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ACOM 2000 - Thinking of Giving up on PowerGenius



  • Eric Gruff
    Eric Gruff Member ✭✭
    edited July 2019
    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.
  • Neal Pollack, N6YFM
    Neal Pollack, N6YFM Member ✭✭
    edited July 2019
    KPA-500 is a rock solid tank.   But, no matter how well something is built, an untrained, un-technical, CB-Head all-knobs-to-the-right, ignore red lights and temperature readings, "Special Kinda' ****" can easily **** it up.  I don't care if it is  a ham amplifier, a Ferrari, a power tool, or an F/A-18 fighter jet;   if someone does not drive a fine machine with care and skill and attention, they can crash it or trash it.
    Cell phones and MicroWave Ovens are made for the distracted general public who just want to mash a button and walk away.   Guns, chain saws, Fighter Jets and Ham Amplifiers are clearly NOT.  Ya' need some attention, understanding, and skill, or you're gunna' become real unhappy real quick.

    But for those who pay attention and watch temperature, SWR, and red alarms while they operate;  I  have beat the **** out of my KPA-500 for several years of RTTY and JT-65 and FT-8.  It takes a licking and keeps on kicking.   Shortly after I bought it I was doing a RTTY contest and it was under max indicated temperature, but making heat-sink hold-down-spring creaking noises.  I called Elecraft to inquire, and they said "Yes, we know,  it's two dissimilar metals that make that noise, but ignore it.  Will not cause a failure. I reminded them I was doing hard digital modes, and they literally said they challenge me to try to break it.   They could tell from the conversation that  I would push the amp, like a fighter jet pilot, but that I would also pay close attention to SWR and the temperature meter.    They said after designing it, for beta testing, they put it out with RTTY contesters and DXpedition folks.   They we very happy with the results and so am I.  That conversation was 3 years ago.   I still kick the **** out of the KPA-500, but with care and respect and a watchful eye on metering.

    That said, I am an engineer who has worked 35 years for manufacturers, and can tell you that no matter how well ANYTHING is designed, parts have statistical failures.   Even if not over-driven, parts have manufacturing tolerances and fall at both ends of a bell curve, with some statistical outliers. For the few weak parts that come out of manufacturing, they will quit on you randomly, no mater if driving the amp at 50 watts out or 1500 watts out.  The parts don't seem to care if they are purchased by Elecraft, Alpha, Palstar, Yaesu, Flex, Icom, or anyone else.  They are just parts.  They can and will sometimes fail when we least expect them to.  So any brand name can have a bad customer experience if you happen to get the wrong part.  [It just appears that MFJ has a special skill for finding more of the bad ones :-) ]

    That above is all about the occasional and somewhat rare statistical failures that occur even if you are treating the machine well.  It should be approx 2 to 5% of customer units, with a lot of variables coming into play.

    But second, we have the general item that applies to ALL of the parts;
    Heat is the enemy of all semiconductors, toroids and ferite cores, resistors, capacitors, and mechanical parts too.   The harder you drive "any" type of product, the less life span it has.  But still, an amp designed for 1500 watts should do just that for at least a decade, if driven with attention and technical care;   not if used for arc-welding CB-radios onto a rusty pick-up truck. :-)   And not if "driven" by someone who never notices poor SWR or border-line termperatures.  These are the same people who hook a frequency counter directly to the output of a transmitter, key up, and then say, humph, dang counter don't work :-) :-)   Um, er, ah, right.
    [Thanks for being the source of 10 cents on the dollar test equipment that I buy and fix after idiots put it on discount for me :-) ]

    But back on topic;   The PGXL and the Elecraft KPA-1500 are both fine designs.  Both are built exceptionally well, and the PGXL also offers a higher level of integration and control options with other Flex equipment.

    If either one of them had blown finals, it would be down to either the random statistical failures I mentioned in manufacturing semiconductors, or it would be down to the Pilot.   We have all met friends who could destroy ANY tool or machine simply by walking within 10 feet of it.

