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6400 / SmartSDR / antenna switch / rotor / remote / no PC?

WX6P Member
I have a tower with a rotor and five different antennas covering all HF bands + 6M. At the base of the tower I have an antenna switch and a six-wire cable that runs in the shack. To use the station remote I'd need SmartSDR, rotor control and antenna switch control.

1. Could I use a BIT cable and configure it in SmartSDR so that it can switch between the different antennas based on the band selected?

2. Are there any options to control the rotor remotely via internet without the use of a PC at the remote location?

Thanks for any tips


  • KD0RC
    KD0RC Broomfield, COMember, Super Elmer Moderator

    You could use a bit cable for antenna switching. Be sure to read all the documentation for the switch and radio so that you get it connected correctly and so that you don't put any inappropriate voltages anywhere.

    Having a PC at the radio location can be very beneficial. I do that so that I can run rotator control, DDUtil, TeamViewer and VPN. Makes remote operation much easier. Mike, VA3MW has some good videos on the subject and on running remote in general.

    When operating remotely, I run SmartSDR using SmartLink. I use the SoftEther VPN to provide connectivity for my homebrew Flex control box, the TeensyMaestro.

    The PC at the radio location does not need a lot of horsepower unless you run CW Skimmer or something like that on it. I use my old laptop for the purpose and it works great.

  • David Decoons, wo2x
    David Decoons, wo2x Member, Super Elmer Moderator

    First off, describe your equipment (radio, amp, tuner, antenna switch, rotor & controller, etc). That will help us to give more informative answers.

    I suggest the Facebook group Ham Radio - Remote HF Station Building. Plenty of people around the world doing remote in all different ways.

    You could do the antenna switching using a bit cable to relays, a SainSmart USB-8 board to back of Flex, Node Red on a Raspberry Pi with various relay boards that work with Node Red, an Antenna Genius, or Green Heron Everywhere capable equipment.

    For rotor control, I have a Green Heron RT-21 plugged into the Pi directly via USB to serial cable and controllable from Node Red. Check out https://groups.io/g/nodered-hamradio We have almost 1700 members in the group worldwide (and very talented people).

    Also take a look at the Teensy board Len KD0RC uses. It is small, uses very little electricity, and customizable.

    Don’t forget AC power control to reset equipment and relays you can control for remote on for the Flex and remote “local PTT” in case you need to re-register SmartLink. A PC on site set up in bios to boot when AC power is applied is highly suggested for firmware updates, etc.

    Believe me, in dead of winter you don’t want to be unable to reach your station unable to do something that can be done remotely. There are many different methods to accomplish successful remote operation.

    To give you an idea on my setup

    Flex 6600m radio, Power Genius amp, Tuner Genius, Antenna Genius, Pi 4 running Node Red, GHE RT21 rotor controller to Pi, DLI Web Switch Pro Internet controllable AC outlet switch, West Mountain Rig Runner 4005i Internet controllable 5 port DC switch (for low current devices), PC, two DLI AC relays for Flex remote on & remote PTT. I have other equipment remote accessible with fiber Internet with cable modem backup (router with auto failover). The above equipment is accessible with Node Red and the AC and DC switching has alternate access in case the Node Red Pi needs rebooting. This is a setup I have been working on for about five years and always tweaking.

    At remote site I use a Windows laptop, iPhone, iPad, and Stream Deck (not all at once). I recently picked up a MAC Mini that I can bring portable if needed.

    Here’s a quick screen grab of my desktop Node Red dashboard layout with SmartSDR running. (Taken from the iPad)


    Dave wo2x

  • WX6P
    WX6P Member
    edited November 20
    Thanks Len for the info on the bit cable. I have come across some more information https://www.youtube.com/watch?v=T7bia-pZbBU and I am confident I can set up antenna switch control using a version of the FDTI cable Flexradio is selling here https://www.flexradio.com/products/usb-to-parallel-adapter-for-the-flex-6000-series/ .

