Alan,

What I like about 811a tubes is that you can push them really hard,if, that 
is, the rest of the amp is over built.  I had an old pair of 572B tubes in a 
Hamerlund HXL1 wired for 220 volts and ran 800 watts output easy and the 
tubes were old, too.  Shoot, with the old 811 Heath Kit Warrior, I pushed it 
as hard as my exciter would run, which was about 105 watts on a couple of 
bands and only changed tubes once in about 10 years.  I noticed the power 
dropping one day and pulled each tube out and shook it.  One of them had 
chunks of the plate bouncing around in the glass envelope and I put them 
back in and still was getting 450 watts output for a few months until a set 
of new tubes came in the mail I had purchased.  Never had any TVI problems 
until I bought the SB220 from a friend and started running 1200 watts 
output, haha.  That SB220 was built by a first phone licensee who kept a 
local FM station on the air and he made all the mods that were out at the 
time for the SB220 models which was about 1992 as I recall.  Well, that's 
when I bought it from my friend.  The only thing I didn't have on it was the 
modification to run on 160 meters.  I still have 49 states on 160 running 
100 watts and need the state of Maine some day to finish that band off, 
smile.

Phil.
K0NX




----- Original Message ----- 
From: "Alan R. Downing" <[log in to unmask]>
To: <[log in to unmask]>
Sent: Sunday, April 27, 2014 6:00 PM
Subject: Re: Al-811H


> Phil, I have an AL811H here, and I typically get about 600 watts out of 
> it.
> I could push it harder than I do, but I don't think that it is necessary 
> to
> do so.  I often leave it tuned up on 10 meters, and when ten is open, 600
> watts is plenty.
>
> Alan/KD7GC
>
>
>
> Alan R. Downing
> Phoenix, AZ
>
>
> -----Original Message-----
> From: For blind ham radio operators [mailto:[log in to unmask]]
> On Behalf Of Phil Scovell
> Sent: Sunday, April 27, 2014 5:04 PM
> To: [log in to unmask]
> Subject: Al-811H
>
> Mike,
>
> It's been awhile since I read about the 811H so can you tell me how much
> power you can get out of it and with how much drive?
>
> Phil.
> K0NX
>
>
>
> ----- Original Message ----- 
> From: "Michael Ryan" <[log in to unmask]>
> To: <[log in to unmask]>
> Sent: Sunday, April 27, 2014 5:12 PM
> Subject: Hopefully this fixes things
>
>
>> Hey all:
>>
>> Just ordered a new set of tubes and a new parasitic board for my AL-811H.
>> Hopefully I will get it back up and running in a couple of weeks as I've
>> missed it, the last couple of weekends when operating.
>> After I had the friend take a look at solving my reduced 20M output, the
>> amp kind of unravelled a little. The parasitic board blew and the tubes
>> failed.
>> Well, one of the 4 failed and rather then replace just one, I ordered a
>> match set.
>>
>> 73:
>> Mike VO1AX
>>
>