Adjust balun component values


Some of the components specified in the schematics were not at hand
in my lab and were thus replaced with similar parts. Furthermore, the
LED color was changed to ease visual identification:

Component	Norminal	Board 1		Board 2
---------------	---------------	---------------	-------------------
LED (D1)	red		red		red-orange
C6/C7		0.82 pF		0.7 pF		0.9 pF
L2/L3		4.3 nH		4.7 nH		4.7 nH

The resulting spectrum should be examined to determine which variant
performs better. Note that the discrete balun circuit shall be
replaced with an integrated balun later on.