David-
I think you have been trimming your copper tape in millimeters.=C2- I did
a couple of calculations this morning and you change resonant frequency is
about .38 inches (around 10 mm) per mhz.=C2- So--if you have been trimmi
ng your foil at 2 mm per check, you would need to trim it 5 times to move i
t 1 mhz.=C2- If you do your graph, you should be able to calculate very c
losely how you need to trim it and do it with a single cut.
Jim Puglise A-283
----- Original Message -----
From: "david park" <dpark748@hotmail.co.uk>
Sent: Sunday, March 28, 2010 7:30:11 AM GMT -05:00 US/Canada Eastern
Subject: RE: Europa-List: Re: Antenna tuning
Bill,
Thanks for the offer but I am in South Manchester, nr airport!. But I may r
ing you when I am next in the garage. Originally with the length at 490mm a
s per=C2-drawing the best SWR was at 133.00. I shrortened it down to 480m
m but could not get best SWR mid frequency range.=C2-I have temporarly ex
tended the antenna to try again.
Regards Dave=C2-
> Subject: Europa-List: Re: Antenna tuning
> From: Billandsue@billbell.co.uk
> Date: Sun, 28 Mar 2010 03:21:15 -0700
> To: europa-list@matronics.com
>
co.uk>
>
> David,
>
> If you are anywhere near me (Aylesbury, so must be closer than Ferg!)) I'
m happy to turn out and provide some hands-on help if you think that would
be useful. I suffer from the delusion that I know a little about antennas (
antennae?) and I have a couple of suitable SWR meters and some practical ex
perience messing about with this sort of antenna. Please give me a call on
01296 689165 if you think that would be any use or you just want some telep
hone advice.
>
> Regards
>
> Bill
>
>
>
>
> Read this topic online here:
>
> http://forums.matronics.com/viewtopic.php?p=292045#292045
>
>
>
>
>
>==============
>
>
>
==
|