Re:Split TX RX Config

[HL2UOK]

The QS1R as dedicated receiver + an HF rig as transmitter -- Chris KC2RGW

• If you wish to run your QS1R as a dedicated receiver but use an HF rig as your transmitter this guide may be for you. The hardware section is somewhat generic and can be applied to any seperate RX and TX combo.

• This is my daily use configuration for HF ops and I've had this working for a while now with excellent results.

Things You Will Need

Hardware to split RX and TX

• QS1R - The ultimate dedicated receiver!
• PTT switches - Momentary switches, normally open type, to key the rig and the relay
  • I strongly recommend the Heil Foot Switch simply because this switch is well constructed and has two leads already staggered with independent micro switches.

• If you use this foot switch, the RED lead keys first and is generally for an amp and the BLACK lead keys slightly later and is for keying your transmitter. In this application, key your transmit relay with the red lead and key the rig with the black. If you run an amp, use a rig to amp keying cable to in turn key your amp as that will then be staggered properly before the rig begins to send RF...and the antenna will already have been switched by the transmit relay.

• HF transceiver or transmitter that is Hamlib compatible - I switch between a TS-2000 and TS-940
  • The TS-2000 with port speed set to 57600 gives near real-time tuning sync. The 940 is 4800b max and has about a 1s lag when it finally 'lands' on where you have tuned SDRMAX. The 940 is still very useful and it is generally the rig I run the most often.

• Antenna TX/RX relay e.g. Dow-Key relay 60-220442 or similar function relay
  • I recommend the Dow-Key over the MFJ 1708 after having had a miserable RFI issue introduced by the MFJ switch that was 100% remedied with the Dow-Key relay. Also a nice advantage is that the Dow-Key has DPDT open frame relays that allow you to also wire left and right audio channels for full muting on transmit.

• This is what a Dow-Key relay looks like.
• 
• The coil is on top and you can see the power terminals to feed the 12VDC (for this model, some are even 117V AC). On the bottom are the open frame DPDT relays that I wired for audio muting.

• A VOM or something that can test for continuity.
• Very basic soldering skills to wire the relay and PTT mechanisms

Software to sync the QS1R with your HF rig as you tune the receiver

• I have built and tested this on an Ubuntu linux system, though it will very likely work on other platforms with some hacking. With Ubuntu you can apt-get everything you need except for my script which is linked below from the QS1R google code project svn site.

• Ubuntu Linux OS or another compatible system.
• Python - Interpreted language engine
• Python hamlib bindings module - Interface for Python to Hamlib
• Hamlib - Open Source rig control software
• My Python script for qs1rcontrol which is Here

Let's Get On With It, Shall We?

Wiring up the hardware to split the antenna between RX and TX

• The physical architecture is essentially this. QS1R into the RX side of the antenna relay. Your HF rig into the TX side of the relay and the antenna that is common into the common port.

• In the example with the Dow-Key relay, you need to supply it with 12V to power the switching coil. Use a VOM to test for which of the coax ports is normally connected to the common port with no current applied. Label this port as the RX port and the opposite port as your TX port.

• Now you need to make a fused power lead that is tied into your PTT switch on the positive voltage lead, for keying the relay.
  • Test your relay by closing your momentary switch. You should hear a light *click* from the relay when you close the PTT and in turn close the circuit feeding power to the relay. Test with your VOM to ensure that you have the RX and TX sides of the relay properly labeled.

• Under power with the relay engaged you should have continuity from the common ANT port through to the TX HF rig port. Without power applied, you should have continuity from the common ANT port with the RX side of the relay. If this isn't working, check that you actually have voltage from your power supply and that the PTT switch connections are functioning properly.

• Cable up the QS1R antenna input to the RX port on the relay

• Cable up the HF rig antenna output to the TX port on the relay

• Cable up your antenna to the common or ANT port on the relay

• Optionally, take the stereo left and right audio and wire them to the open frame DPDT relay on the body of the Dow-Key relay.
  • I simply wired mine so they are making contact when the relay is at rest (normally closed state) so that when power is applied, they open the audio channels, thus muting my main stereo mixer output feed into my computer speakers. I have several radios being mixed into a pair of powered speakers, this ensures that no noise gets into the microphone while I'm transmitting. Wire it so that the positive leads are lifted when the relays open.

