Hi John!
Don't worry about dealing with F12 - they WILL get back to you. I
have a C31XR and they have been VERY helpful, before and after the
sale. I've been pestering them with questions on their other beams,
so who knows, maybe my questions are delaying yours! :)
After putting my C31XR up (72') here's what I measured:
Freq SWR
14 1.5
14.1 1.4
14.2 1.4
14.3 1.6
14.4 1.9
21 1.8
21.1 2
21.2 2.3
21.3 2.7
21.4 3
21.5 3.6
As you can imagine, I was alarmed at the 15m numbers. 20m wasn't
great, either. A quick response from F12 suggested that I tape the
two wires between the 20 and 10M (? maybe 15) driven elements together
so they are about 1/4" apart. After doing this, here's what I got:
Freq SWR
14 1.8
14.1 1.5
14.2 1.4
14.3 1.5
14.4 1.5
21 1.1
21.1 1.2
21.2 1.4
21.3 1.7
21.4 2.2
21.5 2.7
I imagine if I fiddled even more the high-end of 15 might improve,
but I'm not really worried about it. The antenna is a CHAMP, and I
consistently get excellent reports.
Let me know if you have any questions - I'd like to keep in touch
with other C31XR owners!
GL es 73!
-Brian n8wrl
> -----Original Message-----
> From: owner-towertalk@contesting.com
> [mailto:owner-towertalk@contesting.com]On Behalf Of John R Bookout K7JB
> Sent: Wednesday, August 04, 1999 1:57 AM
> To: towertalk@contesting.com
> Subject: [TowerTalk] Force12 C-31XR Tri Band Beam SWR
>
>
>
> Hi Gang:
>
> I just finished getting my Force12 C-31XR tri band beam up onto my 70'
> Rohn 45G tower. If you own one of these antennas, I would like to hear
> from you as to the VSWR measurements you are getting. Especially on 20
> and 15 meters. The antenna specs posted on the Force12 web page:
>
> http://www.qth.com/force12/index.htm
>
> Indicate that the VSWR should be no greater than 1.7:1. However, mine
> is more that this:
>
> 20 Meter Band:
> Frequency Pf Pr VSWR
> 14.000 300 50 2.37 out of spec
> 14.050 300 45 2.26 out of spec
> 14.100 300 40 2.15 out of spec
> 14.150 300 30 1.92 out of spec
> 14.200 300 20 1.69
> 14.250 300 20 1.69
> 14.300 300 20 1.69
> 14.350 300 20 1.69
>
> 15 Meter Band:
> Frequency Pf Pr VSWR
> 21.000 300 30 1.92 out of spec
> 21.100 300 40 2.15 out of spec
> 21.200 300 45 2.26 out of spec
> 21.300 300 50 2.37 out of spec
> 21.400 300 60 2.61 out of spec
> 21.450 300 65 2.74 out of spec
>
> I hired a commercial antenna installer to get this antenna up and he has
> encouraged me to write to Force12. I have sent both Tom Schiller, N6BT
> President and Nathan of Force12 emails concerning this matter. However,
> I have yet to hear back from them. I sure did not get this treatment
> when I was dealing with them on specs and a sale.
>
> My antenna installer is growing impatient and is pressing me to get on
> with the completion of this installation. So I am trying to gather
> actual info from other owners who have personal experience in measuring
> their C-31XR's results.
>
> My antenna is up by its self and should not experience any other
> problems with the environment. The measurements I have done were using
> a Bird Watt meter driving the antenna with a Collins S line with 30S-1
> linear.
> In addition, my antenna installer has gotten the same SWR measurements.
> So we are in agreement. All of the suggested methods mentioned in the
> instruction manual have been tried by my installer and nothing has
> brought my VSWR measurements down to the Force12 specs for the C-31XR!
>
> Thanks John K7JB
>
> --
> Best 73's
>
> John, K7JB Amateur Radio Since 1958
> Collins Collectors Association MEMBER
> QCWA LIFE MEMBER
>
> --
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