Howdy LLYOD
I have a pact that have had for over 50 years ,I have had little problems with it over the years , At first it would go off and on ,so I took it apart ,it had the springs in the connectors where loose so
I bent them and cured that Problem and then years later I was shooting my Black Powder rifles over it and it started to give crazy readings ,So I took it apart and could see anything that could do to make it work ,then I looked at the screen eyes they looked dirty so I took them apart and sure enough they were gruddy ,so I used some windex on them and have had a problem since.
Last fall I bought a Labradar , I'm still testing that machine ,it looks promising.