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Reviews For: Ameritron AL-811

Category: Amplifiers: RF Power - HF & HF+6M

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Review Summary For : Ameritron AL-811
Reviews: 151MSRP: 650
Description:
Uses three tough 811A transmitting tubes
Product is in production
More Info: http://www.ameritron.com/products.php?prodid=AL-811
# last 180 days Avg. Rating last 180 days Total reviews Avg. overall rating
001514.5
K7DUV Rating: 2007-09-21
Lots of BANG for the BUCK Time Owned: 6 to 12 months.
Ordered mine from HRO of Portland (good guys) back in Feb of 07. I like the way MFJ packs up the amp for shipping. I opened up the Amp, unwrapped the tubes, checked for any loose hardware and solder joints. No problem found. Put the Amp inline and she tuned up fine. The MFJ manual sucks! But other than that all is well. 275w RMS and 500w PEP no problem. $670 bucks for a 500 watt tabletop amp, great deal!!!
N6KYS Rating: 2007-08-28
Not bad Time Owned: more than 12 months.
The 811 is a pretty good amp. For what they cost, I'd say that it's an affordable way to put 500 watts or so on your signal. I installed a soft start module, which keeps the power supply from getting hammered at initial power-up. One disappointing point......the proximity of the tube nearest to the power transformer. It's way too close and needlessly heats up the transformer windings covering material, and doesn't allow for much cooling of that tube. The cooling fan in way undersized and does a marginal job of ventilating the cabinet. Lots of people complain in general about Ameritron/MFJ's quality control (cold solder joints, etc), but I've been lucky so far and have not had any problems. The input matching circuits are labeled 10/12 meters for example, but I am sure that they are tuned for a matching bandpass of 10 or 15 meters, NOT 12 or 17 meters, since driving the amp on those frequencies is much more difficult. My 811's have held up OK, knock on glass.

Overall, a nice bang for the buck, but nothing special.
ZL1PHD Rating: 2007-08-15
Great build bar the valves Time Owned: 0 to 3 months.
The build quality is top notch. Who ever built it understood what quality was.
That aside, the fan while does move enough air for to just keep things within spec, I think not enough. It moves 20CFM and it runs on 110v at 60Hz. Where I live I have 230v at 50Hz. So I went out and bought a 12v computer fan of the same dimensions but that one moves 39CFM at 12v. Hence I replaced the low CFM with a higher CFM fan. Unsure why a more powerful 12v fan was not used considering there is a 12v supply in the amp. Again I cannot fault the build quality, the builder did a great job and the design is proven and simple, easy to fix.
The other day I ran the amp without ALC and blue a 1 amp diode that caused the meter readings to be out (rather careless of me).
D15 I think it was. Due to the simplicity of the amp, didn't take too long to figger out what the problem was. I like the Keep It Simple pholosiphy.

The Valves:
The tubes that were inserted were the no name brand Shuguang tubes. One has a nice big welt on the anode. That welt glows bright red/ orange long before the other tubes start to glow a dull red. Who ever inserted these tubes at Ameritron either had no idea or didn't care. The builder needs to have a word with the tube inserter out the back of the workshop as this welt was clearly visible. I saw it there when unpacking the rapping around the tubes, a nice bright silver welt surrounded by the grey getter.
It's bound to fail soon if I tune it for full power. The tube goes bright red on the welt wether 10 watts are feed into it for 50 watts.
If key is down and no carrier it does not glow is BIAS current is not the issue. Just bad tube manufacturing. So I tune the amp for 500watts and it's not too bad, though in doing this if I start to push 600watts there will be distortion so I adjusted the ALC to not let it go above that. At the moment I can get 700watts out of it but I don't go there. If the tubes were all good. I'd give the review 5/5.
W0PPK Rating: 2007-08-13
Still flawless Time Owned: more than 12 months.
Update from 5/1/01. Still running strong with no problems whatsoever!

73's Bob W0PPK

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Earlier 5-star review posted by W0PPK on 2006-03-12

Got it new in 2000. Use almost daily without any problems. Flawless performance.

