SkyCat for Icom 910?

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John Reed

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Aug 20, 2025, 7:51:42 PMAug 20
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Been reading the mail but only now joined the group.

I've been dipping my toes back into Satellite work having been been QRT on that mode for almost 25 years.

Building a satellite station again, and I found Skyroof.

First:  Absolutely LOVE Skyroof.  I've been using it for receive and so far so good.

For Transmit - not sure doppler is behaving well enough with rigctld, so hoping a SkyCat definition for the Icom 910 is on the roadmap for testing.

In any case - keep up the great work - the UI, the settings, etc - so much nicer than what else is out there.

John, N4TII

Alex VE3NEA

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Aug 21, 2025, 9:03:08 AMAug 21
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Hi John,

I will add support of IC-910 to SkyCat, but do not expect too much from this. This radio has a very small set of commands. For example, we can switch the radio to the SAT mode but cannot set the frequency of the other VFO. There is even no command to read or write PTT, so the program has no way to know if it should send the RX or TX frequency to the radio. Despite the support of the SAT mode, IC-910 is only good for TX only and RX only SAT operation.

One way to overcome this limitation is to let SkyCat read and write PTT on the second COM port, using the RTS/DTR line to switch PTT and DSR/CTS line to read the PTT status, but this is a project for the future.

Alex VE3NEA

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Aug 23, 2025, 8:58:54 AMAug 23
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Please try the attached file. Select Simplex in the SkyRoof settings.
IC-910.json

John Reed

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Aug 23, 2025, 9:27:33 AMAug 23
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Hi Alex,

Thank you - loaded up and this is the result when I launch it.. (log file attached )

Not sure if this helps but the pstrotator guys have a "special" omnirig definition for this rig that they are using.   "icom910pst" 

John, n4tii




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skycat.log

Alex VE3NEA

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Aug 23, 2025, 9:28:39 AMAug 23
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Actually IC-910 has a PTT read/write command, it is called " Set/read transceiver’s condition". This means that this radio will work with both RX and TX CAT enabled, but its duplex mode cannot be used since there is no command to set the frequency of the other VFO - or maybe there is, under some unusual name. Hard to tell without physical access to the radio.

Alex VE3NEA

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Aug 23, 2025, 9:35:45 AMAug 23
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Hi John,

Thank you for the log! May I ask you to produce a new one, with more "v"'s in the -vvv command? Three v's print all data.

John Reed

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Aug 23, 2025, 9:45:04 AMAug 23
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Attached....



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skycat-ic910.log

Alex VE3NEA

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Aug 23, 2025, 10:05:50 AMAug 23
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Weird. The radio does not accept the Split Off command. OK, here is another file, without Split Off. Pleas turn the split mode off if it is on using the button on the front panel.
IC-910.json

John Reed

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Aug 23, 2025, 10:29:34 AMAug 23
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There's a Windows "App" based tracking program - and it has some test functions in it - and playing with that yields a few things:

Split on / off cannot have "satellite on" or it'll ignore it.

Focus has to be on the "main" band to turn on or off split.

Couple of command observations:

FE FE E0 60 03 00 28 62 37 01 FD -. get current frequency
FE FE 60 E0 05 10 28 62 37 01 FD -> advance current frequency +10 hz
FE FE 60 E0 16 5A 5D -> get sat mode
FE FE 60 E0 1A 07 01 FD -> set sat mode on
FE FE 60 E0 1A 07 00 FD -> set sat mode off

FE FE 60 E0 07 D0 FD -> select main band
FE FE 60 E0 07 D1 FD -> select sub band
FE FE 60 E0 07 B0 FD -> swap main and sub

With sat mode off / split off:
FE FE 60 E0 07 00 FD -> select vfo a
FE FE 60 E0 07 01 FD -> select vfo b

FE FE 60 E0 06 01 FD -> set mode usb
FE FE 60 E0 06 00 FD -> set mode lsb

FE FE 60 E0 16 42 00 FD -> Tone off
FE FE 60 E0 16 52 01 FD -> Tone on
FE FE 60 E0 1B 00 00 07 44 FD -> set tone to 74.4hz
FE FE 60 E0 1B 00 00 06 70 FD -> set tone to 67 hz

(these commands can only be sent to "main band")
FE FE 60 E0 0F 01 FD -> split on
FE FE 60 E0 0f 00 FD ->split off




Alex VE3NEA

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Aug 23, 2025, 10:41:14 AMAug 23
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Wow! This is very useful. What does the select main/sub band command do? Does it select which band is used for receiving, like Select VFO A, or does it define to which  VFO the Set Frequency and Set Mode commands apply?

The first two commands in my original json files were

"FE", "FE", "60", "E0", "1A", "07", "00", "FD" -- SAT mode off
"FE", "FE", "60", "E0", "0F", "00", "FD" -- Split mode off

The second command failed. I will try to put Select Main Band between them and see if this helps.


John Reed

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Aug 23, 2025, 11:01:09 AMAug 23
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Yes.

