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Post by ozboomer on Sept 28, 2008 5:18:35 GMT -5
This will be a discussion thread to describe my attempt at making my first major electrical modification to one of my guitars. Details of the mod can be found in the primary discussion thread and in the the Schematic thread. John
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Post by ozboomer on Sept 28, 2008 7:04:00 GMT -5
Let's start this off with a couple of photos of the unmodified Squier Bullet Strat: ...and I've created a simple, unmodified recording of some chords (please be understanding of my 'beginner-revisited' technique), showing the different stock sounds in each of the normal positions. Note that I've not fiddled about with the sound very much and I certainly haven't done my normal "noise filtering". The signal path is basically: You can stream or download the sample sounds (1.23MB). The first thing I think I'll try is doing the basic shielding under the pickguard; some thicker aluminium foil and such. BTW... Do let me know if the images are too large for dialup folks and I'll do things a different way.
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Post by newey on Sept 28, 2008 8:21:33 GMT -5
Oz- Your images are fine. Nice new Strat- I see you still have the plastic overlay on the pickguard! Your sound sample indicates a fairly quiet Strat to start with, given that you indicate no noise reduction was employed on the clip. As JA always said on the original Gnutz site, the quieter your guitar is to begin with, the less effect you'll notice from shielding. I'm curious as to how much shielding the Squier folks are employing these days at the factory, so please post some photos of the innards before modding. They may be using shielding paint in the cavity nowadays. Of course, the true test of the noise level is through an amp rather than DI. But if this git is equally quiet through an amp as on your clip, I'd say you're in good shape already. Happy modding!
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Post by ozboomer on Sept 29, 2008 6:14:28 GMT -5
7:40 pm MEL time, 29/09/2008 I don't know why but I think it's something I read somewhere. I've just traced the outline of the pickguard onto some card; maybe the thinking is I'll make a template of some sort, so I can mount the electronics 'temporarily' while I'm making the circuit and the real pickguard (with the shielding foil) won't be damaged. 8:51 pm MEL time, 29/09/2008 I've just pressed some clear plastic wrap onto the front surface of the new/replacement pickguard (3-ply, SSS, white/black/white, 11 holes to replace the single ply, white, 8 hole version supplied stock) to help protect it through the next operations (see photos). To ensure the foil sticks well, I've just sanded-off the gloss from the back of the pickguard. I've given it a bit of a wash and will let it dry overnight. The big moment will come in the next couple of days when I come to stick the foil on the back. A question I have: If I apply the spray adhesive to both surfaces, that is the pickguard and the foil, making a permanent bond, should I try and trim the foil to 1 mm inside the pickguard edge while the glue is 'wet'... or should I wait until the glue is 'dry'? Which way will give the cleanest edge? Do I really need to apply the glue to both surfaces anyway? Someone has also asked why trim inside the edge of the pickguard anyway? If you trace around the edge of the pickguard 'vertically', won't that exactly match the pickguard shape anyway and there won't be any 'messy overhang' of foil, if you do it right?
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Post by ozboomer on Sept 29, 2008 6:28:49 GMT -5
Nice new Strat- I see you still have the plastic overlay on the pickguard! I grabbed this guitar new in 2006 and have been saving it for TheRightProject(tm)... My other guitars also still have the clear film in place, although they're looking a little the worse for wear Your sound sample indicates a fairly quiet Strat to start with, given that you indicate no noise reduction was employed on the clip. Yup.. but you're quite correct when you talk about running it through the amp; I get the classic power supply hum.. but I've generally played using positions 2/4 and with the reverse-wound middle pickup, the noise is not a major problem for the sort of things I do... but the other classic 'feature' of the hum reducing when I touch the strings is also there. *Thinks*... I should probably record that hum out of the amp, for completeness, I guess.... ...and no worries -- I'll be sure to take some photos of the cavity and the stock pickguard.