    Buy the amp that YOU like.  All of the amps mentioned here in this thread are really great, except of course the weakest of the baby SPE.  But the SPE 2K, the Acom, heck even the ancient Yaesu Quadra, are all fine amps that will make you very happy, and be very durable if you treat them with respect.


  • Mark_WS7M
    Mark_WS7M Member ✭✭✭
    edited June 2020
    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 **** 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
  • Ian1
    Ian1 Member
    edited May 2020
    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?

  • hammenitup
    hammenitup Member
    edited September 2019
    It sounds fantastic. But I'd hate to be one of those poorr souls hat have been waiting for two years just to get on a list. Ouch.
  • N5NHJ
    N5NHJ Member ✭✭
    edited September 2019
    SPE forever, 2K is rock solid, if you like something lighter go for the 1.5K.
    Both are fully integrated with the Flex CAT.
  • ctate243
    ctate243 Amateur radio contester Member ✭✭
    edited September 2019
    a decent amp, but SPE cannot handle full legal limit full key down. PGXL Can.  nuff said.
  • ctate243
    ctate243 Amateur radio contester Member ✭✭
    edited September 2019
    PS I have both.
  • Mike-VA3MW
    Mike-VA3MW Administrator, FlexRadio Employee, Community Manager, Super Elmer, Moderator admin
    edited September 2019
    Hi Ian

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


  • Larry - WA7LZO
    Larry - WA7LZO Member ✭✭
    edited March 2020
    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.
  • N2WQ
    N2WQ Member
    edited September 2019
    You may want to consider this when deciding if 1.8 dB is a big deal or not: http://www.ab7e.com/weak_signal/mdd.html
  • KT0AM  - Mark
    KT0AM - Mark Member ✭✭
    edited September 2019
    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.
  • Norm - W7CK
    Norm - W7CK Member ✭✭
    edited September 2019
    I can't see spending all that money just to say "59 73's".  Or worse yet having WSJT-X send it for me.   I have a simple wire antenna and modest station running 500w.  Its all the fun I need.  I had a big tower and antenna at 60' when I lived in Alaska.  It was a pita to maintain and a money pit but that was back in the day when people actually still rag chewed on the air and phone patches kept folks in touch with their families from all over the world.  I felt it was worth it at the time but now in hind site, I wonder.

    I don't have any plans to expand my station.  Happy with wire antennas and my measly 500w amp which I normally only run at about 300w.   I guess if I was a contester I would look at things differently but I never could figure out the attraction to contesting.
  • W7NGA
    W7NGA Member ✭✭
    edited September 2019
    Excellent reply Norm ...
  • Pat N6PAT
    Pat N6PAT Member ✭✭
    edited September 2019
    I agree. I use 300 watts and a small Hustler 6BTV ground mounted vertical and it's a lot of fun especially when I break thru a pileup.

    How does this little setup perform? So far 272 countries 1,814 band points, 10BDXCC (including 60 meters), 17 different WAS band/mode combinations, Triple Play, 5BWAZ, SSB WAZ, Mixed WAZ and just completed requirements for Digital WAZ,

    I added a simple 160 mod and got WAS Digital 160 in just 10 days and now at 123 countries and 28 zones. I need just 2 more for WAZ 160 tier 1. Email me for the 160 mod info. It's very easy to do and works great. Also, just need AK for WAS CW 160 and 5 more for WAS SSB 160

  • Sergey KN7K
    Sergey KN7K Member ✭✭
    edited September 2019
    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

  • David Decoons, wo2x
    David Decoons, wo2x Member, Super Elmer Moderator
    edited September 2019
    Sounds like the KPA1500s with blown finals may have been built before they started adding zener diodes across the gates of the LDMOS devices. The zeners help protect the LDMOS against getting whacked with high input wattage. Dave wo2x
  • Mark_WS7M
    Mark_WS7M Member ✭✭✭
    edited September 2019
    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
  • Michael N3LI
    Michael N3LI Member ✭✭
    edited September 2019
    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.
  • Patrick
    Patrick WH6HI KauaiMember ✭✭✭
    edited September 2019
    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.

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