Hilton

One option is this 7 inch direct screw-in replacement for the cracked original..



http://www.locustom.com/shark2_mast.htm

I bought one mast, and also one complete antenna including new base, gasket and amplifier. Its the same base/amplifier as the OEM (also found on many other cars including VW's, Honda's etc.).

To fit the 7 inch antenna, just unscrew the original from the base and screw the 7 inch into the base.

VehiGAZ

The ground contact comes from the nut touching the metal inside, not from the antenna base touching the painted body outside. Hence the jagged teeth on the OEM antenna nut. If anyone is interested, Staffordshire Shark's thread on antenna replacement, with my write-up for switching to a shark-fin antenna, is here.

Thanks for the write-up! I need to replace my antenna wire, too. I will replace all 6 rear speakers when I do it, so I guess I may as well take the passenger seat out to get good access.

VehiGAZ

I think I have one of these masts if anyone wants it. PM if interested.

SQLGuy

When you did yours, did you sand/grind through the paint/coating on the underside of the roof, or did you feel you got enough of a ground by the teeth of the nut scraping through the coating?

By the way, my ground contact is not from touching the body outside, per se, it's from the exposed metal from cutting the hole through the roof - i.e. the edges of the hole. The top and bottom paint is intact right up to the hole, except where, perhaps, the nut teeth may have scraped through it.

And, on the other, other, hand... if water does get through the seal up top, do you see much difference in rust potential from the bare metal edges of the cut hole versus the bare metal between the teeth of the washer and underside of the roof where capilary action will draw the moisture?

Cheers,
Paul

VehiGAZ

Yes, I feel that I got good ground, but I have to admit that since my coax wire is shot, I guess I don't know for sure. Hmm...

I am most concerned with the bare edges of the hole you cut. That's the first place water will get to (by capillary action), and the first to start showing - after it is already way too late. I would take the antenna off, clean the silly-cone off with xylene, primer the edge, and put a little touch-up paint over it - or any paint really, since it won't be visible.

The chances of water getting to the underside of the metal panel and under the nut and teeth are far, far slimmer, and it won't ever show.

Just my 2-cents, but don't risk all that work you did over the extra effort of taking it back apart (which is really only a 15-min job now that you know how to do it) and putting some paint on it.

Btw, check my previous link and get yourself the "faucet wrench" set from Home Depot - it's SOOO much easier and works better than wiggling other tools in there - and you can just return the set when you're done.

SQLGuy

I don't agree. These two areas are only about 3mm apart and they're both protected by the same seal. Rusting up through 24 gauge or so of steel from the teeth also seems more likely to me to show first versus rusting out 3mm from the hole to where the teeth are.

On the silicone grease: it's used as standard for waterproof seals in divers' watches, so I'd trust it pretty well to help the stock seal on the antenna. The silicone spray I added from underneath is as a water displacer to help protect the bare metal in case the humidity inside the cabin is high.

A faucet wrench will really fit through that little hole? Did you see the picture? I'll have to check that out.

Cheers,
Paul

Franks928s

just curious - did any of you consider using an antenna that looks like a fin..say the BMW 5 series? IF so, curious as to what swayed your direction away from that?

Frank

VehiGAZ

Ok, I guess I'm not sure what your layout looks like. On my '89, the nut tightens up against a second piece of metal - ie, not the roof panel - IIRC. I was answering from that perspective. In any event, I meant that the roof panel and the separate interior sheet metal could start rusting at the same time, but you will see the roof panel but never see rust on the second layer.


I agree that it's a good water barrier. I meant remove the silicone before you primer & paint. Put it back on afterward though.

It worked on mine, but again, that was a factory antenna. It just fit through the access hole with the antenna pigtail tucked inside the faucet wrench.

VehiGAZ

I put a shark-fin antenna that I got from a Rennlister on mine. You have to be careful with what you buy - some of the automaker ones are only GPS and/or satellite antennas. I think BMW has a patent on the ones that include a radio antenna so no one else sells them.

M. Requin

I did this with a shark fin: https://rennlist.com/forums/5318669-post6.html

Franks928s

Hey Martin - nice job! I've wandered if I could stick a XM antenna inside a sharkfinn shell. I think I have read elsewhere on this site that someone also embedded their antena inside of their 3rd brake light...pretty creative if it works.

Frank

M. Requin

I think that was Keith Widom - part of his very cool console project. It's here https://rennlist.com/forums/928-foru...upid-long.html

norcoastal

The antenna on my car is loose. How do you remove the cover in the headliner to expose the area where the antenna is located?

Mrmerlin

Norcoastl, open the hatch pull down on the rear of the sunroof motor cover,
then with your finger press down the spring bar and unhook it from the rear of the cover lower the rear edge then the front edge will come out .

you may need to first remove the motor or gearbox to gain access to the nut, get some needle nose pliers and a helper to hold the antenna in position while you tighten it

norcoastal

Thanks Mrmerlin, is it a big deal taking out the sunroof motor? I don't have to worry about linkages or anything like that right?