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Post by JohnH on Sept 29, 2008 7:29:40 GMT -5
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Post by ozboomer on Sept 29, 2008 7:56:20 GMT -5
...I think I sprayed the foil and the plastic, and then trimmed it off later right to the edge. It worked out neatly enough for me Hmm... I see what you mean - good photo. Actually... it's given me a good idea. I think I might have a go at what you've shown there, with just going right to the edge and cleaning it off later... and then, to borrow from my boomerang construction techniques ( some retired models ), I'll run around the underside once or twice with a rat-tail file, effectively doing a small undercut; that'll make for a rather neat finish
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Post by ozboomer on Oct 2, 2008 5:48:11 GMT -5
8:10 pm MEL time, 1/10/2008 Used a couple of plastic rulers to hold the foil and after applying spray adhesive to both the back of the pickguard and the (matt side of the) foil, I let everything sit for about 5 minutes, to let them all get tacky. I then laid the foil over the pickguard and gently smoothed it all out. It looks pretty good... but I'll let it sit overnight and do some of the cutting-out next. 5:58 pm MEL time, 2/10/2008 Have just spent the last half-hour or so cutting the excess foil away, coming from the plastic-film side. Ooo, those curved bits are a pain.. but I'm not getting overly stressed Some final clean-up still to do. 7:32 pm MEL time, 2/10/2008 Now I've sanded-up the edges of the foil and will leave the pickguard alone for now until I'm ready for the final installation (so the foil remains in good condition). Heck! it's tricky to get a decent photo of something that's all aluminium foil! Hmm... What about the slot where the 5-way switch arm slides back and forth? If that touches the foil (which will ultimately go to ground), will the guitar be shorted-out? How do I protect that sliding arm from any of the foil? 8:21 pm MEL time, 2/10/2008 I have the cardboard pickguard organized and the next steps will be to mount the pots, pickups, etc on this temporary pickguard, so I can do the wiring. (*thinks* ... Maybe I'll just use the pickguard that's in the guitar right now?) Then, I'll temporarily mount the cardboard pickguard in the guitar and see if I can get some sort of sound of the circuit. For now, the most pressing thing I need to do is to take the strings off the guitar and remove the pickguard and get the pickups out. Oooo, this is going to be a big deal(!)... so it'll be another day or more before I get brave enough to have a go
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Post by newey on Oct 2, 2008 6:50:38 GMT -5
Not to worry, if it touches you'll just be grounding the frame of the switch (which will be touching the foil anyway).
Good looking job on the pickguard. I often do my wiring with the components mounted in the guard, you just need to be careful with the soldering iron. I usually use a piece of cardboard cut to fit as a mask around the area I'm working just to catch the occasional stray blob of solder.
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Post by andy on Oct 2, 2008 6:55:34 GMT -5
Don't worry about opening up the guitar. It is literally just screwed together, with a few blobs of solder to un-do. It's putting the thing back together that always scares me... I should imagine that the 5-way will have enough clearance from the foil if you trim it neatly to the slot, but just in case, how about putting a single strip of electrical tape over the slot, then slicing it down the centre, and using a blade to run the excess over the inside edge of the slot? It may or may not stick too well along the inside edge, and in hot conditions, LX can go a bit gummy over time, but I've also seen it last very well, and it would certainly insulate the area.
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Post by andy on Oct 2, 2008 6:57:25 GMT -5
Ha! Newey must have posted at the same time as me. My advice is obviously not required!
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Post by ozboomer on Oct 2, 2008 7:02:21 GMT -5
Ha! Newey must have posted at the same time as me. My advice is obviously not required! Still, there's a couple of good clues there... that I could use, depending how paranoid I feel Into the 'Boodle Box'... and Fanx!, as always...
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Post by newey on Oct 2, 2008 14:47:52 GMT -5
Well, I think I'm right- I've never had a problem there and I've not heard of a problem from others. But long-time members know how wrong I can be sometimes. My thinking is that the switch lever is ( . .. supposed to be) isolated from the contacts, otherwise, one would hear noise by touching it. JA's original shielding article advises using electrical tape to ensure continuity when using the "fold-over" method of shielding with metal tape w/o conductive glue. That's the method I use, and I use electrical tape in guitars for isolating connections, etc, and never have had a problem with the tape coming loose. Granted, I haven't been shielding them for more than a couple of years so if I take them out in the hot sun 20 years from now, who knows?
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Post by ozboomer on Oct 3, 2008 23:37:38 GMT -5
1:12 pm MEL time, 4/10/2008 Have just finished pulling the blender pot apart and removing some of the carbon track, viz (apologies for the poor photo): Note: A good reference for this is Checking DC resistance on your potentiometers at www.projectguitar.com/. *thinks* ... In hindsight, it probably would have been sufficient to simply break the track, wouldn't it? As long as there is no continuous track from that 11 o'clock to 1 o'clock position, I wouldn't really need to scratch off all of the carbon track? Oh well.. I've measured a maximum resistance on the lugs of the pot at about 33k... which would make sense, given the pot is 100k linear. Hopefully, it will be enough variation to do the blending Ok. The next step will be to pull the guts out of the guitar so I can re-wire it all... so that'll be happening a bit later...
