'57 BUICK POWER ANTENNA - A study in trivia

[Guest Rob McDonald]

Here's a power antenna unit for a '57 Buick. I'd like to share what I know about this nifty convenience option.

The unit has an electric motor that's operated by a nice chrome momentary switch, mounted at the bottom of the dashboard. The motor is geared down to slowly drive a vertical-acting pinion. This gear pushes and pulls a long, flexible nylon rod, which has a flat profile of about 2mm x 5mm. I can't see the connection in the various spare parts that I've got but somehow the top of the rod is fastened to the base of the uppermost segment of the telescoping mast assembly. As the rod is pushed up, the antenna rises; as it's pulled down, the antenna descends. Oooo... Ahhh...

There's a mechanical limit device that disengages the pinion, at the top and bottom travel of the antenna mast. I don't know how that works either but you can hear the motor running and a clunk, clunk, clunk sound, when the travel stops are reached.

The bottom of the nylon drive rod hangs below the pinion and exits at the underside of the gear case. The loose end of the rod is contained in a 3/8" diameter aluminum tube that's coiled up beside the antenna unit. The tube has an expanded end that fits into the gear case hole and is secured with a little 2-eared collar. On my spare unit, the tubing was broken at this point, so I used a #3 Phillips screwdriver to expand the end of the tubing to fit the hole. At the bottom of the first loop of the tube is a small diameter drain tube; the end of the main tube is crimped flat.

The mast on my extra unit was broken off before I got it. When I was still driving my rolling parts car, I could flip the switch and the push rod would rise up out of the fender and snake across the top of the hood - good for a laugh! Actually, that whole car was a nervous laugh - passenger side caved in, no mufflers, and brakes that had just two modes - godawful screeching and locked-up. How do we survive our youth? Darned air conditioning wasn't working either.

I'd have to take this device completely apart to tell you any more about how they work. It might be repairable. The push rod has gone missing but I also have a power antenna from some other car, probably a '65 Cadillac. It still has the rod and mast, although the mast is broken. I also have the chrome nut and a tapered plastic spacer that fastens the unit to the Buick's fender. Both these parts are functional but somewhat damaged.

Enjoy the photos, you detail wonks!

Coiled tubing exits bottom of gear case, next to electric motor; bracket secures unit to inner fender

2-wire power lead (up and down), ground wire, and coaxial antenna lead with ground wire

Top of unit and base of mast at fender opening, tapered spacer and chrome nut are not yet installed.

Mast in lowest position

Expanded end of aluminum tube, broken-off

Top of unit with tapered spacer and chrome nut; pointy ends of fixed collar engage underside of fender as nut is tightened

Expanded end of tube and collar, ready to fit in hole in gear body; brown gunk is dried-up undercoating, which flakes off pretty easily

Edited November 23, 2012 by Rob McDonald (see edit history)

[buick man]

You know this whole discussion is great. Kinda gives me a rise just reading it.

[Guest Rob McDonald]

Scintillating, isn't it? I'll spice it up by offering this lump FOR FREE to anyone on the Buick Forums. The recipient would pay the shipping, which would be about $50 to most places in the US.

[Guest Rob McDonald]

It only takes one reply. LANCEMB wrote that he needs this toy for his '57 Roadmaster. He's willing to try to fix it, so I popped it in the mail today. I also took my other spare power antenna apart and sent him the similar pieces that he might need.

Wow, are these things ever complex - and clever. I'd wondered how the smooth plastic push rod is driven up and down, without it having "rack" gear teeth to engage a pinion driven by the motor. Turns out, it's not that direct. The motor drives a steel worm gear that engages a plastic gear mounted under the perimeter of a steel wheel, on which the push rod is coiled. (This is the later Cadillac unit. The Buick unit stores the push rod in an external coiled tube. Lance will be glad I didn't take that one apart, too.) The edge of the wheel is sort of scalloped, such that it grips the push rod. Applying pressure on the other side of the push rod is a plastic band that's loaded with about a dozen little springs, which push against the outside of the housing.

I'm sure this is hard to understand without pictures but this device is a remarkable bit of engineering, for what is really a pretty silly purpose.

Edited December 14, 2012 by Rob McDonald (see edit history)

[lancemb]

OK, so as luck would have it, right after I received this antenna from Rob, I received a lead for an antenna locally that I had seeked months ago before I knew about this antenna, but the lead had come up empty at the time. Being as I only had to drive 30 minutes, I went to look at the antenna available. It appeared to be the same above the motor with a motor having a newer design, so I went ahead and bought it since it was right here and no shipping or further chasing was required. Crazy how this works since I spent months looking for one of these before I got the one from Rob (oh don't worry, I can still use it and still intend to fix it!).

Anyhow, I am wondering if anyone knows what year this is from? Like I said, it appears the same beside the motor that is fully enclosed with the plastic rod and having no freestanding aluminum coil for it. I know some things (such as radio) had same cosmetics, fit, form, and function in 58 with some upgraded engineering; could this be from a 58, or??...

See pics...thanks!

[Guest Rob McDonald]

LANCE, the gear body is very similar to the '65 Cadillac one I took apart but the motor was mounted at 90 degrees to the mast, not at 180 degrees like your "new" one. Seems to me there's acres of space inside the fender, so you should have no trouble fitting it. Up periscope!