Now you're all set with the hardware end of this project. When you key the foot switch, you will flop the antenna over to the TX side of the relay allowing your HF transmitter to send your signal out the antenna. When you release, the antenna will flop back over to the QS1R.

If for whatever reason you aren't using the Heil foot switch, just remember, you want to key your connections in the following order and this is rather important as you can damage your receiver if you feed RF power from the transmitter directly into it

1. Antenna from RX to TX
2. Amplifier if you have one in line
3. Transmitter

Unkeying should be the reverse of that sequence as well.

This is what my configuration looks like. I took the project box to break out connections for the 12VDC supply, Audio L/R IN/OUT and PTT. The multi-color ribbon are the connections between the box that have to be heat shrunk and tidied up into a DIN plug at some point :-)

O.k. Great... Now I have to manually sync my receiver with my transmitter... Now what?

02.15.2010 Hamlib is broken on several recent releases.....my script will no longer work on Kenwood TS-940 or TS-2000, unsure which if any other radios are affected by this issue. A fundamental change to hamlib was made several versions back and it was not caught..this results in hamlib being unable to read or set the VFO frequency. I'm leaving this here to give people an idea of what can be done, more than a complete solution at this point. If yours is working...don't change your hamlib version!

This will only work on linux or similar open source operating system platforms as far as I know. The reason is that the underlying python-hamlib modules don't seem to be built for Windows use and the script depends on it.


This section makes some assumptions. This assumes that your rig is supported by the hamlib control libraries and also that you have a CAT control interface connected and configured and ready to go.

I would recommend if you haven't tried this before, to install 'grig' and get that working first as it is based on the same control libraries I'm using and will likely be easier to get the communications link configured and troubleshooted before you try my script.

Now we're going to get SDRMAX to be the master for tuning and have the rig 'follow' the QS1R as you tune. This way you aren't out of sync with the TX and RX for general use.

Download my qs1rcontrol Python script.

Install Python, hamlib and the python-hamlib module package dependent on your OS platform. I can't go into all the details of doing this due to the vast variations in how this is done between various OS distributions.

Open the script with a text editor and you're going to either modify or just check the following parameters.

# IP that QS1RServer is running on
HOSTNAME = '127.0.0.1'
# QS1R control port
QS1RPORT = 55667

Set those to the appropriate IP and port number for your QS1Rserver instance. This is how the script connects to the server instance for polling.

This next section is where you define the type of rig you have so that the hamlib control library can 'speak' to it over the serial port connection.

I have two sections defined because I switch between two different rigs. The commented out section is for my TS-2000 and the uncommented block is for my TS-940.

If you have the same rigs, you can simply use the rig definition I have there and change the serial port to whatever you are using on your system for the CAT control cable connection to your rig.

To determine what to set RIG_MODEL_WHATEVER to, take a look at this source http://hamlib.sourceforge.net/manuals/1.2.3/html/riglist_8h-source.html or your local copy of "riglist.h" from the hamlib files to ensure version compatibility.

As an example if your rig was a Yaesu FT-920, you would simply change the lines below to Hamlib.RIG_MODEL_FT920 rather than my entries for TS2000 or TS940.

###################################################
#
# RIG Model & Com Port Definitions Declared Below
#
###################################################
 
 
# The next two are for a TS-2000 Kenwood on ttyUSB2
#my_rig = Hamlib.Rig (Hamlib.RIG_MODEL_TS2000)
#my_rig.set_conf ("rig_pathname","/dev/ttyUSB2")
 
# These are for a TS-940 on ttyUSB3
my_rig = Hamlib.Rig (Hamlib.RIG_MODEL_TS940)
my_rig.set_conf ("rig_pathname","/dev/ttyUSB3")

Now, once you have this all configured, start the QS1RServer and SDRMAXIII or 3 or Panoptos...will work with any of those as of this writing, and open a terminal window and run my script. Your rig should now follow the QS1R as you tune it or change its mode.

All this script is doing is simply opening a UDP socket and polling the QS1R for what it's current frequency and mode are and then pushing an update via hamlib over the serial connection to your HF rig.

It is recommended that if your rig will operate at optional higher serial speeds, that you just set the rig for its max speed. My TS-2000 will run at 57600 baud and it tunes in nearly real time sync. My TS-940 is limited to 4800 baud and there is almost a 1 second lag from the time you 'land' on a frequency in the QS1R and the rig is updated. Hamlib will figure out your port speed for you in my script so you don't have to bother with it at the OS end of the connection.