Tuning
I have a couple of reference antennas connected to a PC.
The reference setup lets me make accurate
comparisons between designs. The software reports signal
quality, and allows me to
accurately compare between the dishes I construct. The
reference antennas are 10m away, and 2m from the floor. I use RealVNC to display the reference
box's signal quality on a laptop near the
dish, that way
I can manage the tuning and still see the reference antenna signal
display in real time.
The screens below show
the received signal strength from the two reference antennas. These
values reflect the gain from the transmitter, and the sending and
receiving antennas. By
optimizing each new antenna I build to the reference, I can tweak the
dish gain, and calibrate the alignment. I then epoxy the PVC
pipe to the feed arm, and mark the dish
mounting hardware to give a good starting point for field alignment
and final installation. Drill and pin or wire the PVC to the feed
arm and
antenna to fix their positions if you like, it's more durable.
This shows the Linksys WRT54GS received signal strength in
the BiQuad reference
antenna 10m from the transmitting antenna.
This shows the Netgear WG111T 5 dB omni received signal
strength.
