Tone pot behaviour on 1960s Harmony Rocket

jakeolly

hi people. Need some advice
just bought a Single S-Grille  pickup Harmony Rocket. Pickup sounds great . However the tone control ( According to web info itwill have a 0.02 cap on a 250k pot ) when turned down removes almost all the sound. I understand this can sometimes be a sign of a broken pickup, but it sounds great when tone pot is open or nearly open. 
Might it be a failed cap?
i know i could just try a replacement, but its a fiddly job thro the f holes so so id rather ask a few experts ( you lot) first

if so any advice on sources of replacements? 

Thanks 
chris 

Winny_Pooh

Sounds like the cap is gone and the signal is going straight to ground when you roll it down. 

ICBM

From the symptom it does sound more likely to be the pickup unfortunately. It isn't likely to be a shorted cap unless it removes *all* the sound.

Do you have a multimeter? You can check the pickup from outside the guitar if you plug a cable in, turn the controls up full and measure the resistance at the other end. If you get a normal pickup DC reading (typically 5-10Kohms) then the pickup is fine, if you get the volume pot value then it isn't.

jakeolly

Will try with multimeter. Thanks guys. 
Would the pickup sound so good if it was broke ?

ICBM

jakeolly said:

Would the pickup sound so good if it was broke ?

They can sound surprisingly OK until you compared them with an unbroken pickup. The capacitive coupling from the coil to the cover can be quite large, enough to pass a fair signal.

jakeolly

Hurrah!!. Just tried on multi.—- 9.36 k, both with tone pot open or closed. So that means tone cap faulty/ disconnected?
it was the ‘plug in a lead and try it’ that helped me. Because im a chump it never occured to me to do that 
thanks guys much relief . Even tho i like the sound i couldnt have settled if it had been faulty. 


Sources of replacement caps ?
views on idea of adding a further ( bridge) goldfoil - sacriledge or good idea . Ill see how it performs at rehearsal tonight. 
Lovely thing tho 
Thanks again 

ICBM

Yes, it sounds like the cap is faulty - it must be not completely shorted. Odd, but the resistance reading does mean the pickup is fine.

impmann

jakeolly said:

Hurrah!!. Just tried on multi.—- 9.36 k, both with tone pot open or closed. So that means tone cap faulty/ disconnected?
it was the ‘plug in a lead and try it’ that helped me. Because im a chump it never occured to me to do that 
thanks guys much relief . Even tho i like the sound i couldnt have settled if it had been faulty. 


Sources of replacement caps ?
views on idea of adding a further ( bridge) goldfoil - sacriledge or good idea . Ill see how it performs at rehearsal tonight. 
Lovely thing tho 
Thanks again 

A cap is a cap, despite the voodoo marketing.
AxesRUs sell orange drops if that’s your thing.