| K5TUE |
Rating:  |
2023-04-04 | |
| decent mid-priced amp |
Time Owned: more than 12 months. |
| Seems to work OK, output is usually around 500 to 600 watts average. |
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| WA6JBD |
Rating: |
2023-03-13 | |
| Operates as designed... |
Time Owned: more than 12 months. |
There's very little to be said about the 811H that hasn't already been said. After all, there's 186 reviewers who came before me. I almost didn't need to bother, but I'm going to add my own experiences. Someone might find it useful.
First, remember what this was designed to be, a low-cost amplifier using cheap (when it was designed) tubes. You can't set a brick on the key; it's not designed for that. You need to be gentle tuning it up, it's using 811As. It comes wired for 120VAC, so it's not "legal limit", and depending on your primary power might not even meet specs on power out. It's not going to put up with AM or FM operation for very long. It's just not designed for that, so don't ask that of it. Buy something else.
In a year of operation, I've had two issues. First was blowing fuses after about a year of operation. A quick check on the internet suggested a shorted tube, and that's what it was. I took that opportunity to replace all four tubes with 872Bs. This isn't to get more power, although I could probably squeeze more out of it. The power supply is the limitation on that. I just wanted tubes that are a bit more tolerant of frequent band changes (read that as tune-ups), and a bit of voice processing (read that as increased plate dissipation).
The other issue I had noticed since new. The plate tuning seemed to be a bit unstable. Given a specific frequently used frequency, plate tuning might be set at 2 one day, and wind up at 4 the next. The plate current dip wasn't always smooth, almost like it was oscillating, but the spectrum analyzer didn't show any spurs or splatter. It was just... off somehow.
A month after I changed the tubes, that instability got worse, until one day the plate tuning had no affect at all. No grid current, no output, and very little plate current. I opened it up and quickly found that the coupling from the reduction drive to the insulated plate capacitor shaft was slipping. I locked it down and tested. Suddenly all the weirdness in the plate tuning was gone, and it's now rock solid.
So, getting back to what this thing is designed for, also keep in mind the production values being used to build it. It's an MFJ owned product, so it might come with some minor QC issues.
It was designed to be low cost, so it is not built like a tank. If you're not comfortable opening an amplifier up to do something minor, perhaps these aren't for you. It would have been expensive and frustrating to ship this off for repair twice.
If you're looking for a kilowatt output, this amplifier isn't for you. I could comfortably get 600 watts out with the 811s. My primary power is the limitation there, so there's no surprise to me that's all I get. I see over 5 volts of line voltage drop when it's keyed, and about a 300 volt drop on the plate voltage. That's not the fault of the amplifier. With the 872Bs, I could probably horse whip it a bit higher, but I don't.
It was designed to be affordable, and it is. There are other costs for that to pay instead, so consider what the 811H is and keep your expectations in line with reality. I give it 5 stars for meeting my expectations.
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| NY6U |
Rating: |
2023-01-05 | |
| Good amplifier so far |
Time Owned: more than 12 months. |
| I purchased this amp back in 2014 and it's still operating reliably, including in digital modes. I ensure the per-tube 811A anode dissipation power doesn't exceed the 65W mark. This usually happens somewhere between 75-100 watts at 42% duty cycle. You could probably get higher power out of four 572b tubes since their dissipation is, conservatively speaking, about twice that of 811A tubes. After tuning for a maximum power of 100 watts, it helps to calibrate tube dissipation by carefully measuring and subtracting output power from plate power and dividing it by the number of tubes installed. You need to treat this unit with respect. |
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| LU7BSE |
Rating: |
2022-06-30 | |
| one problem after another, very delicate. |
Time Owned: more than 12 months. |
| I had it for several years, and I don't recommend it, very delicate, it has the 811 tubes, which now only the Chinese are available, to use it in the 40/80 meter band is fine as long as it is not required, in high bands such as 28mhz no It works, in general it is to be used at half power, no more than 500w so that it lasts and does not break. |
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| VK2EAT |
Rating: |
2021-11-01 | |
| Gently Gently |
Time Owned: more than 12 months. |
I've owned an AL811H for nearly 4 years now and have had many fine contacts in its use. By comparison what mode you operate is key as I don't believe this amp would like to the digital modes too long.
Tubes are tubes and knowing there function can go a long way to how carefully you tune your amp. I run tube amps as a musician for a very good reason it's all about their tone. Radio is no different, if you treat a tube gently it will deliver the power you need on time when you need it.
811A's run quite hot in comparison to 572B's but I'm not altogether sold on all the hype either. 572B's will last longer but will not deliver more power.
Currently a set of four 811A's from DX engineering will set you back around $330.00AU. It's still cheaper than buying from the locals here in VK. Please DXE move down under! In all the AL811H will serve you well if you started out on valve tx as I did and spent years tuning.
