| KD0ZV |
Rating:     |
2018-07-20 | |
| Nice amp but not perfect |
Time Owned: 3 to 6 months. |
The LA-1k is well built and has beautiful construction typical to everything Palstar builds.
I am only giving it a 4 for the following reasons.
1) Terrible documentation (typical to Palstar).
2) Has high SWR spike when you first key it even on a resonant antenna until the amp does all its switching to the band you are on.
3) The fan comes on quickly when running CW or digital even at less than half of rated power for those modes. It ramps up to what I consider real noisy while operating but cools down quickly. I guess this would tell you it has plenty of cooling capacity in the fans but might lack in heat sink? At first I wondered why Palstar does not give you the option to switch to Fahrenheit on the display for temps but the temp swings would be much more prominent if they did.
4)Noisy keying relay. Makes a racket when sending CW.
All in all its a fine amp and has not missed a beat. The display is very nice and like the touch screen a lot. Does not have all the bells and whistles other amps like Expert or Acom have. I dislike the USB connector and button on the front for programming. Might be convenient but looks bad.
I would buy it again and would recommend it to others but the relay noise might be a deal breaker to CW operators that prefer something quiet like the Elecraft. |
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| KB8LS |
Rating:      |
2018-05-23 | |
| Highly Recommended |
Time Owned: 0 to 3 months. |
I picked up the new LA-1K amp during the 2018 Dayton Hamvention. Below are my initial impressions and test results.
Many solid-state HF power amps are only rated in terms of Peak Envelope Power (PEP). This type of RF power rating can be misleading to the unsuspecting Ham. For example, if a solid state amplifier is rated at 500 watts PEP, without stating the transmit (on) time versus off time, the operator can rag chew at 500 watts for 30 miniutes, the amp overheats and shut down and still be within the 500 watt PEP specification. In other words, the PEP rating allows the amplifier to be poorly designed and can result in shut down due to insufficient cooling.
As of this posting, the Palstar LA-1K is the only solid state HF amplifier that specifies the RF power output rating as “Intermittent Commercial and Amateur Service” (ICAS). ICAS is a more severe rating than a PEP rating. The only rating that is more severe than ICAS is Continuous Commercial Service (CCS), which means an AM modulated carrier wave transmitted continuously 24 hours per day, 7 days per week, 52 weeks per year etc. except for shut down for maintenance.
The Palstar LA-1K ICAS rating is specified at 1000 watts “Single Side Band voice duty… there is no time limit on transmit time” at this power level. This means you can rag chew indefinitely without the fear of the amplifier overheating. In the CW mode, the RF power output is specified at 850 watts, five minutes on and at least one minute off. For FM and RTTY the RF power output is specified at 500 watts*. For AM the RF power output is specified at 275 watts* (*every on period must be followed by an off period of the same or longer duration). In order to achieve the power ratings above the LA-1K has a well designed cooling system that provides sufficient air circulation to prevent overheating. If any of the ratings above are accidentally exceeded and the internal temperature rises above 100 degrees C, the amplifier automatically switches to the bypass mode. When the temperature drops below 70 degrees C, the unit reverts back to the operate mode. The fans are whisper quiet in the standby mode and are barely noticeable in the rag chew mode.
Upon initial installation of this amplifier, I found that between 30 and 40 watts of drive would produce just over 1,000 watts of RF output power. If the drive is increased to 50 watts, the output power is 1,100 to 1,200 watts.
The amp was setup for 230 volts AC operation. “Power In” was measured with a Bird 43 with a 100 watt slug. “Power Out” was measured with a RF Applications digital wattmeter into a Bird model 82 dummy load. ALC between the exciter and amplifier was disconnected.
The LA-1K uses a vacuum relay for transmit/receive change-over. The amplifier has provisions for up to three antenna outputs and uses three separate relays to switch between antennas.
After several on-the-air rag chew sessions lasting up to an hour, the fan speed would automatically increase to keep the amplifier cool, but the amp never overheated and shut down. I paired this amp with the Palstar HF-Auto automatic tuner. This combination really spoils one use to twisting knobs after a frequency change – there are no knobs to twist for tune-up!
