> Any ideas or suggests as to how to track down the problem?
> Sometime today or tmw, I will look inside the matching box to
> see what I can find. But if anyone as any experience or
> suggests, please let me know.
Check the dielectric in the 20 and 30 meter traps capacitors -
http://www.telusplanet.net/public/telwest/R7/cushcraft_trap.htm
http://www.iol.ie/~bravo/r7_vertical.htm
If SWR is correct on 20 meters and up, it would indicate
the most likely fault is the 30 meter trap - either the
capacitor dielectric or the coil.
73,
... Joe, W4TV
> -----Original Message-----
> From: towertalk-bounces@contesting.com
> [mailto:towertalk-bounces@contesting.com] On Behalf Of Ray
> Sent: Friday, September 04, 2009 12:42 PM
> To: towertalk@contesting.com
> Subject: [TowerTalk] CushCraft R7 Antenna Problem
>
>
> Recently I tried running about 600 - 700 watts to my old
> reliable Cushcraft R7 vertical. Everything went fine on 20m,
> but when I went to 40m the SWR became erratic, then jump to a
> very high level and stayed there (more than 6
> - 8:1). The RX is also quite numb on 40m. The same high SWR
> is on 30m too. 20m is still has a good low SWR.
>
>
>
> It seems that there is an open or something bad at the 30m
> joint or coil, but a visual inspection and ohm meter check
> show every think OK. I have not yet opened the matching box
> at the base. I did remove the heat shrink at the 30m coil
> connects, but those connects are fine with no burn spots
> along the coil.
>
>
>
> Any ideas or suggests as to how to track down the problem?
> Sometime today or tmw, I will look inside the matching box to
> see what I can find. But if anyone as any experience or
> suggests, please let me know.
>
>
>
> Ray, N6VR
>
> _______________________________________________
>
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