chrisanthony1211 Posted April 22, 2017 Share Posted April 22, 2017 I've been picking up some local radio on one of my vintage Precisions, should I look at shielding the cavities or are there any other options? Quote Link to comment Share on other sites More sharing options...
Thunderbird Posted April 22, 2017 Share Posted April 22, 2017 Yes a decent shielding job should cure that Quote Link to comment Share on other sites More sharing options...
PawelG Posted April 22, 2017 Share Posted April 22, 2017 [quote name='Thunderbird' timestamp='1492876009' post='3283838'] Yes a decent shielding job should cure that [/quote] Exactly what I would do. Quote Link to comment Share on other sites More sharing options...
T-Bay Posted April 22, 2017 Share Posted April 22, 2017 Could be useful at a gig if you can time it right ;-) Quote Link to comment Share on other sites More sharing options...
chrisanthony1211 Posted April 22, 2017 Author Share Posted April 22, 2017 It's a 1964 Precision which I had a go at shielding some time ago but gave up, I shielded both cavities with copper tape with just a small amount overlapping onto the face of the body and linked both cavities with a wire, the problem was that whenever I put it back together the pick ups went dead! It has an entire metal sheet under the pick guard and whenever this touched the copper shielding which overlapped onto the body the pick ups went dead, remove the pickguard and the pick ups came back to life...was i doing something wrong? I shall give it another go if I can figure out what I did wrong before... Quote Link to comment Share on other sites More sharing options...
gjones Posted April 22, 2017 Share Posted April 22, 2017 I remember the good old days when you'd get the local taxi radio coming through your amp or PA. It doesn't happen anymore. I assume because amp and cables are shielded better these days. Quote Link to comment Share on other sites More sharing options...
markstuk Posted April 22, 2017 Share Posted April 22, 2017 [quote name='gjones' timestamp='1492882409' post='3283893'] I remember the good old days when you'd get the local taxi radio coming through your amp or PA. It doesn't happen anymore. I assume because amp and cables are shielded better these days. [/quote] Spinal Tap/Air Base :-) Quote Link to comment Share on other sites More sharing options...
Thunderbird Posted April 22, 2017 Share Posted April 22, 2017 (edited) [quote name='chrisanthony1211' timestamp='1492880239' post='3283874'] It's a 1964 Precision which I had a go at shielding some time ago but gave up, I shielded both cavities with copper tape with just a small amount overlapping onto the face of the body and linked both cavities with a wire, the problem was that whenever I put it back together the pick ups went dead! It has an entire metal sheet under the pick guard and whenever this touched the copper shielding which overlapped onto the body the pick ups went dead, remove the pickguard and the pick ups came back to life...was i doing something wrong? I shall give it another go if I can figure out what I did wrong before... [/quote]Yes when you put the bass back together you must of been having the copper sheet touching a pot or the like in the bass in laymans terms it was shorting out also buy the copper shielding with the shielded sticky backing too plenty of videos on youtube to show you how to do it correctly Edited April 22, 2017 by Thunderbird Quote Link to comment Share on other sites More sharing options...
chrisanthony1211 Posted April 22, 2017 Author Share Posted April 22, 2017 (edited) The copper wasn't touching a pot, but it was touching the metal full size metal sheet which runs under the entire pick-guard which I'm guessing in turn would be touching the pots as they go through it! Would that mean I'd either have to remove the metal sheet from under the pickguard or make sure the copper shield doesn't touch it? Edited April 22, 2017 by chrisanthony1211 Quote Link to comment Share on other sites More sharing options...
Thunderbird Posted April 22, 2017 Share Posted April 22, 2017 [quote name='chrisanthony1211' timestamp='1492885257' post='3283929'] The copper wasn't touching a pot, but it was touching the metal full size metal sheet which runs under the entire pick-guard which I'm guessing in turn would be touching the pots as they go through it! Would that mean I'd either have to remove the metal sheet from under the pickguard or make sure the copper shield doesn't touch it? [/quote] No need really to remove the sheet just copper tape the cavity the metal sheet on the pickguard is shielding anyway Quote Link to comment Share on other sites More sharing options...
chrisanthony1211 Posted April 22, 2017 Author Share Posted April 22, 2017 [quote name='Thunderbird' timestamp='1492886898' post='3283952'] No need really to remove the sheet just copper tape the cavity the metal sheet on the pickguard is shielding anyway [/quote] I'm probably being a bit thick, but it was when I put the pickguard back that the metal sheet came into contact with the copper from the cavity causing the short Quote Link to comment Share on other sites More sharing options...
