Connecting an IC-7300 to the Elecraft KPA-500 Amp and KAT-500 Tuner

I have been using the Elecraft KPA-500 and KAT-500 with two Icom rigs; the IC-7600 and the IC-7300. This article details how I have chosen to interconnect the KAT/KPA-500 with my IC-7300. There are many options for interconnecting the 7300 with this Elecraft “power combo.” There also many opinions on the various wiring approaches. A couple of the main issues that I have seen discussed include:

  1. Tuning power provided by the IC-7300 – Elecraft suggests that the Tuner behaves best when it gets at least 20 Watts of RF power from the Transmitter. That would suggest that the use of the TUNE button on the 7300 may not be the best approach. I have found that this works quite well. I have also seen some test data that shows that there is little difference in the Tuner’s behavior when getting 10 Watts or 20 Watts.
  2. Need for BAND Data being sent to the KPA-500 – The Elecraft design makes it very easy to interface with any Radio. It is possible to use just the RF into the Tuner to get the Tuner and Amp configured properly. I prefer to send the BAND data from the 7300 to the KPA-500 amplifier. I just feel better knowing that the Amp knows what is coming, when I key up the Transmitter.

Wiring Interconnections

The following diagram shows my overkill approach for connecting the IC-7300 to the KPA/KAT-500. This allows me to use the 7300 TUNE button or the TUNE button on the Elecraft KAT-500 Tuner Utility when I want to Tune to a frequency.

Connection Diagram for using the IC-7300 with the Elecraft KPA-500 and KAT-500

Details for each of the cables are provided below

Monitoring the Setup While Operating

Elecraft provides two very nice software Utilities for monitoring and configuring the KAT-500 and the KPA-500. I always keep these open on my PC desktop when operating. It allows me to hit the TUNE button, change configurations, or monitor Power and SWR without looking at the front panels of the equipment. Below is a screenshot of each of the utilities:

If you look closely at the KAT-500 App screenshot, it looks like my SWR is off-the-charts. No, I am not using an antenna with a 15:1 SWR. I took this screenshot in the morning following a 160m contest, after changing my antenna (outside the shack) to a ZS6BKW. You can see from the KPA-500 screenshot that the Rig is still on 160 meters. This shows how easily I can see if something strange is happening on my antenna system. In the situation above, it would not be possible to KEY the KPA-500, as the KAT-500 will not allow it due to the apparent excessive SWR. If I hit the TUNE button, the Amp will not be keyed and will probably be forced into STANDBY mode. So I could not possibly transmit into my ZS6BKW while tuned for 160m.


23 thoughts on “Connecting an IC-7300 to the Elecraft KPA-500 Amp and KAT-500 Tuner

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  1. Do you have a wiring schematic for the DIN plug to the RS232 plug on the KPA500 and the 12v power on the KTA500

    1. I do not have the schematic for the DIN cable at the moment. I can provide that when I get back to my shack later this week. You will need a VGA connector for the KPA-500 side of this cable. Wiring is easy if you look at the manuals for the two units. If you do this, don’t forget to configure the KPA-500 settings so that it knows to expect ICOM Band Data on the connector.

      For the Tuner cable, I recommend something like the LDG IC-PAC cables, you can find here:
      When using he 7300, you must take the Tuner power from the AH-4 connector on the 7300, so it knows that you are using an external tuner.


      Tom, KG3V

      1. Thanks Tom. I have both the KPA/KAT500 and a KPA1500, which I just purchased. I am currently using the KPA1500 with my Icom 7610. I have a K4 on order and hoping to receive in the next couple months.

