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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
KH6DC Rating: 2010-04-12
16 Years+ Time Owned: more than 12 months.
Wow, had this linear sine 1996 and it performs excellent since the day I bought it. Haven't had any major problems and still running the original 811A Russian-made tubes (no brand). I've mistuned it many times and it still works. The only problem I had 5 years ago is with the relays no making good contact. Took apart the relay and lightly burnished the contacts with 400 grit sandpaper. I'm keeping this as my field day/dx amp (weekly at the beach or in the yard) and replacing the home linear with a solid-state Tokyo Hi Power HL 1.1KfX. Probably will replace the tubes with matched Svetlana 572Bs.

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Earlier 5-star review posted by KH6DC on 2001-06-05

After the awful review I wrote about MFJ 989C antenna tuner, this linear by Ameritron is excellent. Owned it since 1996 and it has provided me with excellent service since then. It continues to put out about 400-500 watts of clean power. People I worked all over the world say I'm clear and not distorted and/or clipped. I could be yelling into the microphone and the AGC will bring down the signal to a non-distorted signal.

I was going to replace this amp after 5 years with one that's either a solid state unit or a Henry 2K but it works great why meddle with my setup when it's not broken. Think I'll keep this one for a while longer.

Haven't replace the 811 tubes yet nor the fuses.

This one's a keeper and an excellent starter amp for the new hams and old alike.
W7RUE Rating: 2010-04-03
Great Amp Time Owned: 6 to 12 months.
Being new to Amateur Radio, I don't have a lot to compare the AL-811 to. I used an old Dentron as a loaner for awhile because I had to send my 811 back to Ameritron after adding a grid overload protection module (GOP-100) which worked so well that it shut it down and I couldn't bring it back online after miss-tuning it.

The folks at Ameritron went over it very carefully but couldn't find anything wrong with it so they shipped it back to me at no charge. (It cost me $75 w/insurance to ship it to them from my QTH! Ouch!!!) I haven't had any other incidents to report. It has been very forgiving of my ignorance and heavy handedness.

After hearing poor QC press about some MFJ/Ameritron products I went through it with a 'fine-tooth comb'. It really was well assembled! The soldering is excellent, nothing was loose, cock-eyed, or missing, and nothing was broken.

I am getting a little over 700 watts out SSB but I am driving it with 100 watts of RF Power with my Yaesu FT-1000MP. (The plate and current voltage are dead on according to the latest tuning instruction leaflet I received from Ameritron when they shipped it back.) The Grid Overload Protection board is definitely working! So far so good! I am still a happy camper!

W7Rue
K8OIE Rating: 2010-03-31
Excellent Product Time Owned: 0 to 3 months.
Bought the AL-811 new. Packaging also rates a 5.Operating instructions are good [anytime you do not have to call the techs they are good]. There was nothing loose inside and the construction appeared tops...I sold and serviced industrial electronics for years, and this construction appears equal or superior to many products I was into. I am driving it with an Omni D to a Vertical antenna. With the Omni I was never able to get much DX. My first call using the AL 811 on phone got me a Serbia QSO through a pileup. So far I am very satisfied with this product.
WB9FQS Rating: 2010-03-25
18 Years of Solid Service Time Owned: more than 12 months.
I have owned my AL-811 for over 18 years of trouble free service. I use it almost exclusively on SSB (ICAS) and run it conservatively around 500w though I can drive it to over 600w with my Kenwood TS-850S with about 55w on 80-15m. I originally used my Kenwood TS-140S with this amp. The original set-up of ALC/Relay control was straightforward. At the time I needed an amplifier that could run off 120VAC 20AMP outlet.

With my modest antennas (Mosley TA-33JR-N-WARC up only about 30’ / 9m or B&W folded dipole) I am able to compete in a 20m pile-up with all but the biggest guns on the band. I often get 20 over DX signal reports and the difference on 20 meters phone of having 500-600 watts over 100 watts, which provides about a 7dB to 8dB or 1½ S-units increase in signal strength, is the margin of difference of making a contact or not. A legal limit 1.5kW amplifier would only add about 2.5dB over the AL-811A. Of course I do not use the linear when running barefoot when it is possible for making the contact.

