[UK-CONTEST] Help with filters and SO2R please

[Col]

try here Jim

http://www.qth.com/topten/apnote2.htm

----- Original Message -----
From: Jim Martin <MM0BQI at theRSGB.net>
To: <uk-contest at contesting.com>
Sent: Friday, May 24, 2002 4:28 PM
Subject: [UK-CONTEST] Help with filters and SO2R please


> I am looking for some basic information.   I have been unable to find
> positive answers to these questions on the web or in the ARRL and RSGB
> handbooks.  I can tell you lots about the theory and draw nice graphs but
I
> do not have the practical experience to put it into practice.
> My portable contesting set-up is basic SO2R  with MP and IC746 running 100
> watts. The MP will be the main rig and will feed horizontal dipoles on
> 80 -10m.  The 746 will be the mult hunter rig and will use a multiband
> vertical on all bands. They will be about 50m apart fed into the shack
with
> ldf250 and another quality coax, what would you suggest RG214, Westflex or
> another(which is better?)
> (I think) I want to put tuned stubs on the output of the MP to cut down
> interference to the IC746 when I am listening on the other bands.  My
> reasoning is that if I am TXing on the 746 I will be logging a mult QSO
and
> will not be listening to the MP. (?)  The tuned stubs will be connected to
> the main coax with a Tee connector ( one side - rig, other - antenna,
> middle - switch box)  On the switch box a tuned stub will be selected to
> eliminate interference on the 746 listening band.  Some instances need two
> stubs to cover two bands.  Can I put another Tee connector on the output
of
> the switchbox and connect the two stubs there? (or does this screw up the
> impedance completely?)
> I have calculated the lengths of the stubs, but with all the switching I
> will cut a bit longer and prune using the MFJ.  What should I be looking
> for?
> What do I do with the stubs? Do they lie along the floor, can I coil them
> up, if so how tight, should they go in a metal box etc etc ?
> I intend to build a band decoder and automate the process of stub
selection.
> I have found some circuits but would appreciate others and more info.
> I am also building a SO2R controller, again I have circuits and have tried
> out ideas which work but would benefit from other circuits ideas.
> Alternatively, I have $300 dollars left over from my last trip to Libya
> which I am sure Dunestar would change into a nice model 600 automatic band
> pass filter but it would not be as much fun or as interesting !!!
> Thanks for wading through this epistle
> Jim
>
>          *****      MM0BQI  HomePage at  www.qsl.net/mm0bqi       *****
>    IOTA DXpedition to EU92   7-10 June and 26-29 July. Look out for GB5SI
> Member of the GMDX Group - Scotlands DX Association - www.gmdx.org.uk
>
>
> _______________________________________________
> UK-Contest mailing list
> UK-Contest at contesting.com
> http://lists.contesting.com/mailman/listinfo/uk-contest
>