My M2 40M4 is in its second contest season... I too was concerned about
those setscrews... I used Loctite and tightened those setscrews until I
closed my eyes and held my breath because I thought sure they would strip, or
snap... So far, so good, with no evidence of unstable swr... For a more
dependable fix you could remove the shorting bars and and drill/tap for the
next size allen screw... If that does not look attractive to you, then
machine longer shorting bars and drill the holes for the linear rods... then
saw them lengthwise to make clamps out of them and cross drill for clamping
bolts... (the existing bars may even be modifiable, if you cross drill
inboard of the linear rods)...
My beam tuned up within 50kc of the factory chart... we have to remember
that resonant objects.... house wire, aluminum siding, copper piping,
electrical drop wires, other antennas/booms, etc. .... within 1.5 to 2
wavelengths can/will affect the input impedence and resonance frequency ...
plus, height above ground has a major influence on impedence...
the other point I would note is that n8gan and I cross checked each
measurement against the manual, every step of the assembly... the day before
raising the beam Ken went over it a third time and found 2 dimensions that
were off, despite our double check system... you have to inspect the drawings
very carefully to see exactly where the measuring points are... a couple of
them are not what common sense would expect... the manual would benefit
greatly from professional drafting...
The M2 beam is still a class act...
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