Thunderbird Posted April 22, 2017 Share Posted April 22, 2017 It's making a circuit so to speak what you could do is pop the pots out shield it all up then put some electrical tape on top of the shielding then put the pots back in not the pro way but will cure your problem and is easily reversible Quote Link to comment Share on other sites More sharing options...
chrisanthony1211 Posted April 22, 2017 Author Share Posted April 22, 2017 OK, so removing the pots, and I'm guessing jack from the circuit would do the job? Quote Link to comment Share on other sites More sharing options...
Thunderbird Posted April 22, 2017 Share Posted April 22, 2017 Yes as they would be insulated by the electrical tape Quote Link to comment Share on other sites More sharing options...
chrisanthony1211 Posted April 22, 2017 Author Share Posted April 22, 2017 OK, hopefully I should get round to this next week, I shall let you know how I get on, thanks for the advise Quote Link to comment Share on other sites More sharing options...
whizzzy Posted April 23, 2017 Share Posted April 23, 2017 You need to ensure that all of the shielding components (i.e. shielding plates, copper tape, pick-guard shield) are connected to the earth or ground side of the jack connection. This is usually colour coded black but if the wiring has been changed or modified at any time during the life of the bass then it may be necessary to follow back the wiring to determine if it is connected to the hot side of the pick-up (white) or earth / ground side. If any wiring or connections to shielding come in contact with the hot (white wires) then this is when the signal from the pups gets shunted to ground and so the output from the bass is dead. Pay particular attention to any lugs on the pots or the wiring to the tone cap also coming into contact with the copper tape shielding when the pick-guard is put back in place as well. Let us know how you get on. Quote Link to comment Share on other sites More sharing options...
chrisanthony1211 Posted April 23, 2017 Author Share Posted April 23, 2017 Well this is how my Precision is wired up, just the one wire from the jack and earth to tone pot, idiots guide appreciated, don't assume I know anything!! Quote Link to comment Share on other sites More sharing options...
whizzzy Posted April 23, 2017 Share Posted April 23, 2017 All of that looks ok. Just be careful that the wires to the capacitor don't touch the metal pick-up plate (its difficult to tell from the photo how close it is). How and where are you connecting the cavity copper screening? Quote Link to comment Share on other sites More sharing options...
chrisanthony1211 Posted April 23, 2017 Author Share Posted April 23, 2017 OK, step one is to screen the pick up cavity. Step two screen the control cavity Step three, join the two cavities with a wire through the pickup wire hole This is how far I got last time and got nothing when I put it back together, but worked OK when the metal pick up shield was off, what am I missing? There is also a metal plate under the pick ups with a ground wire back to one of the pots... Quote Link to comment Share on other sites More sharing options...
Grangur Posted April 23, 2017 Share Posted April 23, 2017 The metal plate on the back of the pups should be the earth side. If you find it's the yellow wire on the pup that is connected to the plate, then change round the wires. The "hot" wire on the pick-up is the one that goes to the windings, no matter the colour. Also, as said above, just check the capacitor has a nice space between that and the screening. Wherever I connect a jack socket, I would always use an earth wire. I also earth between pots. Quote Link to comment Share on other sites More sharing options...
gary mac Posted April 23, 2017 Share Posted April 23, 2017 I've had this problem a couple of times, the cure has been to spin the output socket around slightly so that it doesn't touch the foil. Quote Link to comment Share on other sites More sharing options...
chrisanthony1211 Posted April 23, 2017 Author Share Posted April 23, 2017 OK, I may have time to have a go at it later, I'm sure i shall encounter a problem or two so will be back! Quote Link to comment Share on other sites More sharing options...
Grangur Posted April 23, 2017 Share Posted April 23, 2017 [quote name='gary mac' timestamp='1492956041' post='3284340'] I've had this problem a couple of times, the cure has been to spin the output socket around slightly so that it doesn't touch the foil. [/quote] That's a good point; the contacts for the tip of the jack could be shorting to the cavity shield. Quote Link to comment Share on other sites More sharing options...
chrisanthony1211 Posted April 23, 2017 Author Share Posted April 23, 2017 All done and working wonderfully, I had the same problem as last time to start with when I put it back together, no sound! I moved the jack around to make sure it didn't touch the side and it worked great As luck would have it though, as soon as I put it back together the tone pot stuck solid, a bit of contact spray has sorted it now though, I'm hoping that the lovely clean copper control cavity will help prevent the pots sticking in future,it would be rather annoying mid gig! Thanks for all your help, I wouldn't have given it another go without it. Now to do the same on my 73 Precision Quote Link to comment Share on other sites More sharing options...
Thunderbird Posted April 24, 2017 Share Posted April 24, 2017 Wooohooo nice one Quote Link to comment Share on other sites More sharing options...
.gif.9ad672bb8b84505709f76b39c8c256ec.gif)
Recommended Posts
Join the conversation
You can post now and register later. If you have an account, sign in now to post with your account.