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Post by ozboomer on Oct 4, 2008 8:13:32 GMT -5
8:57 pm, MEL time 4/10/2008 I've just finished doing a basic recording of how the raw guitar signal sounds (middle pickup only) on my normal recording setup prior to dismantling the guitar. No noise reduction, no artificial boosting, etc on this track. Imagine the guitar resting front side up in front of you, neck pointing to the left. Let's say the "X-Axis" runs longitudinally along the neck left-to-right -- in through the end of the headstock and out through the guitar strap pin at the bottom of the guitar. The "Y-Axis" runs directly away from you, through the middle pickup, parallel to the ground... and the "Z-Axis" runs perpendicular to the front face of the guitar, pointing directly to the sky. Then we have these actions going on in the recording: 00:00.0 - 00:03.5 Normal noise 00:03.5 - 00:20.0 6th string 'E' note, while rotating the guitar about the "X-Axis" 00:20.0 - 00:32.5 5th string 'A' note, rotating about the "Y-Axis" 00:32.5 - 00:45.0 4th string 'D' note, rotating about the "Z-Axis" 00:45.0 - [End] 1st string 'E' note, to indicate the end of the recording I'm still deciding if I'll try to line the cavity with foil or not... ...but we'll see how it looks when I open it up tomorrow..
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Post by ozboomer on Oct 4, 2008 22:08:04 GMT -5
10:38 am MEL time, 5/10/2008 Executive decision - I'll NOT make any measurements of the pickup heights, tremolo height, neck relief, etc and I'll do a set-up 'from scratch' when I finally re-assemble the guitar... famous last words, I know.. but oh well -- I constantly keep a healthy sense of reality here -- it's a A$150 guitar, not A$5000. 11:27 am MEL time, 5/10/2008 Starting by loosening the strings... 6th by 5 half-turns, 1st by 5 half-turns... 5th and 2nd... 4th and 3rd... and repeat for another 5 half turns. Hmm... I hear a bit of creaking... Well, I guess it's hardly ever had the tension off, so the neck is probably feeling some 'real relief' (HA-HA). With the tension gone, I cut the strings up near the headstock and draw the strings out the back of the guitar. Having 'clean' ends makes it easier and less wearing to remove the strings through the bridge/saddles. I immediately notice the tuning posts are a little wobbly/loose; maybe they're cheap, maybe they're just loose... but I note to check them when installing the new strings later. 12:46 pm MEL time, 5/10/2008 I've been fiddling about for the last hour or more just noting all the guff going on inside this guitar(!) Let's see if I can make some sense of it all... Firstly, for newey and others, there is nothing special in terms of shielding in this 2006 model (I believe it is); minimal 'shield patch' under the pickguard and nothing at all inside the cavity. One annoying thing - in their pursuit of a tidy design, somehow they managed to cable-tie the tremolo claw/bridge wire amongst the others, thus preventing me from removing the pickguard (notwithstanding the leads to the output jack). So that cable tie was the first thing to go. Otherwise, the layout seems more-or-less standard, using mini-pots and the 'in-between' rotary 5-way (which I'll have to work out how to wire!). The wiring from the pickups is shielded, with the shields being used for ground and the 'hot' wires being white (neck, bridge) and red (middle - for reverse wound, I expect). The actual wiring is awfully twisted, particularly between the two tone pots; what a mess. There must be some sneaky production wiring reason for doing that... Interesting to see them using a greencap - annotated with 2A473J (0.047uF?) - rather that the dirty ol' ceramic disks ( Ok, I'm biased ). So, here are some photos (there is no gold/copper foil in any of this - the colour comes from the 40+ year old pine lining boards that make the ceiling here ): So now, I'll keep thinking about whether I line the cavity with foil... and will think about pulling everything apart off the pickguard. Busy, busy day, this one
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Post by newey on Oct 4, 2008 23:24:06 GMT -5
. Well, since you're in there already . . . That's one of the main reasons it's A$150. Replacing the heads on budget-priced guitars with better quality ones can make a huge difference in tuning precision and stability. I had never thought of that! Good tip!
