I have measured Doppler Shift on WWV due to a moving ionosphere, both when it is transitioning from day to night and vice versa, and to a lesser extent due to gravity waves in the ionosphere. ?It is on the order of tens of milli-hertz. ?So not really obvious to the casual observer, but really cool to this FMT nut.
Dave
toggle quoted message
Show quoted text
On Sep 3, 2023, at 12:43, Jerry Moyer via groups.io <ac5jm@...> wrote:
?
I don’t mean to start an argument here but I have never associated Doppler shift with an RF path between 2 FIXED objects where the distance between them does not change. ?When the transmitter is at a fixed location and the receiver is at a fixed location, where is the movement happening that causes the Doppler shift? ?Aren’t we really talking about multi-path cancellation? ?That commonly affects VHF and above. ?The way to deal with multi-path is to use multiple polarization or even circular polarization at one or both of the antennas. ?Am I missing something??
-Jerry AC5JM?
On Sep 2, 2023, at 3:01 PM, Da Amazin' man G0FTD via groups.io <punkbiscuit@...> wrote:
?On Sat, Sep 2, 2023 at 08:22 PM, GIUSEPPE wrote:
Good evening everyone, I agree with what Jerry wrote, the WSPR propagation does not determine the openings in SSB,
WSPR allows a typical signal of 30db below the noise to be confirmed depending upon the decode engine used.
1 watt of WSPR = 1000 watts of SSB for a typical S1 signal of SSB.
If you get a decode of -30db on WSPR then you need 1000 watts of SSB to make the trip with
an S1 signal.
WSPR reveals a path, but it doesn't guarantee that some some one on SSB is listening, or
has 1kw ERP to make the trip.
Whence the disparity of WSPR reports vs actual SSB QSO's.
--
- 73 de Andy -
