[Elecraft] High SWR problem

[Bud Rogers]

On Sunday 17 August 2003 14:29, Edward Kenworthy wrote:
> I'm a newbie, so please feel free to state the obvious :-)

Hi Edward,

I'm no expert by any means, but I'll share with you how I would attack 
the problem.

> I've installed a 20m long-wire - on the basis that it was an easy way
> to get on the air. Problem is, I simply cannot reduce my SWR below
> "infinity" :-(
>
> I'm using a manual ATU and following the instructions I started at
> the suggested settings then adjust the transmitter and antenna knobs
> (I assume these are capacitances) with a fixed, recommended,
> inductance. But the SWR doesn't budge

First be sure you have the transmitter, SWR meter, and ATU connected 
properly as Greg mentions.  Assuming you're past that, my first suspect 
would be the ATU itself.  Adjusting the ATU should produce some change 
in reflected power and SWR, no matter how poor the antenna or ground.  
I would substitute another ATU, borrowing one if necessary, and see if 
the symtoms change.  If you haven't already, try different bands and 
frequencies.  

> My house is a single storey and the longwire is attached at one end

I've put up some pretty crappy wires over the years.  I've never seen 
one that wouldn't tune at all.  A 20' piece of wire draped across the 
room will tune, at least on the higher bands.  It won't be much of 
antenna, but it will tune.

> My RF earth is a 4' copper rod wired to my ATU and transmitter using
> *braided* tinned copper wire.  The ATU manual says, in essence, my RF 
> earth is crap. 

Again, I've never seen a ground so bad that it wouldn't work at all.  
Try substituting a piece of insulated wire a bit longer than a quarter 
wave, lying on the floor.  It won't be ideal, but it should at least 
change the symptoms.

> So, anyone have any suggestions ? Is it the location of the long wire
> (I'm wondering if running it near the house is the problem) or is it
> my rf earth ?
>
> If the latter - then is the long-wire a waste of time and should I
> just go for a dipole 

I would prove the ATU before I gave up on the long wire.  Try a 
different ATU or take your ATU to another ham's shack.  Make sure all 
the connections from the transmitter to the tuner are OK.  I once spent 
longer than I should have finding a bad preformed connector on a coax 
jumper.

Good luck and 73.

-- 
Bud Rogers  <budr@netride.net>  KD5SZ  EM05vb