    On the use of a PC at location, I have used it in the past with TeamViewer and AnyDesk but I find it simply too cumbersome to run once I came across elegant solutions like Node Red platforms using RPi for remote operation. Another inconvenient for me is the internet bandwidth required to run a TeamViewer or AnyDesk session, with internet speed not great at the remote site. The whole idea of moving from ICOM to Flexradio was the ease of remote control via SmartLink.

    Now to Dave's response. Like I said above, I am trying to avoid the use of a PC at the remote site. My qth is about 30 miles away, so if I needed to run updates or reboot stuff, I can just go there and do it physically. I am looking for a clean (fewest screens/windows/slides possible), elegant and bandwidth-efficient solution to remotely control the station, antenna switch and rotator, and to me a remote session of TeamViewer or AnyDesk just doesn't qualify.

    So what you described and the screen grab you included is very much what I'm looking to achieve. My equipment: Flex 6400, KPA500, Yaesu G-1000DXA with K3NG Arduino-based rotator interface (https://blog.radioartisan.com/yaesu-rotator-computer-serial-interface/), 6x1 remote coax switch at the base of the tower (https://www.aliexpress.com/item/1005002745829488.html) and a Pi4B connected to the router.

    I had two previous remote configurations, both using an ICOM-7300. One was using the RS-BA1 interface from ICOM, PST Rotator and 4x1 Easy Controller from RemoteQTH (https://remoteqth.com/easy_controller_6-1.php) all of this accessed bia TeamViewer. The second/current configuration is using the remote control system and cloud-based servers from Remotetx.net, which controls the ICOM via RPi, the antenna switch via a NodeRED that controls the relay hat on the Pi4 (https://www.amazon.de/-/en/SPST-NO-Power-Relay-Module-Raspberry/dp/B08PSFK2L2/) and the same NodeRed screen controls the K3NG Arduino-based rotator interface for the rotator. I have to say, this configuration is performing excellent, and the bandwidth is amazing, but the only thing that made me purchase the 6400 is the panadapter, which on ICOM is useless.

    So back to your reply, you mentioned that the GHE RT21is plugged into the Pi directly via USB to serial cable and controllable from Node Red. I guess my question is whether my Arduino-based rotor interface would be controllable from NodeRed. The other thing I wonder is whether there's an amp interface in NodeRed for the KPA500, as I'm not sure how much control of the amp I'll get from SmartSDR.
  • David Decoons, wo2x
    David Decoons, wo2x Member, Super Elmer Moderator

    We already have KPA500/KAT500 flows for Node Red. USB to serial FTDI cable to Pi.

    There is also K3NG rotor flow available.

    For antenna switching, you can use the SainSmart USB-8 relay board that uses USB A to B cable from SainSmart board to Flex. In Flex USB cable setup it gets set up as bit cable, giving 8 relays that can be wired into your antenna switch.

    There are flows to allow Arduino to Node Red communications. You can use the best choice of all solutions provided.


    Dave wo2x

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

    Here is another idea and the video explains some of the power to having a remote PC. Give it a watch first and then see if it makes sense that this is easier in the long run.


  • Larry Benoit
    Larry Benoit Member ✭✭

    FYI, I use a USR N540 serial to ethernet converter and PstRotatorAZ to remotely operate a Green Heron rotor controller and other equipment. No PC required in the shack.

    Although it would be an expensive upgrade the Flex/4O3A Antenna Genius (AG) can be installed outdoors in a weatherproof NEMA-rated enclosure and does not require a PC in the shack to communicate with Flex 6000 transceivers. You might be able to add a wireless access point adjacent to the AG, provided the tower is not out of wireless range.



    Larry KB1VFU

  • David Decoons, wo2x
    David Decoons, wo2x Member, Super Elmer Moderator
    edited November 27

    I’ve used a WiFi bridge initially and it worked fine but now have CAT 5 running gigabit speed between fiber gateway and HP managed switch in my equipment server cabinet.


    Dave wo2x

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