Need help to identify similar movie

Someone posted on the "need to know" community board a question.

original link here:
http://www.imdb.com/board/bd0000001/thread/206817134

Hey last month I got the Logan's Run TV series on DVD, and I thought maybe it
was what I saw on TV long ago but turns out I never saw this series before and
confused it with something else.

Note that I am a HUGE Logan's Run fan and have had the movie on VHS and DVD for
years. Only learning there was a TV series about 12-13 years ago or so.

Now what I remember is kinda mixed up in my memory banks so bear with me.

I remember an old movie that had a couple that were escaping from someone or
something and they were linked together by some kind of collars around their
necks so that if one of them got more than so many feet from the other it would
blow both their heads off. That isn't the movie but I throw that in because it's
like (sorta like) the movie I'm remembering. I'd like the title to this one
regardless but...

The movie I remember is actually older than the one mentioned above and it isn't
Logan's Run TV series or pilot episode.

This one also had a couple of people escaping from some sinister place,
government, or whatever and I just remember this one little scene; they were
wearing something that was like a tracking device (I doubt very seriously they
called them GPS in that day and age but it was basically the same thing) like
the tracking devices the Sandmen used in Logan's Run to locate Runners.

Anyway, this couple or some people were running outside away from their pursuers
and they stopped by a river or creek of some kind and took off their tracking
devices and carefully placed them on something that would float and sent those
devices on their way down the river and then continued to run in the other
direction or off to wherever.

Does anyone know what that movie (or made-for-TV movie) was called?