Nice work Paul! I highly recommend the LA-1K – You will not regret this purchase.
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| N0SP |
Rating:      |
2018-04-24 | |
| It's a keeper... |
Time Owned: 0 to 3 months. |
Well, I have resisted making the change from familiar tube amplifiers (I have three of them) to solid state systems. I never cared for their propensity to pop with a few milliseconds of abuse. The lack of sensory feedback with transistor amps as to what's going on (clang of relays, plates glowing red, etc.), and the ability of tubes to take a glitch or ten and keep on working, have kept me in the high-voltage camp. When I first saw that famous video of an LDMOS amp running full power in to a 65:1 SWR, setting it's board on fire, and STILL functioning, I got mildly interested.
At that point, reliable commercial LDMOS amps from reputable companies were still years away as there were *significant* technical challenges in getting them to work right. I even considered one of the LDMOS "kit" amps, but reading the home-brew LDMOS amp blogs made me crazy and I began to think nobody would take this on commercially. Concerns about proper bonding, cooling, and dealing with the very low native impedance of the devices (2.5 ohms) were significant issues. When finally announced (recently) they were VERY expensive... like $7k(!), and still not delivering. Actually, at the time of this writing, only Palstar is currently able to ship an LDMOS amp at a "market price" for this power level. The only other offering out there is severely back ordered and (according to reveiws here) seems prone to problems. Further, the LA-1K is the only certified one available thats made in America. (unless you want to pay SIX THOUSAND dollars for the Elecraft) If something goes wrong service is in Ohio, not Outer Slovobia!
Once I put this in service I realized how much "work" I had shed in changing bands and frequent tuning. This thing is crazy-easy to operate and performs exactly as advertised. All I do is click the mic, or "dit" the keyer and this amp has switched bands, selected the proper antenna port, and is ready to go. It does so with no connection to the tranceiver except the coax jumper. It works the same whether it's my vintage 1960s AF-67 transmitter, or 756PRO. It simply detects the frequency and instantly changes band/antenna. (three antenna outputs on back)
I'll start by saying I've always been partial to Palstar. I have two of their big tuners, one for 14 trouble-free years, several shack accessories, and their awesome R30 receiver is still working great since about 2002. I almost NEVER buy an expensive new piece of equipment off the shelf. The last time was a new Yaesu transceiver in 1996, (reluctant to spend the money) but after having an opportunity to play with an LA-1K last month and hearing a guy running one on AM(!) at 300 watts carrier (sounding wonderful), I knew I had to have one.
When it arrived two weeks ago I didn't even hook it to an antenna at first. I slapped two Bird line-sections to it's rear panel (INPUT & OUTPUT terminals) and with two Model 43s connected to the line sections I started making measurements of input vs. output. I was VERY impressed. As is common with HF/6 amps, I was sure I'd find some roll-off in performance either down at 160 or up at six meters. NOT! This thing was as hot at 1.9mhz as it is at 54mhz. I wrung it out on every band at several power levels in to a precision dummy load that reads 50.0 ohms on my Fluke. I even thought of putting the value for every band here, but no need. Output numbers for a given input power are within about 5-7% on every band all the way from 1.8 to 54mhz. I changed slugs to keep the readings somewhat mid-scale to enhance accuracy. I couldn't believe how "tight" the LA-1K was across the entire spectrum. No small feat.
Results are below, displayed as inputW/outputW
5/140
10/295
25/650 (25w level had some variation between 610 and 705 depending on band)
50/1120
I then hooked it to the antenna and proceeded to "ride it hard and put it away wet" for over a week. What a joy to use!... bright front panel color LCD displays your exact operating frequency, power output, SWR, heat sink temperature, voltage and current to the finals, as well as selected antenna port and band in use. So, there's still lots to "look at", but nothing to "do". The amp does it all for you.
