View Single Post
  #16   Report Post  
Old December 5th 06, 05:18 AM posted to rec.radio.amateur.antenna
Richard Clark Richard Clark is offline
external usenet poster
 
First recorded activity by RadioBanter: Jul 2006
Posts: 2,951
Default Speaking of I2R losses

On 4 Dec 2006 06:07:44 -0800, "Denny" wrote:

fascinating little instrument - did you know that on a clear day with
the air temperature +12.1 F and zero wind, that a 5 foot diameter
black rubber tractor tire facing the clear sky to the North can have a
surface temp of -2.6 to -3.0 F? I didn't but that is what I found...
OK, I digress again


Hi Denny,

More fascinating was that everyone missed the significance of the
reported temperature.

The coil was found to be +12.9 to +13.1 F and the condenser plates were
+31.5 to +32.3 F... A result which sent me away mumbling to myself...
Not what I expected...


OK, another surprise.

we all know that condensers are 100%
efficient and coils are lossy - right?...


Of course, and then the conversation went towards power factors and
such. Didn't Georg Simon Ohm die for all your sins, folks?

You need another specialized piece of test gear - in tribute to our
departed Reggie's folk-hero: a Kelvin Bridge Ohm Meter. Don't ask for
one at Radio Shack. When (and if) you get one, try measuring the
resistance of your home made cap (and I don't mean lead-to-lead, but
lead-to-plate, and for each plate, and for each lead connection).

For those who would press a Radio Shack Ohm Meter into this service, a
gratuitous -Chuckle-

73's
Richard Clark, KB7QHC