Greetings,
I try to use VARA for local networking on 2 m / 70 cm. My idea is to use broadcast messages in VarAC. I have a working setup of a Windows PC + USB link + FT991A. It works fine on HF under control of (VarAC 9.1 + VARA HF modem). I created an equivalent configuration of (VarAC 9.1 + VARA FM ver. 4.3.7 modem). I set the radio to DATA-FM mode. It seems to have a problem with radio carrier modulation. I set the FT-991A to 144.950.000 and tried to do a VARA TUNE. The radio switched to TX, the external RF power indicator showed a lot of RF power, but moving of the TUNE slide did not affect ALC. It showed S9 + 10dB, and did not change with TUNE slider. Also my handheld radio, tuned to 144.950.000 FM, indicated a lot of RF power but no beep or other audible sound. The same happened when I tried to broadcast something: handheld radio opened its squelch, but there was nothing audible heard from the speaker.
In RX mode, the VU display on VARA FM window reacts to manual SQL setting of the FT-991A. Squelch open => audio input 0dB, squelch closed => audio input around -42dB.
Does the operation, as desribed above, look correct? How to control the FM modulator gain in DATA-FM?
Cheers / 73 Marek SP5ISZ
To my best understanding - in FM , there is always 100% power output no matter the audio gain.
There is always a carrier form, with or without modulation.