Hi Fred,

I had an Ameritron AL-811H for a while that actually blew a tube.  I tuned
it with no difficulty but when it blew, Ameritron assumed I had to be tuning
and operating it wrong because of being blind and refused to honor the
warranty.  Currently, I am using a Drake L-7 and love it.  It runs a pair of
3-500Z's and is built like a battle ship.  I believe these tubes are much
more tolerant than the 811's, especially in terms of grid current.  What you
might do is what Tom, KB8TYJ did and replace the 811's in such an amp with
572B's.  These things will take a lickin and keep on tickin as the
commercial used to say.  An 811H with 4 572B's in it would give you good
service.

Personally, I've always been a little intimidated by amps with the ceramic
tubes in them, especially given the high cost of replacement.

Good luck and very 73. 


 
Kevin :)
Amateur Radio:  K7RX
 

-----Original Message-----
From: For blind ham radio operators [mailto:[log in to unmask]]
On Behalf Of Fred Adams
Sent: Friday, August 13, 2010 08:47
To: [log in to unmask]
Subject: Tube amplifiers

Are any of you guys using or have you used an amplifier with 811 tubes?  I 
have heard some blind hams say that amplifiers with 811 tubes are not very 
easy to tune, what do you think?  I was thinking of getting one or a single 
3-500 tube amplifier.  I would appreciate your comments.  I purchased a new 
Ameritron AL80B several years ago and didn't like it so I swapped it off.



Best wishes,


FRED ADAMS W4HC
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