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Reviews For: Acom 1200S

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

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Review Summary For : Acom 1200S
Reviews: 32MSRP: 3,749.99
Description:
ACOM 1200S Solid State HF + 6 Meter Amplifiers cover the amateur bands from 1.8 through 54MHz. They provide 1000W output power (PEP or continuous carrier) with less than 50W of drive. Their operating parameters are shown on a multi-function high-resolution color display.
Product is in production
More Info: http://www.acom-bg.com
# last 180 days Avg. Rating last 180 days Total reviews Avg. overall rating
35324.2
WJ3Z Rating: 2023-03-05
First Impressions Time Owned: 0 to 3 months.
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Update 3/5/2023
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Now that I have operated with this amp for a few months I have to say I like it. It has tons of protection which is a blessing and a pain. I notice it is very sensitive with SWR changes and when you get near max power. I have had it go into protect mode with the most minuscule SWR change and if I turn up drive power to get the amp to 1100 watts or so. I think like someone else said it only does that on a few bands.

So if you are cautious with tuning and watch the drive power, it is rock solid. I love the no wait power on and auto band switching.
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So I just bought one of these amps from DX Engineering. It arrived today and I got to play with it for a few hours. My first impression is I like it but it is touchy. It required that I turn on TX delay on all of my ICOMs for it to work. I kept getting "Hot swap attempt" errors without the delay. No biggie, I learned something new.

I use an HF auto tuner in line with my radios and the amp and I noticed that it is very sensitive to SWR changes as well. Not high SWR but changes as you move up and down the band.

I think I will really enjoy this amp, still trying to figure out how to get it CAT connected so it changes bands as the radios do. I will post another eval as time goes and I use the amp more and more.
K7TAR Rating: 2023-02-22
Brand new A1200S “fresh off the the boat” - June 3rd, 2021 Time Owned: more than 12 months.
First of, I’d like to thank everyone for their posts and reviews - they really helped me while waiting for my ACOM 1200S ordered back in March and finally received today, June 3rd...

The amp came wired for 240V as ordered and I really appreciated all the help from Maria@DXE to get it to me ASAP. The setup was a breeze for me, as I used to own ACOM 600S - so same settings, same cables, same buttons and menus. I was up and running within 1/2 hour after the UPS guy left.

Now: in all fairness, I must describe my rig and setup:
- Icom IC-7610 with a CAT cable for ACOMs, max 100W.
- ACOM 1200S, in standby mode by default, tuned before going full power.
- PalStar HF-AUTO antenna tuner.
- Hustler BTV6 with radials tuned with RigExpert to 1.2-1.4 SWR on all 6 bands.
This is the same setup I’ve had since 2018 (except I started with BTV4 and later added 30m and 80m bands), which ran with ACOM 600S amp until now...

My first impression: mixed-so-far, because I’m still comparing it to 600S. The amp produces 500-600W with only 10-12% of IC-7610 (100W max) power on any band. The 30m band is a ‘challenge’... must stay at 5-6% to maintain the 200W limit. I did ‘kick it up a notch’ on 20m just to see what happens... full 1,000W+ with 21-22% in CW.

I had learned that ACOM stopped using BLF188 transistor, and replaced it with MRF1K80 or MRFX1K80... no way to tell that without opening the amp, as that LDMOS wonder is covered with a mounting plate. All I can tell you is that the PA voltage is still around 50V, not 65V the MRFX was designed for... perhaps it’ll give it the “concrete reliability” now that everyone wanted...

Tested FT8 without pushing it too much - I’m still “burning it in” — 500-600W no problem, but the fan(s) start kicking in, as PA temp gets to 55-60C. I did not push it any higher yet as my BTV might not take it... Also made a few SSB QSOs at 700-800W, good signal reports from CT, EU and Canada, no issues - the PA temp fluctuates around 56-60C with fans going on and off... also normal.

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Update 06/06/2021: So far - so good.. I gave it a good 24-hour “burn-in” this weekend in the Hungarian DX CW contest, and it held up just fine.. PA temp gets to 56-60C, fans kick in, and it cools down fast as expected. One little thing - when power is above 400-600W it starts making this electrical crackling/humming noise like an old TV set... not sure if it’s really a problem, but I reported it back to DXE and ACOM.

