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Date: | Thu, 13 Nov 2003 20:51:40 -0500 |
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Hey, could you guys change the subject as this doesn't seem to have anything
to do with line voltages.
Thanks, 73's k8sp
----- Original Message -----
From: "Brett Winchester" <[log in to unmask]>
To: <[log in to unmask]>
Sent: Thursday, November 13, 2003 6:39 PM
Subject: Re: OT - Line Voltages, Frequency in History
what this the freq and time for the net please?
thank you!
BRETT K WINCHESTER PM KD7JN VOLUNTEER & READING SERVICES MANAGER
[log in to unmask] http://www.icbvi.state.id.us/brochur=
e/RADIO.HTM=20
Member IAAIS International Association of Audio Information Services
IDAHO COMMISSION f/t BLIND & VISUALLY IMPAIRED - ICBVI
P O BOX 83720, 341 W WASHINGTON, BOISE IDAHO 83720-0012
208-334-3220 ext 104 +7=3Dvoice mail after hours, Fax =
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>>> <[log in to unmask]> 11/13/03 05:41PM >>>
Message-Id: <20031113184200.WMDK17368.imf20aec.mail.bellsouth.net@[68.212.9=
8.27]>
Martin wrote:
>As for why aircraft use 400 HZ, you are all right but there is
>even one more reason. While I don't know why the exact number of
>400 Hertz, the biggest reason for using a higher frequency is the
>size of inductors such as what you have in motors and transformers.
<snip>
>I think that we'd get pretty tired of hearing that mosquito
>whine everywhere very quickly.
I get my share of aeronautical mobiles check in with me when I'm ncs
for the Maritime mobile service net and you always hear a hint of that
400 hz and its harmonics.
Also note that on hf a lot of the aero comms sound like there's a
little rf feedback into the audio. Harder to get a good ground up
there <grin>.
73 de nf5b
Richard Webb
Electric Spider Productions
"They that can give up essential liberty to obtain a little temporary
safety deserve neither liberty nor safety."
--- Benjamin Franklin, NOvember 1755 from the
Historical review of Pennsylvania
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