ACOM 2000 - Thinking of Giving up on PowerGenius

  • 2
  • Question
  • Updated 9 months ago
  • (Edited)
I've been reading about folks waiting for their PowerGenius numbers to come up.  People who paid deposits in 2017, still don't have theirs and continue to hear nothing from Flex.  I only got my name on the list in August of 2018, have already waited 10 months and obviously still have a long long way to go with the same small chance of ever knowing how long.  Add to that the fact that despite many attempts no one has succeeded in even getting information about the antenna tuner let alone specifics so it's probably much further out still, if ever.  Plus the current knowledge base includes at least one major manufacturing issue with a still "Version 1" design, only a small sample of existing users so far, and continued extreme difficulty getting official information from Flex about what's going on.  As usual.  I need an amp and I'm about to give up.

Looking at alternatives, I would sure appreciate some advice.  I'm mostly interested in quality, reliability and a good reputation.  I'd like full power on HF with auto tuning and need an antenna tuner one way or another (I've got big "space sacrifices" in the antenna department I need to deal with).  I don't trust Alpha at all, would like something a little more substantial than say Ameritron (not knocking them - I had one once and they're just fine) and I'm leaning towards the ACOM 2000a based on lots and lots of mostly positive reviews over many years.

There are some posts here on them, mostly about hooking them up.  I exchanged emails with DX Engineering and they advise not bothering with anything but the PTT line and letting the amp do the work when it's actually going to be used (as opposed to following your tuning-around adventures with it's servos, etc).  It seems very beefy, has the power, apparently is a good QSK machine (even my 6600 can't say that (yet?)), built-in antenna tuner and again, years and years of user experience.  I'm beginning to think it's a better move.   Would sure appreciate any thoughts anyone may have.  Thanks in advance!
Photo of Russ Ravella

Russ Ravella

  • 84 Posts
  • 47 Reply Likes

Posted 12 months ago

  • 2
Photo of WW1SS - Steve

WW1SS - Steve

  • 865 Posts
  • 289 Reply Likes
I like the KPA-1500. Had mine about 6 months now and works flawlessly. Have the Elecraft Flex cable hooked up to it and band switching works great. No noticeable fan noise here. It just hums along.
Photo of Russ Ravella

Russ Ravella

  • 84 Posts
  • 47 Reply Likes
                                                   **UPDATE ON ORIGINAL POST**

I wanted to follow up on my post since so many of you were kind enough to respond.  Again, thanks for that!

Given that I'm not willing to chance an ALPHA at this point, the decision actually seemed to boil down to three choices almost immediately.  The same three are reflected in most of the responses here to my post: the SPE, Elecraft and ACOM amps.  It seems like that should make things easy but actually the opposite was true, at least for me.  Based on the information available and especially the responses here in this thread, it's obvious that any of the three would be a good choice.  It could almost be a coin toss.  But I had to decide based on something.

I thought alot about the SPE.  There are LOTS of folks very happy with their SPE's.  My primary concern was actually well described by Richard Zalewski's post that essentially a customer's safety line to SPE is a single one man shop in the US.  He only needs to become unavailable due to retirement or whatever and you'd be dealing directly with an Italian factory with whom you had no relationship whatsoever.  What iced it for me was I sent him an email asking some questions and after two or so weeks he still hasn't responded.  I have no doubt I could get a hold of him with further effort but the lack of response felt like an omen of exactly this concern.  If there were no alternatives I'd go for it anyway but there are.  Also, they require the customer to pay shipping both ways even for warranty service.  Not too impressed with that frankly.  And there's the fan noise issue.  There are reports both ways but having an issue with fan noise feels like a real possibility.  Many people who have reported having no problem with it also seem to operate low duty cycle modes or at reduced power.  Reduced power to at least some extent defeats the whole purpose to me.  If you're going to spend a lot of money for a full power solution to the problem, you should solve it completely.  And, of the three, this is the only one that gives you no choice - if you run a high duty cycle mode, it folds back automatically.  That fact also contributes to a feeling that it's a little fragile, at least compared to the others.  But to my first point, that comment is relative.  This amp has seen a lot of use.  And its been on a ton of dxpeditions and performed flawlessly by all accounts so "fragileness" is apparently not a problem per se.  It would obviously be a very good choice.