Read, read, read W8JI's 'Supplemental Tuning Instructions' and you will follow the rules quite easily all the way to smooth output on all bands and your audio quality to boot. See you on the bands! |
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| K7NSW |
Rating: |
2021-03-06 | |
| 100% SATISFIED WITH MY AMERITRON AL-811-H |
Time Owned: more than 12 months. |
| I am a Ten-Tec fan. I have their Omni VII xcvr and big 1300 watt QSK amp (pair of 3-500Z tubes). Also their high power antenna tuner. I am a CW guy and love QSK. Then I took up operating portable in my trailer out in the wilderness. I needed a more portable rig so I bought a Kenwood TS-590SG. I like having 500 watts of power handy. The Ten-Tec amp is a beast - weighs 80 pounds. Definitely not an amp for portable use. So I bought a new AL-811H and an MFJ Differential -T antenna tuner. I decided I could live with a foot switch on the amp. Am I happy with the 811-H? Yes, 100%. Bought it new from HRO a bit over two years ago. Went through it when I received it - no problems. Much lighter weight. Runs on 120vac. Great for my portable operating. Totally satisfied. At home I love my Ten-Tec gear. Out in the wilderness the Kenwood, 811-H and the MFJ tuner are just what I wanted. I joined the hobby in 1961 and am very comfortable with "dipping and loading". For me a solid state amp offers me very little in the way of improvement so definitely not worth the money. 500 watts gets the job done. Besides, I love the peaceful orange glow of the tubes and the lighted slow action movement of the two panel meters. The 8-11A tubes are doing just fine. Like most stuff, you learn to use them properly and they work great. I have not yet read anything that persuades me to spend a bunch of money to replace those tubes with four 572B tubes.The argument seems to be they take abuse better. Really? Why buy a rig planning to abuse it? Ameritron does offer an amp using those tubes. However, I have read that the power supply in the 811-H is not designed for the 572B. Anyway, my 811-H and the MFJ antenna tuner get 5 stars. In case you are wondering, my wilderness antenna is a G5RV up 30 feet on a fiberglass push-up pole. The Kenwood runs on two big deep cycle RV batteries - bought them at WALMART. A Honda 2kw generator runs my trailer and the 811-H. |
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| VE7REN |
Rating: |
2020-12-28 | |
| excellent,whats not to like! |
Time Owned: more than 12 months. |
update dec 28/2020,still have the 811. never a issue. i use the taylor 811a,and have now aquired another 811h with 4-taylor 811a. both work flawlessly on my 7410 and 7300 icoms. highly recommend for a budget power solution.
nov 2011i liked my 811 3 tuber so much, i traded it off and bought a 811h 4 tuber. beautiful...............gets the job done with 811s no problem.very good for the dollar/performance factor. not hard on the pocketbook like the big dog brands like yaesu,icom, alpha,ten tec,elecraft,hro,etc |
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| VE9AA |
Rating: |
2020-12-27 | |
| Best bang for the buck, dB wise |
Time Owned: more than 12 months. |
| Bought from VE1OP (now SK) and use it exclusively on my 2nd radio for SO2R with a single antenna (ZS6BKW w/ 15m add-on). Runs aprox 550w out (CW) depending on the band. Seems pretty solid. I am an active contester and while not always SO2R, this amp now has lots of hard hours on it over the past several years. I only drive it with about 55w-60w. I had initially run it the first contest or 2 with the full 100w from my rig until I researched it a little bit. The 811A's seem unaffected by this abuse (my bad). Can run it into a moderately high SWR (2.1:1 or so) w/o so much as a whimper, or so it would seem. Scott (VE1OP) gave me a great deal on the amp. May he RIP. I also have a 2nd one bought for parts and someday will see if I can get it going. I'd actually buy another one if the opportunity ever presented itself. |
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| KC2O |
Rating: |
2020-08-29 | |
| Enjoying this Amp! |
Time Owned: 3 to 6 months. |
I purchased this amplifier new from HRO about 6 months ago. I have been a ham for a very long time but never had an amplifier before. I received this amplifier right before the Covid-19 lock-down in NY and it has provided a lot of enjoyment.
The amplifier arrived in working condition and well packed. It worked out of the box - easily connected directly to my Yaesu radio. The LED lit meters are nice - bright and easy to read. I read the manual and several sites on tuning the amp, I found it to be easy. Signal reports have all been great with my Yaesu FTDX-1200 and OCF Dipole.
I recommend this product to others - it has been around for many years now. I am able to use this amplifier regularly and I did not need to add any special wiring for it in my home. It is still priced reasonably well when compared to other amplifier options. Someday, I'm sure I'll upgrade to a SS amp, but this amp fits my needs well today.
As others comment, it is best for SSB and CW use. I would also like to try using it on FT8 & RTTY, but not sure if that is a good idea as it was not designed for the full duty cycle required.
73's de KC20
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| W2VS |
Rating:  |
2020-06-27 | |
| FAILED AFTER A WEEK! |
Time Owned: 0 to 3 months. |
Purchased new AL 811H amplifier and it failed after a week. I tuned it up according to the instructions. Worked fine and got good reports. After about a week it would tune and then amplifier plate and grid meters would go haywire. Power out disappeared.Tried brand new tuner just to rule that out. Same problem. HRO was fine to deal with-shipping it back for full refund. UPS is picking it up.
My understanding is that they are not currently being manufactured. However, I would not purchase another one anyway. I think there are manufacturing quality control issues.
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