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Reviews For: Ameritron ALS-500M

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

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Review Summary For : Ameritron ALS-500M
Reviews: 54MSRP: 799.00
Description:
500W Output Mobile Solid State Amplifier on 12VDC for US
Product is in production
More Info: http://www.ameritron.com/Product.php?productid=ALS-500MR
# last 180 days Avg. Rating last 180 days Total reviews Avg. overall rating
00543.9
N3EG Rating: 2022-02-09
Works great when treated correctly Time Owned: 0 to 3 months.
I bought mine used and not working. Previous owner said they had replaced the transistors and it still didn't work. Opened it up and found one half had a transistor shorted base to collector, then wiped the silicone grease off the other transistor and looked under the temperature sensing diode and found out why! The other transistor had been put in bassackwards!!! Replaced both transistors and two output combiner resistors, set the bias and fan temperature control, and it works perfectly. Ammeter reads low, useful for relative indication only. Nice and compact, runs on standard low voltage DC, does what it's designed for.
KK2DOG Rating: 2021-07-04
Mighty Fine Jewel Time Owned: more than 12 months.
I fried mine once due to operator error and had to send it in for new final transistors. Lesson learned big time! Since then, I've ran this thing in the shack at about 400 watts SSB constantly without issue connected to an Astron RS-70A power supply and an Icom IC706MKIIG. Lately I've been using it at about 100-150 watts on FT4/FT8 and it has worked flawlessly! I bought my ALS-500M from a fellow ham and if I were in the market for a 500 watt solid-state amplifier today I would buy one again.
AF5NF Rating: 2021-06-28
Works well but use some caution Time Owned: 6 to 12 months.
I own two of these and they do the job for me. I blew the finals in both before I figured some things out. I haven't had any problems since I started watching ventilation and input power. I am no expert so you can decide what this advice is worth. My first one was installed maritime mobile in a compartment near other equipment and I don't think the ventilation was good enough and it overheated. I replaced the finals, installed a extra cooling fan in the compartment, and relocated it. Now it is hanging under a shelf with nothing else near it and it has worked fine ever since. These units have no ALC. I normally drive 30 watts in and get a bit under 400 out. When I burned up the finals in the second amp I was running 100 watts barefoot in an event. The issue happened when the calls to my station built up into a pile up and I was doing a lot of transmitting. One station was having trouble hearing me so I simply turned on the amp and forgot to cut the transmit power on the transceiver down from 100 watts to 30. After several minutes of rapid fire transmission I lost the finals on that amp. I replaced the finals on both amps with HuaGao knockoffs (HG 2SC2879) and have had no problems since.
HB9FLU Rating: 2019-08-05
does the job Time Owned: more than 12 months.
I own this amp for 4 years and use it quite often. It's with 10m and remote control. My power supply is a 95A, 15.2V from Microset. It delievers around 500w on all bands. It's low noise if you don't push it at the limit on SSB. Seldom use it for digi modes - it's not designed to do that with more then around 150w! Never forget: it's a MOBILE amp.

The signal quality is very good for a 12V tool. Control your ALC on your radio, it must not show action all the time. Little or no ALC results in a clean signal without splattering over the band and disturb others QSO's around your QRG. With my Flex 6400, a TS2000, a Yaesu FT991A and a FT891 I always reach a IMD3 which is 35dB or even better! But once again: NO or just a little bit of ALC action on your transceiver! Have you ever heard about ALC? When watching the bands there are many completely overdriven, overmodulated signals, sometimes as wide as 10kHz or even worse. Using this amp in such a way makes you losing friends. And it's a sign of lacking some of the most important basics or in worst case it could be a sign of egoism.

I never had any problems with this handy toy. I use it mostly in my shack and drive my MIDI loop with it.

It's a winner and I'll keep it.

73 de Manfred, HB9FLU
KD8NCP Rating: 2019-05-01
Beware hot switching this amplifier! Time Owned: 0 to 3 months.
I have been very happy with this mobile amplifier and I'm driving it with an FT857D with Menu 20 set for 15 watts. It took me a while to figure out why the amplifier alarm lamp kept tripping when I would key up and the problem was RF hot switching, which you want to avoid at all costs (also thanks to my Elmer on this problem). You can solve the hot switching problem by adding a Time Variable Sequencer Unit, DX Engineering DXE-TVSU-1B, or similar, to delay the RF to the amp. I used a 26ms delay and that solved the problem. Otherwise you can probably kiss your finals goodbye.
KD5HZ Rating: 2018-10-01
Bought Used - Love It! Time Owned: more than 12 months.
In reading many reviews of this amp, seems people fall into two categories as absolutely love for it's reliability and simplicity or hate as it fails on them. I must say, my experience has been wonderful.

I bought used and untested along with an Astron RS-70M power supply from an individual who bought at an estate sale. It was lacking the power cord but I took a chance on buying and then getting a cord from MFJ on having either a working unit or ending up selling for parts on eBay.

After hundreds of QSO's works like a charm. While mine is older and doesn't have front plugs for automatic bandswitch, it is still really easy to use as no tune and a simple knob band switch to operating band.

I do use with an automatic tuner, MFJ 998, which is a bit of an overkill since it will handle legal limits (spend more on tuner than amp) but it is all super simple. Since tuner protects itself on transmit and remembers setting for various frequencies, I never worry about tuneup; just select frequency, listen and transmit.

