement for the original 811a's that were stock. Now I have real tubes in my amp. Output is substantially increased with much cooler operation. I now drive the amp with 65w producing 650w out on 20 meters with no problems noted. Seems to loaf along on all bands. Use the amp regularly on 40 meters with 50w drive for 500w out. I have at times cranked up the drive and see 700w out on 40, still seeming to loaf along. These tubes may outlast me!. Outstanding.
K8DXX Rating: 2002-11-25
No problems in 18 Months Time Owned: more than 12 months.
I purchased a matched quad of Taylor (now made in China) 572B tubes from RF Parts. These were installed in my Ameritron AL811H amp... not for extra power just greater ruggedness. Compared to the Cetron 811s they replaced, they appear to have much higher gain, giving 500 watts our with 26 watts drive (using RF Applications digital meter). They came with individual test data (to show they were reasonably matched), warranty information, etc. MTBF data on the Taylors is reported as being better than Cetrons. At $200 for the set, I think they're a pretty good deal. To date, I have not tried them in my other amp, an AL572 which continues to work well with the no-name 572s installed by Ameritron.
W6TH Rating: 2002-03-28
Better Chinese 572B's Time Owned: 0 to 3 months.
I mentioned in my last review of "Chinese" 572B vacuum tubes as to not being up to par. Amateur Electronic Suppy has made good on those bad tubes. I have now been sent a pair of 572B tubes, but of a different "Chinese" manufacture. These tubes are by Penta Laboratories at Chatsworth, California. I heated the filaments five minutes before applying the plate voltage on them. Applied plate voltage and being pretuned with my Taylor tubes previously,and checked the input impedance and the output power. I was overjoyed with the efficiency of these tubes. 800 watts into a 50 ohm dummy load with 90 watts drive. 600 watts output with 70 watts drive. Very easy to load to the 500 ma plate current. I don't push tubes and the 600 watts can do just as good as the 800 watts so will be operating with the low drive and the 600 watts output. Many thanks to Amateur Electronic Supply as they have always treated my sales with the kindest respect and also to Penta Labs as it has been years since I last purchased any tubes from them.There you go, three great tubes manufactures to supply our needs for these wonderful 572B vacuum tubes.
M0BCG Rating: 2002-03-06
chionese 572b tubes Time Owned: more than 12 months.
i use NATIONAL ELECTRONICS 572B tubes in my sb200 linear and have had no problems at all, have also fitted a set in another sb200 heathkit too .
mine are used almost daily in a converted sb200 for hf & 50mhz but its used solely on 50mhz and not on hf at present.
line input is between 230-245v ac depending on location amp is used ,and plate voltages are between 2100-2400v dc depending on input voltage.
i dont know if these are the same tubes as i use, but mine were bought here in england , obviously imported from somewhere !.
73 ian M0BCG
JAMES_BENEDICT_EX_N8FVJ Rating: 2001-04-22
Failed-Limited Warranty Time Owned: 3 to 6 months.
Bought pair for HF amp. After 5 minutes warmup, one tube lost filament. Never applied RF input to measure output! Now the bad news- Sqirreled away for 6 months before use- Well known Florida area distributor said, 'Too bad, no warranty'. Better ask before buying spares, OUCH!