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write your own review of the Ameritron AL-572B.
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PA1ZP
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Rating: 3/5
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Oct 30, 2011 11:28
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works but not perfect
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Time owned: more than 12 months
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Bought my AL572BCXE abt 4 1/2 years ago.
Worked OK for abt a month and then a intermitted problem accured.
One of the chinese tubes would "rattle" every now and then.
Brought the AMP. back to the shop and they looked at this problem.
They couldn't find anything wrong with it.
Took it home after 2 weeks again and the problem seemed to be still there but not as often as before.
After 2.5 years had to replace the tubes , they were gone completely, and I couldn't get more as 750 watts out of them.
Also input SWR got a lot higher in time.
I replaced these chinese tubes with 4 from another chinese manufactorer.
I bought 18 tubes at once, 12 for my friends (some of them for replacing 811A tubes) and 4 for myself, 2 spares if there were any defective tubes delivered.
The coincedence was that the only defective tube from 18 new tubes had exactly the same problem as the one wich caused the problems at first hand.
A anode rattling inside the glass envelope, but these tubes do work as they should, only they make a strange noise every now and then.
And with the high voltges and powers it does not give you a comfotable feeling at all
I put 4 new tubes in the amp. and they worked FB from day one all problems were gone.
Only other problem the amp still has that it will not work OK on 10 mtrs though this version should work on 10 mtrs as it is the European export version.
I even will not bother to get the problem fixed as I rarely work on 10 mtrs and I do not need the extra power on 10 mtrs.
The first 2 1/2 years I would use the AMP daily and I abused it almost daily at full pull.
The tubes went soft but the last 2 years I only use it about 2 or 3 times a week.
And I do not use the max. power out anymore.
I have not got much time for being onair these last 2 years and the station I would work a lot went SK.
The new chinese tubes from High Hope compny work very good every time I use the AMP.
Would I buy another AL572BCXE.
NO, the problems with the 572B tubes happen to often with these amps and I would go for the AL80B now, it does not give the same amount of power but 750 watts here is more then I may and want to use.
Chances of trouble with one tube are far less then the chances of having trouble with one of 4 tubes.
The AL80B is also cheaper now as the AL572B
Chinese replacement tubes were not expencive and cheaper as one chinese 3-500, but as I said before if I had to do it again I would go for the AMP with one 3-500.
I run the AMP on 240V 50Hz as this is standard AC in my country.
The wiring from the street to my house is so thin, that all lights in my house will blink very slightly when using the AMP in CW.
The 3 is for not giving all bands and for the troubles that can occur with the tubes in this amp.
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AB3ME
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Rating: 5/5
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Jul 20, 2011 18:58
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Great Amp for the money
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Time owned: 3 to 6 months
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I bought mine in April 2011 from HRO. I replaced an SB200 with this amp due to the fact I live full time in an RV Park and only have access to 120 volts to my QTH..which most of the time only runs at 118 during the winter, and down to 104 in the summer when the park is full and everyone is using their air conditioning. The SB200 worked fine if the voltage would stay up....The Ameritron with the adjustable taps solved this problem. I produces 900 watts on 10 thru 17 and a full 1200 plus on all other bands (I don't use 30M) It is easy to tune, and performs great especially with the 3 second warm up time allows chasing DX is easy. I am very happy with this amp. My only problem has been it reads only 2600V instead of the 2800V per the manual. The tech at Ameritron believes this to be due to my voltage problem, but did offer to look at it if I decided to ship it back to them as it is still under warranty. This does not seem to effect performance and per Ameritron, 800-900 watts on 10-17M is about what one should expect from this Amp. All in all I am very happy with it and would recommend it to anyone looking to get almost full legal power.
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N1CKX
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Rating: 4/5
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Apr 6, 2011 18:27
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Good Amp Once It is Fixed
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Time owned: more than 12 months
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Now that the bugs are pretty much worked out, the amp is a great performer.
We measured 1340 Watts using a dummy load and a Scope.
I won’t mention where I bought the amp to protect the Innocent, but was warned to “carefully check ALL hardware and ALL solder joints. Good advice as I found a lot of loose hardware and two bad joints.
Out of the box (after rework above) it worked for about 2 hours before it began to produce a high pitch high voltage arcing sound (Like an old TV Flyback Transformer breaking down)
Turned it off and called Ameritron and they told me to check the 50 ohm resistors on the Grids, and the 3055 transistor that controls the Dynamic Bias. (This transistor dies on nearly all the Amps, More on this Further down)
This was obviously not the problem, so I removed the top cover and bypassed the interlock (Yes I know the dangers and I have worked with much Higher voltages)
Powering up the amp and tuning it produced the noise again, high voltage high frequency arc with NO excessive current on the plate. This arc was very pronounced under load, but reduced dramatically with no drive.
Turns out one of the 572B tubes had a poor connection on the graphite anode where the wire that connects to the plate cape passes through the anode. A visible arc could be seen when the tube drew current under load.