        Everett N4CY

      2. You have some fine equipment. I now keep the KAT/KPA-500 connected to my IC-7600 and I THINK that the wiring is the same for the 7610. Been very happy with this combo and the 7600. I found that you do NOT have to take Tuner power from the 7600, and it lets you know very clearly that it is using the external Tuner. I did also post some stuff about this combination on the Blog,


        Tom, KG3V

      3. Tom, I really be more interested in how you hooked up your KPA/KAT500 to you 7600. Once I receive the K4 I will be using the KPA1500 with it and setup a second station with the the 7610 and KPA/KAT500

      4. I posted an article on the Blog about connecting the 7600 to the KAT/KPA-500 before posting the one on the 7300. If you try any of this with the 7610, I would love to hear how it works out. I am guessing the wiring is the same, but do not have a 7610. I will try to send you a shot of my wiring sheet for the DIN connector next weekend.

  2. Thanks Tom, great info. You mention several times “you can then use the tune button in the kat500 utility to tune”. I assume with this setup, you can also use the tune button on the front panel of the kat500, correct?

    1. Chris,

      Yes, you can always use the TUNE button on the KAT-500. Using the TUNE button on the radios seems to be a challenge, depending upon your interface setup. That is why I mention that. Since my Rig is at my fingertips and the Tuner and Amp are not, I prefer to use the Rig’s button for Tuning. Actually, I now often keep the KAT-500 APP on my screen and use that button – even easier.


  3. Can you tell me more about cables 1/3? I assume this is a cable you made? I have the 7300 with this combo, and am interested in setting it up like yours. Thanks! 73, K8JLW

    1. Reid,
      Yes, I built the cable for connecting the DIN pins to the KAT/KPA-500. I believe Icom includes a DIN connector with the 7300 that brings out all of the wires (but I could be confusing my Icoms..). If so, you can use that. As many have said, the BAND connection is something extra, but I like having it. If you only want to use the SEND connection, I think that is also available on an RCA jack, so you could use an RCA cable just for that.

      If you are going to do any of this, please be sure to read my article about using the SEND line on the IC-7300. I do not know if the reported issue has been resolved in any way. But I have been told that no rigs have been damaged…


      Tom, KG3V

  4. Yes the 7300 comes with this connector! So from reading the manuals, the cable should be – DIN Pin 1 to Aux Pin 1; DIN Pin 2 to Aux Pin 5 AND Phono Shell; DIN Pin 3 to Aux Pin 10 AND Phono Tip; DIN Pin 5 to Aux Pin 6. Am I on the right track with that? I’ll be sure to check out the SEND info you mention as well.

    1. IT sounds like you have it nailed. Don’t forget to set the KPA-500 settings to expect ICOM Band Data. Please let me know how you make out, and especially if you run into any trouble. I think you will find this to be a very nice setup. Use the two Elecraft software Apps to monitor the KAT-500 and KPA-500 status. They are a great tool for monitoring your station and antenna matching operation. You will see the Band change when you change Bands on the 7300.

      73 and enjoy your new setup!,

      Tom, KG3V

      1. Finally got a VGA connector in so that I can make my cable. I’ll let you know how it goes!

        73, Reid K8JLW

  5. I have to admit, I can’t seem to find how to configure the KPA-500 to expect Icom Band Data. I don’t see that anywhere in the utility. How is that done? Thanks!

    1. In the KPA-500 manual under MENU, see the “RADIO” setting. You should set that to ANALOG, which tells the KPA-500 that ICOM Analog BAND data will be provided.


      Tom, KG3V

      1. I do NOT put the KPA-500 into STANDBY to perform Tuning. I think it should automatically reduce the power to a safe level to allow the RF-sensing to perform tuning without a Fault. There are some settings that drive AMP behavior, such as automatically going into STANDBY when changing Bands. I suggest going through all the settings and configure them to your liking. Elecraft made this Amp very flexible so it can work with any radio. That does present the risk of having settings that are not what you want. When I bought mine used, it took me several days before I realized I needed to personalize the settings.

        I also found the KAT-500 behavior to be a bit complex if using multiple antennas. But it is also very forgiving.

        I usually keep the Elecraft Apps open on my PC when using the Amp. That provides ample info on operating conditions including SWR, Power output, antenna selections, etc.