One thing I worried about a bit is cooling. I live at 9,000ft elevation where air-cooled systems are somewhat compromised by the low air density up here. I deliberately ran a few 5 to 10 minute diatribes at full power and never got the heat sink temperature higher than the mid-40s (degrees C, amp shuts off at 100 degrees) The 3-speed fan adjusts with increasing heat, but never gets loud. I held it key down on FM for quite a while and the temperature approached 80. The fan at full speed is still much quieter than any of my Ameritrons, not even close. Quiet is nice! With AM operation at 275 watts it never got close to cut-off temperature.
Some happy things I discovered after delivery...
1) SWR protection cuts in at 2.5:1. Notably, the amp doesn't care how much power you're running. Whether 20 or 1000 watts, at 2.5:1 it faults to STBY, period. If you correct the condition, amp comes back on upon next key-up.
2) Wattmeter bar graph is very accurate and tracked nicely with my Bird 43. Watt meter automatically changes scale in standby mode so you can accurately set drive power prior to engaging the amp.
3) The internal power supply! This thing is amazing. There is NO voltage sag at max power. I peeked in and looked up the module used by Palstar then looked up the specs. It's a commercial industrial/medical grade unit which has it's own internal high-current/short-circuit/temperature protections and two temperature-controlled cooling fans. (never hear them tho) If the power supply shorts or overloads it simply shuts off, and comes back on in about 2 seconds. While inside the cabinet I couldn't help but admire the quality of Palstar's construction... VERY solid.
4) TWO year warranty (rare in ham radio circles)
5) This amp is SO light and quiet. I've always associated high power with noise, weight, and all sorts of drama. The hardest part of installing this amp was lifting the 77-lb Ameri-Monster-Tron off the desk to make room for the LA-1K.
6) SWR readout on display is in actual numbers (eg. 1.2:1) rather than a bar graph and continuously displays the value as you transmit. I found it to be very accurate.
7) Palstar ships the amp with two power cords. Both the standard 230v plug used by other manufacturers and conventional 3-prong 120v cord come in the box. To change voltage you just change the cord, no changing jumpers inside the cabinet.
8) Clean clean clean... I began getting un-solicited reports on how good my audio was... these of course are subjective, but the beauty of these LDMOS devices is the great 3rd Order IMD number which is well in to the -30s with Palstar's implementation. (LDMOS amps can be dirty if not set up correctly) The LA-1K has a "Pure Signal" output port in the back for the modern radios using that feature to get 3rd-order way down in to the noise... -60db or better.
9) While I'll never use them, the amp has data connections on the rear for communicating with Elecraft/Kenwood/Yaesu/Icom, etc. The manual lists detailed pin-out info for any kind of remote control, either by computer or another radio.
10) Thoughtful design... it seems Palstar anticipated everything. Even when the amp is in STBY it will change bands when you key the exciter for tune up. Again, LOVE the re-scaling of the internal wattmeter bar graph for very accurate setting of drive power.
In summary, I am very happy with this unit. Apologies for the LONG read here, but there was much to say. I think this is a ground-breaking product at a fair price. It's a well-built full kilowatt in a single 26 pound package that will fit in the overhead bin for a nice hamcation. HIGHLY recommended.
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| AA9NN |
Rating:      |
2018-04-04 | |
| Very well designed Amp |
Time Owned: 3 to 6 months. |
I purchased this amp from HRO in Milwaukee, very light amp for a KW out. As I did a deeper dive into the construction and power supply they used, the more impressed I was.
you have to run this on 220V to get 1200 out, although I did try 120V and got 800 watts out no problem. Not a lot of controls on the front!! auto band switching takes the guess work out that your configured correctly!
I did call Palstar as I did have some questions. Talked to Paul directly. I recommend a call if you have concerns after looking over the manual on line. Yes, I'm a bit biased as I own a couple of HF auto's (which are the best auto tuners PERIOD) The LA-1K is quiet, runs pretty cool, and makes just over a KW. Built in Ohio and has a 2 year warranty. so, so far so good! :)
73!
Jim AA9NN
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| VE3VCV |
Rating:      |
2018-04-03 | |
| Wonderful Amp |
Time Owned: 0 to 3 months. |
I have had this amp in operation 2 months and use it every night for 3 hrs on 40 meter SSB And daily on 20 meters. It is a joy to use and delivers as promised. I usually would wait for something to be on the market for awhile before I commit to a purchase. But After buying a hf auto and being so pleased with it I took the plunge.