I had a real hard time with the KPA-1500.  It seems to be a nearly perfect amp.  Excellent reputation company you'd deal directly with here in the US, obviously an excellent design and very full featured.  And I got OUTSTANDING super fast support with some detailed questions from them.  The ONLY thing that bothers me about it is the fan noise thing.  I think it's just possible I'd wish I'd made another decision after using it for awhile based on lots of reports.  Some people have reported returning it the very first day because of fan noise while several others have reported it's not an issue at all.  Since I can't try it out in my own environment first, how do I know?  They've done a firmware update recently addressing it and my guess is it wouldn't actually be a problem but I can't be sure.  And of course it's not like you can send it back for a refund because of something like that.  Obviously it's a potential issue with SS amps in general.  I've heard the same kind of reports about the PowerGenius as well.  Although they can obviously be made to work very well, SS amps are less robust than tube designs.  For everything on the other side of the great power divide I'm just inclined in favor of brute force and overkill.  Also, surprisingly, the Elecraft only has a one year warranty while the others have two (I can't find the warranty period for the PowerGenius - 2 years like the radios?).

As far as I can see, there are no equivalent risks with the ACOM 2000a.  Obviously, any of the three could have some kind of problem out of the box and there are reports of that with all three.  But given their reputation from many customer reports I think it's about equal and unlikely with all three.  I know going in I have to find another 6M solution but it's going to be quiet, reliable and just idle along at full power even with high duty cycle modes.  Feels like bringing a bazooka to a knife fight.  Again, I've been attracted from the beginning to the ruggedness of tube designs and the ACOM is sort of a well seasoned, modern/old-fashion implementation of that.  And (apparently) stable service is available right here in the US.  I've been interacting with DXEngineering about it and their responsiveness has been nothing short of phenomenal.  If their after purchase customer service is anything like that, all is well.  So I decided on the ACOM 2000a and just placed the order.

I've already got the feeling I'm going to wish I'd ordered both of the other two from time to time.  But I also have the feeling I may have REALLY wished I'd ordered the ACOM instead if I had.  I know it sounds stupid but I'd buy all three if I could justify it.  It's a hobby right?  It's supposed to be about having fun.  It doesn't have to make sense.  But it is expensive...

Again, thanks to all for the help.  It really DID help!
Photo of W2PP


  • 311 Posts
  • 45 Reply Likes
I've had the ACOM 2000a, and have both the KPA1500 and the Expert 2K-FA now.  I love both the SS amps.  The reason I sold the ACOM was the tubes are getting harder to find.  They are around right now, but, as time goes by that will change.  The warm up period was a bother too, maybe it's just me but every time I listen for a rare DX I don't have my amp on!!   The issue with fan noise on the two SS amps is old news.  The KPA1500 even with FT8 is pretty quiet and the 2KFA is quiet as well, just isn't an issue.  You'll love the ACOM 2000a, I mean its a tank and behaved flawlessly here.  I loved it.  Just the potential tube issue and the lack of instant on.  I, again, need instant on as I frequently drop into the shack for just a few minutes and often times catch something I'm interested in.  

Photo of Chris Tate  - N6WM

Chris Tate - N6WM, Elmer

  • 1017 Posts
  • 282 Reply Likes
Although I am a proud and happy PGXL owner, I have to comment that a good pair of GU-74 tubes should outlive most of us unless abused.

Photo of Eric Gruff

Eric Gruff

  • 68 Posts
  • 28 Reply Likes
Just to add my $0.02:

Disclaimer: I wanted to buy the PGXL, but was sent to the waiting list purgatory, so am treating it like vaporware at the moment. Also, I am very hard on amps as I run FT8 frequently on 160 through 6 Meters. I expect my amps to be able to handle at least half-rated power in this style of operating.

