You have to use *something* that will take the precise 10MHz (or whatever it is) from the
GPSDO and PLL (phase-locked) convert it to 9.6MHz (square wave at 3.3V for the CPU clock).

We had to use 9.6 MHz mainly because of the DAC in the dsPIC instead of 10MHz. The options for
various divide/clock radios in the part are RATHER limited. As I recall, there wasn't even a way of
getting the necessary 16Ks/s sample rate on the ADC from 10MHZ, either.

Jim

From: monty@ke7jvx.com
Date: Tue, 1 Dec 2015 21:27:18 -0700
Subject: Re: [App_rpt-users] Thru Hole Voter Board Firmware Update Procedure
To: telesistant@hotmail.com
CC: app_rpt-users@ohnosec.org

Jim,

I was able to load the new firmware and it does work a lot better! But you are right, we are having a intermittent heterodyne in the overlapping areas of coverage. How would someone modify the voter board and GPSDO to do so?

Monty

On Tue, Dec 1, 2015 at 4:39 PM, Jim Duuuude <telesistant@hotmail.com> wrote:

Yes, I think it is MORE then safe to say that the newer firmware will work a WHOLE lot
better for simulcast. It would also be helpful to modify the board to provide external
GPSDO-synchronized CPU clocking (unless you want to play the "fun" game of "gee, where's
the overlap grunge zone this week?").

If your firmware is THAT old, you will probably also see serious performance enhancements
on properly representing the S/N ratio of weak signals.

Jim

From: monty@ke7jvx.com
Date: Tue, 1 Dec 2015 14:48:30 -0700
To: app_rpt-users@ohnosec.org
CC: ke7jvx@gmail.com
Subject: [App_rpt-users] Thru Hole Voter Board Firmware Update Procedure

Hello All,

I have three thru hole voter boards with firmware from 2012, l am wondering if anyone has a procedure on how to update the firmware?

Also, I see in the svn there is a Simulcast portion, and I do have two of them setup as a simulcast, is there something different with the firmware for simulcast operation?

Monty

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