开云体育

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.

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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

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Oh Gawd.?? So Yaesu is screwing around AGAIN with the usage of the supposedly standardized 6-pin Mini-DIN data port!?? I have 5 other Yaesus - three that conform with the standard, two that don't, and now the '991 doesn't in yet another way...... ??

I have considered a '991A for my radio trailer "Studio B", but this is another reason not to -- after the excessively high DC power drain on receive (almost 3 amps).??