[Amps] turns = henries question

[Radio WC6W]

Hi Gary,

The coil as you've described should be about 80 uH.

A 3" winding, other dimensions remaining constant, will provide 60 uH.

Calculations performed on an American Hydromath Calculaide Frequency Computer (circular slide format), 1955 vintage.

FYI: At 45 TPI, the wire is likely #24 enameled.

73 & Good afternoon,
   Marv WC6W 

http://wc6w.50webs.com/


--- On Sat, 2/21/09, Gary Smith <Gary at doctorgary.net> wrote:

> From: Gary Smith <Gary at doctorgary.net>
> Subject: [Amps] turns = henries question
> To: Amps at contesting.com
> Date: Saturday, February 21, 2009, 11:21 AM
> Hi,
> 
> For you math whizzes out there (math is not my strong
> point)...
> 
> I need 60uH for a plate choke. 
> 
> The existing coil apparently uses 23 guage wire and the
> coil form is 
> .676" OD. There are 45 turns per inch and the length
> of the windings 
> on the coil form is 4.052" long.
> 
> Accdording to wikipedia
> 
> http://en.wikipedia.org/wiki/American_wire_gauge
> 
> My wire measures .022" so acording to the chart, I
> call that 23 
> gauge. Radio shack has enameled wire but the closest guage
> is 22 
> Gauge and that measures .025" which also jives with
> the chart.
> 
> I don't know how many turns of the 23 guage on this
> coil form will 
> give me 60uH. Can anyone help me out on this?
> 
> Thanks,
> 
> Gary
> KA1J
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