[TowerTalk] Cable on a reel using a formula?

[Pat Barthelow]

>How
>to calculate the amount of cable on a reel using a formula?
>Anybody know this formula.
>GM0LZE

I used to have an Allied Electronics reference guide from the 60s
That had a formula for big audio inductors where the bobbin 
dimensions(diameter and spool length)
the wire diameter were entered and it could calculate inductance, 
resistance....

Hmmm...mebbe a better way...er two better ways...if the cable is newly 
manufactured, it often
has foot or metre markers with  numbers marked on the jacket every 
foot..look at both ends and subtract...but that  would be too easy.. so 
probably not an option in your case...
If Coax, and very long, take a good hi res ohmmeter, short one end, and 
measure the
loop resistance and look up the factory loop resistance figures for that 
kind of cable..so

Maybe some old solenoid design engineering formulas can be had to do the 
trick....

Or, Get an MFJ 259B, and connectorize the free spool end, and use the legth 
function of the 259B to calculate the length to the end...

73, DX Pat AA6EG  aa6eg at hotmail.com