Check out the excel spread sheet for the AH-4 long wire antenna
lengths in the file section of the group
--- In YaesuTuner@..., "Clive" <l81ker@y...> wrote:
Aha, so basically I hit smack in the midst of the next "bad"
point,
277ft (84.4m) to 283ft (86.25m) - my landlord is advertising for
rent the place adjoining mine, and he's already given the ok for
the
ham antenna, and cos he's showing the place I slung my wire up
without research or planning, and the longest bit to hand that
wasn't bright red or yellow/green happened to be that long :>]
Seems like I need to trim it to 270ft! (82.29m)
I'll try trimming it and see what happens next....
Keep you all informed and if success is my reward then I'll post
pics.
Cheers
Clive
OH/G1WZM aka 9V1AZ
--- In YaesuTuner@..., gkstemple@a... wrote:
In a message dated 1/23/2006 1:59:31 PM Central Standard Time,
l81ker@y... writes:
Hi folks, after moving to FINLAND where its very cold now, I
put
up a
longwire loop of approx 84 metres of wire. Its fed with 300-
ohms
radioshack line.
The tuner WON'T tune this on the lower bands (but its fantastic
on
20m.)
I'm going to try shortening the loop slightly to around 81m,
but
before that has anyone got any advice? Why is the SWR so high
for
the
tuner?
Antenna is about 5m up, and the feedline is about 4.5m.
Ground here is solid granite rock... hence the loop!
Cheers
Clve4
The short answer is "High Current."
Look at the AH-4 Graphical Wire Length Calculator in the files
section of
this group. Yes, the AH-4 is an Icom product, but it is the
wire
length that
is important, not the brand of tuner.
The file is in Xcel 2003. As is, it's set for dipole/long wire,
but the
constant is given for loops too.
Plug in the constant for loops and AVOID the lengths shown on
the
chart.
Try to find a length that has no data points on the graph.
Remember to start
long and trim slowly.
_
()
73
Gary
KC9DJQ
