"Compared to even a full sized 2 element yagi, a properly engineered Moxon
will have better gain and F/B bandwidth, considerably higher F/B, a somewhat
broader front lobe, and only marginally less gain (0.5 db or so)."
So does it "have better gain" or "only marginally less gain"?
Marsh, KA5M
-----Original Message-----
From: TowerTalk [mailto:towertalk-bounces@contesting.com] On Behalf Of David
Gilbert
Sent: Friday, August 01, 2014 11:57 AM
To: towertalk@contesting.com
Subject: Re: [TowerTalk] TowerTalk Digest, Vol 139, Issue 51
Rick's comment below is spot on ... all of it. Compared to even a full
sized 2 element yagi, a properly engineered Moxon will have better gain
and F/B bandwidth, considerably higher F/B, a somewhat broader front
lobe, and only marginally less gain (0.5 db or so). I don't remember how
front-to-side compares.
Anyone interested should check out the fairly exhaustive work on the
topic by Cebik (whose books, ironically enough, are periodically
promoted on this reflector).
73,
Dave AB7E
On 8/1/2014 9:15 AM, Richard (Rick) Karlquist wrote:
>
>
> 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
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