Messages

1

Configuration, RRC 1258 / Win4K3 lag in Twin mode with RRC1258 (works fine with RRC Micro and flrig)

« on: 2026-04-20, 14:42:11 »

Hi,

I’m looking for some advice regarding CAT performance when using an Elecraft K3 over RemoteRig RRC1258 in Twin mode with a PC-based control setup.

Setup:

Remote side: Elecraft K3 + RRC1258 (Radio unit)
Control side: RRC1258 (Control unit) + PC
Using Win4K3 for control (no physical K3/0 or K3/0 Mini)
A minimal Python script is used to emulate K3/0 presence (responding to PS;)

Observed behavior:

Win4K3 does connect and CAT communication is working
However, VFO tuning is very slow and jerky
PTT is delayed
In practice, the system is almost unusable due to the lag

Important comparison:

Using the same setup with RRC Micro → Win4K3 works perfectly (no lag at all)
Using flrig on the same RRC1258 CAT port → also completely smooth and responsive

So CAT itself is working correctly through the RRC1258, but Win4K3 becomes very laggy in this configuration.

Network latency is low and stable.

Question:

Is this behavior expected when using RRC1258 Twin mode without a physical K3/0 control head?
Is there any known difference in CAT handling between RRC Micro and RRC1258 that could explain this?
Are there specific RRC settings (COM mode, buffering, timing, etc.) that could improve responsiveness?

Additional info:

RRC COM2 mode: Mode-7 (CAT to COM2)
Baud rate: 38400 (same across K3, RRC and PC)
Firmware: (can provide exact version if needed)

Any insight from users running similar setups would be greatly appreciated.

Has anyone successfully used Win4K3 in Twin mode without a physical K3/0? 

73,
HA5ATP

2

Configuration, RRC 1258 / K3 Twin Mode with RRC-1258 – CAT not working without K3/0 (COM port in use)

« on: 2026-04-12, 20:48:40 »

Hello everyone,

I would like to ask for help from someone experienced with RRC setups, especially with Elecraft K3 Twin mode.

I have recently joined a group sharing a remote station. The remote side setup is:
Elecraft K3 + RRC-1258 + K3/0 (Twin mode).

Previously, I successfully used an RRC-Micro + Win4K3 setup.

Now I have purchased an RRC-1258 control unit. I can establish the SIP connection and audio is working, so the basic connection is fine.

However, I cannot get CAT control working between Win4K3 and the remote K3.

I understand that in Twin mode this is not a simple CAT passthrough, but involves K3/0 protocol handling.

On the PC side, I see multiple Microbit virtual COM ports (COM3/4/5). However:

Win4K3 reports the COM port as "in use"
Serial terminal access is blocked when Win4K3 is running
When the port is free, I do not see expected CAT traffic 

From what I understand, the RRC expects responses from a local K3/K3/0 (for example PS; commands), and without these responses the remote side eventually drops or shuts down.

I was also provided with a Python script that emulates responses (PS1;), which suggests that K3/0 emulation is required in this setup.

For reference, my RRC firmware version is 2.7.1 with bootloader version 1.9.

My question is:
What is the correct way to provide CAT control for Win4K3 in K3 Twin mode when no physical K3/K3/0 is present on the control side?

Any guidance on correct COM port usage, routing, or required emulation would be greatly appreciated.

Thank you in advance!
Vy73! HA5ATP