Hi Greg,
I also have the ATB-34 and have added the A-743 40M add-on to it so
mechanically it will work with only a few modifications. How well it works
is something else! My antenna is only at 35 feet so the 40M is a cloud
burner at best but it does save me a run of coax and I don't have to switch
when I QSY to 40. I can't say that I have noticed any degradation on the
other bands (20, 15 and 10). That should answer you first question.
-- There was NO 40M add-on kit for the original ATB-34 and when I asked
Cushcraft about using the A-473 on it, they pointed me to buying the A3 or
A4. Since I had a free A-743, I went ahead and tried it.
-- I think the concern with the A-743 add-on to the ATB-34 is the driven
element center insulator. The elements are fitted inside and I don't think
the material is as robust as the later A3/A4 version. On the other hand, I
have had the add-on up for a number of years without any problems.
And lastly, I think, but don't remember for sure, that the A-743 was meant
to be used on either the A3 or A4 so using it on a so-called "4-element"
beam shouldn't make any difference.
As for the modifications that I had to make, they were the sequence of
tubing to go from the end of the driven element of the ATB34 to the
additional tubing for the add-on. The sizes are different but I was able to
just do a little juggling with the existing tubing and got it work. The
attachment point for the line from the king post was further out on the
element and you might have to get some longer line. I got the 3/16" black
stuff from the Wireman, I think, but any source should be acceptable. I have
not had any problems with deterioration so far.
If you want, I have a few pictures of the antenna with add-on as installed
that I can email.
Hope this helps.
73 de Bob W5RN
----- Original Message -----
From: "G.P. Widin" <gpwidin@comcast.net>
To: <towertalk@contesting.com>
Sent: Sunday, January 04, 2009 8:57 AM
Subject: [TowerTalk] Cushcraft 30/40m kit for W3S work on ATB34?
>A friend has an update kit for the Cushcraft A3S for 40/30m, that he's
>willing to sell. My old AES catalog says this is an A-743.
>
> My tribander is a Cushcraft ATB34, the predecessor of the current A4S
> Cushcraft beam. I'm interested in adding the 30/40m kit to my older
> tribander, but I don't know if it's truly compatible, despite the apparent
> very high similarity between the two series of antenna. Also, his kit is
> for the A3S the "3-element" yagi, while I have the (so-called) 4-element
> version in the ATB34.
>
> With that background, I have a few questions--
> --Does anyone know whether the update kit for an A3S will work on the
> ATB34?
> --Does anyone have the instruction sheet for the 40m update kit for the
> ATB34, assuming that there was one?
> --Is there anything inadvisable about trying to add a 30/40m update to the
> ATB34?
>
> Of course, I could set up instead to load the boom on 40m, as suggested by
> N4KG some years ago, but of course that involves some experimentation...
> On the other hand, maybe the experimentation to do that would be no worse
> than that to adapt a "3-element" update kit to a "4-element" beam from the
> older series.
>
> Answers and comments, please?
> --
> 73,
> Greg, K0GW
> Reply to k0gw AT arrl DOT net
> _______________________________________________
>
>
>
> _______________________________________________
> TowerTalk mailing list
> TowerTalk@contesting.com
> http://lists.contesting.com/mailman/listinfo/towertalk
>
_______________________________________________
_______________________________________________
TowerTalk mailing list
TowerTalk@contesting.com
http://lists.contesting.com/mailman/listinfo/towertalk
|