[SOC] Re: G5RV/antenna matching

[Steve W0OOW]

I have good success with my G5RV, however... it does require a tuner. The
book HF Antennas For All Locations by L.A. Moxon, G6XN is excellent on this
antenna.  The copy I have is available via the RSGB.  I am not sure of the
edition etc. but in mine on pp 157-159 there is a section on the G5RV, and
on p 55 (fig. 4.32) there is a nomograph that is interesting.  Mine works.
Actually, it is orineted N/S and kicks on polar paths on 20.
gl es 73,
Steve
CW - It's still magic !


> Hi All,
>
> Here's a proper radio question.
>
> I'm still learning about this so apologies for any gaffs.
>
> I have an Elecraft K2 (with which I'm extremely happy) running into a full
> size G5RV.
>
> The G5RV consists of a horizontal dipole with an impedance matching ladder
> line dropped from the centre.
>
> It currently terminates in a BNC connector and thence to a length of 50
ohm
> co-ax to the transceiver.
>
> It works tolerably well on 40 but is hopeless on other bands.
>
> I'm uncomfortable about going from the unbalanced co-ax straight into the
> ladder line without a balun though it's more intuition than having done
the
> sums.
>
> I'm mean and impecunious so I want to use what I have to hand. I have an
> ex-military ATU built by Redifon. This takes a 50 ohm unbalanced co-ax
feed
> and matches to an arbitrary dipole. BNC connector on the front, two
> terminals on the back for the antennae and a further terminal for a ground
> stake.
>
> Of course the best place for the ATU would be at the base of the antenna
but
> this is impracticable so the ATU must reside in the shack.
>
> I'm only using 10W so I want as much of the transmitter power to be
coupled
> to the antenna and waste as little as possible in the feeds.
>
> My guess at the moment is that what I need to do is to connect the 50 ohm
> output of theK2 into the ATU, take the ATU outputs and feed into a balun
to
> drive the coax feed and then have a further balun at the base of the G5RV
to
> match to the antenna.
>
> Does this sound sensible or am I completely barmy?
>
> Paul M3CRQ
>