If you have a chance to find one of these in good condition, grab it.
KB8YIJ Rating: 2018-09-30
ALS 500 Story Time Owned: 6 to 12 months.
I bought a new in the box ALS500M in Phoenix AZ at HRO I'm driving a semi truck so when I had a load out there I stopped in and grabbed one they only had one.

OK with 10 watts in it was putting 100 out so I decided to be easy on it and drive it with 30 watts SSB and used 10 watts CW to fine tune the antenna (A HP40 Tarheel Screwdriver)of course I got the match good on the radio first.

With all that done it was putting out a little over 300 watts PEP on SSB 20 and 40 meters and all was well THEN one day it was down to 100 watts for no reason. Also when you changed bands it would trip the overload on the remote unit.

Called them up sent it in three weeks later got it back hooked it up it lasted two weeks then the same problem all over again only 100 watts out and overload still tripping for no reason?

Well I sent it back again same problem as last time they told me the finals were blown and the whole time was only driving it with 30 watts. This is when I got a little pissed and told them hell CB amplifiers are more durable than theirs why can they get it right!

So this time they had it almost a month got it back SAME THING AGAIN blown finals after three weeks of using it maybe three hours a day at 30 watts drive.

Called them up told them I want a new amp never used or my money back so they sent me a new one except this time they added the 10 meters mod for free.

After that I have been using it everyday for about six months not one problem at all it puts out 450 to 500 watts (With 45 watts drive)on all bands except 10 meters which is about 400 PEP. All SWR is good in and out on all the bands no problems at all.

I'm thinking the original amp I had was built on a Friday or something LOL I don't know but something was wrong right from the start.

My thoughts are if you get one that's good they are a good amp they work as advertised also get one with 10 meters in it because the kit for 10 meters is part of the tank circuit. All the time I was blowing finals without the 10 meters installed and once I got one with 10 meters in it never blew finals again?

I know I might be reaching on that last statement but they could not figure out why it kept blowing finals either.

In closing I will say they always worked with me on the phone and never made me pay extra for anything they even covered the shipping every time.
KM6OKU Rating: 2018-08-16
Nightmare MFJ amp with cold solder... Time Owned: 0 to 3 months.
OK I cannot believe I blew the power transistors up after one week of use and then I went in it and found solder balls all over the power transistor board and a loose half inch long piece of solder floating in the uncleaned solder flux next to the power transistors. Then I found the emitter on one power transistor was cold soldered. Then I found the main 8 guage power line was cold soldered to the high power jack at the back of the case.

So I called Ameritron from here in Germany and they said they would send me free new set of power transistors if I paid for the fed ex so since they were PP100 Chinese clones of the Toshiba 2SC2879's as Japan no longer makes them, I said syonara and just paid $260 for RFParts.com to Fed-X me the 4 transistors and got a matched set of RFP 2sc2879's as nobody can beat RF Parts for reliability, not even Ameritron :) and I had my amp back up and resoldered in 4 days.

Never buy any amp any more unless it has the next generation LDMOS transistors that are the BLF188XR Ampleon (NXP is fine as Ampleon is their new name). These old 2sc2879's are a 40 year old technology and cannot handle any bad SWR. The new 3rd generation BLF188XR technology can handle a 65:1 SWR and will never blow up on you. Do not buy any Ameritron with LDMOS as MFJ bought Ameritron and their quality is akin to being made in China now.

Seriously, I work in Electric Engineering and take it from me, never buy any tube amps or old style transistor amps anymore as they stopped making tubes and transistors to replace them so you are stuck with using the best Chinese replacement transistors and tubes that RF Parts can buy and that is about as trustworthy as a Chinese Junk Boat, which I would not use to cross a river in.

The BLF188XR is the latest tech and is made today and will allow you to short the coax running to your antennae with a copper wire and still not blow up your transistors.

Unless you want a lot of soldering practice then go ahead and buy a ALS-500M. They work for a few weeks very well before the tranny's are toast :)
KT7G Rating: 2018-05-16
very good & reliable Time Owned: more than 12 months.
I have owned and used one of these in my mobile and at times in the home shack. I have a 125 amp alternator in the mobile and a screwdriver type antenna. This amp is designed to protect itself from High Swr and mismatch. anything wrong out there and it drops the relay to protect the devices. Tune the antenna with the amp out of the circuit, then turn the amp on and mine has worked for me for the last 8 years flawlessly.
I used it in the shack and forgot that sequence and had a LDG autotuner work faster than the protection. It got to go visit its parents on that one. I had the remote option installed then and are still using it today. I have six plaques here for high power mobile in 7QP
because of it. The service has been great also.
KE0MPH Rating: 2018-05-15
All good Time Owned: more than 12 months.
I messed up, I bought this amp , and a 75 amp power supply to use as backup for my Acom 1000 .
IMy Acom has never had a problem. I tryed to use the 75 amp power supply and ALS 500 with a generator 2000 watt Honda generator couldn't run it so it sat in my basement for 2 years.
Unused...
I was thinking of buying a new radio from Roger at R&L I,started talking about stuff sitting around, He said put that amp in your car!!!!!!
So I added a second battery for the amp, a 10 gauge wires to charge other battery when receiving.
My radio indicated 14.2 volts on this driving around,with a 40watt drive amp shows 500 watts on the LDG 1000 auto tuner .
In to Hustler 20 and 40 meter antennas,most contacts think I am on a base .
What a great mobile amp