73's Bob W0PPK
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Earlier 5-star review posted by W0PPK on 2001-05-05

Got it new over a year ago. Use it almost daily at 400 watts output without any problems! Excellent reliability, quality and performance.
The Sherman tank of amplifiers.

73's - Bob - W0PPK
AA2SM Rating: 2007-08-08
Did Not Last Long Time Owned: 3 to 6 months.
Had the 811 for about six months now. The Grid Current Guage is not working. If I give it a few hard raps it might start up again. From what I understand, its a common problem.
KG7RS Rating: 2007-07-29
An MFJ By Any Other Name.... Time Owned: 0 to 3 months.
Hi Folks,
This little amplifier has probably received fairly good reviews for a few good reasons. For one, it's the only thing commercially available in an inexpensive 500-watt amp. For another, it's easy to use and tune, is compact, runs from a 120-volt line and is not a bad looking product. One possible bonus is the fact that the tubes can and do withstand some moderately ham-fisted tuning episodes, and even when they finally give up, are inexpensive to replace. As far as my experience, that's where the praise ends. This is the second AL-811 I've owned. Upon opening the cabinet to remove the factory tube packing, I got to marvel at the quality construction. Yeah, right. All kidding aside, the construction quality of this amp is deplorable, at least with regard to lead forming and soldering. I buttoned it up and set to operate. It performed flawlessly on 20 meters. After recently purchasing a new antenna tuner, I was anxious to give it a go on the low bands. While tuning the amp on 80 meters, I noticed some intermittent symptoms with the load control. Disconnect everything and off to the bench. A careful inspection of the tank components quickly revealed the cause: the bottom end of the low-band tank coil was not soldered to the loading variable cap lug! It was pressed against it, but no solder. This was quickly repaired and other suspect connections were reflowed, or in some cases removed, properly installed and resoldered. Filament leads were originally butt-connected to the tube socket pins and one had a cold solder joint. Overall the soldering workmanship is the worst I've seen. The remainder of the mechanical assembly is reasonably good. The first AL-811 I purchased in 2001 exhibited fairly poor workmanship, not as bad as the current amp, and no operational problems. The current amp is operating fine after my cleanup. Yes, it's an inexpensive amp, but why should one need to work on a brand new product? The AL-811 fills a void for an inexpensive medium power amp of reasonably good design. I had to call several dealers to find one in stock. The factory is well behind schedule trying to meet demand. I have to wonder why a responsible company that cares about and understands quality principles has not stepped in to offer a competing product, even at a somewhat higher price? Palstar, are you listening? I have to believe if there was a quality alternative to (MFJ) Ameritron products, the company would either "get religion" or go out of business. I can in good conscience rate this product as "OK" based on the solid design and desireable concept, however it does nothing to promote the pride of "Made in USA". In my observation, MFJ and their holdings have earned the poor reviews they routinely receive.
73, John, KG7RS
DUBCROSS Rating: 2007-07-08
Nice Amplifier Time Owned: 3 to 6 months.
I've had a bunch of amplifiers through the years and I'd have to say that my 811 is one of the best. It tunes easily and puts out over 500 with an input of only 40 watts!

At first I got worried because I had to turn my knob completely to 1 to achieve max output on the 75/80M band (the manual says don't go below 3) BUT when I contacted Ameritron the (very nice) gentleman told me that as long as grid current was increasing as I turned the knob counter clock wise all was well.

I use my 811 daily and have yet to experience any problems with it what so ever.

