All, for anyone interested, we figured out how to increase the FM deviation of the Icom 910H. It takes a fairly simple single resistor change to the rig. A brief overview is online. Thanks to all those who offered comments.
http://exploration.engin.umich.edu/blog/?page_id=668 --James, KF6RFX On Fri, Dec 23, 2011 at 11:21 PM, James Cutler <jwcut...@gmail.com> wrote: > Dear AMSAT, > > Has anyone successfully increased the maximum FM deviation of the 910H > when using the 9600 setting on the radio? We have not been able to. We > have two units, and one is maxed at 2.5 KHz and the other at 3.2 KHz > deviation. > > We've used the service manual to adjust the deviation to max higher values > (>7KHz). But, this doesn't affect the 9600 input path. Looking through > the service manual, on page 10-1 lower left corner, it shows that the gain > control we just set doesn't affect the 9600 path. > > So, I'm thinking of modifying the over modulation detection circuitry to > allow for a larger peak to peak voltage signal to be input. The components > that see that voltage appear to be able to handle it. > > Has anyone tried this, or know of another way to increase the deviation? > > 73, > > --James > > _______________________________________________ Sent via AMSAT-BB@amsat.org. Opinions expressed are those of the author. Not an AMSAT-NA member? Join now to support the amateur satellite program! Subscription settings: http://amsat.org/mailman/listinfo/amsat-bb
