[RFI] Hum in Bose QC2 headphones

David Jordan wa3gin at comcast.net
Wed Jan 14 13:59:28 EST 2009


If the headsphones have a ground problem the issue might be reproducible on
another piece of equipment (PC, stereo, walkman, etc.).

73,
Dave
Wa3gin

-----Original Message-----
From: rfi-bounces at contesting.com [mailto:rfi-bounces at contesting.com] On
Behalf Of WX5L
Sent: Wednesday, January 14, 2009 1:52 PM
To: Gary Smith; Rfi at contesting.com; Gary at doctorgary.net
Subject: Re: [RFI] Hum in Bose QC2 headphones

Gary,

At this point you need to check that the ground(s) in the headphone jack are
still secure to the chassis of the rig. It seems that the result of a poor
ground from the jack to the chassis could be the culprit. Open the rig and
inspect the grounds. There may be seperate ground paths for tip and
ring(stereo). The ground for one side may have been interrupted.

Randy
WX5L
--


WX5L
Thibodaux, LA

---- Gary Smith <wa6fgi at sbcglobal.net> wrote: 
> >From the other Gary Smith.
> Are those Bose headphones *really* worth that kind of money?  Have seen
their ads, just curious if they are that much better in service on a HF rig
than other brands.
> 73,
> Gary...wa6fgi
> 
>   ----- Original Message ----- 
>   From: Gary Smith 
>   To: Rfi at contesting.com 
>   Sent: Wednesday, January 14, 2009 6:32 AM
>   Subject: Re: [RFI] Hum in Bose QC2 headphones
> 
> 
>   > Are you certain that both ends of the cable are plugged 
>   > in securely? I've heard the symptoms you described when
>   > the plug on the headphone wasn't fully seated. Please
>   > let us know what you find.
>   > 
>   > 73
>   > 
>   > -Kirk  K4RO
> 
>   Hi Kirk,
> 
>   Indeed they are all the way in on both ends & that pesky hum remains. 
>   While assuring they are seated well I tried something, which was to 
>   have the headphones on and the stereo plug unplugged at the distal 
>   end.
> 
>   When not connected there was no hum but when I touched the bare end 
>   of the plug to the equipment ground the right sided hum showed up. 
>   Nothing surprising here but the same hum showed up regardless of 
>   which terminal was touched to ground be it tip, ring or ground.
> 
>   Interestingly if I touch the bare connector with my fingers, there is 
>   no hum whatsoever.
> 
>   The plot sickens
> 
>   Gary
>   KA1J
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