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Reviews For: Sovtek / Ryazan 811A

Category: Electron Tubes

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Review Summary For : Sovtek / Ryazan 811A
Reviews: 3MSRP:
Description:
Thoriated-tungsten-filament type used as AF power amplifier and modulator and as RF power amplifier and oscillator. Requires small four-contact socket and may be operated in vertical position base down or in horizontal position with pins 1 and 4 in vertical plane.
Product is in production
More Info: http://www.vaco.ryazan.ru/HTMLs/oscillating-lamp/SV811A.htm
# last 180 days Avg. Rating last 180 days Total reviews Avg. overall rating
0034.7
N6CIC Rating: 2022-05-07
Good robust tubes, but watch for defects Time Owned: 6 to 12 months.
I have four Sovtek/Ryazan 811A tubes in my Ameritron AL-811H and they are performing very well, even if the grid current gets temporarily high and they get very hot. However, I have ordered back-ups on eBay and found it is important to check them upon arrival. In a batch of four, one had a broken filament and the other a loose base. The other two tested very well. I presume these defects are simply due to the fact that these tubes have been in storage for about 40 years and the jarring in shipping caused the defects I observed. Since they are not expensive, I still recommend them.

To follow up on my review, I reported the defects in the two tubes to the seller in Ukraine, and he promptly replaced them. To save him postage, I ordered two more. When the four tubes arrived, they all tested very good. I will continue to use them in my 811H amplifier.
N8FVJ Rating: 2022-04-07
Far Superior to Chinese 811A Tubes Time Owned: more than 12 months.
This is a high quality and ultra high vacuum 811A tube. Vacuum is so high the tube does not need a getter flash. The tube is a 60 watt ICAS plate as this tube is the same tube as produced by Svetlana. I trust Svetlana 60 watt ICAS rating over a hams best guess. Here are the absolute maximum tube data from the tube manufacture:

Constant anode voltage

2500 Volts

Anode current at maximum signal

210 mA

Power dissipated by the anode

65 W

Grid current

50 mA

Impressive ratings!

Bottom line is I get 600 watts PEP out without any visible red plate and been doing so for over 5 years. Not a 2 rating, this tube is a 5 rating all day long.
VK3BL Rating: 2016-02-11
Svetlana 811As by another name Time Owned: 0 to 3 months.
Its not well known, but Ryazan was the OEM factory for Svetlana's 811A product. If you look closely, you can even see the Ryazan logo on Svetlana 811A tubes.

The only difference between the NOS Ryazan G-811 tubes and the Svetlana 811As is that Svetlana 'dressed' the tubes up with a ceramic base and a little ceramic insulator on the plate cap; other than that the tubes are exactly the same with the same internals.

Ryazan NOS tubes can be had even cheaper than the Chinese/Shuguang FU-811 ('811A').

After having a 3/4 Shuguang tubes develop cracks in the plates along the bends after 15 hours transmitting time (run within 45 Watts CCS), I decided to explore my options.

I recently purchased a set of 4 from the eBay seller electrikua and couldn't be happier.

Even though they were NOS, the glue on the base and cap plates were fine (unlike the Centron 811As floating about), and they powered up at 1700V idle with no glitches!

I will write a follow up review after more testing has been done, but for now ill ask this:

Why settle for poorly made Shuguang tubes when you can buy 4 Ryazan tubes - exactly the same internally, made at the same plant as Svetlana 811As - for $70 USD? Bargain!