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Flex-6500 and Ameritron ALS-600 auto band switching

I've tried to do a search on here and find what I needed but haven't had much luck and found conflicting info so I though I'd ask. What is everyone using to interface their solid state Ameritron amp. In my case its a ALS-600 but I think a ALS-1300 series connects the same way. Anyway, do I need Ameritron's ARI-500 Automatic Band Switch device with all it's cables or I saw in a post on here that one guy had some success perhaps with Flex's USB cable and a null modem adapter? If so, trying to figure out how this was connected to the amp. I'm hoping someone can set me straight on what all I need to get auto band switching running with the least amount of cabling possible. Thanks everyone. 73 Matt W5LL


  • w5ll
    w5ll Member ✭✭
    edited May 2021
    I guess no one knows.
  • Roy_W5TKZ
    Roy_W5TKZ Member
    I can understand your frustration. I wanted to do the same thing with my 6500 and ALS-600 but Ameritron doesn't provide cables for the Flex.
    So I did the next best thing and built my own. I purchased a converter cable (USB to serial) and built my own relay box (replaces ARI-500). Works fine with my setup. But unless you are electronics knowledgeable and have the tools, I would recommend you "bite the bullet" and keep what you have.
  • halmassey
    halmassey Member ✭✭
    I did this with my Acom 700S. I can give you the basics. The outline will be the same for any amp. I studied the available inputs on the Acom via the Acom user manual which came in the box and was also available on line. Then I studied the outputs that were available on my Flex 6600M using the user manuals. Using the 6600M USB cable option I built an adapter cable for the Flex FTDI USB to RS-232 cable that allowed me to get connected electrically to the RS-232 CAT control on the Acom amp. I set the Acom menu up and the Flex USB cable menu up and viola! I just have never done it for any Ameritron Amps. As a reminder you will need to get one of the PTT output lines from the Flex to the PTT input on the amp. This requires you to study the signal levels. There is also a Flex document on connecting to several different amps via the Flex USB ports that is very handy. It is in the Flex Document repository.
  • w5ll
    w5ll Member ✭✭

    How would one go about constructing their own relay box? I am fairly competent with a soldering iron and can read a schematic.

  • Mike-VA3MW
    Mike-VA3MW Administrator, FlexRadio Employee, Community Manager, Super Elmer, Moderator admin

    Sorry, but we don't have the equipment to test with, so you will have to do your own research.

    Here is the document that describes the FlexRadio end. https://www.flexradio.com/documentation/usb-cable-interface-guide-pdf/

    This is how it works:

    • The radio will send RS232 data to the amplifier in Kenwood format.
    • Add the cable to the radio and configure it in SmartSDR to have it follow TX slice (if on a 6400) or follow Antenna port if on a 6600 or 6700.
    • The Amplifier needs to be able to receive the data in Kenwood format at the same baud rate - 9600 is plenty fast enough and very reliable.
    • You have 3 wires to connect from one to the other TX Data, RX Data and Ground. There is likely a DB9 connector on both ends and the data is on pins 2 and 3 and ground is pin 5 (this is the NULL modem adapter you mentioned). You might even be able to buy one on Amazon. We used to send one with our cables when you order the USB/RS232 adapter from us.
    • Even if you don't understand which pin, it is likely 2 to pin 3 and 3 to pin 2 (and ground on pin 5 to pin 5)
    • If it doesn't work, switch the wires on pins 2 and 3 on one end and test again. Not to worry if you get it wrong, you won't break anything since these are just low level voltages.

    That should get you started.


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