[NJARC] Cleaning a tuner

[davesica at juno.com]

-- "Wayne Zakaras" <wcz at exit109.com> wrote:
...a dumont continuous tuner. Can i just use a spray cleaner or something different?  

Wayne,

What type of trouble are you having that indicates tuner cleaning? I have never taken apart any of my inductuners, but by their nature, they avoid the type of contacts that plague the more common strip tuners that seemed to have been designed primarily to sell contact cleaner. If there are switches inside, they might benefit from cleaning, but the variable inductance mechanism by which these tuners worked should be immune to the type of problem that we typically try to remedy with a squirt of tuner cleaner and a bit of hope. Perhaps someone who has taken apart one of these beasts can verify if there are any contacts in there that would benefit from cleaning. Steve McVoy at the Early Television Museum (www.earlytelevision.org)has several Inductuners in sets in his collection and (unlike me) actually gets around to restoring all his junque, so he may have some first hand information on the subject and if he does, I know he would be happy to share it with you.

For what it's worth, here's what I was know about contact cleaning. There are two types of spray cleaners: lubricated and non-lubricated, just like some other products. The old TV repair guy I worked for as a teenager taught me that tuners (we're talking strip tuners now) should always be serviced using the lubricated type. Some people say this contributes to future buildup of crud, but I was taught that it was actually supposed to help protect the surface and keep the contact from re-oxidizing, plus help prevent wear. I doubt that excessive wear would be a problem with the amount of use the average vintage TV gets these days.

When you have easy access to the contacts, my grandfather taught me (I've been working on pinballs and juke boxes since I was seven)that the best way to initially clean an oxidized or dirty contact was to use a pencil eraser; just the right amount of abrasion, self renewing, inexpensive and always available. Brush or blow away any rubber debris from the area, squirt with cleaner if you like, and you are pretty much guaranteed to have a 100% functional contact again. This applies only to tuner contacts or printed circuit copper edge type contacts. Replaceable contact points such as on relays (I learned this technique on the mechanical pinball games) require a deft touch with a contact file (coarse) or a contact burnisher (fine), taking care not to distort the original profile of the point (at least one point of the pair should be slightly convex rather than filed flat).

Hope this helps!
--Dave Sica






























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