Ok so ive finally decided that im tired of losing dogs and spending days searching for them or hoping someone else will find them and not steal them so im looking into getting a tracking system. Is there any benefit or difference between frequencies? Say for instance is 221 better then 216 in some way? And on the collars lets say I pick 219.xxx do the last 3 digits need to be way different then each other? Im wondering if I picked something like 219.123, 219.124, and 219.125 would they interfear with each other and maybe throw off my tracker or something since the numbers are so close? And finally does anyone have a reccomendation on a good tracker that gets good range and wont break the bank? Alot of them ive looked at will run hundreds of dogs and all and thats nuts to me! Mine will never run any more then 5-6 dogs max. Thanks!