was obtained using Spectravue
on the SDR-IQ receiver, using the Continuum plot function.
My 10GHz system uses a 60cm Andrew
DEMI 1dB preamp and DB6NT transverter (system nf about 2dB).
The mast is in the down position
so that the dish is looking below the
Spectravue is set up with
0.5dB/Division and an FFT of 2
that the 9cm plot
at 0.2dB/div due to the much higher noise temperature of
This plot was taken using a 112
element quad loop yagi and nearly 6cm feeder loss into the 1dB nf
The same features can be
recognised as in the other band plots.
1.3GHz horizon temperature plot
The vertical scale depends on
receiver system gain and is slightly different on each band. 23cm has
slightly higher gain than 13 and 3cm.
The 13cm system
uses a 84 element G3JVL quad loop antenna, whilst the 23cm system uses
2 x 44 element yagis (Wimo).
The receiver system noise figure is about 2dB in each case.
Antenna gain on 23 and 13cm is roughly the same. The plots seem to
indicate that the 13cm antenna is not working as well as the 23cm one
as the variation in peak to trough is slightly less. However,
performance is probably perfectly acceptable for 13cm terrestrial use.