I have an Alpha 9500 that I've owned for about 7 years. When it's working, which is usually, it can put out full legal limit on 160-10 M pretty much continuously and forever. I have had to have it repaired three times, each due to failure of HV components. Two of these failures are known to the manufacturer as occurring in older amps. After the last repair, which included replacing the RS-232/USB chip, the same chip failed in about a month, so I have no remote control capabilities and do not want to ship the beast back to  Alpha.

I have an Acom 2100, which covers 160-6 M at full legal limit albeit as a fully-manual tuner. This amp is very solid and well-designed, and can run full legal limit on FT8 without issue as it has a power tube final. If you don't need automatic band switching and tuning, I would highly recommend the Acom 2100. 

My SPE 1.3K-FA, the little brother of the 2K-FA and 1.5K-FA, is now a paperweight. Long story short, it has burned up three times. Twice, Bob Hardie repaired it under warranty while telling me it had to be my fault since he'd never seen this happen before. The latest immolation occurred running 750 W on 80 M FT-8 into a 1.06:1 SWR. No warning, just lots of putrid smoke and $4k down the drain. I know the 2K-FA is much more rugged, but I will not spend another penny on an SPE amp given the poor design of the 1.3K-FA. The RF deck cooling is very poorly designed. On a less critical note, the beeping of the amp when it doesn't like the antenna or some other condition will drive you crazy.

FInally, I bought the RF-Kit RF2K. It is NOT a turnkey amp. You have to do quite a bit of tuning, and I've managed to destroy one BLF188 during use and another during the amp tuning setup after upgrading the firmware. As noted above, the amp is nowhere near legal limit on 6 M and possibly some of the HF bands. It's a promising experimental PA, but if you're looking for something to plug in and use, I'd steer clear.

Again, I'm close to a worst-case user of amps given my FT-8 propensity (I also contest and DX), but I do expect $4-7k PAs to at least work properly and not immolate themselves in protest. I don't intend this as a gripefest, but I'd like to save at least one of you from the very expensive mistakes that I made in the past. SSPAs are not for everyone is the take-home lesson.

73 and good luck with whatever you wind up with,

Eric NC6K
Photo of Russ Ravella

Russ Ravella

  • 84 Posts
  • 47 Reply Likes
Thanks Eric.  Your experience aligns with the impressions I developed trying to decide which amp to buy.  There are clearly happy customers using all the candidates.  But folks are expecting different things and using them in different ways and it's not always easy to line those things up with what they're reporting. 

Hopefully ALPHA is on it's way back but I'm not willing to risk it.  Your experience is consistent with what make me nervous about them.  And as I mentioned in my last post, I sort of get the feeling that in at least some sense, the SPEs are somewhat fragile.  Obviously not always but versions of experiences like yours are reported a little more often than with the other manufacturers.  And the support situation seems sub optimal.  I've had one experience just trying to communicate with Expert Linears myself and it wasn't good.  And, just in general, SS amps are less robust than tube amps and all that entails.  Like the SPE, there are lots of positive reports on the Elecraft but a few too many scary ones with blown finals and so forth.  You keep hearing things like, "...they're just fine as long as you don't run them too hard".  But why accept having to worry about that at all.  And reports of a lot of fan noise keep surfacing.  So for me anyway, a tube based battleship with a good reputation and support, and lots of positive customer experience seems like the right choice - in my case, the ACOM 2000a.  We'll see if it was a good choice.  Again, thanks for your advice!
Photo of Eric Gruff

Eric Gruff

  • 68 Posts
  • 28 Reply Likes
Russ - sounds like you have a very solid perspective, and I think you've hit the nail on the head as far as hit or miss. One thing that hasn't come up in this discussion that is germane is that SS PAs with multiple power devices are less likely to go up in flames as those that use only one (like my late 1.3K-FA). The heat dissipation of a single device running hundreds to 1.5k Watts is an awful lot for that relatively tiny package.
Photo of Chris DL5NAM

Chris DL5NAM

  • 738 Posts
  • 163 Reply Likes
Photo of Mark - WS7M

Mark - WS7M

  • 1466 Posts
  • 549 Reply Likes
I bought the SPE 2K-FA because one became available at a great price at the end of last year.  Bob made me a great deal and I seriously doubt I will ever sell this amp.  There are just too many good things about it.