The only problem I have had (after 18 years), which was quickly remedied, was the D16 (IN4007) diode that controls the metering function recently shorted causing improper meter readings. The amp still functioned and I used it at lower power (400w) to be on the safe side. Ameritron service provided information about the repair by the technical service on their web site plus I made a follow-up phone call to correctly identify the position of the diode on the circuit board before making the repair. Ameritron suggested one possible cause was one of the tubes may be going gaseous considering their age, causing a brief arc thus causing the diode to fail

While having the top off the amp making the repair, I decided to replace my original 18 year-old 811A tubes with new 572Bs. The original tubes showed no sign of the age. With the 572Bs I noticed I needed a bit more drive (65-70w) to get up to the full power levels power which is to be expected with a tube designed for plate voltages of 2.5kVDC as opposed to the 1.5kVDC for the 811A tubes.

Certainly I do not expect any more power with the 572Bs but the are a bit more forgiving than the all ready rugged 811A of mistuning plus giving a higher plate dissipation “headroom” at full power.

As with any mass produced product, I am certain there are some AL-811 users that have had product failures. However, as for my experience and for the cost (I paid $579 in 1992), I have had outstanding success with this amplifier and would highly recommend it not only as an entry level amplifier, but maybe the only one an amateur would ever need.
K6FAF Rating: 2010-03-04
Good Value for the money Time Owned: more than 12 months.
Bought mine used from an estate sale.
Put it to work not knowing it had Chinese tubes as replacement. Lasted 15 months not driven hard, then one tube arced in the middle of a DX chase, poof.
Replaced with Svetlana 572b Trio from RF Parts in 2009. Running smoothly at 50-60W input and 1850V, typical 650W out. Helps a lot in the pile.
Great Amp with excellent customer service.
K0ZN Rating: 2010-02-20
I like it but have had problems. Time Owned: 6 to 12 months.
This is a follow up review after owning the AL-811 for about 10 months. You can see from my initial review that I liked the amp and was initially happy with it even with the initial QC problems I found in it. I still "like it", but I had a LOT of problems in the first 6 months. (I will list them below.)

I will say that Ameritron's technical support seems good, at least in the two cases I contacted them via their email system. Responses were 2nd day at the latest. After the TR relay failed, I sent it back to the factory for repair and the turn around time was reasonable. I did find it literally impossible to get through to them on the phone, which is the main reason I ended up with email exchanges via their "trouble ticket" system.

Failures experienced:

1.) One of the 811A's failed by going gasseous. This tube short blew the meter protection diode (as it was designed to do) to protect the meters.
This was easy to fix. I just replaced the diode. (trouble shooting assistance from Ameritron was correct).

2.) I could not get the amplifier to load properly on the low end of 80 Meters; would not load a 50 ohm load! (low end of the CW band). Ameritron tech suggested I needed more capacitance in the load capacitor, so I added a cap. It still did not load. (Tubes got too hot/excessive plate glow). After further checking I concluded that possibly the 80 M tap on the tank coil was in the wrong place. A call to Ameritron confirmed that it WAS tapped wrong. I moved the coil tap and it was better, but still not where it should be. Apparently more C is still needed. Mis-tapping a tank coil is a BAD manufacturing Quality Control error.

3.) About 2 weeks after sorting out 1. and 2. above the Transmit/Receive relay failed and stuck in "transmit"; no signals were passed through the unit. This relay is mounted on a PC board and kind of "buried". Since (fortunately) the unit was still under warranty, I was not about to do the disassembly necessary to get the PC board loose and fix the relay. I boxed up the amp and sent it to Ameritron. They repaired the T/R relay and so far it has worked properly.

Note the initial QC problems I found in my first review.

BOTTOMLINE: I LIKE the amp; when it is working correctly it is pleasant and easy to operate and the 300 watts (CW) or 500+ SSB makes a surprising improvement in signal/success levels.

At leat in my case, cold reality is that this unit has been seriously UNreliable. I am strongly hoping the "infant mortality" failures are now past and I can enjoy it long term. Any further failures and I would conclude it is not a good product; I have a lot of time invested in trouble shooting/repairing and shipping the amp. I would not want to continue doing this.

FYI: Make no mistake! This is a 300 W (output) amplifier on CW. That is what 811A's are rated for with only 65 W of plate dissipation and the amp running about 60 to 65% efficiency. You can easily see that the plates glow "too much" if you start exceeding 300 W output on CW by very much. Above the 300 W level on CW you are begging for short tube life or catastrophic failure of the tubes. This is NOT a design problem or short coming of Ameritron... it is just normal spec's for 811A's. If you run RTTY or data I would HIGHLY recommend you stick with the CCS ratings on the 811A which are even lower. The amp will easily exceed these spec's but you are kidding yourself about tube life/reliability if you do.

