tag:blogger.com,1999:blog-7396057548824140336.post7954514225630576490..comments2023-07-31T22:42:16.719-07:00Comments on WA0UWH - Electronics & HAM Radio Blog: Prop Controlled Receiver - SuccessEldon R. Brown SRhttp://www.blogger.com/profile/16271671761017534867noreply@blogger.comBlogger2125tag:blogger.com,1999:blog-7396057548824140336.post-14436335537815351052012-07-23T20:07:19.848-07:002012-07-23T20:07:19.848-07:00Doug,
In general, a Crystal is a 50ppm device, an...Doug,<br /><br />In general, a Crystal is a 50ppm device, and accuracy is dependent on the circuit in which it is connected, and stability is dependent on temperature. The RF Freq that can be directly generated with a Microprocessor is dependent on the Crystal and any Calibration Correction that you apply. At 50ppm and 10MHz RF, that can be 500Hz off freq. With a normal Crystal, temperature is critical and will normally foil your attempts even with a computed Calibration factor.<br /><br />For the most accurate and stable RF, I have started using a 10MHz TCVCXO (at 2ppm) as the master clock for the Prop Processor. I am sure something like that can be used with the PI. See my blog and search for TCVCXO.<br /><br />Regards,<br />Eldon - WA0UWHEldon R. Brown SRhttps://www.blogger.com/profile/16271671761017534867noreply@blogger.comtag:blogger.com,1999:blog-7396057548824140336.post-84110722804254941812012-07-23T19:28:26.029-07:002012-07-23T19:28:26.029-07:00Hoping to get some time to try this with my raspbe...Hoping to get some time to try this with my raspberry pi. It just occurred to me the other day that these processors are so fast you can generate rf directly. How is the frequency stability?Doughttps://www.blogger.com/profile/09856253803743292805noreply@blogger.com