[GreenKeys] What type of wire for loop?

[Jim Cooper]

On 14 Jun 2019 at 19:16, Joe Herdler via GreenKeys wrote:

> Would field telephone wire work? I
> am assuming that the wire should be
> twisted. 

you are dealing with DC in the loop, so twisting 
for the usual reasons is moot. 

as for the wire, the larger guage that you 
can 'afford' the better, since it will be the 
resistance of the wire loop (essentially) that 
will limit getting the proper DC loop current ... 

keep in mind that most of the 'field telephone' 
wire I have seen is IRON not copper -- with 
quite a bit more resistance than copper wire 
would have ...  another tradeoff in the plan ... 

that's one reason they went to 20mA loops !! 
3 times easier to get 20mA than 60mA. 

keep in mind though, that the capacitance and 
inductance of the length of wire will begin to 
play tricks with the square wave signal and your 
span of the Range Finder will get narrower. 

w2jc