Author Topic: Black wire running along length of pickup rail?  (Read 755 times)

Offline Gescape

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Black wire running along length of pickup rail?
« on: January 15, 2018, 09:52:23 AM »
Hello all! This is my first post and it is about that black wire that runs along the length of the pickup rail- what does it do? I have a 1973 Mk1 Stage 73 that doesn’t have it, it looks like it may have been removed at one point, yet the piano works normally- there is output that gets to my amplifier. Any thoughts? Thanks!

Offline pnoboy

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Re: Black wire running along length of pickup rail?
« Reply #1 on: January 15, 2018, 11:32:07 AM »
The wire runs the ground connection of the RCA jack to the treble end of the pickup string, while the left end of the pickup string goes to the output connection of the RCA jack.  The piano shouldn't work without it

Offline pianotuner steveo

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Re: Black wire running along length of pickup rail?
« Reply #2 on: January 16, 2018, 05:37:08 PM »
I'm really surprised you are getting a signal. Was a different ground wire added and you didn't notice at first?
1960 Wurlitzer model 700 EP
1968 Gibson G101 Combo organ
1975 Rhodes Piano Bass
1979 Wurlitzer 206A EP
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Offline conke

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Re: Black wire running along length of pickup rail?
« Reply #3 on: January 16, 2018, 06:17:06 PM »
I'm guessing a longer wire with more give was used to replace the original and is dangling between the harp and the back wall.
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Offline Gescape

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Re: Black wire running along length of pickup rail?
« Reply #4 on: January 17, 2018, 08:39:27 AM »
Hello and thanks for the replies. There is in fact a bare wire, looks like picture frame hanging wire, in the back behind the harp RCA output, not quite sure what or where it’s attached to, but that could be the answer. I’d post a pic but am at work, away ftom the piano. So at least now  I don’t have to worry about the missing black wire.

Offline pnoboy

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Re: Black wire running along length of pickup rail?
« Reply #5 on: January 17, 2018, 11:36:33 AM »
Usually, that's the wire used to ground the aluminum damper bar.  At the right edge of the harp, where the last pickup is, you should see a wire from the last pickup to something.  Usually, that's the black wire, but in your case it's something else, I guess. 

Offline Jenzz

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Re: Black wire running along length of pickup rail?
« Reply #6 on: January 18, 2018, 01:52:25 AM »
Hi .-)

The piano will work even without this wire. The wire doubles the connection that is already established by the aluminum tape that connetcs all pickup mounting brackets to ground.

The bare wire is used to connect the damper bar to ground, thus eliminating hum and buzz. If the damper bar is not grounded, capacitive coupling into the damper arms will induct hum and buzz to the pickups. Remember, the damper arms are going under the pickup coils, esp. in the upper ranges.

Jenzz
« Last Edit: January 18, 2018, 01:56:47 AM by Jenzz »

Offline pnoboy

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Re: Black wire running along length of pickup rail?
« Reply #7 on: January 23, 2018, 12:27:55 PM »
Yes, assuming the tape conductively contacts the frame, which may not always be the case due to corrosion, etc..  Fender supplied a soldered wire to guarantee a solid ground over time.