Billy, you covered it well! The boom, the brackets, the inner
element lengths, the stepping, the tubing diameter, etc. Just about
everything, just like I said. YMMV :-)
It was enough that Bob and I decided it would be better to buy a XM
and convert it, rather than trying to re-model it for the CD.
Dino
At 11:53 PM 3/17/2008, Billy Cox wrote:
>Dino, have you gone past comparing the two
>owner's manuals and actually tried this yet?
>
>In comparing the 40-2CD and the XM240, CC
>uses the same loading coil assembly (LCA) and
>also shows very similar distances from boom to
>the loading coil(s) ... 160" is what you want for
>the W6NL redesign per page 2 of the PDF.
>
>I note the inner spec 40-2CD reflector to be 160" and the 40-2CD
>driven element to be 161" <most likely due
>to the construction of the 40-2CD center insulator?>.
>
>As the sections being replaced/extended are 7/8" diameter<in the
>XM240 AND the 40-2CD> I don't understand the concern from that point out
>if you use the new tubing lengths/sizes in the text for
>the extensions and the tee loading elements?
>
><Yes, there may be slight taper concerns due to
>the slight differences in the inner element sections, exactly how
>much really? I don't know this piece yet. As both stock designs,
>taking the differences in the end tips into consideration, worked as
>designed in a stock 40m setup, this may not be a significant
>factor at all> <Calling K4SAV, any input here?>
>
>So, yes, the end tips <past the LCA> are different
>lengths as are the tubing sizes ... and as the W6NL
>redesign uses modified XM240 tips specs <and NOT
>the 40-2CD stock ends> ... I don't see where that
>difference matters anymore if you simply use material
>based on the W6NL/XM240 spec'd end pieces. QSL?
>
>Dave, W6NL, even has a footnote on page 2 on this saying they don't
>have to be the original CC parts ...
>
>Mechanically, the 40-2CD elements/boom needs
>some beefing, and that's not news, several articles
>over the years have provided the details for that part
>via W6NL and N4KG. W9RE used to offer a "kit".
>
>The XM240 reflector is not grounded, but I recall
>W6NL stating it could be grounded, so that issue
>goes away as the 40-2CD IS grounded stock.
>
>I am not so convinced of the "EVERYTHING"
>statement ... please enlighten me! B-) B-) B-)
>
>Exactly what else needs to changed?
>
>Thanks es 73 de Billy, AA4NU
>
>----- Original Message ----- From: "Dino Darling" <dino@k6rix.com>
>Sent: Tuesday, March 18, 2008 12:15 AM
>Subject: Re: [TowerTalk] Full Size Moxon is Up
>
>>Not without some upgrades to the 40-2CD. As pointed out on this
>>reflector a couple of months back, AA6PW and I sat down with BOTH
>>manuals side by side, and the XM model is a bit more robust than the
>>original CD. The tubing diameter is smaller which would require
>>re-stepping the elements and beefing up...EVERYTHING.
>>
>>But to answer your question; YES, it can be done.
>>
>>Dino
>>
>>At 06:50 PM 3/17/2008, Dick Green WC1M wrote:
>>
>>>Can this mod be done to a 40-2CD?
>>>
>>>73, Dick WC1M
>
>
>
>
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>
>
>
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Dino - K6RIX
dino@k6rix.com
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