Here are the downsides first:

1 - Not completely integrated with Flex.  By that I mean that when I hit the SSDR tune button I'd like the amp to go offline so tuning can be done at reasonable power.   There is no built in functionality for this so I had to write my own.  

2 - Can't maintain more than 1000W out continuous key down.  There appears to be firmware that samples the output and duty cycle and automatically steps it down to keep it around that 1000W even though the amp has yet to get hot.  So far this is not a severe limitation but FT8 does push it into the realm.  I've yet to need more than 1000W in FT8 and usually try to use FAR less.

3 - Like most amps there is significant fan noise in just operate mode.  

4 - There is one case where transmit power from something feeding an input can appear on the SO2R port of the amp.  This is a big concern and why I do not use that port currently.  I notified Bob at Expert Linears, he confirmed that and the factory has been notified but I don't think it is a simple firmware fix.  Not too big a deal for me personally but scary as you could do some serious damage to radios listening on that port.

5 - Internal Tuner cannot match SWR worse than 3:1.  It simply gives up.  I would prefer it simply got to the best it can get and gave a message.  

6 - The state of tuning in progress/complete is NOT part of the status packet you get over RS-232 which makes it hard for a program like mine to know that tuning is completed by the internal tuner.

The last two items for me are the ones that I would love to see changed in a firmware update.  One thing I really like about the internal tuner is that it has memory and the changes are instantaneous.

I wrote a small program that drove my flex from band edge to band edge and every 5 khz I initiated tuning in the amp.  The result was that no matter where I went I was instantly ready to put on full power.  No tune cycle needed at all!

This worked well for all bands the internal amp tuner could handle.  But for bands where my antenna is just not great (80m loop). I could not get the tuner to give me even a reasonable SWR so I literally could not operate there at all.

While I get that operating on an antenna with bad SWR is never a great idea, at lower power I figure it is ok for a short period but the way the tuning works in the SPE I simply cannot get there.   If I use my HF auto then I can get there and I can run some power.  Not much as I know the feed line and other stuff is getting hammered.

But for an antenna compromised soul like myself if the internal tuner was a little more beefy and could handle a worse match it would be great.

A few upsides:

1 - Connection and control of the amp for remoting is well documented and easy to implement assuming you are willing to do a tiny bit of work.

2 - Having 6 antennas is really very cool, if I ever get some way to run 6 feed lines it would be great.  The amp is setup so you can define which antenna for which band and it auto switches.

3 - The amp is incredibly well protected.  A few times I've done something stupid and amp just beeps and lets me know what an idiot I've been.

4 - Service and support are fantastic as long as Bob stays in business.


The amp meets my needs pretty well.  I wish the tuner was a little more able.

If FRS would some day provide an API that would allow external devices, non flex devices to be integrated into SSDR it would allow developers like myself to make the SPE amps almost as handy to use as the PGXL.

If I could run 6 feed lines, to 6 mono band antennas of good quality then it would be possible to instantly switch bands and be able to run power instantly.

If you are single antenna ham like myself then you have to toggle a few switches to get things tuned and ready.  But still it can all be done remote.  You just need to put a little work into it.

