[PSDR] Reference antenna problems

[Bart Kus]

Hello,

So I tried to measure the reference antennas (simple dipoles).  It's 
kind of a disaster.  With the antennas only 2ft apart:



The received signal is pretty weak:


The marker is down 20dB from the previous measurement:

I guess that pair of sectors I was using were really helping things 
out.  I'm also concerned about the uneven response, but that could be 
multipath given the really low signal levels.  Does anyone have any 
experience with antenna measurement like this?  I'm thinking my next 
step is using the 21dBi parabolic dishes as the reference antennas 
instead.  Having thought about it, the high directional gain, although 
it would need precise alignment to make accurate measurements, would 
help with ignoring/overcoming multipath, no? Some of those peaks and 
valleys might disappear.  A 20dB range over the spectrum is pretty 
ridiculous.

--Bart

-------------- next part --------------
An HTML attachment was scrubbed...
URL: <http://mail.hamwan.net/pipermail/psdr/attachments/20121211/46f3df3d/attachment.html>
-------------- next part --------------
A non-text attachment was scrubbed...
Name: bbegcifc.png
Type: image/png
Size: 1536990 bytes
Desc: not available
URL: <http://mail.hamwan.net/pipermail/psdr/attachments/20121211/46f3df3d/attachment.png>
-------------- next part --------------
A non-text attachment was scrubbed...
Name: jaecjaee.png
Type: image/png
Size: 6072 bytes
Desc: not available
URL: <http://mail.hamwan.net/pipermail/psdr/attachments/20121211/46f3df3d/attachment-0001.png>
-------------- next part --------------
A non-text attachment was scrubbed...
Name: gdhgbabi.gif
Type: image/gif
Size: 8699 bytes
Desc: not available
URL: <http://mail.hamwan.net/pipermail/psdr/attachments/20121211/46f3df3d/attachment.gif>