In SSB service which is about a 25% duty cycle, thing should run "forever" at 500 PEP output.

Based on the experiences I have had so far, even though I "like" the AL-811 I have to be objective
and give it a 3.0 on this review.

73, K0ZN



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Earlier 4-star review posted by K0ZN on 2009-06-17

This is an initial review of the AL-811. I will do a follow up in 6 months or so. I purchased this amplifier as a back up to a legal limit amp I have which has indirectly heated cathodes with the attendant time delay when you turn it on. For casual operation, I wanted an amp that was essentially instant on, which this amp is with the 811A tubes. I also did not want to fire up an expensive pair of air cooled cermaic tubes just to rag chew for fun. I work mostly CW and have found that 300 to 400 watts output is usually more than plenty for casual operation. Initial casual DX chasing has proven that the 350 watt level where I run the amp is very effective; if I can hear them, I can work them and that does NOT always happen at 100 W.

The Good news:

So far, after about one month, the operation of the little AL-811 has been flawless. It is easy to tune and takes less drive than I expected. i.e. it has pretty decent gain for an 811A amp. It is surprisingly quiet... you almost wonder if the fan is big enough. I have made a couple of careless mistakes with the exciter settings (which I caught immediately, fortunately) and the AL-811 seems to have handled the mistakes OK. The fit and finish on the unit and front panel are very good for this price class. The cover comes off easily and reinstalls easily; the screw holes all lined up well. I thought it was well packed and they had reasonable packing around the tubes.

Operationally, >> SO FAR << I am quite happy with it. I do not push it hard and have no intention of doing so; there is no point in flogging it at this power level. If a station can't hear you at 300 W they certainly won't hear you at 400!! 811A's have a plate dissipation of about 65 watts, so 100 W output per tube (assuming 65% efficiency, which is typical) is about as hard as you really want to run them on CW if you want to stay on the conservative side. SSB is a lower duty cycle, so you can go a little harder. The owner's manual seems to be basic but adequate. I understand the 3 tube amp uses the same power supply as the 4 tube, so that is a bit of "reserve" for the 3 holes I would think.

The BAD news.

Based on what I have seen with other MFJ/Ameritron producsts, you
ABSOLUTELY >> MUST << go through any new unit with a fine tooth comb and do a "Quality Control check". Ameritron designs a decent product in the price range, but it is utterly beyond me why their management can't comprehend that they are shooting themselves in the foot with poor QC. To wit: with this unit I found a couple of things that *could* have been very damaging. (1). I found a couple of tiny solder balls/splashes in between the circuit paths on a couple of the power supply diodes; not good. I am sure the unit passed initial operation tests ( I HOPE they do that !!!), but these were an arc/short looking for a place to happen...and possibly would have killed some diodes. (2). I found one of the meter leads almost touching the tank coil. That CAN'T be good....so I repositioned it. (3.) I found two HV powersupply wires not really well positioned for HV lines and I repositioned those. These are little things but CAN be a cause of a failure and/or a warranty claim. I found one screw totally loose (fortuantely, it was a non-critical, mechanical fastener). Several screws were clearly not adequately torqued down and some of these were component grounding screws. It took me less than 10 minutes to find and correct these items. Again, it is beyond me why MFJ/Ameritron's management cannot comprehend the great benefits they would receive by looking for and catching these little things at the factory. There is no question it would cut their warranty costs and generate a ton of customer satisfaction/positive word of mouth advertising....instead, they threads like this! About the only design aspect that I did not really care for was the fact that the three tubes are in line and the cooling air *probably* is not as effective/cool by the time it gets to the 3rd tube. Operated properly and with in specifications, it appears to be a good medium power amplifier.

Bottomline: It is a good basic amplifier and (so far) operates very well and gives a useful boost over a 100 W signal. I WANTED to give it a 5 out of 5, but I just can't when the customer has to do the final Quality Control check !! ...so a 4 out of 5.