NOTE! THIS IS NOT A SHORT. This is a connection failure, and is not uncommon with graphite anode tubes. This has been reported with Svetlana tubes as well.
(By the way, research seems to indicate that Svetlana tubes, while having better Quality control, cannot handle the 2800 volts that the AL-572 amp runs, and tend to fail in a spectacular way doing a lot of damage)
I took photos of the arc, called Ameritron and the “Tech” I spoke to had no clue what I was explaining to him. I finally got him to agree to have me ship the tubes back for replacement.
Before I packed up the tubes I ordered a new set of Shuguang Tubes from a Vendor on E-Bay, which incidentally is the same tube Ameritron uses. They just clean off the name and Logo. Turns out it was a good thing I did.
The E-Bay tubes arrived in 6 days and are still working Great a Year later.
IT TOOK AMERITRON 6 WEEKS, THATS A MONTH AND A HALF, TO REPLACE MINE.
Then when the “Fully tested and Matched” Ameritron replacements arrived, I opened the boxes and noticed one of the tubes had a discolored Anode out of the box.
Plugged in the tubes, turned on the Amp, and immediately the grid current pegged negative and the plate showed about 150 milliamps of current.
The tube with the discolored anode was blushing quite red with NO drive.
Turned off the amp and put my E-Bay tubes back in and the amp ran normally.
Back to Ameritron went their “Tested and Matched” tubes with a nasty gram asking that they Actually test the next set. And I requested that they don’t take 6 weeks this time.
THREE WEEKS LATER the new set arrived. At least this set was OK. Had I waited for Ameritron I would have had a large $1700.00 paper weight for more than two months.
The Amp ran fine for another month, then suddenly began to draw 100 milliamps of plate current without drive. This time it was not a tube issue, Q3 the bias control transistor was dead.
This is such a common failure that it is the first question Ameritron asks every single time you call. (I didn’t bother calling them this time.)
I did some research on line and found some mods to replace this with a Darlington Transistor that has almost twice the voltage and Current capacity, but also requires you to put “Swamping” resistors on it to prevent it going into oscillation.
More research and I found a transistor, NTE-331, that was NOT a Darlington and had only slightly more gain and nearly double the power handling capacity. Go to the NTE web page for local dealers. Installed it with no modifications and the amp has been working great for a year without a hitch.
The Only remaining item is that the amp could use just slightly more capacitance on the Load Capacitor on 40 meters. The band selector switches in fixed capacitance in parallel with the variable capacitor depending on band.
On 40 Meters, my particular amp peaks just as the load capacitor turns through the maximum capacitance, and adding a few Pico-farads on that switch position should fix this. It’s so close that I haven’t bothered. The rest of the bands are in the middle of the Range of the variable Cap.
Final evaluation is I like the amp a lot. Easy to tune, very forgiving and great signal reports without even asking. Cheap tubes ( $140.00 Set of 4) that I could replace every year and still be dollars ahead of most other amps.
AL-800 with Eimac 3CX800A7 puts out 1250 watts (claimed) and costs $2595.00 and the replacement tube will cost you $600.00 or more. And requires at least a 3 minute warm up. (Can you say missed DX)
AL-572 with four 572B tubes puts out 1300+ (measured), costs $1795.00 and a set of replacement tubes are only $140.00. Warm up about 3 seconds.
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AA6QQ
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Rating: 5/5
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Nov 5, 2010 04:53
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Oldie but a goodie
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Time owned: 6 to 12 months
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It was born in the fall of '97, serial number 00024, the original owner bought it from AES in '98 and had it for eleven years, he replaced it with the Yaesu Quadra, I purchased it from him last year for about .50 cents a watt, he told me he didn't use the amp much and pretty much only on 15 and 12 meters. It puts out a little over a kw on 110v with the original Svetlana tubes. I did a lot of research... probably too much and was going to wait until I could afford something solid state because I thought it would be a hassle to tune a tube amp. I had read that Ameritron amps were more MFJ junk and you had to buy a used one that had all the bugs worked out to get a good one. Then a friend told me about this little gem that was for sale.
After watching how to tune a tube amp on YouTube, reading the manual and going to the Ameritron web site I gave it a try. I was pleasantly surprised how easy it is to tune and how consistent it is. I have a "cheat sheet" with the settings for each band, dial in the numbers and then fine tune for that freq. I'm amazed how tuff this guy is from all the times I over drove it with my 200 watt Yaesu MK V, had the band switch on the wrong band and countless other mistakes. The only problem I had with it was one day one of the tubes didn't light up, I called Ameritron, great service by the way, I have never waited more than about 20 seconds for a tech, after talking to Richard I wiggled the tube back and forth and it lit up.
I'm glad I didn't wait and bought this when I did, I should probably get a set of matched Taylor's some day and I will, but for now the original one's are working just fine. I suggest purchasing the plastic allen wrench from Ameritron and tuning all the bands from the holes in the back. Yes sir, it's solid as a rock, if you can find one locally from a good ham, snap it up. I wouldn't buy one on eBay, you never know what has been butchered up for eleven meters.