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Update 06/13/2021: according to both, DXE and ACOM the noise comes from the power supply, and is normal for this kind. I ran it for hours on 20m in WWSA DX contest this weekend at 1,050-1,100W power with long CQ TEST bursts and only 25-30W input from my IC7610, and PA temp never got above 52C. Fans work quietly, on-and-off as needed. PA DC monitor shows 50-52V / 30-32A from the PS. I think this is a keeper :)
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Update 10/03/2021: so far, so good. One thing I noticed is that it trips if PA current gets close to 34-35amps… which only happens on one band, where the antenna may not be perfect. In any case, I’m able to put out 1,000-1,100W on most bands, but lately been operating mostly on 17m with a MonoGap vertical (added in July) driving 1,000-1,060W in FT8 without any problems - got 93 DXCC countries confirmed in 4 months so far.
So - no, it’s not really a 1,200W amp as far as I’m concerned, but a very good 1KW workhorse. Definitely improved with the new MKRF transistor, which is working at lower voltage reliably.
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Update 02/2023: still no complaints, worked ARRL DX CW for many hours, solid 1,000-1,050W on 20m with only 21-22%/W drive from my IC-7610 for two days, never got hotter than 43 degrees C.
EI8JB Rating: 2022-12-26
Excellent Solid State Amplifier Time Owned: more than 12 months.
I have used my 1200s in line with my 04AT at my station without any problems for over 2 years at the time of this review, it has been a very reliable piece of equipment and a valued investment.

I have had some questions regarding some errors that was appearing occasionally on the display while in operational mode but after various emails to Val at ACOM when these happened Val was able to direct me to complete various tests built into the menu and software which resulted in no fault with the product.

I find the ACOM 1200s reliable and customer service from Val and his team at ACOM very helpful.
K4TJ Rating: 2022-09-28
smooth quiet amp Time Owned: more than 12 months.
Run it at 1kw, the final is rated for 1400 but the power supply runs out about 1200. Cleanest at a KW. Never had a problem in 2 years of ownership.
MI0HOZ Rating: 2022-05-28
Great Amp and great service from Acom Time Owned: more than 12 months.
I've used this with a Hexbeam and a Windom for a few years now. It worked great for a few years then one day it would not turn on. A quick email to Acom and Val described the fault and how to fix it. It was a small mains to 12v transformer. It cost me £20 to fix it. Val in Acom sent me the schematics and fault finding instructions. I can't recommend this highly enough. Forget about valves or tubes, solid state is the future. It connects to my Yaesu FT-2000 with band map data so I just choose a frequency and transmit, no tuning or changing bands on the amp.
RK3TD Rating: 2022-05-16
Quiet and reliable! Time Owned: 0 to 3 months.
I was looking for an amplifier to use in the field or mobile position. In contesting I have enough tube devices. However, tube amplifiers are practically difficult to take out into the field or into the car. My choice fell on several manufacturers: OM-Power, Acom, Burst, THP etc. But first of all, I noticed that Acom works excellently with a gasoline generator and is very unpretentious in conditions of large temperature differences. As for its characteristics: I really liked the work of protection systems, it is almost impossible to burn out the output MOSFETs, since protection is triggered in case of any errors. The fan noise is not annoying. I hardly hear him.
PY2KNK Rating: 2022-05-14
great amplifier Time Owned: 0 to 3 months.
Before giving my evaluation I would like to thank my friend Bob K7JQ who gave me precious tips to work with this amplifier.

Very good amplifier, but you have to know some details before buying it:

To work with this amplifier, especially in RTTY, you need extra ventilation on the outside.
second tip: ideal is monoband antennas or with ROE less than 1.4 so that it has less reflected power and does not raise the temperature and disarm automatically.

I worked with him in several RTTY contests, especially, where he demands the maximum from the equipment, and with maximum power of 1Kw, without any kind of problem, with the extra ventilation the equipment maintained an average temperature in which it did not trip due to excess temperature.

I am very satisfied, because I have an amplifier that gives me 1Kw in all bands in any mode, and according to the manufacturer's guidance if the temperature is within the limit and the reflected power too, there is no problem to use it at its maximum power especially in RTTY.

I suggest that ACOM could add more ventilation to the amplifier, I believe that this would not increase the price of the amplifier too much and would work very well!

A great purchase, I am happy and satisfied.


I hope I could have contributed with my experience, I wish you all excellent DX and contest.

73

PY2KNK Leonardo (PV2K)
K7JQ Rating: 2022-01-18
One year update...still runs great. Time Owned: more than 12 months.
Despite some of the rather dubious reviews on this website, I decided to replace my Acom 1500 with the 1200S. From its release three years ago, Acom admitted it had some "growing pains". But I was reassured by the U.S. vendors, the Acom repair center, and Acom in Bulgaria that the last two production runs, with redesigned boards and firmware, were operating problem free. I've only had it for one month, so time will tell of its reliability.

