The Ultimate Solution for Power Amp & ATU, IMHO

[@kb9jqu]

Doug it’s also probably worth mentioning that Elecraft currently does not require a deposit when you order an amplifier. So you have about 6 to 8 weeks to generate the funds before you need to pay for it. Once the amplifier is ready they send you an invoice and then they wait for you to pay before they ship. I’m sure they would have no trouble at all selling an amplifier that did not get paid for. So that might get some folks who are hesitant to place that order to go ahead and do it if they know they have a way to raise the funds within 6 to 8 weeks. Maybe this comment should be pinned to the top.

[@n4hnhradio]

That’s a great point, Curt. 73, de N4HNH

[@marks2254]

I’m thinking of an amp so this video came at exactly the right time. Thanks to you and Curt for putting it together.

[@kb9jqu]

Your most welcome. If you have questions on the 500 combo, shoot me an email.

[@n4hnhradio]

You’re very welcome! Elecraft is very well designed and constructed. And they do not pay me to say that. It is my objective opinion. I hate to like Yaesu but I like to like Elecraft. Elecraft listens to their customers better. 73, de N4HNH

[@tommytr]

Doug thanks for this video, and for answering my emails a couple weeks ago about this very same content. I am also going take your advise and get me the tuner and amp. I almost ordered the tuner this week but I am going to save up a little more money and order the combo since the tuner seems to be on backorder atm.

[@n4hnhradio]

Everything is on back order these days, Tommy. But it’s worth the wait. KB9JQU will attest to that. He said if anyone has any questions to feel free to contact him. His email is on QRZ.com. 73, de N4HNH

[@kb9jqu]

Tommy order it and forget about it. The 6 to 8 weeks goes by quickly. However do plan your new station layout and think about what you will need so you can operate right away (e.g. patch cables). Also download the manuals and read them a couple times. When I opened my boxes, I was on the air within 30 minutes and had a QSO with Doug an hour later.

[@kb9jqu]

Another thing to consider Tommy is Elecraft does not require a deposit. So you do not need to pay for it until they build it and are ready to ship it. In my case it took somewhere between 6 to 8 weeks from the day I ordered it until I got the invoice email and needed to pay for it.

[@tommytr]

@@kb9jqu Between the extra money and the fact that at the moment my station is in the corner of our bedroom beside a closet is what made me decide to wait to squirrel away the money to pay for it and moving the station into our spare bedroom. I already got a good sized desk that used to be my sons but I will have to run the coax into that room for my antenna also. ATM I do not have room on the desk I am using to even buy the SP30 or a CW key. I will try to get with you when I do get this ordered if that is ok.

[@kb9jqu]

@@tommytr I’m happy to share what I know from direct experience. Talk to you soon.

[@kb9jqu]

I don’t mind at all Doug. The KPA-500/KAT-500 is likely the biggest bang for the buck. Having the 3 antenna ports automatically selected allows me to band hop and hunt parks at a fast pace without transmitting on the wrong antenna. I’m very spoiled for sure! Thanks for the recommendation Doug.

[@n4hnhradio]

More great points Curt! 73, de N4HNH

[@thomashenderson603]

Doug, I did get the KPA500 / KAT500 but always have my eyes out for the KPA1500! One question I have is, the ones I have seen for sale all have had the finals replaced or need to be replaced. Would you know why that happens, is it operator error? Thanks Tom K1CXS

[@n4hnhradio]

Mine had to be replaced when it was new. Elecraft made an improvement to it. All under warranty. That was in 2020. One LDMOS failed. No problems since. But, if you haven’t watched my video about Decibels, S-meters, Amplifiers, and Gain, I recommend watching it before you spend the $$$$ on a legal limit amp. Plus, your KAT-500 has 3 antenna ports and can match up to a 10:1 SWR while allowing up to 1kW through it.

