Bigguy2017

Lovely - my first decent bass was one of these.

Try  Home - Marten Cables  they can make to length with HO7RN-F Rubber Cable

Also  https://www.designacable.com/

Meant for an upright acoustic bass?

That is a classic example of 'green goo'.

It happens when the plasticiser in the insulation reacts with the copper wire and corrodes it.

It's a manufacturing defect in the cable and was (is?) reasonably common in mains (and other) cables of a certain age of manufacture.

Google 'green goo in cables'   What To Do About Green Goo | No Shock Electrical 

Only fix is to bin the cable and replace.

2 hours ago, BassmanPaul said:

Sorry @Bigguy2017 Dioxit is more likely to wreck the pot.

No, it isn't.

I've fixed so many dirty pots with Deoxit and it is actually formulated for this purpose. 

Also if the pot's f!*ked anyway what have you got to lose? It's easier than replacing the pot, which may finally be necessary.

Over 45 years as a Broadcast Engineer I have never had Deoxit harm a pot - cleaned literally thousands of carbon track pots this way - entire mixing desks.

Don't believe ignorant chat on the internet... 

https://caig.com/cleaning-and-maintaining-pro-audio-gear-deoxit/

Does tapping the knob produce the crackle?

Could be the pot itself or it could be a dry solder joint.

  Give the pot a squirt of Deoxit and a few twists.

  Resolder the pot's connections on the PCB.

  Tap around the PCB with a plastic pen or similar, to identify dry solder joints - reflow any suspects...

  Replace the pot.

lighting stand top plate / tilting top plate ?

In lighting circles I've seen similar called a baby plate ...

I'm not finding anything small exactly like this - closest are adjustable AV/speaker stands  Pyle Pro Swivel/Adjustable Wall/Ceiling Speaker Mounts PSTNDC31 

Acesonic NB-901 Speaker Mount 

 Headliner HL31001 Speaker Stand Mounting Plate for TV, Monitor, Projector, or Moving Head 

A much chunkier thing is a Unicol CP6 tilting ceiling plate, so a small projector ceiling mount might do...  

The Polytune also has a DC loopthrough so one PSU plus a single short DC cable will power these neatly.

They never seem to last for long. Switchcraft are better than most.

Has anyone tried the Pure Tone ones with four spring contacts?

21 minutes ago, Dad3353 said:

 

This does not compute. There are only two wires from that p/u, no..? One goes to earth (so no buzz, naturally...), the other (the white one...) gives a buzz..? If that's the case, but no sound from the p/u itself, the p/u is dead. Is there a sound if you tap the p/u with something metal, such as a screwdriver blade..? When plugged in, volume turned up a bit, you should hear a harsh metallic tapping when you tap the pole pieces. If not, either change the p/u or get it re-wound.
The ultimate test, if the p/u is to be removed anyway for exchange, is to connect the p/u wires directly to the jack socket. If there's still nowt, it's definitely dead. It's looking more and more likely, I'm afraid.

Yes, looks like there is an open circuit in the pickup - as the two halves are in series it could be in either one.

Unsolder / clip the black + white pickup wires and check for continuity - you should see around 8.5K to 10K Ohms.

If open circuit unscrew the pickups and have a good visual - check the fine coil wires where they are soldered to the output wires. Check each half for contunuity - expect around 4K to 5K per coil.

Carefully reflowing the solder joints on the pickup wires may fix things...

3 hours ago, Martin E said:

Thanks everyone, I'll get one of those Planet Waves jobbies and enjoy the luxury of a string winder, good price as well.

I have several pairs of supposedly half decent cutters and none of them will cleanly cut through a string hence my question.

 

Most (?) side cutters are for electrical or electronics work and are only rated for copper wire. The jaws on these will dent when cutting hardened steel wire, and the jaws may break.

Cutters rated for hard steel wire are required for cutting strings.

4 hours ago, chris7273 said:

Facom

Yes, these  Facom 192.16CPE 160mm (ffx.co.uk)  (they are now replaced by a newer model) 

Great cutters for hard wire, even low B etc.

Lower your pickup.

Check Amazon for folding step stools...

https://www.amazon.co.uk/PopStep-Folding-Compact-Perfect-Bathroom/dp/B07DH994NT/ref=sr_1_7?crid=2ALIGIK3TDVN3&keywords=step+stool&qid=1669653083&sprefix=step+stool%2Caps%2C77&sr=8-7

As the string separation increases from nut to bridge, you'll need three different spacings...  😉

Otherwise slant the pickups a wee bit to fit exactly?

You can test the pots and wiring this way...

remove the pickup leads from the pots (two white, two black)

plug bass into amp - adjust volume (!)

touch the centre lug of a volume pot - big hum on amp - turn pot - does volume pot work? Turn tone pot - does in alter 'tone' of big hum?

If all the above work then the pots, jack and wiring are functioning correctly.

As well as can be seen from the photos, the wiring appears correct.

The control plate, pot bodies and jack sleeve are all common ground, with a plain wire to the bridge earth.

Make sure all the pot and jack nuts are nipped up tight.

It's possible the pickups are not working.

So, do you have a soldering iron? Do you have a DVM? 

If yes, then unsolder black and white pickup wires from the pots and use DVM on Ohms/resistance range to test the pickups - they should read around 6K.

If not, you need to make up a test cable - normal mono jack to croc clips - if no croc clips then twist wires together.... plug jack end into amp, clip (or twist) black and white pickup wires (one pickup at a time) to other end of cable.

Does the pickup work? Test both...

If pickups are OK then (obviously) it's a fault with the pots or wiring. (The top pot looks like it has been replaced in the past).

Use DVM to measure pots - expect 250K or thereabout. (DVM across outside lugs reads the track - 250K, outside to centre should vary with knob position 250K to 0)

I pickups and pots are OK then it's a (simple!) wiring problem - take a very good look at all the joints and follow the wires - re-do the solder joints...

See attached wring diagram - you are using the LH version.

Jazz Bass WIRING 01D.pdf

GHS SuperSteels ?

26 minutes ago, SteveXFR said:

 

Do you cut from both sides toward the middle with this so it's a little smaller in the middle but the right size at the ends of the hole?

Yes

These hand reamers are good and go from 10mm to 25mm

TAPER REAMER 10-25MM WITH 8 FLUTES FROM HALL SHEFFIELD | eBay

Malvern and Worcester.

Yes, the metal plate is used to connect the jack outer to the pot bodies (ground). Some Jazz basses do this too.

No problem as long as all the pot nuts are tight - star washers are preferred.

No advantage to running an earth wire - no harm either.

For 3.5mm to 1/4" mono cables I buy a long (4m) moulded, quality 3.5mm to 3.5mm cable, cut it in half and solder on Neutrik 1/4" jacks.

IMHO the moulded 3.5mm ends are generally better than home-made 3.5mm ends.

The Ugreen braided cables on Amazon are good quality.

For full home-made the Rean 3.5mm jacks are very good and have a solid cable clamp. They do one with a large cable hole too.

Snake Oil Strings?

It's not easy to do - 18V needs 5 x lithium cells which is awkward.

A better bet are rechargeable 9V batteries   - EBL USB Rechargeable 9V Batteries - 5400mWh Long Lasting Batteries with Micro Charging Cable 

or bulk buy 9V ProCells

If you could tolerate a DC cable you could use a clean 18VDC supply (MeanWell are good) for practicing.