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Old January 29th 14, 02:34 AM posted to rec.radio.amateur.antenna,sci.electronics.basics
amdx[_3_] amdx[_3_] is offline
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First recorded activity by RadioBanter: Aug 2013
Posts: 154
Default I have question about R L Mathematics

On 1/28/2014 8:11 PM, Jeff Liebermann wrote:
On Tue, 28 Jan 2014 15:44:38 -0600, amdx wrote:

It is a lot. But when I put it together 15 years ago, I seem to
remember about 4000 ohms.
No, I'm measuring shield end to end.
Here's a picture, maybe that will give you a different opinion.
http://s395.photobucket.com/user/Qma...40099.jpg.html



The resistance from shield to shield should fairly close to zero.


My Kelvin resistance device says the the shield is 0.047 ohms end to end.



Same with center pin to center pin.



The center conductor is 0.105 ohms end to end.


If you're not getting near zero, you have an open somewhere in the circuit.


Looks good here.


My guess(tm) would be the crappy old PL-259 connectors and UG-175 reducers. Check your
continuity.


I just did.

You will see in the picture I stabilized it and tapped the whole
thing.


Perhaps you meant "taped" as in wrapped with duct tape?


That is what I meant.

The center hole is not big enough for RG-6/u.


Peel off the RG-6/u outer jacket and it will probably fit.

No need for that, This is just a curiosity.

Not sure where we have disagreement, do you disbelieve the 3,350ohms at
3.58MHz?

If I short one end shield to center pin, and measure the other end
would that double impedance?
I'm going to find out.
Mikek