[@thomashenderson603]

Thank you ! Tom@@n4hnhradio

[@larryoob8754]

Doug.... great Vid. Question..... I have a similar set-up: 120' inverted V, 40' apex 12' on the ends, fed with 38' 600 ohm ladder line. 4:1 current balun into 30' LMR400 (cant get the ladder line to the shack) with the KPA 1500 I can get legal limit on all band except 80/75. On 80 I'm de-rated to 750. In your opinion.... would you call it good, or is there something i can do to get more output? I have tried 130'. 1:1, different feed line lengths. Thanks in advance Larry W0LRF

[@n4hnhradio]

Hi Larry, Mine allows 1025W on 75 meters. It cost me some ladder line while I experimented, but changing the ladder line length in 1/8 wavelength increments plus or minus allowed me to find the sweet spots. It is a compromise. Improvement on one band can cost you on another. Once you find the length that works for you, you will have solder joints or twisted together junctions up and down the ladder line. Measure the total length and replace it with a fresh run of ladder line. Or solder each junction together and cover with liquid tape or Scotch 33. You can take some of the guesswork out by following the guide on the Balun Designs web page. You might find the link below helpful. www.balundesigns.com/reference/antenna-matching-problems-using-ladder-line-or-open-wire-feedlines/ 73, de N4HNH

[@JamesJ7851]

I current use an AT Auto with either my Yaesu Quadra or Acom 600S, or one of the tube amps I own. The 600S has been flawless, and is so quiet. That and the AT Auto has been one of my favorite ham radio tools to use with my preferred open fed antenna. However, I'm thinking about purchasing a solid state legal limit or close to legal limit amp within the next 12 months. Top contenders are the new Flex Radio PGXL and Tuner Genius XL combo, 2nd is the Acom 1200S and 04AT, third is the Elecraft KPA1500. I'm waiting to see what Acom brings to the table with the new but unreleased 2020S. Thanks for the video, an SK friend had the KPA1500 and really liked it.

[@n4hnhradio]

The KPA-1500 was my dream amp. I could never have afforded one if it had not been for the auction. I evaluated Xpert and ACOM. I was concerned about their limited support options, being that they are from Europe. I will not purchase an amplifier that needs to be controlled from the Tuner port. Nor will I purchase a tuner that needs to plug into the Linear port. FTdx10 can be damaged by mixing that up. It’s disappointing that some manufacturers were so short-sighted in that respect. I also liked that Elecraft is made in the USA. But the appearance of the Elecraft is phenomenal too. Having the “speedometer” for power and SWR, plus a digital readout for more precision, is very nice. I ditched my super-accurate wattmeter because the wattmeter in the amp was tracking perfectly with it, even for PEP. I found out it is calibrated to the NIST. I’m so spoiled by the KPA-1500, my AT-Auto will probably not return to the shack. 73, de N4HNH

[@thomashenderson603]

Doug, I'm new to Amps and thinking of getting one, I have a FTDX101MP and would like something to work with that. I looked at the al-811H and ALS-600S and the Acom 1010, all vary in price range. I notice a lot of videos on repairs of the al-811 and ALS600, the Acom has good reviews, but very had to find another tube right now. The KPA-1500 is a little out of my price range. I would like to be under $2500. Would you have any suggestions? Thank you Tom K1cxs

[@n4hnhradio]