To sum it up it's a great near legal limit amp that runs on house current, runs cool, is rugged and the fan isn't much louder than my computer's
73's
Roy AA6QQ
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KB8E
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Rating: 4/5
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May 6, 2009 08:21
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No Issues
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Time owned: more than 12 months
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I purchased this amplifier 9 years ago with the Svetlana tubes installed. No real issues. Tunes up nice and makes 1 kW+ with 50 watts drive. Works best from a dedicated 220-volt line, no flickering lights, voltage sags, etc. Also, tapped primary to reduce HV to 2500 VDC no-load. No change in performance and the next set of tubes (if there ever is any) should appreciate it. Installed QSK-5PC kit and it works well. Recommended, only reason for not a 5 is that good 572B tubes are apprently hard to come by now.
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W3NRL
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Rating: 5/5
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Feb 10, 2009 20:22
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Sweet
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Time owned: 0 to 3 months
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I traded for this unit and sent the unit to Ameritron for just going over and getting a clean bill of heath, also managed to get 4 Taylor 572b's and wala and sweet!!!!
I recommend this amp
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W1IT
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Rating: 2/5
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Nov 3, 2008 14:11
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Bad Tubes as sold
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Time owned: 0 to 3 months
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I just took delivery on a NEW Al 572, I owned this rig before I moved from New England and it was a powerhouse when working. However, the tubes supplied tend to gas arc causing damages.
Oh, yes, I never learn, the new amp just arced and took out a 50 ohm resistor, Q2 and Q 3 in the bias line. I called Ameritron and after a little help the tech told me to check the four tube bases, 50 ohm resistors, to discover which tube was bad. That done the bad tube was discovered, leaving only three more tubes to arc, at some other date.
I am an engineer retired and know how to swing a soldering iron, so they are shipping me two 50 ohm resistors, and Q 3 and Q 2.
I should have known, this amp is only a good as its tubes and you should save yourself aaggraation, just buy four balanced 572 B Taylors from RF Parts and not even try using tubes supplied.
Over all this amp is a lilttle work horse with near legal output at a cool temperature, but beware of the bad tube issues. This problem has not disappeared.
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KA2ZNI
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Rating: 5/5
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Jul 14, 2008 20:56
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One terrific Amplifier
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Time owned: 6 to 12 months
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When the original tubes are replaced with Taylors look out... This thing really wakes up and get's with it. I wired it for 220 immediately, I feel anything Kilowatt status or plus is only doing it favors.
The amp is easy to tune, I have had it going on a year and the thing has been trouble free, even occasionally using it on AM while keeping the Plate current at .275 mills and the plate voltage at about 2600 volts when keyed, yields roughly about 250 watts, which is what it should be rated at with a little headroom for asymmetrical modulation.
The Amplifier on SSB with Taylors/220 volts yields about 1400 watts out and I have run it continuously that way for extended periods on 20 meters with no ill effects or excessive heat build up.
In today's market where the prices of amps is going thru the roof, this one you cannot beat for the the price, durability and output in an inexpensive tube.
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KB3LAZ
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Rating: 4/5
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May 26, 2008 00:49
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Not Bad
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Time owned: 3 to 6 months
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The 572 is not a bad amp, nor is it a great amp.
Iv had it for around 5 months now. Relatively quiet fan. Keeps cool rather well after extensive use. However the output power stops increasing at about 65w of drive, which only gives me around 900w. I only have 110 in my shack but others swear that I should still get full output power. So Im going to switch to 220 and see if It will do full output then. If not 900w will suffice. Although i will continue to run at about 1kw. I just think running 1200+ w with these tubes would only shorten their life. Not a bad amp but if I were able to do it all over I would just buy the 811H!
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W7OVE
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Rating: 3/5
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Apr 11, 2008 10:42
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3.5/5
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Time owned: 0 to 3 months
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This an update of my last review of the 572B amp. I was unable to completely resolve the issues with 15/17 meter tuning..After putting this amp on the air I noticed the swr between the transceiver and the 572 would suddenly jump to 3.5 to 1+ during a "qso".This of course cut the exciter power to almost nothing, forcing an end to said "qso" I contacted Ameritron and and talked to Mike. I expressed my dissatisfaction with the 572B, and asked if I could return it for credit and purchase an AL-82. Mike agreed to make the exchange and I paid the difference. Because I spend 80% off my on-air time on 17 meters I am not a fan of this amp. For me there are to many compromises with 15/17 meters. Having said that I have to say Ameritron is a very good company to deal with. Mike understood my concerns and making the exchange for the AL-82 was very easy. I would recommend any Amateur who is looking for an amp give this company a chance. I purchased the 572 because the tubes are inexpensive to replace, but as I found out, that should not be the only concern depending on what your operating parameters are
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