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Author Topic: 2-811 amp question  (Read 2725 times)
AE5SB
Member

Posts: 35




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« on: November 15, 2015, 08:04:27 AM »

I am using a 811 amp with 2 tubes.
Getting about 200 watts with 25 watt drive
What is the normal drive for 2 811 tubes in GG?
Yes I have til my eyes hurt and the numbers are from 15 to 50
What is the max as I do not want to overdrive them

Thank you for any help.

73 David AE5SB
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KM1H
Member

Posts: 5541




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« Reply #1 on: November 15, 2015, 06:34:19 PM »

About 20W per tube and no more than 50 ma per tube grid current. At 1500-1600V you can expect 300W from a pair safely if using USA 811A's and not the earlier 811's.

Carl
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AE5SB
Member

Posts: 35




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« Reply #2 on: November 16, 2015, 02:18:14 AM »

Carl Thank you so much the post.
I have a Yaesu ft 900 that only does 25 watts (qrp ver) so I guess 200watts
is ok.

thank you again & 73
David
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VE3LYX
Member

Posts: 814




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« Reply #3 on: November 16, 2015, 04:12:35 AM »

I have a 2 811A amp, a homebrew. I used an untuned front end and drive it with a Dx60B and have for several years. I needed just a bit more power for one group I worked because before I was just at noise level. It does the job nicely and is all I needed. Because the untuned input is not real efficient overdriving is not a problem. I use Chinese tubes and have not had to repalce them so far after a few years. I run them at about 1250 volts.
donVE3LYX
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