Help Getting Split Operation


For several weeks I’ve requested help on this forum to try and get my FDM-DUO to perform satisfactorily when operating split. I’ve received some valuable insight, but overall I remain stuck with not being able to get FDM-DUO SW2 software to perform split correctly.


So at the risk of boring everyone, I am going to ask again. How does one operate FDM-DUO SW2 in split mode?


Here is my set-up:

1.      PC running Windows 7.

2.      When FDM-DUO is turned on, Windows system manager shows ELAD samplers, the COM port to the radio, and the FDM-DUO sound card drivers appear in the display.

3.      Windows sound control shows that the “playback” driver” as FDM-DUO Audio V 1.04 is “ready”.

4.      Windows sound control shows that the “recording” driver as “Microphone FDM-DUO Audio V1.04” is default device.

5.      I run HRD as my logging program.  CW and SSB work fine. When operating digital modes, I have the HRD MD-780 sound card options set in Device as Microphone (FDM-DUO Audio V1.04), and Output (transmit) as Line (FDM-DUO Audio V1.04).

6.      CW paddle, and Headphone Jack are inserted in FDM-DUO, and operate normally. The headphone mike connection is also inserted in FDM-DUO. SSB works correctly. Audio in headphone is detected in all modes if receive and transmission, also normal.

Under these settings CW, SSB, and Digital Modes work perfectly.

When I boot FDM-SW2, all operates normally. Simultaneously, FDM-SW2 and HRD rig control operate normally in controlling tuning, mode, etc. FDM-SW2 operates correctly in controlling band filter, mode, and several other rig control functions not available in HRD Rig Control.

With FDM-DUO SW2 I can command RX1 as well as RX2, RX3, and RX4. With RX1 selected, and RX2 also selected and designated as the TX slice receiver I transmit on the RX2 selected frequency. The RX1 selected frequency remains as selected. With RX2 designated as TX while RX1 is set to receive, RX2 transmits on the RX2 frequency. This appears to be normal split operation setup.

This is what I expect up to this point, but here is where the difficulty starts.


Under those conditions I CAN’T get the headphone stereo sounds to give me RX1 in one ear, and RX2 in the other.

So I CAN’T work split.

Nothing I tried to date resolves this matter in spite of some comprehensive assistance from this group.

I’ve been told that in order to work split using FDM-DUO SW2, the headphones must be inserted in the PC and NOT the radio headphone jack.

In addition, I’ve been told that the driver assignments on the PC must be changed to use the PC sound card as the audio processor so the split can be heard as one would expect.

This has not worked for me either. And when I try to do this and run HRD the digital mode transmissions do not work.

What am I missing?

Can someone help?

73 de NN3V


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