[TowerTalk] TowerTalk Digest, Vol 139, Issue 51

[Richard (Rick) Karlquist]

On 8/1/2014 8:38 AM, K7LXC--- via TowerTalk wrote:
>>   I'm leaning towards buying a Cushcraft XM240 and then modify it with  a
> Moxon modification as a few of you suggested.
>
>      Okay, what are the big advantages of a Moxon over a  stock CC 2L 40?
> The CC has 250 kHz of bandwidth and for a given boom length the  gain would be
> the same or similar. Please elucidate.
>
> Cheers,
> Steve    K7LXC

The 250 kHz of bandwidth is only SWR bandwidth, not gain or F/B, and it
is specified at the fairly high SWR of 2:1.  We don't know what the gain 
or F/B bandwidth is, and the manual recommends one of 3 settings:  CW, 
low phone, or high phone.  That is a red flag.

A Moxon, for several reasons, has a greater bandwidth both in terms
of gain and SWR, and has a F/B that is unobtainable with an ordinary
2 element Yagi.  It is actually better than a full size 2 element Yagi. 
  It's the next best thing to a SteppIR.  Actually, it
is better than the SteppIR when working large frequency splits (still
prevalent in contests), since the bandwidth is instantaneous.

It is amazing to me the amount of corporate inertia that must
be present to prevent Cushcraft from offering the modified version
of their XM240 as an off the shelf product.  The engineering has
fallen into their laps.

Rick N6RK