No regrets. If you are tired of twisting knobs this is for you. Nothing to do but turn it on and enjoy. The La1k and Hf auto Stack nicely on my desk and look great also. The 3 speed fan is quiet and very efficient. It took longer to un box it then to learn how to use it. And if your a Dxer jumping around the bands you will be able to pounce on the DX immediately.
Try one
Gord VE3VCV
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| K3GC |
Rating:      |
2018-03-29 | |
| Amazing Amplifier |
Time Owned: 0 to 3 months. |
I have only had my LA-1K for a bit over a week and it's a love affair. :)
It is deadly accurate and more automated than I have ever seen. I have two antennas, a hex beam and a vertical for 40m. It automatically the proper antenna when the band is selected.
It weighs in at a svelte 26 lbs and is the quietest linear I have ever experienced.
It is almost boring to have - there is so little to do. It just sits there and does its job - perfectly.
My only criticism I have is the paucity of information in the users manual - that is a lack that Palstar should address. A trouble shooting guide and some help with setting ALC would be good.
This amp does deserve at least a 6. |
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| KM4FTK |
Rating:      |
2018-03-20 | |
| Very happy with this amp! |
Time Owned: 0 to 3 months. |
| I have had this amp a week and it is performing just as advertised. Got it with a Palstar HF-AUTO tuner at the same time. As they said, they are designed to work well together and they do. The nice color display on the new amp though makes one wish for such a nice color display on the tuner. Drove this a few days on 120v till got my 240v line in. 600-800 watts out from 120v. With 240v get 1050 watts out when driven with 55 watts in from my ICOM 7300. Very pleased and highly recommended. |
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| KD4POK |
Rating:      |
2018-01-15 | |
| A solid easy-to-use performer. |
Time Owned: 0 to 3 months. |
| I have recently had the opportunity to spend some quality time with the LA-1K HF LDMOS amplifier, one of the newest solid-state amplifiers for HF (1.8 to 54 MHz) from Palstar. Their products are built in the USA and are known for their quality, support and exception performance. My Icom 7610 connects to the LA-1K with a single RF jumper. The LA-1K then connects to the Palstar HF-Auto tuner with another single RF jumper. I have three antennas attached to the HF-Auto tuner allowing flexible operation across the HF bands. The 7610 allows me to switch bands very easily, just one key-press and I'm good to go. I then change modes to RTTY and tap the PTT... This is when the magic happens. Within seconds, both the HF-Auto tuner and the LA-1K have detected the TX frequency and automatically adjusted for the correct antenna, tuned for lowest SWR and switched bands ready for 1Kw transmit. All this happens without special proprietary cables between the units. Both the HF-Auto tuner and the LA-1K sense the frequency upon transmit each and every time and make automatic adjustments, compatible with any HF radios without the need for programming or interface cables. The touch screen on the LA-1K is about the same size as the IC-7300's touch screen and is very clean and intuitive for use. Having the ability to make menu settings or placing the amp from operate mode to stand by with just a tap of the screen is very nice, completely silent and no wear and tear from mechanical buttons, knobs or switches. I usually drive the LA-1K with about 40 watts from the 7610 which produces just under a kilowatt of ultra clean RF to the selected antenna. I previously avoided pile-ups because it was too difficult to get through to the station calling CQ. Now, I look forward to the challenge. Armed with the LA-1K it usually only takes a call or two and they come right back to me, almost always commenting that my signal is strong with clear audio. It is a pleasure working with this high-quality amplifier and it is evident to just about everyone I talk to how clean and strong my signal is, regardless of the mode or band I am operating on. I can't say enough good things about the new Palstar 1Kw solid state amplifier. It’s as easy to use as my 12v power supply, just turn it on and off with the single switch on the front and it does the rest by itself. It is a solid piece of equipment and a worthy investment. Hope to catch you on the air, 73 KD4POK |
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