Good question, Thomas. I will try to provide a detailed analysis from multiple angles. First of all, I’m afraid amplifier prices have risen on a gross scale, just in the last 2 years. I paid $1349 for my AL-80B 22 years ago. Before COVID-19 it had risen to $1899. Now it is $2800. That’s a tube type amp that Ameritron rates at 1kW, though the tube is actually rated to dissipate 800W max. So amp prices are continuing to balloon out, especially as components are becoming scarce. I would recommend a solid-state amplifier. Tubes are becoming hard to get. American companies are out of business. We have been sourcing from Russia and China for 20+ years. Now the Russian source has all but ceased. The Chinese tubes aren’t as robust as the American made tubes were. So, even the tubes that might be available in the future might be of poor quality. Tubes also wear out slowly but surely. I rarely ever ran my AL-80B at more than 700W. The original tube is still in it, though it has degraded by approximately 100W. A transistor is not going to degrade. It is either good or bad. There is no in-between stage. Plus, transistors are easier to source than tubes. There might be a slight shortage on transistors at the moment, until the supply chain ramps up again, but solid-state amps are becoming the norm now, thus the demand for tubes will diminish, reducing the motivation for the tube manufacturers (in China) to keep making tubes. Okay, so what do I suggest? Elecraft KPA-500. No question. It uses what could arguably be the most tried and true transistors ever used in an amplifier. It can loaf along at 450-500W, because the 4 transistors are each rated for 150W. And these are transistors that have been manufactured in bulk for many years. They aren’t something exotic. So, technically, it is a 600W amplifier. I know several people who own one and they report 630W if they want it. Elecraft is made in California. I own an Elecraft and I can attest that their support is first rate. The Elecraft amps are ready for full break-in QSK operation. They are visually stunning. They even have a built in wattmeter and SWR meter that is calibrated to match the National Institute of Standards and Technology (NIST). The first 400 watts makes the most difference in your signal, but especially your audio. The S-meter scale actually relates to sound. It takes a 6 Decibel change in volume for your ear to note the difference. That’s why the IARU established a 6dB per S-unit standard, though few manufacturers provide an S-meter to truly holds to the standard; very few. That’s why I always say, ignore the S-meter; go by sound. The S-meter can be useful for relative readings but that’s about it. So, when you go from 100W to 200W (3dB of gain), that is a gain of 1/2 S-unit, on an accurate S-meter. Double the 200W to 400W and you’ve gained another 3dB, or another 1/2 S-unit, for a total of 1 S-unit of gain, compared to 100W. More importantly, your audio punch has risen significantly. Now, you will have to go to 1,600W (100W past the legal limit in the USA) to achieve one more S-unit of signal strength. So, an amplifier that is capable of 600W gives you 200W of headroom over the 400W that makes the most difference in the first place. I had a QSO with KB9JQU, Curt, last night. He has a KPA-500 plus the optional matching KAT-500 antenna tuner. He bought the combo deal that Elecraft is currently offering. I believe it to be the absolute best value there is right now. Curt turned down from near 600W to 450W and I never knew it. He told me he had turned down after he had done it. I never noticed the difference. What’s more is that the KPA-500 can be powered from a standard household electrical outlet. It doesn’t require 240vAC. If you can’t budget for the combo, or you have no need for an antenna tuner, the KPA-500 is priced only slightly above your $2500 budget. The advantage of the KAT-500 antenna tuner is that your entire operation becomes fully automated. You never turn a knob to tune the amplifier, as with a tune type amplifier. The tuner is also fully automatic. You go through an initial setup, letting it find a match every 25 kHz for each band, transmitting in AM mode at 20W. It stores these settings In memory. Every time you return anywhere near a recorded frequency, the KAT-500 immediately recalls the settings for that frequency. You do nothing but start talking, working CW, FT8, etc. Finally, my problem with ACOM is that they chose to interface their amplifiers to the FTdx10 using its 8-pin tuner port, instead of the 10-pin Linear port. There have been reported failures of the tuner port as a result, not to mention that it prevents you from having the tuner port available for a tuner. LDG did the same thing in reverse. Their control cable for their antenna tuners plugs into the 10-pin Linear port on a FTdx10. So that ties up the Linear port, which you need if you want to use an amplifier. Elecraft made the amplifier control cable to plug into the Linear port. You need to tell them that you have a FTdx101D or MP when you place your order. The cable for the FTdx101D or MP is different than the one for the FTdx10. But Elecraft wire their cables to use the correct port. With the Elecraft control cable, the transceiver sends band data and the keying signal to the amplifier, with no moving parts involved; no relay to eventually wear out. If you also purchase the KAT-500, the control cable how to it and it has a jumper that continues the control data and keying signal to the KPA-500. That way you only use one cable from the transceiver to control antenna match, band changes, and the keying signal. I know this is much to digest and consider. I wanted to take the time to lay it all out there from various angles, for you and others who might someday read this. 73, de N4HNH

[@thomashenderson603]

@@n4hnhradio Thank you! I going to choose the KPA500, solid state and made in USA :) one more question, could I use my palstar manual tuner instead of teh KAT500?

