Discussion in 'Amateur Radio News' started by KB7TBT, Mar 19, 2020.
Ham Radio - 630-10 meter antenna software modeling results.
How many videos can one YouTuber have on the front page "News" section at one time?
WHY is this "promising"??
Malheureusement jl n'y a pas de miracle !
At 630 meters it's not about the gain, it's about the efficiency. How much of the applied power is actually radiated ? Can his software calculate that? And also, what is the comparison antenna in terms of what someone would normally build? I'd like to see it compared to a base-loaded monopole of the same height as one of the supporting poles, using a loading coil made of regular THNN 12 gauge wire you'd pick up at Home Depot. Maybe with a simple top-hat of the same radius as the spiral?
No, I probably wouldn't build a base-loaded vertical for 630m, either. It's the least efficient option, but the most simple mechanically. How about a THNN 12g loading coil (practical dimensions for optimal Q) at the top of the (single) mast of the same height, and a top-loading wire?
In these terms, with a reasonable ground plane and (relatively) high Q inductive loading due to the large diameter of the spiral, this might be practical on 630m.
Would it stay up ???
The 'gain ' calculation shown includes the inefficiency caused by ohmic losses.
Pleas: let's not get into one of those 'gain' vs 'realized gain' discussions. The value shown incorporates the losses, demonstrating it is highly inefficient.
If they ran the model with NO LOSSES, then the efficiency can be estimated by comparison, but it will be bogus-- the ground is not modeled accurately and the 'model' uses radials rather than a single ground rod into poor to fair ground.
From what I can see, its simply a giant air core loading coil without the usual so-called "Stinger".
I've seen enough of 'TBT's posts before, to understand that being "accurate" is not one of his priorities ...
So much Negativity!! Without experimentation we would have never left the cave!!! Keep on it KB7TBT!!
While there is negativity and for good reason, there is also reality.