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Re: Arrow Cheap Yagi



Hi Bob!

>From the picture it looks like there is only one set of elements for both 
bands (is that an optical illusion?). If there are only one set to cover 
both bands, then the uhf side has to be using the 3rd harmonic...which is 
fine IF the elements are in a "V" configuration to keep the phasing on 70cm 
correct. The elements are not V'd, so I'm having trouble understanding the 
design. I thought odd harmonic operation required the elements to be "swept 
forward" in a V in order to work properly ...this is used on many TV 
antennas.

What am I missing?

Currently, I'm using a dual band nested quad for LEO's. 4 elements on 2m, 8 
elements on 70cm...works very nicely...but not as well as my CP-30 70cm RHC 
uplink antenna. The 4 element quad on 2m with antenna mounted gasfet works 
quite nicely for VO-52...big signals!

I might be interested  in trying the antenna you are referring to, if I 
could properly understand the design.

73,

...hasan, N0AN
----- Original Message ----- 
From: "Robert McGwier" <rwmcgwier@comcast.net>
To: "amsat bb" <amsat-bb@amsat.org>
Sent: Wednesday, June 28, 2006 6:37 AM
Subject: [amsat-bb] Arrow Cheap Yagi


> Kent Britain, WA5VJB,  has done some nice work on the Arrow antenna.   He 
> has discovered what appears to be a serious design fault.
>
> It appears the antenna element lengths are correct for elements that are 
> not grounded to the conductive boom.  Unfortunately,  those metal elements 
> in contact with the metal boom do not qualify!  That is as much as I will 
> say because Kent is going to publish a cheap yagi variant except to say 
> this much,  this would be easily correctable if only the max gain or max 
> F/B were lower in frequency than required.  Unfortunately,  it is quite a 
> bit higher..   I love Britain's work.  It is demonstrative of what one can 
> do with inexpensive materials and some mental exercise.
> At last measurements,  the "Cheap but not Broken Arrow" weighed in at 
> quite a few dB better than the commercial Arrow on the satellite bands.
>
> Kent is still publishing his CQ magazine family satellite articles and we 
> are attempting to get him to do more for the journal as well.
>
> Bob
> N4HY
>
> -- 
> AMSAT VP Engineering. Member: ARRL, AMSAT-DL, TAPR, Packrats,
> NJQRP/AMQRP, QRP ARCI, QCWA, FRC. ARRL SDR Wrk Grp Chairman
> Time for a new motto, what should I choose?
> ----
> Sent via amsat-bb@amsat.org. Opinions expressed are those of the author.
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----
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