[Elecraft] K2 and a noise bridge

Fri Mar 5 13:42:21 2004

That seems like how it should work.

I was thinking more like a bug catcher antenna or a shorted
transmission line, which would show a frequency dependent
null.

Michael

-----Original Message-----
From: N2TK [mailto:[email protected]]
Sent: Friday, March 05, 2004 11:02 AM
To: Masleid, Michael A.; [email protected]
Cc: [email protected]
Subject: RE: [Elecraft] K2 and a noise bridge

I tried a noise bridge with my K2, with AGC ON and with a dummy load =
into the UNKNOWN port. There is definitely a sharp null, regardless of =
frequency.
#3481
N2TK/NP2
Tony

-----Original Message-----
From: [email protected] =
[mailto:[email protected]]On Behalf Of Masleid, Michael A.
Sent: Friday, March 05, 2004 10:50 AM
To: [email protected]
Cc: [email protected]
Subject: RE: [Elecraft] K2 and a noise bridge

Hi,

>Plenty of noise but however slowly I move the resistance and reactance =
dials the noise stays the
>same and the last LED is constantly lit.

OK, I'm just guessing here.

The noise may sound the same regardless of level if AGC is turned on, =
since the K2 will
increase IF gain to make up for cutting down on the RF input.  If the =
number of LEDs change,
then the bridge is doing something.  Turn off AGC to hear it.

Now, the null will be at only one frequency.  If the "Q" is very high, =
there may be some
noise left to either side of center frequency, and that may still be in =
the K2 band pass.
If that's true, you should hear a difference in "pitch", and see the =
notch move on a
spectrum display.

73, de Michael, AB9GV

_______________________________________________
Elecraft mailing list: [email protected]
You must be subscribed to post to the list.
To subscribe or unsubscribe see: =
http://mailman.qth.net/mailman/listinfo/elecraft
Elecraft Web Page: http://www.elecraft.com
Also see: http://www.elecraft.com/elecraft_list_guidelines.htm