Antenna sanity check

I have a 2000 Jetta that I bought used. Shortly after I bought it, I replaced the head unit with a Blaupunkt unit I bought from Europe. I had no idea that the Jetta uses an amplified antenna (is this all models?) but other than having to move a wire in the factory harness, it seemed to be a fine exchange. I lost my AM channels but I just assumed that was due to it not being a US head unit. FM was fine as far as I was concerned.

In the past few years, the coating on the whip started to break down. Eventually, my FM reception has deteriorated. I thought it was probably just the whip which I recently got around to replacing but this didn't help things. Today, I measured continuity and found it not present (though this may be OK with an amplified antenna?). So I'm wondering if the damaged plastic on the whip allowed water to get into the antenna body and damage the amplifier.

So I'm guessing first thing is to check that the radio is really putting out 12V on the antenna? That should just be a simple voltage measurement at the back of the radio, right? Is there a next step after that other than just replacing the antenna base? The antenna base I see available has a connector close to the base. Is this factory or am I going to have to splice something in? (Never mind this bit. Shows well in this video https://www.youtube.com/watch?v=K2z_YURcm7w)

There is a printed circuit board in the base that gets corroded. Sounds like you just replaced the mast.
Cheers

That is what I was thinking. It sounds like a bit of a bear to replace.

Does anyone know where to get a genuine replacement at a good price? It seems like there are a lot of fakes out there without the amplifier.

Try:
https://www.idparts.com/antenna-base-a4-p-786.html

When I replaced my Monsoon radio with a Kenwood I bought a power injector from Crutchfield to send 12V to the base.

I don't know if your Blaupunkt does that.
I would think a voltage test would show it but I never tried it.

I also got a base that looked brand new from a VW that was wrecked.
Reception was great.

Yeah, I'm actually now skeptical whether I actually had a powered antenna all those years. I still have the original radio so I'll try plugging that in, measure that and then repeat with the newer one. Though I might change the head unit out anyway. It's been a while.

The quality has definitely dropped off in the last couple of years though.

That price at idparts is kinda high (Looks like that's the going price from reputable places though). I would be interested in seeing the innards. It might be possible to refurbish them. Aha. Video here: https://www.youtube.com/watch?v=5k_d2zTiHp8 Edit: Oh, he doesn't repair it, he just eliminates it.

I got one for around $30 and you can splice into the 12v power on the standby so it's not powered on the entire time.
It does need power to work though

Sent from my moto g(7) power using Tapatalk

I did an a-topsey on my dead one.
A few components fell off the circuit board.
Did not know which one should have gone where and if the capacitors were polarized ones which way they should go.
Circuit board was not a pretty picture either.

As far as I know the Monsoon radio had the amplifier.
It came with the car new.