[@n4hnhradio]

Sure, the KPA-500 doesn’t care which tuner you use, or even if you use one, as long as you keep the SWR at 1.7:1 or less. Solid-state amplifiers don’t tolerate a 2:1 SWR as well as tube type amplifiers do. The main advantage of the KAT-500 is pure convenience. Once it records the matches the first time, you never need to initiate a tune cycle again, unless you change antennas on that particular antenna port. It actually has 3 antenna ports. It can automatically switch to your favorite of up to three antennas for each band. It stores the match data separately for each antenna port. If propagation is such that your less favorite antenna makes more sense for a particular contact, you can switch ports and it will instantly recall the settings for that antenna. So, like I said, the KAT-500 just represents pure convenience. That’s why, even if I get my Palstar auto-tuner repaired, it will not be my main tuner again. Even though my Palstar is automatic, I still must wait up to as long as 30 seconds for the motors to reposition the capacitor and roller inductor. You could always add the KAT-500 at a later date, as more funds become available. It took me 40 years to get my station to its current state. 73, Doug

[@thomashenderson603]

@@n4hnhradio Thank you! I will put that on my list for next item... you have done the best to explain all of this for me. keep up the good work on you tube, always look forward to your new videos! -Tom K1CXS

[@n4hnhradio]

I’m glad to help, Tom. I see so many hams who get hoodwinked with clever marketing buzzwords and it bugs me. Plus, I have found that I actually save money by purchasing the better choice the first time, rather than buying what is popular, or cheaper, only to later realize I made a mistake, and then buy what I should have bought in the first place. I just don’t like buying twice. I can’t afford to buy twice. 73, Doug

[@DanMagers-lj7mq]

Don’t get rid of the AL80. The KPA amps are notorious for oscillation and dumping hundreds of watts into the transceiver. I have one in the shop now that has wiped out three radios. This is a flaw with the full break in TR switching that Elecraft uses.

[@n4hnhradio]

I don’t plan to get rid of the AL-80B. It has been a workhorse for over 25 years. It still has the original Eimac tube. But I kept it at 700-800W maximum. Much more than that isn’t discernible on the receiving end. QSB makes it near impossible to see/hear need difference. That said, my KPA-1500 has been flawless for 3.5 years.

[@AlejandroGonzalez-AGS]

Nice info Doug…saving “mula” for the KAP/KAT combo to mate my FT-710! Now need to figure out my HOA requirements 😂 really? Looks like Chameleon will come to the rescue with their Hybrid Mini (deck mount) and a EMCOMM II on a horizontal NVIS configuration (house to back Shed, 10-12’ high). They should hold 400-500W! Cheers..73, K9YTT

[@n4hnhradio]

That sounds like perfect setup, Alejandro. The KPA-500 is capable of 630-640W so be careful not to exceed the antenna specs. The good news is that you gain the most improvement in your signal strength/punch factor in the first 400W. 73, Doug

[@AlejandroGonzalez-AGS]

@@n4hnhradio I have both antennas already. The Hybrid Mini is serving duty on the back deck, and the Emcomm is going up as soon as the weather gets nicer. I’m having a blast with the FT-710 on 10m!

[@AlejandroGonzalez-AGS]

@@n4hnhradio That’s my intention Doug, keep it at 400W max.. when needed. 73, Alex (for short)

[@Spike-sk7ql]

Question. When you put up the note that said "tune with 20 watt AM carrier", is that how you should tune all the time? Say for instance, I'm using the ATU in my 991a, and I'm doing ssb on 40 meters. Should I be switching to AM, and not turning the power all the way down to 5 watts? I ask, because obviously I don't want to be doing it wrong, and because sometimes when I do it like I have been, when I turn the power up to 100 watts, I notice that the swr on my meter doesn't seem to be where it should. When I run my analyzer on my antenna (40-10 efhw home made) I get between 1.5-2:1 on 40 meters, in the general voice portion of the band. I use the tuner towards the upper portion of the band. Shouldn't the tuner at least bring it under what the antenna analyzer is showing me? This also doesn't happen all the time. Sometimes it will match it perfectly and my swr will not even move on the meter.

