Over the winter I've been trying to find out what's wrong with my electric antenna. It is the original Hirschmann one that came from the factory. Hirschmann electric antennas are extremely high quality and usually last for the lifetime of the car, but may require service and if neglected, may die completely. My problem was that one segment of the telescope was not extending and finally the antenna was getting veeery slow to operate and might not even come back down completely. My mission was to find out whether the electric motor was tired beyond repair or whether I could still salvage the thing with a service.
Untitled by
jkohvak, on Flickr
The antenna is attached to the car basically with one bolt. Remove it, then remove the antenna wire, grounding wire, and power wires, and the whole camera unit can be wiggled down and out. There is also a trim nut on the outside that needs to be loosened but that's pretty much all there is to it.
Untitled by
jkohvak, on Flickr
Here are the guts of the thing with 25 years worth of black crud removed. Very little of the original red lubricant was salvageable, it had turned into black goo with all the foreign particles that had been making their way into the antenna assembly over the years.
So basically here you have the electric motor that spins a transfer gear and the electronics which run the motor. The main gear, which has two sets of tooth, one for the drive and one for the antenna "spine". Then you have the wheel which collects the spine. Then the main housing which all the parts mount to.
The actual antenna box has clips on the outside lip which hold it shut. It's a good design, tight and not so prone to breaking even after quarter of a century.
Untitled by
jkohvak, on Flickr
Here are the main parts mocked together. The antenna spine enters the housing from the top and of course runs with the tooth of the main gear. Roughly between the two screws is the drive gear of the electric motor. The electric motor drives that gear with a rubber belt. It appeared to be in excellent condition.
Untitled by
jkohvak, on Flickr
Here is the actual antenna. Telescopic with 4 segments that collapse into the fat part visible in the first picture. Behind it all of course is the spine that is toothed all the way and permanently mounted to the uppermost segment. The spine was completely filled with crud to the point where it looked like it had no tooth. It cleaned up pretty well with brake cleaner. Worse problem is that over the years it has gained a curve as you can see here, and therefore it's a total bitch to install inside pipe-like parts with unreachable narrow openings inside.
In summary my efforts were 2/3 a success and 1/3 a failure. On the upside I got the fourth segment free by holding the antenna in the vice and wiggling the segment in question with some pliers. It was just stuck from.. getting stuck some time and then years of non-use. Also, upon cleanup and testing afterwards, it's pretty clear that the motor is OK and anyway most of the antenna assembly is in good condition.
The downside is that even after cleanup the operation of the antenna telescope is very jerky and the antenna gets stuck on just the electric motor. So I definitely need to do the "big service" which means buying a new telescope (with spine) for it. Thankfully it's a readily available part and should cost me about 85 EUR shipped. So I don't need a complete antenna package which costs multiple hundreds for a genuine Hirschmann.
I'll get on that, and in the meanwhile I have the antenna locked to the fully extended position so that I can use the radio.
We have had some pretty good weather recently and the snow is on its way out at least in Southern Finland. I plan to put the coupe on the road again if not next weekend then on one of the following weeks. I have a long-ish trip coming which would be fun to do with this car.