KPA Cooling Fan Whine

[Cloud Runner-3]

Recently obtained a new headphone, the Kenwood HS-5.  this phone has a communications range, 150-4000 ohm, and that is a good thing; no hiss, no bass.  It is extremely sensitive, so much so that one must turn the AF gain way down, to in the order of 8 o'clock, and one must reduce the sidetone to 003.

However, when the KAP cooling fan came on, with it arrived a nasty whine in the headfones, perhaps a very unclean 600-700 cycles.

I put my other headfones on the radio, turned the gain back up, and when the fan came on, indeed no discernable whine.

Thoughts on getting rid of the whine besides not using those headphones???

72,  Fred kt5x
K2 # 0700
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[Darwin, Keith]

I have a pair of Sony studio phones that are very sensitive.  Using them
I get a lot of hiss off rigs because I have to reduce their output and
thus their S/N ratio.

My solution was to get an in-line volume control from Radio Shack.  It
is a little pigtail with a volume control.  Put it between the
headphones and the rig.  Turn the in-line control down and the rig back
up.

- Keith N1AS -
- K2 5411.ssb.100 -

-----Original Message-----
From: Trail Fox

Recently obtained a new headphone, the Kenwood HS-5.  ... It is
extremely sensitive, so much so that one must turn the AF gain way down,
... KAP cooling fan came on, ... nasty whine in the headfones ...

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