Legal Limit Solid State Amp - SPE 2K-FA, KPA-1500 or ??

mikeatthebeach .

Have the 2K-FA here but also have on order a PGXL 
For serious duty cycle, the PGXL in a SSPA is a must for me !

Station 1 here is the 2K-FA for SSB/CW work

Station 2 will use the PGXL for hard core 1.5Kw 
heavy duty instant on  for FT8/RTTY use for SSPA's
in the radio shack !

73 Mike

Varistor

Wow, the first PGXL went up for sale on QTH.com. I would have bought it, but someone beat me :-(

W2NER

HUMM

W2NER

I have a SPE 2k for sale if you're interested

Chris DL5NAM

N3NER .... but you forgot to say your "good friend" buy also PA's from Elecraft and after 4 weeks he send back, then he buy from Acom and after 4 weeks he send back and from Expert  .....

All that with many, many trouble and cost for the dealer. To his friends he says ... i got for free to testing ! This guy is a shame for all Ham's ! ( we know his callsign - he is also on our list )

Now he is on "black list" of many dealers! Dealer dont want make business with him anymore! You have a real good friend !

So forgot you stories about this guy ! Tell your own experience and not bla bla from other you have heard !

W2NER

I say what I know is true and I'm sure at some point he will chime in with this post.   There are three great amps as I see it, Acom, Elecraft and Flex..

Bill -VA3WTB

I have a close friend Roger KW2Q who had a PGXL on order from very early on. He canceled his order and bought a KPA1500. He decided that the PGXL had capabilities he would never use and need.
Roger is very satisfied with his KPA1500 although he never pushes it very hard, only on SSB at low duty cycle at around 800w. And it communicates well with the Flex 6500 through the USB connection.

Rick - W5FCX

After some time with the SPE 2K-FA I must say it’s a wonderful amp and tuner/antenna switch combo. Like others, my only complaint is it dropping out of MAX power mode after 10 seconds of steady power out. That’s not what’s expected from a legal limit amp with headroom over 2KW! I’m not sure why it does this, given it has every other angle covered for over-temp, SWR, etc. Alas, I mostly run SSB so it doesn’t affect me today.

Bill -VA3WTB

It simply can nor cool to keep up with full duty cycle

HCampbell WB4IVF

Yes.  Looks like it was designed that way, per the User Manual Section 17, page 52.

Howard

 

Neal Pollack, N6YFM

Just a question, I'm still learning;   While I use RTTY ocassionally, and therefore fully understand why you might need 1500 watts at times, I don't understand why/when you would need that much for FT8?     On bad propagation days, (um, let me correct myself, they are all bad at this solar minimum),  on really really bad propagation days, I have found I need at least 100 watts to rarely almost 300 watts to close a link with far DX (like Spain from California).   But that is really rare, and I have a compromise simple rotating dipole on a 20 foot mast on the side of my house, not a nice beam on a 50 foot tower.

So when is that much power required on FT8 to close a link?
(and if you use that much, don't you make every pan-adapter in a 4-state radius solid red?  :-)  )

Thanks,

Neal

Neal Pollack, N6YFM

1.  But this is a Flex forum :-)

2.  My Flex 6600, driving my KPA-500 amp  (according to PSKreporter), apparently puts out a "clean enough" signal to decode at many many far away places.

No argument that you could be a little cleaner with A.P.D.  (Pure Signal), but it seems to work just fine right now, for hundreds and hundreds of FT8 users, even without being perfect.   Also no argument, if A.P.D. was put into Flex and Icom and Kenwood and Yaesu, it would be even that much better.   And maybe someday it will.

But for now, good enough seems to be working just fine, and the lack of A.P.D. on all these other brand rigs does not seem to be preventing people from using and enjoying the bands.    (Yes, I want to see the improvement some day, but I am not loosing sleep while waiting....)

Cheers,

Neal

Bill -VA3WTB

Good thought Neal. with the way SSDR is right now being able to transmit clean at least 40db down is plenty clean,,

One question I have is what amount of -db is acceptable? Anan users will say 70db,,,really?

KY6LA_Howard

@Neal I have 201 Countries worked on FT8 with172 confirmed now from California Spain is a local station for me. As I work it regularly U need that 1.5KW power when working very weak -20 to -24 signals ...like Midwest or Africa. Or Western Asia. Why? You have a 6 dB gain advantage over legacy radios so when ur copying a -24 it’s very likely that they are not hearing you. So by adding power gain you just might breaking their threshold. Further. Splatter is a function of how hard you drive the DAX TX gain. Keep the audio in the green and you will not splatter. Also splatter actually makes u harder to copy. So don’t overdrive when running power.

Neal Pollack, N6YFM

Howard:   Thanks.  That explains why I have very little of the middle East and Africa.

[To run more than my 300 watts, I am going to need larger, taller antennas, hence
a new QTH (yes, please?), and trade my KPA-500 in for a PGXL.]

I had not asked about splatter, but since you mention, I have a question;
I run the transmit audio level on SmartSDR with the peak marker just below 0 dB,
as instructed by a "How To" article from Flex.   At this level, the Audio Meter histogram bar, and the little peak marker line, are Yellow.

