DC power source is a dual DC transformer that was used for HO trains many years ago. Gap on the Tach reader is fine, black stripes are clear and sharp. Thought about it, and changed the tach reader - it definitely was a defective tach reader. Why I did not think of that in the first place is beyond me. First time for everything, a defective tach reader in a new upgrade kit, first time for me. I keep numerous spare, new tach readers.
Thanks, Joe
Bruce