The Icom 910 is the predecessor to the 9700 - so it's a full duplex / 3 band radio.
On the icom 910 - similar to the 9700, you have two "bands" displayed at any given time on the screen  - top one is "main" and bottom is "sub"
Select "MAIN" and additional command focus is on the "main" band - whatever is the "top" item.   
When focus is there, set vfo, set freq, set mode, set tone on, etc.... they will be applied there.
Likewise, if focus is on "main" , when the mic is keyed, it will be that band that "TXs"
Select "SUB" highlights the "lower" band - and similar - set freq, mode, etc.    
Only the "main" band can activate split.





Alex VE3NEA

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Aug 24, 2025, 11:57:53 AMAug 24
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Here is the iC-910 file with Main band selection before switching Split off. It looks like it is possible to use this radio in the duplex mode, but let us make simplex work first.
IC-910.json

John Reed

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Aug 24, 2025, 3:07:18 PMAug 24
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Better - but still some errors.



skycat-910.log

Alex VE3NEA

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Aug 24, 2025, 3:21:16 PMAug 24
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Thank you for testing! We are making progress. The radio rejects only one command, Read PTT. Now that the format of the .json file is published, you can experiment with it yourself. Please see if you can fix PTT Read (1C). Does it require a zero as a second byte?

John Reed

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Aug 24, 2025, 4:11:55 PMAug 24
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Hey Alex,  

Read or set PTT state doesn't appear to be a command you can query on this radio.

From the 910 CI-V Command List, no commands past 1A are defined... 

(Page 79 of the Icom 910 manual).

Found a cool app called "CI-V Scout" where I can send / receive commands to/from the rig .   Anything 1C gives you the "FA" (no good) reply.




Alex VE3NEA

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Aug 24, 2025, 5:50:25 PMAug 24
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In my copy of IC-910H Instruction Manual dated 2010, page 79, there are 1B and 1C commands. Worth trying.

1C.png

John Reed

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Aug 24, 2025, 6:00:41 PMAug 24
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Interesting - I have a 2000 copyright manual that stops at 1A (but I know the 1B commands work ... ).  Just downloaded a manual, and sure enough, it has some additional commands in several sections.

(and looks like my 2000 manual has some errors, too, in the CI-V command structure - especially around 03, 04, 05 area ... so perhaps this contributed to the reprint0.

I'll go back and try again with these 1C's and see if I can generate a validly formatted command and report back.






John Reed

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Aug 24, 2025, 8:49:32 PMAug 24
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Hey Alex,

So, this command in fact does work (I'm going to run on the assumption that the (C) 2000 version of the 910 manual has errors on the CI-V command page) - and yes, need to include that additional byte of data:

Tried in both Satellite Mode as well as "normal" VFO mode.

Here's the command SETTING the value:

image.png

You can see from the output above:

1C 00 00 :   Sets radio to RX.
1C 00 01:    Puts radio into TX 
1C 00 00:    Set radio to RX.

And - it also works for reads/queries:

Read radio.
Held down the mic PTT and read radio again.
Released and read radio a 3rd time:


image.png

I made the appropriate edits to the .json file - and fired up the program.

In "simplex" mode, I did yell at me when it was attempting to "set" frequency because the "main" band was in 2m and it was trying to set a 430mhz frequency - but once I swapped bands and put UHF into the "main" I monitored the output interactively and it was slowly incrementing the doppler on the radio:

image.png

So ... so far so good.  So error messages in the output.

I'm attaching my updated 910.json.







IC-910.json

Alex VE3NEA

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Aug 25, 2025, 12:55:34 PMAug 25
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Perfect! Thank you very much!

There is a solution to the band change error. We can use the "alt_messages" field to specify what to do in the command fails. Below is an example from the IC-9700 file. When Set Frequency fails, the program will swap Main/Sub and then send Set Frequency again. The example also includes another trick: it sets Split Off after setting the frequency, since the radio sometimes auto-enables split on frequency change.


    "write_rx_frequency":  {
      "messages": [
        {
          "comment": "select sub receiver",
          "command": ["FE", "FE", "A2", "E0", "07", "D2", "01", "FD"],
          "reply": ["FE", "FE", "E0", "A2", "FB", "FD"]
        },
        {
          "command": ["FE", "FE", "A2", "E0", "05", null, null, null, null, null, "FD"],
          "reply": ["FE", "FE", "E0", "A2", "FB", "FD"],
          "command_param": {"format": "BCD_LE"}
        },
        { "command": ["FE", "FE", "A2", "E0", "0f", "00", "FD"], "reply": [ "FE", "FE", "E0", "A2", "FB", "FD"], "comment": "split off" }
      ],
      "alt_messages": [
        {
          "comment": "swap Main and Sub",
          "command": ["FE", "FE", "A2", "E0", "07", "B0", "FD"],
          "reply": ["FE", "FE", "E0", "A2", "FB", "FD"]
        },
        {
          "comment": "select sub receiver",
          "command": ["FE", "FE", "A2", "E0", "07", "D2", "01", "FD"],
          "reply": ["FE", "FE", "E0", "A2", "FB", "FD"]
        },
        {
          "command": ["FE", "FE", "A2", "E0", "05", null, null, null, null, null, "FD"],
          "reply": ["FE", "FE", "E0", "A2", "FB", "FD"],
          "command_param": {"format": "BCD_LE"}
        },
        { "command": ["FE", "FE", "A2", "E0", "0f", "00", "FD"], "reply": [ "FE", "FE", "E0", "A2", "FB", "FD"], "comment": "split off" }
      ]
    },
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