Paul:
I recommend the AL811H over the SB220. The ability to use it on 160
meters makes all the difference. My SB220 (with an external fan added)
runs too hot on 10 meters in a contest and will shut down periodically.
No problem on the other bands.
I have owned two AL811H amps (unmodified). One I used for years on
Barbados as 8P9Z and 8P9HT. I used it constantly for 48 hours in CQWWCW
each year. Only had one problem with it ever and that was when one of
the parasitic suppressors at the top of one of the tubes fell off during
a contest. They no longer use that design and I understand the current
design for the parasitic suppressors don't have the problems that the
older design does. If you order a new one after a failure on the older
design, they send you a complete new unit for the top of all four tubes.
Both of my amps had the same problem and one was fixed and sold and
the other one that is loaned out will soon have the updated suppressors
installed. It works well on the WARC bands too.
The only things that the AL811H lacks that my Alpha 78 and Titan amps
have is full 1.5 KW output and QSK keying. QSK keying can supposedly be
added to the AL811H with the use of a QSK-5 unit that can be purchased
from Ameritron. I purchased one and was never able to get it to work,
but that is no indication that you would have a problem, as I am
severely technologically challenged. QSK is important to me for
contesting, but you do have to spend more money to get it. Ideally, you
would also like no-tune band changing. But for a first amplifier for
contesting, it is hard to beat the AL811H for the price. For full power
output, the AL1200 is also a good deal.
73,
John, K4BAI.
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