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Reviews For: Elecraft KPA-500

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

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Review Summary For : Elecraft KPA-500
Reviews: 124MSRP: 1999.95 Kit Form
Description:
KPA-500 Solid State Amplifier 160-10M Plus 6M, Auto Band
Switching via RF sense or cable connection.
Product is in production
More Info: http://www.elecraft.com/
# last 180 days Avg. Rating last 180 days Total reviews Avg. overall rating
251244.9
VA3MW Rating: 2014-06-01
Excellent Value Time Owned: 0 to 3 months.
I bought my KPA500 to replace my SGC500 as I wanted to run 6M at my remote base.

If you know how to use a screwdriver, then I would recommend getting the kit. The instructions are very well written which is normal for Elecraft.

My amp will be used in a remote base 100% of its time. In my initial testing, I ran into a few issues, but the simple answer is to run your RS232 port to the amp at 38400 (don't change the default). If you do this, you won't have an issue with remote power on/off. Thanks to the Elecraft developers for jumping right in on my dialogue to help me debug this very quickly.

I love its size and ease of operation. I use it with a TS480 and I have only run it with a PTT lead (no ALC or Rig RS232). I keep an eye on the health of the amp with the Remote Utility. I am also running mine with 120AC and I have not seen a voltage sag at all.

An excellent choice. (I only give out 5's if it is worth it).
K2MK Rating: 2014-05-20
Absolutely Terrific Time Owned: 0 to 3 months.
I do have one regret. Why did I wait so long to purchase a KPA500? I have a big amp which I don’t see myself selling any time soon but I do expect to be using it less and less. The KPA500 is so transparent that it is truly as if I were operating a 500 to 600 watt transceiver.

I’ve been using it a lot lately chasing the W1AW/n portable operations. What a pleasure to jump between bands and modes as the spots appear on the cluster. No warm up, no tune up and super quiet QSK.

This is a really easy and fun kit to build. I highly recommend the kit version. I also really like the additional benefit of using it with a K3. When the KPA500 is in operate mode the K3 power levels are as I set them on each band to achieve full output on the KPA500. When the KPA500 is in standby mode (or off) the K3 power levels are as I set them to achieve full output on my big amplifier.

Regardless of what rig you own, you will be extremely happy with a KPA500.
K6SBA Rating: 2014-02-26
Perfect Operating History Time Owned: more than 12 months.
I have a relatively early serial number (#191)KPA500. Since purchasing,. I have operated the amp almost everyday into nonresonant antennas, originally matched with a Palstar manual tuner, but now with a KAT500 since it became available.

I haven't had a single problem, except for operator-induced ones, and the amp's protection circuits have kept me out of trouble.

I have used the amp with both my K3 and other transceivers without any problems. The K3-KPA500 combo is enhanced due to the communications between the two, but RF sensing has also worked fine with two different models of Yaesu transceivers.

No product is going to be 100% perfect, and component failure can happen especially from sourced parts over which the amp manufacturer cannot have complete control of QA/QC.

I can give an unqualified recommendation for the KPA500 to anyone who is looking for a medium power amp.

73 de K6SBA
David in Santa Barbara, CA

M5LRO Rating: 2014-02-25
Lovely BUT Flawed Time Owned: more than 12 months.
The KPA500 is a super little amplifier but has its issues, issues that were for me unreasonable.
The amplifier worked fine from day one and I enjoyed many a good Q using this little machine. It works seamlessly with the K3/P3 combo and is just there on the bench ready to fire up and work. That's superb and I take my hat of to the guys at Elecraft for the intuitive design approach.
However, the amplifier I owned suffered not one but two failures which have been documented before. For some reason this little amplifier has poor components or design in the output matching stages. I was operating on 15m one day and had been for a while when all of a sudden cracking and smoke appeared from the top of the amplifer. Upon further investigation this appeared to be evident as a capacitor blown off the matching board on top of the RF deck. Elecraft swapped out the part, unit still well within warranty at this stage. Not really a good explanation as to what went wrong but back up and running. There was no reason for this to go faulty other than component failure as I use a Hexbeam here and that is resonant at all times on all bands.

Some months later, now out of warranty I powered up the station only to hear a pop from the KPA500. On testing found no output whatsoever, on inspection found both transistors almost surgically removed from the PA board, no smoke, no burning - but then I had not transmitted????

Now at my significant cost the unit had to be shipped to Italy for repair. I had to pay for shipping both ways (KPA500 was now out of warranty - but the Power Brick was not - that was an earlier warranty replacement!!)

Not impressed and the last time I used it other than to test on return from Italy.

Sold it and have gone back to a big Tube, can never go wrong with a Tube!!!

Such a pity as my K line is now incomplete - buyer beware, this product is not as good as other outstanding Elecraft products which is a real shame.

WM6P Rating: 2014-02-01
Perfect Time Owned: 0 to 3 months.
I bought the KPA500 as a kit and had fun putting it together. The unit is silent, small and radiates very little heat. The power supply is built in and runs off of 115 or 220 VAC. It measures approximately 11X11X4 inches and weighs 26 pounds. It senses your transceivers RF signal, providing auto band switching. Circuits protect the unit from excessive drive or high SWR.