73, K0ZN
VE7REN Rating: 2010-02-12
well worth the money Time Owned: more than 12 months.
ive had nothing but great success with this amp.mine is 2 yrs old,and does full 600 if i push it. i normally run 500 and it loafs along also with 60 watts drive .
price versus performance you cant beat it. sure.......its not no 1000 watter,but i knew that before.on the used market,they are a steal.it gets me up above the noise,and further talk power,and fits well in the shack with its small footprint.
well done ameritron
VK2AAH Rating: 2010-02-11
I'm Impressed Time Owned: 3 to 6 months.
I purchased my 811X via HRO at Anaheim. This has been one of the best purchases I have ever made & worth the $300 in freight to get it to Australia. I used Fedex and it arrived beautifully packed in only 72 hours door to door. The unit itself works beautifully and at the Australian 400W limit is just coasting. I bought this unit to last me forever & I can't see me every parting with it. Build quality is superb and it shows in the performance. It takes very little drive to drive it to 400W, and little more to 600W.
WD0FIA Rating: 2010-02-11
Plenty of bang for the bucks! Time Owned: 6 to 12 months.
I have owned the AL-811 for six months now, with no issues. I seldom use an amplifier, but I have found that the AL-811 puts out enough power to get me over the noise level.

I wish I hadn't waited so long to decide to buy one, it is nice to get the "Good and Readable" or "Loud and Clear" reports when conditions are borderline.

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Earlier 5-star review posted by WD0FIA on 2009-12-25

I have owned it for six months, and have had NO problems with it. I tried several used amps, and ended up paying way too much. I should have bought one of these at the start. After owning Collins, Henry, and Dentron, I really appreciate a current production amplifier. No old capacitors, degrading resistors, gassy tubes, or corroded parts to deal with.
NR7N Rating: 2010-01-20
Great Value & Quality Time Owned: 6 to 12 months.
This amplifier is truly one of the great values in amateur radio today. A look at the interior shows that it is well thought out with decent quality components and solid construction. I know that Ameritron does share some corporate connection with MFJ but at least with this product the connection stops at that.

I have had it since last April and it has been a solid performer. I use it 90% of the time on 20M on both SSB and RTTY with excellent results. I have read most of the previous reviews on this amplifier and I believe that many of the issues have to do with running this amplifier at too high a power level.

I have had no incidents with the Chinese 811A's but I have never had a piece of equipment with them before but I have used many 811A's over my 50 year ham career.

The manual that comes with the AL-811 is a little fuzzy on just where to run this amplifier. It is straight forward though to determine the sweet spot for the three tubes.

The AL-811 runs a little higher plate voltage than a typical 811A in ICAS service. The recommended voltage is 1500 VDC and mine typically is at 1600 VDC under load which is not a deal breaker but needs to be noted to find the correct plate current.

In SSB mode, ICAS service, the plate dissipation has a maximum of 65W although there is a bit of air from the small fan on the back of the case. This would give a plate dissipation of 195W for the three tubes. For an initial data point I assumed an efficiency of 65% which is fairly typical for this tube at 20M. As an initial test point I loaded the amplifier to 435 Ma at the plate voltage of 1600 VDC. This gives a plate input power of 697W and an output power of 500W. I have ignored any effects of feedthrough power to keep things simple as it is fairly low. The total plate dissipation is therefore 697 - 500 = 197W. Not to bad of a guess for a starting point.

In RTTY service things are different. The tubes should be run at CCS service ratings so in this case the maximum plate dissipation is rated at 45W for a total of 135W for the three tubes. RTTY can be brutal and many amplifiers are ruined by running them too hot in this mode. In this case, I run the AL-811 at a total plate current of 295 Ma. This results in a power input of 472W. The power output hit 335W which resulted in a power output of 335W. This gave a total plate dissipation of 137W.

I therefore run my AL-811 at 20m in SSB at 435 Ma and 500W out, in 20m RTTY at 295 Ma and 335W output. At these power levels both the tubes and the amplifier itself should run for many years.

Finally, a word about 572B's in this amplifier. The 572B is actually a much larger tube as others have noted and it was typically run at 2500 VDC or so. They will work in the AL-811 but I would bet that the efficiency is a bit lower as this tube is not great at lower voltages. If you must run 572Bs I suggest that you don't run them too much beyond the operating points for 811A's as the limiting factor will be the power supply.

The 572B was always a very hard tube to make and requires a very good vacuum and precise element alignment. I think the reported problems with Chinese 572B's will unfortunately be the course now as there are no longer any domestic manufacturers. This fact in itself would make me shy away from this tube now. The best 572B's were probably made by Cetron before the mid 1980's when they started to experience filament problems.