[Elecraft] K1 sidetone overpowers headphones

Sun May 4 16:27:00 2003

I had a similar problem with my noise reduction Bose headphones and my K2 until
I did the following...

I bought an RF choke (two halves of a rectangular ferrite core and a pastic
case that holds the two halves together) from Radio Shack and wrapped up the 3'
accessory cord that came with the Bose headphones completely in the RF choke.

It seemed to help quite a bit!

I guess that the audio line into the noise reduction device was picking up
stray RF from the K1/K2.

- Daniel/AA0NI

--- Robert J Greenwalt Jr <[email protected]> wrote:
> Don't know if this is an unusual situation or not -- My K1 works fine on
> speaker but when I plug in a set of Bose noise cancelling phones the
> sidetone during keying becomes an overwhelmingly loud crashing tone in the
> phones.  Its almost painfully loud.  When I set the K1 output to zero the
> keyer sounds fine in the headphones.  When I turn the power back up to
> actually transmit, I get the crashing effect.  Reducing the StL level has no
> effect.  The Bose phones have an audio amplifier in the line to produce the
> noise cancelling effect -- could RF be causing this?  I'm using a long wire
> antenna with the built-in ATU.
> 
> Bob
> 
> _______________________________________________
> Elecraft mailing list: [email protected]
> You must be a list member to post to the list. 
> Postings must be plain text (no HTML or attachments). 
> See: http://mailman.qth.net/mailman/listinfo/elecraft
> Elecraft Web Page: http://www.elecraft.com