[Premium-Rx] RA6790/GM display madness

[Robert Nickels]

On 4/19/2021 1:23 PM, Nick England via Premium-Rx wrote:
> What the heck is going on!

Hi Nick,

Have a look at page 4-43 in the manual where it describes the radio 
control section.  In the middle of the page is a note "LCD displays 
operate from low frequency square wave pulse trains.  The contrast of 
the display being a function of frequency".

That's where I'd start - a 4047 multivibrator generates a 100 Hz signal 
that goes to the DF inputs of the LCD drivers and the backplane inputs 
of the LCD displays - it's on page 7-55 of the manual I'm looking at 
which is on the radionerds site (in contrast with the uselessly 
low-resolution one on BAMA).

Hope it's that easy!

73, Bob W9RAN