Here is the impedance and mismatch loss for this antenna if the op build it per design and uses it in more less free space.
It appears to somewhat on the high side.
I Love Music" Why not show what he can do or direct him to a article rather than just point all the the problems.
I believe that this is what I did.
If a balanced antenna is directly fed with coaxial cable, the common mode current of the outside of the coaxial cable can have a negative impact on the performance of the antenna. One should at least us some ferrite common mode chokes at the feed point.
As Brian as points out, a coaxial common mode choke provides a reasonable amount of common mode current reduction, but using several ferrite common mode chokes may be easier to implement for some.
solid 8 db across the entire band.
I do not understand your issue with using the correct terminology. Is the quoted gain above dBi or dBd, it makes a difference, that is all.
I have shared accurate information for OP and others that might be interested in building an FM broadcast band antenna.
For those that are looking for plans, it is not a bad idea to understand the role that boom length plays in the gain of the antenna.
Here is what i would do Cut driven element to length and remove 1" from center
I do not know the actual length of the OP's driven element, but if it is per Brian's design, there should not be a need to make it shorter. Brain gives the dimensions of the driven element and how he matched it, impedance wise. Why would it need to be shorter? Why would one need to remove an inch?
Of course, if one has access to a VNA or other form of antenna analyzer, one can teak the antenna how they want.
The article use the term db and dBd.
Yes it does, but for different things. There is a difference that needs to be understood. dB by its self is just a ratio. Because an antenna is a passive device, gain must be relative to some reference. When it comes to antennas it is usually an isotopic (non-existent) ideal radiator or a dipole antenna.
dB by its self is used when he talks about antenna loss and F/R ratio because a simple ratio is correct and dBd is used when he talks about antenna gain, because it is relative or referenced to the performance of a dipole antenna.
He could have used dBi as the reference and that would have increase his numbers by about 2.15 so it can make a difference when specifying the performance of an antenna or when comparing two different antennas.
Again, I mean no disrespect, I am just curious about the gain of the antenna that you built.
Is the gain in dBi or dBd?