[@n4hnhradio]

The internal tuner is a “touch-up” tuner. It should be able to take up to a 3:1 SWR and drop it to under 1.5:1. Often it can get it down to 1.05:1. I use 20W to tune because some wide-range auto-tuners recommend it. If I tune with 5 to 10W, I might not get the best match. I’ve done that and when I powered up the amplifier, I had a higher SWR than expected. Some of the built-in auto-tuners will automatically lower the power output during a tuning sequence. The FTdx10 drops the power level down when I long-press the Tune button to let it find a match. But when using an external tuner, I go to AM and set the power to 20W. The maximum power output in AM mode is 25W and that’s okay, but I try to tune with the lowest power level that the tuner requires, just to protect the finals in the transceiver. But I only need to use AM during the time when I’m letting the auto-tuner seek and save match parameters. I do that for each band. After that I don’t need to go to AM mode. I just start talking and the ATU detects the frequency, even with SSB, and it recalls the match in milliseconds. It will do the same for CW. That is of course with the Elecraft ATU. There are others that can do it too. I think the MFJ-998 can recall when you speak. I should add that, with a manual tuner, or an auto-tuner with manual mode, adjust until you get the most signal/noise on the S-meter, during receive. That should get you close enough that the key-down to fine tune the SWR won’t take so long, and you won’t start the tune sequence with a dangerously high SWR. 73, de N4HNH

[@miker8379]

If your using a built in tuner, there is no need to switch to anything. It probably switches momentarily to cw for the tune and reduces power automatically. Am transmits a much wider signal than cw or? I used to use rtty on a 706 just because it was easier and a narrower signal. The analyzer and swr meter rarely agree and swr can be different depending on exactly where along the line you measured it.

[@ronjoseph7973]

For the average operator, there are more reasons NOT to get an amp than to shell out the $$$ to properly set one up. It comes out to approximately $2.28 PER WATT less the power supply, tuner, and whatever mods you have to make to your outlet and wiring. With all the nonsense on 75/80 meters and now creeping into 40, it’s just not worth it. Set up the best antenna system your budget will allow, get a good transceiver, autotuner, mic, and antenna analyzer and with good technique and learning about propagation, you will make all the contacts you could ever want. KC5RJL Houston, TX

[@n4hnhradio]

I didn’t buy an amp until after my second HF base station purchase. And I’ve only purchased 3 HF base stations in 41 years. I worked the world with 100W. I tell people that 2500W isn’t enough if propagation isn’t in your favor. The amp does come in handy from time to time, when I’m trying to chat with someone on 40 or 75m. There are times when those are the only bands that provide propagation to the people I want to chat with. The amp helps to overcome the high noise level on those bands where even an S9 signal will have atmospheric noise mixed in with the audio. Of course IPO, ATT, RF Gain, and DNR help immensely.

[@paulhastings3109]

I think the combo is the way to go. Just have to put some coffee money way hi hi KQ4CD Paul

[@n4hnhradio]

Indeed it is, Paul. Such a great deal for equipment that is so well designed and built in the USA. 73, Doug

[@miker8379]

Nice stuff but open wallet wide. I got a bare bones k3. Thankfully Elecraft gives you that option.

[@n4hnhradio]

An Ameritron AL-80B is $2,899.95 for the version that is QSK capable, like the KPA-500. Even the least expensive version of the AL-80B is $2,319.95. The KPA-500 is currently $2699.95, when purchased alone, not as part of the combo I mentioned in the video. Ameritron rates the AL-80B at 1kW, but to reach that level you have to drive it very hard, and expect to replace the tube more often. My AL-80B has lasted 22+ years because I kept it at 600-700W. So a solid-state amp with no tube to wear out, that can reach 600W with approximately 40W of drive, costs a little less than the top-of-the line AL-80B. As far as tuners go, the MFJ-998 provides auto-tuning for just under $700, while the KAT-500 does it for $879.95, when purchased separately from the KPA-500/KAT-500 combo. An AL-80B combined with an MFJ-998 auto-tuner costs approximately $3590. And you still need to purchase control cables, one to key the amp and another to control the tuner. An AL-80B with a Palstar HF-Auto would cost $4,449.90, so I won’t even go there. Although I ran that setup for nearly 20 years. The KPA-500/KAT-500 combo is currently selling for $3524.90, and that includes the cable for your particular transceiver. Realistically, the AL-80B is an 800W amplifier, if you wish to operate the 3-500Z within limits that won’t kill it prematurely. The plate can dissipate 500W. In SSB mode, the tube can produce in excess of 800W, and stay within its published operating parameters. But 800W or less is considered to be better for the 3-500Z. That’s why I kept mine at 600-700W. So, I look at it like this. Is having an amplifier that I must tune when I change bands, and maintain a tube, worth more for the extra 200W? The KPA-500 can deliver 600W, so it’s a 200W difference - hardly noticeable on the S-meter. With the 600W KPA-500, there is no tuning necessary and no tube to eventually replace. And I say this as someone who grew up in the tube era. I like tubes. But I can admit that solid-state has the edge nowadays. These are some of the reasons why I think the Elecraft KPA-500/KAT-500 combo is such a great deal at $3524.90. 73, de N4HNH

