[TenTec] Tuner

[Geoffrey S. Mendelson]

On 7/9/2013 9:45 AM, Richards wrote:
> Really?   Please explain.
>
> I ask because Rick DJ0IP and I have both spent considerable time
> researching and building various OCF dipoles to build multiple-band
> antennas which do not depend (or which depend less) on a tuner or
> matchbox than other designs (e.g., a G5RV).


Most people don't even know what a G5RV is. It is NOT a multiband 
antenna, it was a 20 meter(ish) dipole fed with coax. The dimensions 
were not chosen by some radio magic, the length of the top section was 
the size of Vareny's garden.

The wire line feeder is not actually a feeder, it's a matching stub 
whose length was chosen so that at the radio end of it, it presented a 
50 ohm impedance so that the radio could be fed with unbalanced coax.

The fact that it does appear resonant on other bands, or at least can be 
matched using a tuner was an accident. Some people are happy about it, 
some that think it is working when it is not are not so happy.

It really is proof that no matter what its length is a dipole is a 
useable antenna, at any frequency, and the longer it is the better. The 
transmatch (tuner) is there to keep your radio from blowing up when you 
transmit, it does not affect in any way the resonance of the antenna, or 
its performance, although I have heard many hams say that it does. :-(

BTW, there are many G5RV "type" antennas on the market that bear little 
or no relation to the original antenna. It has become a generic term for 
a dipole with an open wire feeder matching section, and in some cases, 
an open wire fed dipole. :-(


73.

Geoff.


-- 
Geoffrey S. Mendelson,  N3OWJ/4X1GM/KBUH7245/KBUW5379