[TowerTalk] 160 vertical question (Top Hat)

[Joe]

Yes, to all the suggestions that Rick and others have made.  The top 
loaded system models very reliably on Eznec.  The resonant frequency is 
not only dependent on radial length but also on the angle they make with 
the vertical radiator.  I'm using a 107' top loaded vertical here with 
three radial wires, which do double service as guys.  With switchable 
L-matches at the base, it works well on both 80 and 160M.

73, Joe
K2XX

On 2/3/2018 8:44 PM, Richard (Rick) Karlquist wrote:
> You should really model this on EZNEC.
> Having done this many times, I can say
> that the length of the vertical plus the
> length of one of the top wires should be
> about 120 feet to hit exact 1830 resonance
> without a loading coil.  However,
> there is absolutely no compelling reason why
> this is necessary.  A loading/matching coil
> is far more convenient if you keep the wire
> length to 25 feet.  Therefore, it should
> never be necessary to put it up and down a
> bunch of times to get it "just right".  There
> is no "just right" with respect to the antenna
> proper.  Use the taps on the coil to do the trimming
> to make the system just right.  This has been
> discussed many times on this reflector.
>
> Rick N6RK
>
> On 2/3/2018 5:20 PM, Bill via TowerTalk wrote:
>>
>> Planning on putting up a 160 vertical, but of course a 1/4 wave 
>> vertical is out of the question here in HI since we have a height 
>> limitation.
>>   Here's the question:  I'm putting up around 50 feet of 3 inch 
>> aluminum tubing  (left over from various antenna takedowns).  I plan 
>> on putting up on top of that around another 10 or 15 feet of smaller 
>> diameter stinger for a total height of around 60-65 feet.  I 
>> obviously need to make up for the lack of height and I was planning 
>> on making a top hat of four wires coming down from the top of the 
>> antenna at around a 45 degree angle.  The problem is how long to make 
>> each of those wires.  My guess is around 25 feet based on my past 
>> experience in making Tee-topped 80 meter verticals.  However, it is 
>> only a guess and I don't feel like yanking the 3 inch pipe up and 
>> down a bunch of times to get it just right.
>>   I know some trimming will be necessary since this is not an exact 
>> science.  I just need an educated guess for where to start with the 
>> length.  Any ideas?
>>   Bill K4XS/KH7XS
>> _______________________________________________
>>
>>
>>
>> _______________________________________________
>> TowerTalk mailing list
>> TowerTalk at contesting.com
>> http://lists.contesting.com/mailman/listinfo/towertalk
>>
>>
> _______________________________________________
>
>
>
> _______________________________________________
> TowerTalk mailing list
> TowerTalk at contesting.com
> http://lists.contesting.com/mailman/listinfo/towertalk
>
>