There has not been a post since 2007 on the AL-811. So, I will review what I consider the best two HF amplifier used bargains. New is not necessary and is expensive. First, either amplifier does not require rebuilding replacing the power supply capacitors or out of tolerance resistors. Keying is 12 volts at 100ma, no high voltage interface required. The AL-811 can be purchased for around $450 used. This amplifier has the same power supply as the AL-811H with four 811A tubes. Bands are 160 meters to 10 meters with a tuned input. This amplifier is very reliable giving service day after day. The issue with the AL-811 is the weak tubes. You cannot safely get more than 450 watts PEP out with three 811A tubes. The only reason I list this amplifier is it can be upgraded with three 572B tubes. Four 572B tubes in the AL-811H is a waste of money, does not produce any more power and requires neutralization unlike the three tube AL-811. The 19lb power transformer is powerful enough to support 800 watts PEP out with 572B tubes reliably year after year. Three tubes is about $150 and these are new. The 811A tubes in a used amp may be soft anyways. For $600 with new 572B tubes + shipping costs, it is a lot of power out for the money. For about $800 used, you may want to consider the Ameritron AL-80B. This amp is 160 thru 10 meters with a tuned input and same low voltage relay switching as the AL-811 amplifier. These amps are new enough that rebuilding is not needed. The AL-80A & Heathkit SB-1000 is at times a little less expensive vs the AL-80B and about the same as the AL-80B. Avoid the AL-80 as it is a different amp and not reliable. The AL-80B has a huge power transformer weighing 26lbs. It will produce 1000 watts PEP out. Using a single 3-500Z, a replacement tube costs $200. The 3-500Z tube is very heavy duty with a 500 watt plate dissipation rating. Three 572B are rated 480 watts plate dissipation, but I consider the 572B closer to about 130 watts plate dissipation per tube. In my opinion either of these amplifiers will produce within 1 S unit of a legal limit output HF amp and the replacement tubes are not too expensive. Some new replacement ceramic tubes can cost as much as these amplifiers. I would not own an AL-811 without the 572B tubes though. You should enjoy years of trouble free service at a reasonable cost. Failures are very uncommon in either amplifier.