Ku-Band Interferometry

From the Society of Amateur Radio Astronomy Mailing List 12/12/2025:

We operated a Ku-band interferometer with two 1.2-m dishes placed on a 10-m baseline in east-west direction. It is dismantled at the moment as we are working to refurbish and relocate it.

It uses two PLL-type LNBs which were modified to accept an external reference as described by a French amateur here: http://f1chf.free.fr/LNBPLL/inside.pdf

In order to minimize phase drift both the cables supplying the reference and the IF output were of the same length and exposed to the same environmental conditions. Temperature effects therefore partially compensate.

We encountered temperature effects again with our L-band interferometer. While the cables were of equal length, carefully phase matched, not the same length was exposed to sunlight and we saw quite some drift. We corrected that later on.

Best regards,

Wolfgang