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Reviews Categories | Electron Tubes | Svetlana 4CX800A ceramic tetrode Help

Reviews Summary for Svetlana 4CX800A ceramic tetrode
Svetlana 4CX800A ceramic tetrode Reviews: 7 Average rating: 5.0/5 MSRP: $$100
Description: Svetlana's $100 answer to Eimac's $500 3CX800A,
Product is in production.
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M0HDX Rating: 5/5 Nov 30, 2017 15:18 Send this review to a friend
Robust..Reliable  Time owned: more than 12 months
Four years since my last review the original Russian GU-74B in my amplifier is still producing full output and used most days.Very reliable and still reasonably cheap to buy compared to other tubes(3cx800)...I have 6 NOS spare GU-74B but at this rate i doubt i will need to use them.

Secret is do not try squeezing every last watt out of the tube and it should last a long time.
WB2VVV Rating: 5/5 Jun 30, 2016 20:25 Send this review to a friend
Great Tube!  Time owned: more than 12 months
I bought a few of these tubes when they were first introduced and very attractively priced. I subsequently built up a mono band 6 meter amplifier using one of these tubes, and have been very satisfied with its performance. I am only using modest (quiet) airflow at the 500-600 Watt output level and the original tube is still working well. Gain is 13 dB and IMD is excellent!
N4RSS Rating: 5/5 Aug 26, 2010 11:37 Send this review to a friend
very good  Time owned: 0 to 3 months
Just installed two NOS GU74b's into my QRO, dates codes 1984 and 1990 I believe, ordered from QRO Parts. The originals were fine after 9 years but I wanted spares.

Getting the pins to mate with the socket was tricky but that's my problem.

Power output of the new ones same as old, 45 watts in on 20m gives 1950 watts out.
K7ORK Rating: 5/5 Jan 7, 2009 10:51 Send this review to a friend
Nikmatvey for 91b replacement tubes  Time owned: 0 to 3 months
Alpha informed me that the AC trip problem with my 91b (purchased 1997) was caused by the GU74B (4CX800A) tubes going bad. I panicked when they could not recommend a source for replacement tubes.

After searching eBay for replacements, I ordered two tubes from Nikmatvey in Russia for $400 plus $30 for shipping. The tubes were not tested nor matched. They arrived about four weeks later.

The tubes were installed in less than fifteen minutes. They work great…less drive power to get full output.

Now, I don’t have to consider replacing the 91b because of lack of tubes. is a source offering matched and tested GU74B tubes, but at a higher cost.
G8LIK Rating: 5/5 Jun 5, 2005 23:09 Send this review to a friend
These tubes rock!  Time owned: more than 12 months
As the proud owner of an Acom 1000 I can say the 4CX800A/GU-74B really delivers the goods without fuss, splatter or any other nasties at the 1KW power level. But have to wonder what will happen if/when the Svetlana NOS stocks dry up and you have to pay the full whack for those produced by SED. Some suppliers already charge over $200 for a single tube.Maybe a case of stock up now for rainy days whilst they are still around the $65 level on ebay?
W5VYY Rating: 5/5 Aug 3, 2004 17:56 Send this review to a friend
Great price  Time owned: more than 12 months
The Svetlana 4CX800A ceramic tetrode has a great power to price ratio. I just purchased two spare NOS tubes on ebay for $52 each for my QRO HF2500DX amplifier. What a bargain compared to the price of the 3-500Z, 3CX800, 8877 and other tubes built by Eimac. The 4CX800’s provide a power gain of 40X or 16dB on 160 and 80 meters where I do most of my operating. 40 watts of drive gives 1500 watts output and 65 watts of drive is an easy 2500 watts into a dummy load of course. I can not think of any tubes that provide high gain and high power at such an affordable price.
WB9WHE Rating: 5/5 Dec 21, 2002 23:07 Send this review to a friend
Dream come true!  Time owned: 6 to 12 months
At 20% of the price of a Eimac 3CX800A, the Svetlana product is just as good. While Eimac's product is shiney and very, very pretty, the Svetlana product is Russian millitary, butt-ugly. But at 1/5 the price of the Eimac tube, who cares!

Some thay that the Eimac has slightly better specs...kinda like saying there is a difference between 1400 and 1500 watts. IF there is a difference, you will NEVER be able to detect it, no matter how hard you try.

My tube is 1/5 the price of your Eimac ...and if you shop carefully, you can find Svetlana 4CX800a tubes at $55 street price, or about 1/10th the price of Eimac. I bought 4 as spares!

ETO and Alpha have already switched. Ameritron has not. Why? I have no idea. As for me, I'll follow Alpha's lead.


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