its just several dipoles in parallel on the higher bands fed on the gap (almost similar to a fan dipole)
except on 10m where it is 3 quarterwave ... on 40m it is a quarterwave against bent radial (the gap is "bridged" with the folded coax stup inside)... on 80m its a loaded vertical where the cap on the top is transformed to a coil via the folded coax inside ... so it is NOT a colinear design
dg9bfc sigi
Am 13.11.2024 um 07:48 schrieb Colin McDonald via groups.io:
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A co-linear vertical dipole design. Using coax as the elements to linearly load the element.
Fed like a dipole in the middle instead of an end fed like most vertical antennas.
Sure you can put that into modelling software. Though perhaps not the free ones.
Also, an educated guess suggests gain would be the same as a dipole, or a DB or two more in the strong lobes at particular direction and angle.
The manual for these is online.
I am unaware of any equipment other than field strength equipment used to compare a known antenna like a dipole, that can provide a gain measurement.
How do they determine that a particular antenna has gain? Well, it's theoretical for the most part, but antenna makers also measure the field strength of the antenna to determine how much RF energy is being sent out and in what direction and at what angle.
Or they should. I suspect most just provide standard estimates based on the physical design of the antenna and don't really test anything beyond the stuff you can check on a NanoVNA.
73
Colin, VA6GG
On 2024-11-12 8:26 p.m., Michael E Wilson Sr via groups.io wrote:
Modeling wont work. This antenna uses multi coax sections folded and placed inside the tube, with the feed point at the mid point, and section dropping below the tube with the coax connector. So far I have found no one that has the spects for all of the bands. It covers 80 thru 10 meters (less 160 and 60 meters). It is a great antenna, I would just like to know more about it.
Hope someone out there has de-structed one and figured how it is put togethere and has some written data stored away somewhere.
73
Mike, KE5WCT