You mention "Keep it in the Green".   I assume you really meant just below 0 dB,
which would be yellow, correct?   In order to keep the transmit audio meter fully green,  I found the level needs to be much lower than 0 dB, hence the power output
drops very far. 
[I have been running at just below 0 dB since I got the rig in June 2018, and have made many approx 700 QSOs with no complaints so far.  Am I doing it right?]

ref:  https://helpdesk.flexradio.com/hc/en-us/articles/202037343-Configuring-WSJT-X-and-SmartSDR-for-Windows

Can you please clarify for my education?

Cheers,

Neal

Jim Runge

could you e-mail the info on your amp for sale.  Tnx, Jim K6JR  k6jr@outlook.com

KY6LA_Howard

Two answers When running barefoot, you’re OK keeping it below 0 DB or in the yellow When running power, you need to reduce the gain so that you’re below -10 DB or in the green Or you will create IMD which you will be amplifying And actually make your signal harder to copy

KY6LA_Howard

The flex article was written for Running barefoot

Edward Armstrong-WB2K

Hi all I have been sitting here thinking about writing this letter I do not usually post a lot of things here but I do from time to time.
I have been reading the comments that one fellow made about the RF kit and how hard it is to build and not be plug-and-play well let me tell you this I've built the RF kit and if you can solder and use a vom meter you can build this amp.
Any problems that I have had or questions Reinhard replies immediately no matter what the time of day. The strong points of this amp which you are not mentioning because you do not have the amp. Okay let me mention the strong points the amp sits on the desk and you cannot hear the fans in this amp no matter how close you get to it another strong thing about this amp is the software which is a dream to use.
The next thing is that this amp is exceptionally clean as far as imd goes anyway sorry about this long drawn out letter but when somebody talks about his friend having problems that something I would not write unless I had built the amp.
Okay as going out I would buy this amp 1 billion times over because of how quiet and the quality of the material take care WB2K

Neal Pollack, N6YFM

Agreed regarding FCC, but it *is* a double  edge sword;    Higher gain amps can make for more efficient low power exciter drive levels, but higher gain stages can also have more stability problems in less than near perfect engineering.   The rule needs to go away though.
No argument.

Neal Pollack, N6YFM

Howard:    Thanks.  Crystal clear now.
Last night I tried driving the amp at -10 on the audio level meter, and running about 50% amp power, I called CQ to a friend on the other coast  (USA West to East), and he said the signal was super clean.    I can work with this just fine.
Thanks for taking the time to explain.

Cheers,

Neal

KY6LA_Howard

@Neal Now go work some of those -24 DXstations that could not hear you

sky

Ria: What antenna were you using on low bands? Anything special?

K1UO Larry

I got a brand new OM Power 2000A+ auto with new spare tube I would swap for an KPA1500 or outright sale.

Larry  K1UO

Varistor

Keep the OMP!

Bill -VA3WTB

Visitor, I am interested why you would keep the OM over the KPA1500? Not that I disagree, but what reasons do you have?

Varistor

My main reason is ROI- for $4K I purchased an amp with warranty that can do full duty cycle at full power until the cows come home. I run the fan at full speed all the time, vs the auto or PTT settings, and the noise is not an issue at all, even without headphones. The OMP integrates well with Flex and all other rigs that have CAT. Or you can do RF sending. In my case, I use CAT. Also, unlike other amps that have zillions of antenna outputs, the OMP has a single output PLUS two outport ports for 1) BPF and 2) antenna selection. I firmly believe that antenna switching should be done remotely, at the tower base. I no longer need my microHam box. Auto tune is instant and very reliable. The RF deck is based on a classic, timeless platform that is well understood and refined over the years. It is beautiful to look at! The finish is outstanding and compared to anything Elecraft is luxurious. The touch screen is vibrant and gorgeous. Ability to do auto, factory, or user selected bias (aka the Meffa thing that 4o3a promotes as unique). Last but not least, remote access is the best I have experienced. There is nothing to dislike about the amp. The warmup time has never been an issue in my 30+ years in DXing and contesting.

Bill -VA3WTB

Interesting, I don't own such nice amp so I learn from people who do... Thanks..

KF4HR

Expert Amplifiers recently released the letter below::

• Dear Customer,
  I want to inform you that we started the production of the Expert 1.3K-FA and Expert 1.5K-FA, both versions II.  This was necessary to comply with the new EU rules which are much stricter than the FCC.
  The most significant example is the minimum harmonic attenuation in HF which must be -50 dB, while in the 6m band the minimum attenuation must be -70 dB.
  This involved:
  - A new filter unit design.
  - A new output transformer design.
  On this occasion we have also added many modification. Among them is the soldering of LDMOS to the heat sink, which is very important and greatly facilitates its dissipation.  These changes have led to significant improvements in the use of our linear amplifiers.
  We have, for example, thoroughly tested one 1.5K on FT8 on 6m at FULL power for over 6 hours continuous without problems.
  Unfortunately the changes are such that it is not possible to retrofit the hardware of version I to make it a version II. Therefore version I's hardware and performance will remain the same.  The future software for the 1.3K and 1,5K will be compatible with both version I and
  version II.  Only the second series amplifiers, version II, will be produced and delivered, and the prices will remain the same.
  I hope this continuous effort made by SPE for the improvement of its products will be appreciated.
  My best 73s
  Gianfranco I0ZY
  
  
  
  
  
  

Mike W9OJ

soldering of LDMOS to the heat sink ?

Mike W9OJ