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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
VK4FW Rating: 2011-10-16
Spot On Time Owned: 3 to 6 months.
My amp is #75. I have been using it here at the house since it arrived just to put it thru its paces before packing it ready for the upcoming dxpedition to 3D2T and T2T.
I will write an update after we return as we will have 3 of the amps on the trip along with 3 of the K3 transceivers.

I love the design and actual size and basic value for money when it comes to having an amp that is suitable for light aircraft travel to dxpeditions...... congrats to Elecraft for another fine product.
W9VNE Rating: 2011-10-08
Fantastic piece of gear Time Owned: 0 to 3 months.
I have had my KPA500 for two full months. I also own a K3 and a P3. I also am starting my 60th year in Ham Radio this week. I have owned Collins, Drake, Heath and Ten Tec gear. I would rate the KPA 500 as the best piece of gear that I have ever owned. It does everything well. You can get a nice 600 watts if you want to use it at that level. I had to laugh at the person who gave a 4 rating. Comparing Elecraft with MFJ / Ameritron is an insult. This is the best there is. With its built in power supply and ability to use 110 vac or 220 vac its versatility is excellent. Its extremely small size makes it great for road trips. Try that with MFJ / Ameritron and there two piece amps. If you can not afford it that is an unfortunate part of life. It does not impact the rating of the amp. There are more expensive amps for sale too. This is real quality. Setup follows the KISS principle. Thanks Elecraft.

Jim W9VNE
WB4OOA Rating: 2011-09-06
A New Era of Amplifiers Time Owned: 3 to 6 months.
1. I think that it is the perfect size. It is the same size and matches the K3. It looks like a small Alpha. It is light weight but still feels heavy for its size.
2. It is completely quiet. No fan noise and not even any relay noise.
3. Very little heat is generated under normal SSB operation and the fan never turns on. In CW mode the fan will turn on.
4. No internal wiring changes needed to go from 120vac to 240vac. The wiring changes are made when you turn the fuse holder upside down. It is a very neat way to accomplish fool proof Input voltage settings.
5. Solid mechanical steel chassis construction. Powder Coat Paint.
6. Digital LED Bar graph wattmeter measuring Forward Power (Peak Reading with Peak Hold) and second bar graph for SWR. The wattmeter even works in Stand By Mode.
7. The Software Utility Operate page, shows all the operating parameters in real time on your computer. It also allows for easy Firm Ware Upgrades.
8. Good clean power output, gives 500 watts with 25 watts drive.
9. The K3 announces (on its display) the state and condition of the KPA500.
10. It is fairly forgiving of high antenna SWR (over 2 to 1) and it is well protected from all Operator errors.
It is an absolute dream to use. I have been using it for 3 months and it is a winner. This is the end of tube type amplifiers for me.
QRPNEW Rating: 2011-09-06
Poor Value Time Owned: 3 to 6 months.
I am very happy with this amplifier. It has met my expectations. I mainly got it to complete my K line station. My only gripe with it is that it really represents poor value and is overpriced for what it really is. It roughly costs 4 dollars per watt delivered. If you are looking for good value you would be better placed looking at the new Ameritron ALS1300. This amplifiers delivers at 2 dollars per watt and gives you 3db more head room at close to the same price.

If you dont mind the premium price, you will be happy with this amp.
K6LEN Rating: 2011-09-04
500 watt K3 Time Owned: 0 to 3 months.
This little amplifier is a perfect addition to my K3 transceiver. I have been running it for less than 2-weeks now, and it has performed flawlessly (more so with the latest firmware version 1.11). The seamless integration with the K3 makes is very satisfying from an operational persepective, and I now feel like I am running a 500-watt K3! The little but mighty amplifer follows any frequency changes made from the the K3, while the K3 can be set up to allow the amplifier to operate at any per-band output power desirable.
It is also very easy to switch to "barefoot" operation with one button push.

Prior to this amp, I was running an Acom 1000, and while that is, in my opinion, one of the finest amplifers made, the smaller footprint of the KPA500 better suits my current operating style. Sure the KPA will not do a KW, but what's 3db among friends anyway? (half of an s-unit)! I have received great signal reports from stations all over the world, so my 5/5 rating is well-deserved for this amp.
VK5CP Rating: 2011-08-18
Easy to build - worked 1st time Time Owned: 0 to 3 months.
Put the kit together in one evening (5 hours), ran out of screws for the top lid, but other than that instructions were excellent, easy to follow and the amp worked first time (a first for me in kit building).

Excellent work Elecraft - now for the K3!
WD1W Rating: 2011-07-26
Amazing Amplifier! Time Owned: 0 to 3 months.
Received SN 0146 last Friday. This thing is as solid as a rock ... I get the feeling that if it was dropped, it would survive ... although I won't perform that test. At 26 pounds, it sits on top of my TS-590. How many amps can you do that with? Make 4 connections ... power cord, PTT, coax in and coax out. Choose a frequency ... and transmit. The amp's ability to identify the transmit frequency and switch to the proper band is instantaneous and ingenious. 20 watts in gives 400 out. The fan is the quietest of any amp I own (4 others). It looks great and performs flawlessly. The side carrying handle and rubber feet were unexpected and a nice touch. A bit pricey ... but a lot of toys are. Sure ... more watts would be nice. I hope this is just the beginning of future 800, 1000, 1200 and 1500 watt versions. I will definitely upgrade to the 1000 watt version should Elecraft produce one. As for this KPA-500, it's a keeper. Time to start thinking about selling my other amps. Bottom line: if you can afford one and the power level suits your operating style, you'll love this amp.
W1TXT Rating: 2011-07-24
Impressive Time Owned: 0 to 3 months.
I started planning for the KPA-500 in the spring of 2010 with the sale of my mint Ten-Tec Centurion applifier. Elecraft delayed the availability of the KPA-500 until early April, 2011 and I decided to order the kit version. The kit arrived on 7/21/11 and I completed building it in about 10 hrs. I think the toughest part of building the KPA-500 was sorting out the parts and taking the inventory before starting to build. Some screws were missing and I contacted Elecraft where they were promptly shipped out. Once everything was together (using some screws from the K3!), I looked over the amp for almost an hour, reviewing the assembly manual to see if I missed anything and also re-reading the owners manual prior to the initial power up.

