On 2/13/19 5:59 PM, Jonathan Weirmeir wrote:
On Wed, Feb 13, 2019, 2:59 PM Bryan Fields <Bryan@bryanfields.net wrote:
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The traditional way to use the RTCM/voter is to remove the crystal reference on the transmitter PLL replacing it with the generated GPS clock. In most radios this will remove the dual point modulation provided by a diode across the crystal. Now modulation balance will be way off, and it will be much harder to get audio to line up.
Could this device give new life to old crystalled repeaters, such as Motorola Micor, GE MASTR II, etc? If so, anyone have any notes to share?
I've fixed quoting for you. No, this will not work, as the crystal is directly modulated in these old radios; you would need some way to modulate the incoming clock signal. Now some higher end products you can do this with, but not the SIlabs chips. If you could directly modulate it, then you can do dual point modulation in a PLL based radio too :) It's a great option if you have a radio where you can replace the reference of a PLL (and it has filtering in there), but not great to replace a directly modulated crystal. Micor's are dead, long live the synthesized radios :D -- Bryan Fields 727-409-1194 - Voice http://bryanfields.net