All sorted out - thanks for all the contributions.  The dummy load had a
defect, and the tuner need to beswitched off in order to get the correct
readings.

Kallie Swanepoel
 
Piano Tuner/Klavierstemmer
 
Skype Name:
KallieSwanepoel

Phone: +27 (0) 12 379 3762
Mobile: +27 (0) 83 261 6942
Voice Link: +27 (0) 88 129 8775
Fax: +27 (0) 86 633 2999

http://www.kallieswanepoel.co.za


-----Original Message-----
From: For blind ham radio operators
[mailto:[log in to unmask]] On Behalf Of John Miller
Sent: 15 November 2006 15:49
To: [log in to unmask]
Subject: Re: TW1 Inconsistancy


Not to mention, if the reading at first is with the SWR off and the
radio's 
cutting back, you hit the tuner and get the radio up to the 100 watt out
put 
again because it's seeing a load it likes, that can vary the readings a 
little too.
----- Original Message ----- 
From: "Butch Bussen" <[log in to unmask]>
To: <[log in to unmask]>
Sent: Wednesday, November 15, 2006 6:07 AM
Subject: Re: TW1 Inconsistancy


> Actually, the internal tuner can effect the readeings.  If you want an

> accurate reading, be sure the tuner is off.  The tuner makes the radio

> see 50 ohms, but the impedence of the line and load on the output, the

> antenna, and the load back toward the radio, the tuner, can be far 
> from 50 ohms.  The meter is designed to run in a 50 ohm circuit, which

> it isn't any more.  I fought this battle a while back trying to tune 
> up a six meter antenna on the 2000, and got all kinds of strange 
> readings until I remembered to turn off the tuner.  The tuner does 
> effect things, because it can present a high impedence to the meter on

> that end.  Also, you'll find that sometimes just changing the length 
> of the cable between the rig and the meter can change readings.  I had

> a regincy 2 meter rig once and I was just a beginner in all this 
> stuff.  I had run another radio on my 2 meter beam and knew the beam 
> was working great.  The regincy worked great on my mobile, but when I 
> hooked it up to the beam, no output.  As they came from regincy, they 
> were very sensative to a "high s w r", and would shut down.  I thought

> o.k., I'll check the swr.  Put the meter in the line, and radio worked

> fine.  Took the meter out, and no output.  I finally found that by 
> either adding 6 inches or cutting six inches off of the line made the 
> thing work.  It was dependant on exactly where in this run of 70 feet 
> of coax the radio was. This is why if you are checking the s w r on a 
> 72 ohm line, you have to change some resisters in the meter so it 
> matches the line. 73s Butch Bussen
> wa0vjr
>