interference questions and advice

**1idejim** · August 8th, 2010, 02:27 PM

hi guys, been awhile.

i need some input and advice on the matter of interference.

i'm using a 1748kh locator for irrigation valve and wire locating, i very seldom have issues that i can't work through but i get asked often about interference from power sources.

i can talk bleeds and faults through without problems but i could use some input on high freq. locates in congested areas around transformers and close proximity to parallel paths.

an extended earth ground helps but i could use a tip or two.

thanks

**ProfessionalLocator** · August 8th, 2010, 08:15 PM

I find a spot not too far away and induce from there in order to refine the marks where there is a lot of bleed off. But I set the box off the mark, not directly over the utility and on the side of the mark that does not have the offending utility. This way I induce a signal strong enough to read but too weak to bleed off.

**headcipher** · August 9th, 2010, 11:37 AM

1748 khz? That is an extremely high frequency that will bleed off on a lot of different utilities especially in a congested area. Now if you mean 1.748khz, that would be a quite good locate freq. for congested areas. For the most part, the electric will be deeper and less likely to be bled off on from a irrigation line, I have the opposite problem at times. Induction from a confirmed isolated point or as ProLoc describes works well. Or if there is a problem, locate the electric by connecting to the transformer/vault/meter to eliminate the confusion as to what facility you are on. The only time I find a problem around vaults is when another facility grounds to my vault.

**1idejim** · August 9th, 2010, 07:45 PM

both the armada and the greenlee use 1,748 khz. i believe that the reasn is that the signal distorts at the solenoid for locating purposes when using a closed loop.