Absolutely perfect copy of the GPS locked BPSK signal from Jim at the low
power setting. Although, at this power the signal can still just about be
detected by
ear, so I'll be more convinced when the level is reduced another 10 - 20dB.
The attached plot, (if it passes through the reflector) shows my reception
over the period from 2100z to 2135z covering the interval when the Tx power
was reduced to 10Watts. The left hand half of the screen shows the
recovered phase in ten seconds units synchronised eactly to UTC and th3
transmitted data. The colour of the trace changes at each two minute
boundary each time the
sequence repeats. The RH side is a vectorscope plot of the signal at one
second intervals (so in 1 Hz
bandwidth) and shows clearly the power reduction. It is interesting to see
there is a phase shift of what looks to be 15 - 20 degrees associated with
the drop in power.
Andy G4JNT
Readad04.pcx
Description: Binary data
| 