I put the amp through rigorous operation the last two weekends in the CQWW RTTY and ARRL DX CW contests, and it performed without a hiccup for many hours on end. The amp is rated at 1KW continuous, and up to 1200W PEP. In the RTTY contest, I ran it at about 850-900W, and the temperature never got real close to the protection threshold. I ran it close to 1KW in the CW test, and the fan never got past the second of its four speeds. MUCH cooler operation than my Acom 1500 tube amp, and QUIET.

In an antenna restricted community, I run the amp with an Icom IC-7300 into a high power capable ground-mounted Tarheel screwdriver, far away from the house. As it presents no more than a 1.6:1 (and mostly lower) SWR on all frequencies 80-10M, no tuner is needed. One thing I found out (and confirmed by Acom) is that if you try to drive it to 1KW with an SWR in excess of 1.5:1, the protection circuit is programmed to trip. On the few areas where SWR is 1.6:1 and my voice peaks on SSB hit in excess of 1KW, the amp will soft-fault. Reducing drive where voice peaks are less than 1KW, no problem. At SWR less than 1.5:1, voice peaks can reach 1200W PEP with no problem. Just something to get used to. On CW and RTTY continuous carrier modes, where there are no voice peaks, I can go to 999W at 1.6:1 with no fault issues. I'm not sure where the ultimate SWR trip point is at any power. Usually on SS amps it's around 2:1. But I *think* on this amp, if you substantially reduce power, it won't trip. Don't quote me on that. LDMOS PA devices are supposedly more rugged than previous MOSFET's.

Aesthetically, the amp is a stunning piece of equipment, with an LCD screen (not a touch screen) that provides a flexible ton of operating information at a glance. A nit-pick...the letters and numbers are quite small for ageing eyes. I use a CAT cable between the 7300 and the amp, so changing the band on the radio will do likewise on the amp. Without the CAT cable, the amp's frequency counter will also change bands with a "dit", but I'm not a fan of that feature. Construction and circuitry is typical Acom top quality. I was surprised at its size and weight for a SS amp...almost as large as the Acom 1500, considerably lighter but still quite heavy.

Again, only owning it for a month, I'll have to update my review in the future. But I wouldn't let the previous poor reviews deter you from this amp. So far, I'm very pleased with its operation, and it has a two-year warranty.
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Update-one year of use:
I have now used the amp for a little over one year through many extended contests...CW, SSB, and RTTY. I don't do FT8. The amp has operated flawlessly with no issues at all. The highest drive power needed on any band is about 19W to achieve 1KW output. Fan noise is not objectionable at all to me. Like with all SS amps, watch SWR, drive power, temperature, and you shouldn't have any problems.

Nothing more to add to my initial review...still very satisfied, and highly recommended.

73, Bob K7JQ
VA3LUK Rating: 2021-12-26
Great choice for me Time Owned: 3 to 6 months.
Because of the pandemia, I had to wait about 5 months for this amplifier. When I got and connected the amplifier I am pleasantly surprised. A large nice display is also easy to use. The only small minus or maybe not a minus but plus is the amplifier is very sensitive to a bigger swr and already at 1.5 does not allow to use full power, the protection shut off transmission. Drive power from transceiver max 20W. I haven't looked inside the amplifier yet. LOL, but what I see is professionally made. The instruction manual could have been better. Expensive but worth buying.

UPDATE: A few weeks ago I connected the AT04 antenna box from Acom and noticed that the box does not work. I sent email to ACOM for help and the next day I got instructions on how to do tests to find out if the at04 is damaged or 1200s. This time, the power amplifier was damaged and exactly the power supply that powers the antenna box. You will not detect this fault until you will connect AT04. Acom after 2 days sent me a module of the power supply via courier express, which I replaced myself and everything works correctly. I am satisfied with the product and with the technical support from Acom.
KT4WN Rating: 2021-05-28
Excellent amp Time Owned: 6 to 12 months.
I bought this amp, despite some negative reviews, because of my satisfaction with my Acom 2000A. I'm quite happy that i went with my gut instincts. I have had no problems or issues with the Acom 1200S. It easily puts out rated power on all bands and is a pure joy to operate. I have several tube and solid state amps in the shack. Most of my amps are capable of legal limit and are solid performers. With that said, I find myself using the Acom 1200S about 95% of the time i operate. Yes, I use the Icom 1200S more than the Acom 2000A. I don't have SWR issues; and I don't push the 1200S beyond rated specs.