[Date Prev][Date Next][Thread Prev][Thread Next] - [Date Index][Thread Index][Author Index]

Question Regarding Doppler Correction



I'll admit it up front, I'm a newbie!

While working AO-40 for the first time, during Field Day on Sunday morning, 
I was struck by the need for a better method than "swishing dots" to find 
my signal in the downlink.

Since my station was entirely manually-tuned, I decided to build a quick 
Excel spreadsheet to compute a desired transmit frequency, given a 
displayed frequency on my 2-meter downlink IF rig, and taking into account 
the downconverter LO, LO error, downlink doppler, and uplink doppler.  At 
times, this seemed to work very well, and later on, not so well.  I know... 
there is a spreadsheet available for download.... but it seems 
unnecessarily complex for my needs.

The problem may be in fact due to problems with my spreadsheet, but I also 
want to make sure that by basic understanding of doppler correction is 
correct.  If I am correcting "up" on RX (tuning higher than the actual 
transmit frequency of AO-40), then I need to correct "down" on TX (tune 
lower than the actual A0-40 RX freq) on TX, right?

Thanks in advance,

Paul W4SKI  (was W4MOE on Field Day)


----
Via the amsat-bb mailing list at AMSAT.ORG courtesy of AMSAT-NA.
To unsubscribe, send "unsubscribe amsat-bb" to Majordomo@amsat.org



AMSAT Top AMSAT Home