Powering up the amp was flawlesss and everything tested according to specifications.

As other K3 owners have said, the amp makes the K3 seem like a 500 watt radio. The amp was worth the wait and will sit next to the K3 and P3 for years to come.

Regards,
Tom / W1TXT
W0MU Rating: 2011-06-27
Built like a Brick! Time Owned: 0 to 3 months.
I just finished building my Kit SN-101. The build was straight forward and was completed in about 5 hours.

The amp is very well built. It is a great size for traveling, dx-peditions etc.

Automatic band switching with an auto sense circuit is brilliant. The amp is quiet and loafs along at 500 watts.

It is easily switchable 110v or 220v. The built in watt and swr meter means one less item on the shelf or in the luggage. A great feature!

Another fine additions to the Elecraft line! I wonder if a 1500w version might in the works.

W6LG Rating: 2011-06-11
An Extension of my K-3 Time Owned: 0 to 3 months.
Recently I received my newest amplifier from Elecraft; the KPA-500. It is a 500 watt solid state amplifier that covers from 160 to 6 meters. The KPA-500 is a very interesting design that takes its cues from the Elecraft K-3.

For me, this linear amplifier is like an extension of the K-3. It has the same size cabinet and similar controls. The K-3 can talk with the amplifier and vice versa. For example, when you put the amp into the operate position, the K-3 displays a message that the amp is ready to operate. You can change bands on the front panel of the amplifier and the K3 follows. The point needs to be made here that this new amplifier can be used with just about any transceiver.

The KPA-500 weighs in at about 26 pounds. As I indicated, it is the same size as the K-3; approximately 4x11x10 inches. It has 2 transistors that are powered by a linear power supply. So, there is no noise that can be a problem with switching type power supplies. It has 3 voltage setting for 95 to 125 volts and 3 settings for 190 to 250 volts. Mine is on 120 volts. It is of course, instant on. Firmware for the amp is easily updated with just one click using a serial port.

It has nice metering with an LED bar graph and an LCD screen on the front panel. For example, you can see the output in watts on the LCD and the ramping LED's at the same time. Voltage, current, band, temperature, menu settings and fault information is on the LCD.

Speaking of faults, it is very well protected. There are soft faults and hard faults. Soft faults can be resolved very quickly and somewhat automatically. Hard faults require a reset the amp from standby to operate. As can happen, I did cause a hard fault by transmitting 100 watts into the amp by mistake. It stopped in a split second and sounded an alarm with the built-in speaker. Since that time, I have set up the firmware so that the K-3 drops to 30 watts when the KPA-500 is put into the operate position. I no longer have to worry about the drive setting. It is changed automatically. Again, the amp is like of an extension of my K-3. With a soft fault, the amplifier microprocessor reduces the output by 2.5db and rechecks to see if the fault has been corrected.

There is a square muffin type fan on the back. It controlled by the microprocessor and has 6 speeds. For the most part, it is a pretty quiet box. The amplifier can deliver 500 watts key down for 10 minutes! In playing with the amp, I found that it would occasionally go passed 600 watts. I think it will do a fault at 700 watts to protect the finals. I have chosen to set my drive to automatic so that the amplifier will deliver 450 to 500 watts. There's no point in pushing it to 600 watts. With about 500 watts output, my signal strength is roughly an S unit stronger. Tests on the short path to the Ukraine with UU5JZ confirmed about a 1 S unit increase with the amplifier.

This amp uses a pin diode in place of a transmit/receive relay. Fast QSK is no problem. No external interface is needed for the keying line. Any transceiver should be able to key this amp. Also, band data from most transceivers can to used to change bands on the KPA-500 automatically.

I currently have an old Drake tuner following the amp. I frankly don't like to use tuners because they don't tune antennas. My antennas are close to a 50 ohm load at the feed point. The tuner is used to lower the SWR at some band edges . I believe that Elecraft will have a tuner ready for sale late this year. If they do, it would be nice if the tuner were automatic and had a built-in antenna switch.

This amplifier replaced an SGC Power Cube that I now have on Ebay. The KPA-500 was purchased from Elecraft assembled. My guess is that the kit amplifier could be assembled in 3 evenings after work. Assembling the kit looks to be very straight forward. The kit is about $2000.

As with most things from the folks at Elecraft, I appreciate the quality of the design and the execution. There is an active discussion group that is good about providing help. As you know, customer service at Elecraft is stellar. I am very happy with my purchase of the KPA-500 linear amplifier. I think it will provide many years of service.

73, Jim Heath W6LG
www.hamcq.com