[TowerTalk] remote tuner Vs lumped constants

[K8RI]

On 7/24/2013 2:53 PM, Jim Brown wrote:
> On 7/24/2013 11:25 AM, K8RI wrote:
>>
>> The fan dipole on 75 can  give much wider, usable areas.
>> With SS amps I'd like to be able to QSY with all the knob twisting.
>
> Yes. It's easy to make wire spreaders by cutting 1/2-in PVC conduit into
> 18-in lengths and drilling holes for the wires. If one of the wires is
> bare copper, the spreaders can be held in place with wire looped across
> the spreader and soldered.  I use hard drawn copper that I "make" by
> buying #8 bare copper from a big box store, tying one end around a tree
> and the other around a trailer hitch, and slowly stretching it until it
> breaks. The resulting hard drawn copper has stretched by roughly 10%.

I used plain old stranded "antenna wire" that I hah on hand.  I too used 
1/2" conduit for a single end spreader about out 4' long
http://www.rogerhalstead.com/ham_files/AntennaSpreader1.htm
This is fed with LMR-400 using one of the current baluns described in 
your tutorial http://www.rogerhalstead.com/ham_files/AntennaFeed2.htm

That antenna is supported by ropes to large trees on the low end and a 
rope through a pulley near the top of the 100' 45G. That rope is then 
coiled up and tied off at the base of the tower making the raising and 
lowering to prune quite easy.  That antenna is under several hundred 
pounds of tension.

  I've been thinking of using the same approach on the 160 half sloper
except it's end fed of course.

I think these antennas with stubs might at least come close to what I want.

>
> I consider copperweld antenna wire a terrible choice for serious antenna
> work. My neighbor, W6GJB, built a 2-wire fan dipole using copperweld and
> RG8, and hoisted it between a couple of redwoods with pulleys on both
> ends and a weight on one end. It was on the ground the next day -- the
> copperweld broke.  We rebuilt it with the hard drawn copper.

Only tried Copperweld once. Never purchased any more.

I've also used that method to "hard draw" the wire,  You can also use a 
lever (pipe, wood, what ever) the wire will stretch easily, but will 
reach a point where the force required rises rapidly.  and you don't 
have to break it, although breaking does guarantee it is as hard as it's 
gonna get. <:-))

>
> The Power Point shows another elegantly simple and effective method of
> broadbanding many resonant antennas that W6NL teaches in his classes at
> Stanford. With SimSmith, you can simultaneously model both SWR and loss,
> making it easy to optimize a design.
>
> 73, Jim K9YC

73

Roger (K8RI)