Re: [amsat-bb] All-Mode Satellite Transceiver Choices?
At the risk of posting something that is already known, I would agree that success with 9600 baud is a matter of both a transmit and receive audio/data bandwidth of 8-12 kHz, which unless that is under SW control in your particular radio, it can’t be addressed with a FW mod. I have successfully moded both Yeasu FT-726/736R (many years ago) and more recently, the Icom 970 by accessing the FM discriminator and modulator directly and bringing those signals via shielded cable to either an added connector on the rear panel or utilizing unused pins on one of the existing rear jacks, which is then attached to an external TNC. In the case of the Yeasu, I also changed the IF filter to wider BW. BTW, that added IF BW in FM mode on the Yeasus when not using 9600 packet was a compromise for FM voice, but worthwhile for me. I know that performing surgery on a new expensive radio which is still under warranty may be scary, but it’s the only answer I have found, and it actually isn’t an extensive mod - just soldering the cable(s) directly to the appropriate points. Since I don’t own a 9700 (still using the IC 970), I haven’t looked at the schematic to locate the appropriate attachment points, but maybe worth a look if you can’t find another option and 9600 is critical for you. Here’s a link to the mod for the 970 for reference as to what is typically required: https://manualzz.com/doc/23724528/modifications-for-the-icom-ic-970-ic (it’s the 2nd mod down)
73, K4CKB (Chris)
Hi Chris,
Thanks for the reminder about modifying older rigs for 9600 baud. I've done maybe 4 TS-790S rigs like this over the years.
The "new" IC-970 is an SDR based radio, so there is no FM discriminator chip or varactor diode to tap! We are at the mercy of Icom, which presumably is as "simple" as a firmware update with appropriate code...doesn't appear they are interested in making this happen. If the FM-D mode in the 9700 worked like the FM-D mode in the 9100, we'd be set...but alas, it doesn't.
73,
Mark N8MH
On 10/24/2020 10:20 PM, Chris Busch via AMSAT-BB wrote:
At the risk of posting something that is already known, I would agree that success with 9600 baud is a matter of both a transmit and receive audio/data bandwidth of 8-12 kHz, which unless that is under SW control in your particular radio, it can’t be addressed with a FW mod. I have successfully moded both Yeasu FT-726/736R (many years ago) and more recently, the Icom 970 by accessing the FM discriminator and modulator directly and bringing those signals via shielded cable to either an added connector on the rear panel or utilizing unused pins on one of the existing rear jacks, which is then attached to an external TNC. In the case of the Yeasu, I also changed the IF filter to wider BW. BTW, that added IF BW in FM mode on the Yeasus when not using 9600 packet was a compromise for FM voice, but worthwhile for me. I know that performing surgery on a new expensive radio which is still under warranty may be scary, but it’s the only answer I have found, and it actually isn’t an extensive mod - just soldering the cable(s) directly to the appropriate points. Since I don’t own a 9700 (still using the IC 970), I haven’t looked at the schematic to locate the appropriate attachment points, but maybe worth a look if you can’t find another option and 9600 is critical for you. Here’s a link to the mod for the 970 for reference as to what is typically required: https://manualzz.com/doc/23724528/modifications-for-the-icom-ic-970-ic (it’s the 2nd mod down)
73, K4CKB (Chris)
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participants (2)
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Chris Busch -
Mark Hammond