[@n4hnhradio]

I could never afford the K3 for SOTA. That’s how I ended up with a FT-891. But K3 is the standard for portable ops.

[@kb9jqu]

Very good points Doug. I looked at several solid-state amplifiers at the recommendation of DX engineering and never considered Elecraft until we spoke. Once I took a look at Elecraft I realized I was getting a tremendous value in the combo deal. Your numbers illustrate that nicely. Another thing to consider is if you do run into a problem down the road, you’re dealing with a company based in the USA and may find getting service to be much easier if not quicker.

[@miker8379]

@@n4hnhradio my story is I was wanting a tabletop radio instead of 706. I was getting QRM on 20m from 2.5kc away. I was looking at a yaesu ft-950. Figured for $500 more I could get a bare bones 10w k3 so that’s what I did. Shortly after I stumbled into a deal on a als-600 that was modified for QRP drive. For portable k3 will operate down to 11.5v I believe and you can turn of backlighting on the display to save battery. Eric is the hi-power co owner and Wayne is the QRP guy. Their roots are in QRP but I think hi power has taken over. I think guys like me that use it for conversation not 5/9 next are in the minority. I’m definitely a fan boy of down conversion which really is just new age lingo for old school. Of course direct sampling sdr is going to be the way forward or hybrid like yaesu is doing.

[@n4hnhradio]

You’re right. Most people don’t realize that superheterodyne receivers were down-conversion (1st IF down within the HF amateur bands - actually between bands) until the late 1970s. The manufacturers increased their profit margins by going to up-conversion (IF at 40 to 70 MHz). They went to up-conversion to get away from the need for preselectors. Of course there is no good substitution for a good preselector. And the roofing filters were not nearly as tight at 40 to 70 MHz. We owe Ten-Tec a big thank you for changing back to down-conversion in 2003, with the Orion. Yaesu got on board in 2010, with the FTdx5000. Slowly Kenwood came aboard, but not completely. The TS-990S and TS-590SG are only partially down-conversion. They use down-conversation on 15, 20, 40, 80, and 160 meters. The TS-890S finally puts Kenwood back into the full down-conversion column. Still today, not all superheterodyne receivers are down-conversion. FT-891 isn’t. But the DSP filtering helps make up for it. FT-991A isn’t either. But again, good DSP filtering helps offset that. FTdx1200 isn’t down-conversion. It’s easier to say what is down-conversion. FTdx3000D, FTdx5000, FTdx101D, FTdx101MP, and FTdx10 are all down-conversion, with the last three being a hybrid superheterodyne and SDR. I saw the SDR as another move by manufacturers to increase their margins by making us think it is so much better. Really it’s cheaper to build. But the FPGA chip has merit. It provides us with the magnificent waterfall. So kudos to Yaesu for combining the merits of a down-conversion superheterodyne receive architecture with the merits of the FPGA chip, in the FTdx101D and MP, and the FTdx10. And they even brought back the preselector in the FTdx101D and MP. 73, de N4HNH

[@alanshaw6161]

ATU=Liar Box 😆

[@n4hnhradio]

Well, not exactly! I do like to jokingly say that an “antenna tuner” only fools the transmitter. But he truth is, it acts as an impedance transformer. There isn’t as much loss through the ATU as many people believe. It is just acting as a transformer. Loss in the coax? Yes. But even at a 3:1 mismatch, the loss in power isn’t astronomical. But, I prefer ladder line. Even with a mismatch of 5:1, there is minimal loss, compared to coax.