John,

I'm not really a fan of oiling antenna masts. Volvo specifically says to use WD40 for wiping the mast clean at each service -no mention of using any lubricant. WD40 leaves an ultra-thin residue which acts mostly as a rust inhibitor (its original purpose), but it also has some minor lubricating properties. I would expect that a film of heavier oils, even 3-in-one, would tend to pick up dirt faster than a film of WD40 residue. Plastics, like that geared nylon drive strip on the end of the mast, could also be chemically attacked by oils leading to their early demise. In sub-freezing weather, I'll take WD40 over oils any day to prevent the mast from sticking at mid-salute as it goes under the garage door.

Of course that's just my personal preference backed up mostly by hypotheses. For all I know, there may be somebody out there who's put a grease nipple on the gear box so they can load the antenna cavity with heavy axle grease and whose antenna masts last longer than mine.

Cheers -Dave