[TowerTalk] A4S High SWR on 15m

Lane C. Zeitler km3g@cts.com
Wed, 12 Nov 1997 21:48:44 -0800


Bill,
First step is to remove the antenna connection at the end of the hard line
and install a dummy load. Next, check the vswr on the 15 meter band but
sweep from 20.5 to 22.0. If it's flat then the hard line is fine--isolate
the antenna problem. if it isn't flat then look at the hard line or
connectors or remote switch.

Lane

----------
> From: Bill Hinkle <kb3aug@juno.com>
> To: towertalk@contesting.com
> Subject: [TowerTalk] A4S High SWR on 15m
> Date: Tuesday, November 11, 1997 8:01 PM
> 
> Hello all,
>                      I just installed my Cushcraft A4S w/40 meter kit @
> 58 feet on a new tower. The SWR looked good every where,(90% sure of
> this, it was a lot of work to do in 1 weekend). I decided to replace the
> 145 foot run of 213 with a 125 foot piece of LDF4-50A between the shack
> and tower mounted  RCS-8V remote switch. After doing so, the SWR on 15 
> is, 21.008 = 1.5, 21.108 = 1.2, 21.208 = 1.4, 21.308 = 1.9, 21,408 =2.5.
> The antenna is set to the phone settings. There is no more adjustment
> between the 10 meter trap and the 15 meter trap to make it shorter. This
> antenna has been installed at 93 feet, 30 feet and now at 58 feet. The
> SWR has always been good till I put the hard line in. The hard line was a
> brand new in the box factory made hamfest find. Even though the SWR
> looked good when the antenna was at 30 feet, I felt there was something
> wrong with the way it played. Could I have a bad trap? There is a Comet
> 510 2m/70cm 4 feet above it and a 1/4 wave sloper for 75m 4 feet below
> it. The 75m sloper is somewhere around 67 feet long for 3.8MHz which is
> to long but, the SWR looks good. Any ideas on why it's so long? There has
> been to much QRN  on the band to tell how well it works. I can say it
> does work better then the dipole at 20 feet. I guess there is not much I
> can do before SS but, I would feel better knowing what to look for when I
> have the time. 
>              Thanks for any help in advance.
>                                                                          
>   73, Bill
>                                                                          
>    kb3aug@juno.com
> 
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