Revisiting an old project

• VHF / HF X-Gate Project

DTMF Commands on VHF Port

• Re-install all the hardware:
  • IC-M710
  • Raspberry Pi X-Gate controller
  • X-Gate Interface with syllabic squelch and DTMF decoder
• Test in full-duplex VHF/UHF mode to identify any issues that need addressing to bring back to normal function
• Suspend or stop completely VHF APRS to free up V/UHF for X-Gate
• Test remote operation from Vehicle - V/UHF coverage is unlikely to be very good…
• Revisit Python code if necessary to add/remove features.
• Actually have real QSOs on HF using the X-Gate!

• Connected X-Gate Interface, R.Pi controller, IC-M710 and FT8900
• Initial problem with crashing due to USB problems on R.Pi causing USB/Serial adaptor (for control of IC-M710) to fail - this was cured by using different 5V USB power supply.
• Speech clipper removed from HF TX audio path due to distortion and poor audio quality.
• HF Audio drive level set to give correct HF SSB Power out
• Web server status page available by port forwarding at http://gm4slv.plus.com:42109/
• VHF uplink changed to split-band
  • Input : 144.650MHz
  • Output: 435.400MHz
  • This allows control even when in permanent “Monitor” or “Talkthrough”
  • Enabled a 15-minute CW ident on the UHF port which identifies with my callsign and the current HF frequency/mode.

• Xgate software runs in a Tmux session with 3 panes
  • Xgate software - printing commands etc. from the running controller code
  • Relay control - independantly control various Xgate relays (PTT, Monitor, Mute, CW tone) directly, while main xgate is running.
  • a shell for editing code etc.

• Is the “HF Channel” 4-digit input selection really of any value?
  • It requires memorizing channel numbers and saves entering only one or two digits.
  • Will probably drop this function unless I find a use for it soon.
  • Perhaps change to 2-digit channels and limit to a few frequently used frequency/mode combinations?

The current channels are: Memory Dictionary (4 digits)

mem_dict = {
        "0101" : ["1942.0", "LSB"],
        "0102" : ["1933.0", "LSB"],
        "0103" : ["1957.0", "LSB"],
        "0104" : ["1985.0", "LSB"],
        "0105" : ["1966.0", "LSB"],
        "0301" : ["3773.0", "LSB"],
        "0302" : ["3760.0", "LSB"],
        "0303" : ["3615.0", "AM"],
        "0501" : ["5276.0","USB"],
        "0502" : ["5279.0","USB"],
        "0503" : ["5298.0","USB"],
        "0504" : ["5301.0","USB"],
        "0505" : ["5304.0","USB"],
        "0506" : ["5317.0","AM"],
        "0507" : ["5320.0", "USB"],
        "0508" : ["5333.0", "USB"],
        "0509" : ["5354.0", "USB"],
        "0510" : ["5363.0", "USB"],
        "0511" : ["5366.5", "USB"],
        "0512" : ["5371.5", "USB"],
        "0513" : ["5378.0", "USB"],
        "0514" : ["5395.0", "USB"],
        "0515" : ["5398.5", "USB"],
        "0516" : ["5403.5", "USB"],
        "0521" : ["5258.5", "USB"],
        "0522" : ["5278.5", "USB"],
        "0523" : ["5288.5", "USB"],
        "0524" : ["5366.5", "USB"],
        "0525" : ["5371.5", "USB"],
        "0526" : ["5398.5", "USB"],
        "0527" : ["5403.5", "USB"],
        "0531" : ["5330.5", "USB"],
        "0532" : ["5346.5", "USB"],
        "0533" : ["5357.0", "USB"],
        "0534" : ["5371.5", "USB"],
        "0535" : ["5403.5", "USB"],
        "0591" : ["5450.0", "USB"],
        "0592" : ["5505.0", "USB"],
        "0701" : ["7160.0", "LSB"],
        "1091" : ["10051.0", "USB"]
        }
 

mem_dict = {
 
        "01" : ["5279.0","USB"],
        "02" : ["5320.0", "USB"],
        "03" : ["5366.5", "USB"],
        "04" : ["5371.5", "USB"],
        "05" : ["5378.0", "USB"],
        "06" : ["5395.0", "USB"],
        "07" : ["5398.5", "USB"],
        "08" : ["5450.0", "USB"],
        "09" : ["5505.0", "USB"],
        "10" : ["7160.0", "LSB"],
        }

• One change in main xgate code:

 if len(command_two[2:]) == 4:
 

becomes

 if len(command_two[2:]) == 2:
 
 

                elif command_two[:2] == "*1":
                    write_file("Frequency / Memory")
                    #if len(command_two[2:]) == 4:
                    if len(command_two[2:]) == 2:
                        new_freq = float(mem_dict[command_two[2:]][0])
                        new_mode = mem_dict[command_two[2:]][1]
                        write_file("Memory Channel selected %s" % mem_dict[command_two[2:]])
                        set_frequency(new_freq)
                        set_mode(new_mode)
                        write_status("freq",str(new_freq))
                        write_status("mode",new_mode)
                    else:
                        new_freq = float(command_two[2:])/10
                        set_frequency(new_freq)
                        write_status("freq",str(new_freq))

• modified main xgate code to be able to start in simplex or duplex mode by the choice of commandline argument:
  • for simplex (single frequency/band uplink/downlink) which will disable the continuous monitor function to avoid getting locked out →

./xgate_current.py s

• for duplex (separate uplink and downlink bands) which will enable the continuous monitor function, as it is always possible to send a command on the uplink band while the downlink is transmitting →

./xgate_current.py d

I've updated the mercurial repository - added new files, committed recent changes and made a clone of it on the shack laptop - in Dropbox (which might be a bad idea?)

There's another page about simple Mercurial , as an aid to remembering how to do it each time.

If the X-gate is set to simplex mode (single band for both in and out) on VHF it should be possible to access the system via a mobile cross-band repeater from a low power UHF handheld.

This extends the range of the local VHF network.

If you are within UHF simplex range of the V/UHF cross-band repeater (vehicle mounted?) and the vehicle is located within VHF range of the X-Gate (eg on a distant hill-top) it should be possible to access the X-Gate and log in/change frequency and operate through it on HF from the UHF side of the vehicle's Cross-BAnd repeater.

I am beginning tests on this using a TM-D710 mobile and TH-D72 handheld.

From the RSGB Band Plan

• 144.9750, 144.9875 MHz Low power / Adhoc repeater inputs (Note 11)
• 433.8000-434.2500 MHz Digital communications & Experiments

I'm choosing to use 144.975MHz for the X-Gate VHF uplink frequency - as there's little chance of a clash with any “ad hoc repeater” and to use 433.825MHz for all UHF activity (either the mobile cross-band repeater or when the X-gate itself is using split/duplex uplink). These frequencies are totally clear here in remote Shetland!

• Uplink changed to Simplex : 144.975MHz