Mark - WS7M
Photo of Pat - WH6HI

Pat - WH6HI

  • 649 Posts
  • 116 Reply Likes
Hi Mark, I agree with you on all your points. In my case I managed to use all 6 ports. Port six is my dummy load. My antenna system is a set of dedicated antennas, and kind of avoids to running problems. My main antenna is a log periodic and is flat from one end to the other, except for the band edges at 20m and 10m. My 40m rotary dipole is the same in that only the band edges need tuning. My other antennas are purpose tuned for FT8 on 80 and another on 75m for a narrow range of SSB frequencies. Oh yes one antenna for 60m dedicated to Net frequency here in the islands. I love the amp, and especially like the ability to assign up to 3 antennas per band. Example: I can select port six , which is my dummy load on each band. Or you n another case 40 meters of n two different antennas. I love that feature! Any way love my SPE 2K-FA.
Photo of KM4CQG


  • 275 Posts
  • 46 Reply Likes
Hi Guy's

I have been a Flex user since 2014 owning both the 6500 and 6700.
While mostly digital Modes and contest I do on occasion use Phone.

Currently running the SPE 1KA that I bought several years ago it will run up to max 500 digital  and 1.2KW on Phone. Seldom is there a need to run these values at my QTH.

I put myself long ago on the PG wait list have never heard a peep.
Does anyone know whats going on with it?
I spoke with both Lou and Gerald a few times about it Gerald told me it's noisy when the Fans kick in. Watched a few videos and it sounds like a Turbine winding up so might need to locate it elsewhere.

Bottom line how much longer till we see these units in regular production any idea's?

Photo of Michael Walker

Michael Walker, Employee

  • 1384 Posts
  • 412 Reply Likes
Hi Ian

If you call the Sales line and talk to Matt, he can update on the delivery for you.  

Photo of Larry - WA7LZO

Larry - WA7LZO

  • 186 Posts
  • 47 Reply Likes
You may want to consider the new, and beautiful, Icom PW2, when it is offered for sale. Keep in mind 1.5kW represents not even one-third of an S-unit increase in received signal strength over 1kW, as even 6dB of power gain provides but 1 S-unit increase in received signal strength. I seriously doubt anyone blindfolded could possibly objectively notice an increase of 1.761dB of power gain, which is a tiny 0.2935 S-unit increase in received signal strength. The PW2 has a gorgeous and extremely useful removable front panel. It is also fully SO2R capable, too.
Photo of N2WQ


  • 61 Posts
  • 12 Reply Likes
You may want to consider this when deciding if 1.8 dB is a big deal or not:
Photo of KT0AM  - Mark

KT0AM - Mark

  • 25 Posts
  • 4 Reply Likes
Thanks for sharing this study, Larry. It was interesting to observe a real-wold systematic analysis on the effect of noise on a signal under controlled conditions. We talk about power but it's often difficult to quantify what the discussion really means.
Photo of Sergey Abrikosov

Sergey Abrikosov

  • 420 Posts
  • 61 Reply Likes
If you do not need this amp, it is ok, you do not have to make excuses.
You are contacted 300 contries with 100mW, great. Keep going.

I am getting mine probably next month and happy about it.
Also, using Acom2000A for about 10 years and still going strong.

Sergey, KN7K
Photo of Mark - WS7M

Mark - WS7M

  • 1466 Posts
  • 549 Reply Likes
I also put in a vote for SPE-2K-FA.  Flawless for me as well.

The only downside is that the amp will auto dial down output if the signal duty cycle is close to 100%.  So it is not a full legal limit amp on 100% duty cycle.

The only place this ever is an issue is RTTY or FT8.  In both cases the most the amp will produce is about 1200W and that is stretching it.

However, I find that 1000W is usually more than enough to do what I want.   

As a developer I've integrated the SPE amp into my logging software so FRLogger offers complete control of the amp.   

I have most of my ham gear in a shed about 30 feet away.  But from anywhere, including my office, I can control my radio and amp.

Mark - WS7M
Photo of Michael N3LI

Michael N3LI

  • 252 Posts
  • 82 Reply Likes
I have a linear, the PW-1. I've been asked why I don't get a real amp by some folks. It does what I need and I like it. And ahem..... some folks consider full legal limit too restraining. Not sayin', just sayin.