Assembly took about six hours and it fired right up. No alignment is required. All modules are factory tested. Elecraft has superior service. I also purchased the matching auto tuner that is great. This is replacing a Henry 2K and 30L-1.
Important tips: Buy a quality number 2 Philips head screwdriver. Do a careful inventory of all parts for familiarization and sort all screws prior to beginning.
WM6P
K6RIM Rating: 2014-01-05
Truly Excellent! Time Owned: 0 to 3 months.
Purchased the KPA500 as a backup to my Alpha 9500.

The KPA500 is my first solid-state amplifier.

There certainly is a lot to like about the KPA500, including instant-on, auto-tune and almost silent operation. And all of these features come in a small (and relatively light) package that looks similar to a baby Alpha 87A.

To date, the KPA has performed reliably and admirably, including a major DX contest and a RTTY contest.

I have become so fond of the little KPA500 that I use it most of the time, and I expect that the bad-boy Alpha 9500 will see significantly less use in my shack. For most of my garden-variety DXing, the KPA500 does the job and does it well. For the tough situations, and for my more serious contest efforts, the bigger amp will be called upon.

Kudos to Elecraft for designing and manufacturing a superb solid-state amplifier! Highly recommended!




WV2M Rating: 2013-10-31
Turn for the Worst Time Owned: 0 to 3 months.
This is an update to my review on August 1. The unit had been working flawlessly until last week when it would not amplify on 12 meters. There was a slight chattering sound and burning odor when applying the exciter power. All other bands were unaffected.

I called Elecraft and immediately got through to tech support. I explained the problem and the technician straight out knew what was wrong - a failed capacitor in the RF deck. He said this has happened before but usually on first power up after building the kit. In my case it has been 2+ months. He arranged for a replacement RF deck to be shipped to me. That was last Friday. I received the new RF deck yesterday (Tuesday) and installed last night. It took about 1 hour to disassemble and reassemble. All is well again!

I examined the old deck and indeed one of the surface mounted capacitors (C45?) was vaporized.

Since this is not an isolated incident, I am concerned that there is a latent design flaw (vs. a faulty component) and that this will rear it's ugly head again after the warranty period is up.
So regretfully I must reduce my rating pending a modification or redesign to correct the issue.

On the plus side the unit is a joy to operate and customer/technical support is outstanding!!

AC8BT Rating: 2013-08-07
Sturdy little amp Time Owned: 0 to 3 months.
I built the kit in a very leisurely 6 hours. In a way, I was sad to be finished. Growing up with Heathkits the assembly is always part of the fun. There is no good reason that I see not to go with the kit. The build is all mechanical assembly and the well-documented assembly manual makes it a breeze. The way I look at it, I saved $300, or $25 per hour while enjoying the thrill of building my amp.

I have a full K-Line station now, K3, P3, KAT-500, and now the KPA-500. Using the enhanced interface cabling with the K-Line neatly integrates everything together. Tune the K3 and transmit, and the KPA-500 instantly switches - no tuning required. Likewise the other way around - press one of the band buttons on the amp and the K3 switches to that band. Alphanumeric messages appear in the K3 that echo the status of the amp.

I am able to get a full 500 watts with only about 30 watts of drive. I mostly work SSB on the low bands and, even in a windy QSO, the fan only comes on to level 2 (of 6). The amp is fault tolerant and will reduce power or shut down to protect itself, depending on the severity of the fault. Clear the fault and you're back in business in a jiffy.

Integration with the KAT-500 is likewise seamless, with the Elecraft enhanced cabling. The KAT-500 will hold the key line open while it tunes to protect the amp, if needed. A quick press of the Tune button on the K3 and away you go. The KAT-500 can be rather noisy as it searches for a match, but it memorizes matches throughout the bands and immediately switches the appropriate L an C into play when you key up on a band segment that has already been used.

All-in-all, the KPA-500 is a rugged, well-integrated, and robust amp that is a joy to build in kit form.
N1KDO Rating: 2013-07-25
It makes a 500+ watt K3 Time Owned: 6 to 12 months.
Used with the K3, it is like having a 500+ watt radio.

It is better than seamless integration with the K3, because if you use the proper interface cable, the band select buttons on the KPA500 change band on the K3 -- it actually adds features to your K3, not just power.

The amp is quiet, lightweight, and small. It is the same size as the K3 and a match in styling. It looks good on the desk next to the K3, but where it really shines is in how it works.

The integration is complete with the K3, just press the "OPER" button and the K3 reduces power to drive the amp to rated output. The fans are quiet, and even after extended use, I've never heard them on full speed.

I had a near-legal-limit amp before, with a pair of 3-500s, and though the KPA500 is slightly less than half the output power, it is far more satisfying to use. The tube amp required re-tuning for band changes, and that slowed down QSYs to chase spots; the KPA500 is no-tune, instant band change, 160-6. Change bands and transmit, no more knob twisting.

I've only used it with the K3, and I must say I am very happy I bought it. An excellent piece of gear.
K6RB Rating: 2013-07-24
Love it Time Owned: more than 12 months.
Built the KPA-500 almost two years ago and it replaced a Ten Tec Centurion in an SO2R set up. I have had zero problems with it, and use it in a K3/P3 station. I did not get the cable that switches bands in step with band changes in the K3. Instead, I let the unit sense the band change from the RF sample. Works fine. Very robust. Has been operated full blast in many contests including RTTY ones. Never missed a beat. I am currently contemplating replacing an Alpha 87A with another KPA-500 so that the SO2R station would be just 500 watts out. The fact that I'm even considering it should tell you how much I've come to enjoy using the KPA, and how much respect I have for it.