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

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  • Updated 9 months ago
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Looking at solid state legal limit amps with integrated tuner for use with 6700. The SPE 2K-FA and recently introduced Elecraft KPA-1500 look pretty sweet and similar. I have a KPA-500 which is a great amp but looking for a bit more punch to break through pileups with my Spiderbeam.

Not sure what other amps should be on the shortlist.

Rick, W5FCX
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Rick - W5FCX

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Posted 2 years ago

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Bill -VA3WTB

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I think I would stay with poor IMD thanks..lol
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Varistor

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Wow, the first PGXL went up for sale on QTH.com. I would have bought it, but someone beat me :-(
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K1UO - Larry

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

Larry  K1UO
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Varistor

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Keep the OMP!
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Bill -VA3WTB

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

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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.
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Bill -VA3WTB

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Interesting, I don't own such nice amp so I learn from people who do... Thanks..
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W2NER

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HUMM
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W2NER

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

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could you e-mail the info on your amp for sale.  Tnx, Jim K6JR  k6jr@outlook.com
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Rick - W5FCX

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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.
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Bill -VA3WTB

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It simply can nor cool to keep up with full duty cycle
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HCampbell WB4IVF

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

Howard

 
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KF4HR

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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









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Mike W9OJ

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soldering of LDMOS to the heat sink ?

Mike W9OJ
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John Culliton

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For best heat transfer, the ldmos devices are soldered to a copper plate that is screwed to the heatsink.