  6. Hi Tom,

    I ordered the KPA/KAT power combo in early October and finally received them almost exactly 3 months later. During the waiting period, I had ran some searches looking for user experiences using the combo with a IC-7300 which I have. I found your blog and am very appreciative of you posting you comments on setup and issues. Like you, I preferred to interconnect the 7300 and KPA500 for direct band switching and find this works very well except for 6 meters (I know the 12/17 bands don’t work as Icom created the band voltages before WARC bands were available). I am curious if your KPA will follow your Icoms when switching to 6 meters. It’s not a big deal as I also keep the KAT/KPA PC apps open to monitor the units and can change bands there. Also, I seem to have the often reported warmer amp “clicking” issue from the Z bar support that I have read about on the internet. I had read that Elecraft supposedly redesigned the Z bar to stop this. I also wonder if you have experienced this. This also is not a real issue for me although I know it annoys some hams. I am typically running around 350 w with my KPA as I only really wanted a bit more power since the 7300 is only 100 w and I have had a FT1000D for 20 years so I am used to having that extra 3 dB or so. I haven’t had or used an amp for over 20 years, the last one being a SB200 which I sold after getting the 1000D as I just wasn’t using it that much.


    John K5QX

    1. John,

      Thanks very much for the feedback and I am glad to hear that my experience (good and bad) are helping someone else with their Station. I am now using the IC-7600 with the KAT/KPA-500 so that is the basis of my comments, but it all works very much the same with the IC-7300.

      The BAND data does not correctly select 6 meters for me either. It also does not correctly select the WARC Bands. But with the App open, I just select them manually. Elecraft says that the RF-sensing process will always select the correct Band, and that will override any manual settings. Here is a Link to a discussion about this:

      I have not had any experience with the Z-bar thermal expansion issue and my Amp is an older unit. I DID kill my 80 meter Bandpass Filter Section once and had to remove that Z-bar and those boards for repair. That was quite a chore, but there are some very helpful resources on the Web and I found one that had many photos of the process.

      I also run my Amp at relatively low power levels, usually between 150 and about 300 Watts, as I really bought the amp to get a little more punch during Phone contests, to make them bearable. My main focus is on CW Contesting and this setup just works great for that.

      Hope it all working well for you now. Enjoy!


      Tom, KG3V

  7. I’ll keep trying different settings. I’m only using 1 antenna, I’ve got my cable made and when I checked it all of my connections were good. I’ve got everything routed as you do in your picture above. I do run both utilities on my PC. It seems like the amp is not reducing power when I try to tune with either the 7300 Tune button, or the KAT500 Tune button – unless I have it in Standby. The amp lights up power to about 150 w and then I get the Power Fault on the tuner. I’ve got to have something just not set correctly but not sure what. I’ll keep digging!

    1. I just checked mine, but this is with the IC-7600 which is now connected to the KAT/KPA-500. I can change Bands at will and press the TUNE button without getting a FAULT. It goes through a normal Tuning cycle. This happens if I use the Tune Button on the Radio or on the KAT-500. I do recall having a FAULT issue initially after getting the setup together. All I can remember is that once I got all the settings the way I wanted them, there are no longer FAULTS when I Tune.

      You may want to double check and make sure your SEND LINE and the line between the Tuner and the Amp that inhibits Amp keying when there is not a good antenna match, is working. That sounds like the most likely issue to me – that for some reason the Tuner is not inhibiting the Amp, which I think it should do during the tuning cycle.

      It sounds like you are very close to Nirvana …..


      Tom, KG3V

      1. I just remembered one setting issue. There is a setting on the Tuner that can be configured to tell it that it is being used with a KPA-500 Amp. You want that, as it tells the Tuner that it is OK to suddenly inhibit the Amp at any power level, if necessary. Take a look at the Tuner settings. i think that is where I killed my FAULTing issue.


        Tom, KG3V

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