Probably of no help,? I have the FC40 ATU the schematic shows all the signal wires going directly to the main processor. The pins are tx inhibit, reset, sense, data in/out, gnd, tx gnd and 13.5 v.?
On Sun, Nov 17, 2019, 09:40 John Powers <
john@...> wrote:
On Tue, Aug 16, 2005 at 08:19 AM, "OREST ZAJAC" <n1cjg@...> wrote:
ALSO HAS ANYONE FIGURED OUT A WAY TO USE THE FC-20 AND CAT CONTROL AT
THE SAME TIME?
Interested in following this up. (I have asked the same question on the FT100 forum/s)
Short answer - I haven't found anyone.
Longer answer ….
Clearly, the antenna tune mechanism is fundamentally different to ATAS tuning, where the TRX (FT100 in my case) provides a dc control voltage for the antenna?and monitors SWR during tuning itself.
It seems that the FC20 is continuously checking the FT100 status using CAT and captures a TUNE command. It then takes control of the FT100, sending back tx mode, power and key commands to provide an appropriate rf level. It does this until the FC20 is happy with the SWR.
That description is guesswork, however, based on what I observe doesn't happen and on how I would use the available signalling.
So the problem is that FC20 is continuously keeping the CAT interface busy and that's probably why it's not easy to share the CAT port.
I believe, however, that nothing's impossible, it's just the degree of difficulty. I can see a solution where a PIC sits in the CAT interface monitoring the comms between the CAT program (say HRD?) and when the TUNE button is pressed, or HRD commands it, the PIC switches the CAT to the FC20, or even emulates the FT100 on a separate tuner data lead. It's only programming,?after all.
I looked into the bhi CAT-Mate. It uses a solution where a monitor switches the CAT lines between two CAT devices?but the manufacturers unambiguously state that this 'Y' unit won't support a tuner on one of the two CAT ports. So the technique is valid but the FC20/30/40 use a different protocol to other devices.
The LDG tuners (YT100 and Z817) also use the CAT interface to set the FT100 to generate an appropriate tuning signal.?As the TUNE command is issued from the button on the ATU, rather than the FT100,?it can switch the CAT control from the PC to the Tuner whilst tuning and then back when tuning is complete. There's no need to monitor the FT100 status for a button press. The LDG tuners have a CAT passthrough port which works in this way. Indeed, this is one solution for me - to replace the FC20 with a YT100 and then add in a PC driven switch contact to 'push' the YT100 Tune button using HRD.
If you find any detail on the FC20 protocol - that is, have I guessed correctly - then I'll happily work with someone to develop a solution. I have a perfectly good ATU (FC20) and don't want the expense of changing it just because I want to remote control the station using CAT!??
