View Single Post
  #203   Report Post  
Old October 9th 03, 05:49 PM
Tom Bruhns
 
Posts: n/a
Default

Hi Tam,

Yes, the lower reactance -- lower Q, and the lower frequency, will
both help keep the disturbance from the meter at a reasonable level.
If you simply re-tune the 50pF cap in Cecil's 7.2MHz 'speriment, you
still end up with about 1.2:1 SWR, because it's effectively a "T"
impedance matching network. But the same line at 1.8MHz with C and L
at 50 ohms reactance, re-tuned to resonance after insertion of the
meter, gives about 50dB return loss, and you'd be lucky to resolve
that with a typical SWR meter. Of course, you're stuck with 1.8nF of
capacitance too.

Let us know how it works out when you have time. I like your idea of
peeking inside the bridge; I had the same thought.

Cheers,
Tom

"Tarmo Tammaru" wrote in message ...
"Tom Bruhns" wrote in message
m...

(Tam: my recommendation is to do the test yourself. It will be a lot
easier to play with "what-ifs" and to check out things that don't at
first make sense if you have direct control of the experiment.)

Cheers,
Tom

Tom,

I read you, but first I have to paint the kitchen. I was going to use 50
+/& -j50. I also want to get inside the meter and look at the voltage and
current separately. It's a Kenwood, no sealed slugs. Good point about the
meter changing the reactance; 160 m might be a good place to do this, or I
might use a variable capacitor.


Tam/WB2TT