[TowerTalk] cushcraft D40 resonant too high

[W0MU Mike Fatchett]

Have you taken everything out of the line and hooked the antenna 
directly to an analyzer or the rig?  Make sure the tuner in the rig is 
off if you have one.

Can you rotate the antenna, if so does the SWR change much?


On 11/27/2017 8:00 PM, Dave Thompson wrote:
> Ted,
>
> I have a 2 el Cushcraft 40 I took down and the driven element is the same as the D40. It is true the joints do cause problems at times but that should cause the D40 not to have resonance at all.  I suspect either the lengths are wrong so check them out as you should all be CW, mid band , or SSB on all settings.  If that checks out look at the capacity hats.  If one is loose this can cause the problem. If that checks out is there an antenna nearby?  I tested my driven element and at first it was nearly 2 to 1 at 7150 when before it was 1.3.  I moved the reflector away as the tip was only 3 feet away.  Then the SWR was just below 1.4 but at 12 feet that seemed to be OK. Hope you find it OK.
> 73 Dave K4JRB
>
>>
>> On 11/24/2017 9:45 PM, Ted Boerkamp wrote:
>>> Hello all.....I had my D40 reinstalled on my tower a month ago and all was
>>> good...swr curve right where it should be...
>>>
>>> 7.080  swr 1:1.....now today I turn on the radio and it is all out of
>>> wack.....swr so high it trips the radio....
>>>
>>> I tuned around the radio a bit and notice the resonance point is now at 7.44
>>> at swr 1.3:1
>>>
>>> I went out to check and the entire antenna is still on the tower. Nothing
>>> missing.
>>>
>>> Could one of the two feed wires be open to either side of the dipole??
>>>
>>> What would cause this??? My other antennas on the tower appear to be
>>> fine....they are all fed from one coax
>>>
>>> thru an ameritron RCS4 switch box. Any suggestions or words of wisdom are
>>> welcome.
>>>
>>> Thanks
>>>
>>>    
>>>
>>> Ted VE3SS
>>>
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