For the money and quality I give mine a BIG THUMBS UP!
KI4GJV Rating: 2007-05-11
Not really that complicated. Time Owned: 3 to 6 months.
I bought mine new from AES (had to catch them when they had one). It arrived in good shape tubes were loose but they may have been shipped that way on purpose. Removed the interior packing checked every thing I could see and buttoned down the cover. I did consult a few guys who advised me on the tune up. But its not hard if you go step by step and watch your meter readings. Make sure to use a dummy load and have a tuner rated for at least 800 watts even with the 600 watt model. Make a check list of your tune up routine and use it. Amps need a little TLC and maintenance from time to time but this one is a tried and true design. I would have given this a 5 if the manual was a little better.
KG6R Rating: 2007-04-12
It's Great Time Owned: more than 12 months.
I bought a used AL-811 from ebay. It had a relay problem that was minor. I routinely put out 500 watts on all bands. This design is bullet proof.
The tuning up of this amplifier is a snap. The price is reasonable and if you ever need service, the ameritron folks are terrific.

73, Jim KG6R formerly KG6QHP
K7IWW Rating: 2007-03-19
Excellent Cost/Benefit Ratio, Great Reliability Time Owned: more than 12 months.
Picked up a MINT AL-811 at the SEA-PAC flea market, from an estate, over five years ago. The amp had been used less than 2 hours. Got it for $275! Over five years later, it is the ONLY amp I own that has NEVER failed. The only thing I don't like is that stock, it's no good for QSK CW. I am an antenna experimenter and have been rather hard on this amp; I have replaced the 811's only once. A tip: follow the advice in the manual about keeping the loading above "3."

It has always run straight from the 117 VAC mains in the shack. With brand new tubes and tuned for full output on 20M into a well-matched triband yagi (close to 700 watts), it threw the circuit breaker in the house's main breaker box. Since then, I rarely run it over 400 watts out on any band.

I recommend a very high quality, high-Q ATU if you operate 160M or the full band on 75/80. Tuning on those bands can be a bit diffcult with a mediocre impedance matching system betwen the amp and the feedline.

Also, eventually the dial lamps will go out. Ameritron promptly replaced them for free after the amp was over two years old, without my asking, when I emailed them for the part number! It makes more sense, though, to replace them with ultra-bright white LEDs.

In addition to the AL-811, I have the Icom PW-1 and Icom IC-4KL solid-state amps, and an old Swan 1200X. The PW-1 had one of its dual-final PA sections go out after less than 100 hours of use. The 4KL, which I got used and operated from 240VAC, worked like a champ for about 150 hours, when the power supply developed a fault. I won't go into the Swan 1200X...many hours spent modifying and upgrading it, only to have it fail for the second time after five hours on the air.

But the trusty AL-811, like a Timex, takes a lickin' and keeps on tickin'!

It is a bit soft on 10M and 30M, but those are two bands where full output isn't needed. If you can't make it with 250 watts on CW on 30M you aren't gonna make it with 600 (and besides, there IS a legal limit on 30M that is well below the amp's capability, don't forget!). When 10M is nicely open, the amp is needed only for the closer-in contacts and breaking pileups.

I have dedicated the AL-811 primarily to daily net usage these days, though it got quite a workout working DX on both SSB and CW before the solar cycle took a precipitous dip. I have checked the linearity of the amp on a scope and it is excellent. On CW, it does have a bit of a slow uptake, but not objectionable. This amp has made the difference between repeating my call 2 or 3 times, and being told "great signal," on the Noon Time Net on 7268.5 kHz each day.

The debate over the utility of replacing the 811s with 572Bs has been interesting (and colorful at times). I plan to give it a go. The 572Bs should be more robust and forgiving especially when the amp is not run to its full potential output. It's interesting to read that some have gotten 750+ watts after replacing with 572Bs, whereas others claim there is no output increase, only unneeded increase in plate dissipation capability. With varying power measurement devices, loads, etc. among the various reviewers, it's difficult to resolve the issue. I look forward to finding out what the result will be here.

In sum, I give the amp a "5" not so much on its own merits (which qualify it for a "4" or so), but by comparing it to other amps I have used and owned. (Soon I will be comparing it to an FL-2100B). Whether you get an AL-811 brand new, or used in good condition, it's hard to find a better value in such a robust, easy-to-use, and reliable ampifier.

- Kevin WA7VTD
Oregon City, Oregon