On Sat, Feb 15, 2025 at 09:31 PM, WA8LMF wrote:
I would think that it should be WIDE, but perhaps someone else can confirm that.
The built-in sound card of the FT-991 (identical to the external Yaesu SCU-17 interface)? lacks the audio bandwidth for VARA-FM wide.? To achieve the highest speeds VARA-FM is capable of, you have to use an external sound device connected to the "9600 packet" audio pins of the 6-pin mini-DIN "data" port on the radio.
Stephan;
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You are correct about the FT-991A internal sound card system not having the audio bandwidth to fully support VARA FM 'WIDE" mode, but keep in mind that VARA FM RMS Gateway (and P2P) stations configured for VARA FM WIDE will connect with VARA FM NARROW client stations.
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Your recommendation to connect the USB sound card to the "9600 packet" audio pins of the 6-pin mini-DIN "data" port doesn't apply to the FT-991 and FT-991A radios, however...
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When connecting an external USB sound-card rig interface device to the FT-991 / FT-991A radios, ops need to be aware that the mini-DIN6 'RTTY/DATA' connector on the back of the FT-991A does not have a dedicated "9600 packet" audio output signal, as is commonly available on the 'DATA' connector of other transceivers.
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On the majority of radios with a mini-DIN6 'DATA' connector, pin 4 is a wide-bandwidth audio output, direct from the FM discriminator circuit. On the FT-991A, pin 4 of the mini-DIN6 'RTTY/DATA' connector is configured as the RTTY "SHIFT" input, for direct FSK keying.
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When connecting an external USB sound-card rig interface device to the FT-991 / FT-991A, receive audio must be taken only from pin 5 ('DATA OUT'), regardless of whether the system will be used for VARA FM WIDE or VARA FM NARROW operation. Unlike other radios, the FT-991A can switch the signal routed to pin 5, depending on whether the radio is set for '1200 bps' or '9600 bps' data operation.
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Mark - AD7EF
Mark Davis