Hi Tree, many thanks for the background on the dream beams! QSL on the
effective tower length. ON4UNs book says aunt feeding will work up to 140
degrees. My friend is doing the modeling and it’s hard to imagine we’re more
than 120 degrees. We’ll see. Fingers crossed
Regards , Kenny K2KW
> On Dec 10, 2018, at 12:01 PM, Tree <tree@kkn.net> wrote:
>
> Some anecdotal info on use of Steppir antennas on loaded towers.
>
> I have never heard of anyone experiencing arcing. This also includes using
> other antennas with isolated elements (like KLM). There just isn't going to
> be a potential difference.
>
> I have helped several locals load their towers with Steppirs on them - and
> nobody has had an issue. ZL3IX uses an original Monster - as do I - on a
> loaded tower.
>
> When I first did mine - I purposely connected the elements at each end of the
> boom to the boom electrically. This was on a 77 foot tower and I found
> putting the Steppir on 30 meters yielded a good mach with a gamm up about 45
> feet. However, I had one issue that might - or might not - have had anything
> to do with 160 meter operation. After a few months - both motors at each end
> of the boom were frozen. This was a mechanical issue. The antenna I put up
> was used - and had many miles on it - so it is hard to say what was the root
> cause. I did have some lightning that could have been a contributor - but
> how connecting the boom to the element would affect the motors is beyond me.
>
> After fixing the motors - I decided to home the elements and use a loading
> wire off the tower of the tower. My new installation doesn't need any
> loading from the elements - since my tower height is now 97 feet and the boom
> alone is enough top loading.
>
> I still feel your tower is too tall - but we have already talked about that.
> I do not know if modeling really works for this - but haven't seriously tried
> it.
>
> Tree N6TR/7
> Manning, OR
>
>> On Mon, Dec 10, 2018 at 8:47 AM Kenny Silverman <kenny.k2kw@gmail.com> wrote:
>> Hi All, we’re planning on gamma loading a 130’ tower with a stack of
>> StepIR antennas using a cage for the shunt wire. We have modeled the tower.
>> Question: is the model sufficient to determine the gamma wire height? Or is
>> the procedure to use a single wire to per the model height first to find the
>> 50 ohm point and then build the cage to fit the length?
>>
>> Also, any tips on shorting the elements on the StepIR dream beam so they
>> won’t arc? Any anecdotal info on StepIR antennas on the shunted tower?
>>
>> Regards , Kenny K2KW
>> _________________
>> Searchable Archives: http://www.contesting.com/_topband - Topband Reflector
_________________
Searchable Archives: http://www.contesting.com/_topband - Topband Reflector
|