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Post by ozboomer on Oct 5, 2008 6:16:45 GMT -5
. Well, since you're in there already . . . Hmm... Well, d'you think it will be sufficient to simply foil-line the cavity and ensure the foil is all continuous and goes over the edges so the foil on the pickguard is in contact with it?... maybe even out to some of the pickguard screw points? I don't want to go too feral on the shielding side of things, y'see...
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Post by andy on Oct 5, 2008 6:32:50 GMT -5
That is rather a nice coloured guitar... I agree with newey on snipping the strings prior to removal- I really had never thought of that, and just resorted to a-yanking and a-scratching! Those tuners will also be good to replace, although I have found that plenty of guitars have slightly wobbly posts. Under string tension they rarley cause a problem as such, as they are held firm by the strings themselves, but smooth solid tuners are always a worthwhile and easy investment. I have to mention those pickups too- it looks like they have base plates like a Telecaster pickup would. I wonder why that might be, and whether they are removable. It might be worth trying them with and without to see if the sound is improved, so long as that plate is not intergral to holding the things together. As a sideline to that, I'm always an advocate of putting in new pickups- it can be expensive, but will push you $150 guitar much closer in tone to that $5000 mark!
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Post by ozboomer on Oct 5, 2008 7:03:27 GMT -5
Those tuners will also be good to replace... Hmm... Time to start talkin' to GuitarFetish ... after I see how these other mods go. Although I like the feeling of the neck and so on with this guitar, I want to have a good go at playing with the setup when the electronics is... 'done' ( does that ever happen, once the 'modding bug' bites!? ) 'coz there were always a couple of buzzes on this guitar. I have to mention those pickups too- it looks like they have base plates like a Telecaster pickup would. Ya, I was thinkin' the same thing. I remember reading about the Fralin 'baseplate'... but was put-off by the waxing operation... but over the past couple of days, I was thinkin' about the output of the pups in this guitar and they were reading fairly 'hot' using ChrisK's [url=http://guitarnuts2.proboards45.com/index.cgi?board=reference&action=display&thread=3186&page=1#28098 ]post to check on resistances of pups, etc[/url] - something like 8.5k - so I was wondering a bit about that... but that's really a whole other project(!) As a sideline to that, I'm always an advocate of putting in new pickups- it can be expensive, but will push you $150 guitar much closer in tone to that $5000 mark! Yes... and over the last couple of years, I've read many posts about how people luck onto a good Squier and, with various upgrades of the components, they end-up using their Squier more and liking the guitar more than their MIM Strats... So, I'm thinking there's nothing really 'wrong' with going the budget route to start and then 'tricking it up' some
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Post by newey on Oct 5, 2008 9:13:08 GMT -5
Yes. Yes. Yes. And Yes.
With the proviso that it does have to be grounded somewheres.
No, don't go too feral. Feral types generally don't have computers and so don't post much! ;D
For first time shielding, we always recommend following the original JA scheme to the letter for best results. You can, however, omit the safety cap if you are not going to be using tube ("valve") amps.
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Post by ozboomer on Oct 5, 2008 22:41:06 GMT -5
Alright, folks... Let's say I'll have a go at doing the shielding in the body cavity. What's your experience of performing the task?
From what I read (in various sources), it's often ineffective to try the shielding paint (for various reasons - metal particles can cause troubles, as can the carbon -type paints), so we won't go that route.
If I use copper foil, I have the advantage of being able to solder directly to the foil... but copper foil is expensive... and here, at least, difficult to find.
So this leaves us with some form of aluminium foil treatment.
If I use everyday contact adhesive to glue the foil to the inside of the body, it will get relatively expensive (at $7 per 30 ml and I can see a couple of tubes of glue at least being required for the one guitar) and the job will be fairly messy, having to apply glue to the cavity AND to the foil.
If I use the spray adhesive I used on the pickguard, it will probably go a fairly long way... but I have to deal with preventing overspray from getting onto the face of the body, so I'll have the extra job of masking everything up before I spray.
If I try self-adhesive aluminium foil tape, it looks like it might cost ~A$20 for a fairly decent-size roll, with a width of about 3- inches/75mm (although, the same roll can vary in price from A$18 to A$30, depending on the non-electronics shop I look in)... So I expect I'd be able to do more than one guitar with that roll of tape.
So, all-in-all, it seems like the aluminium foil tape might be the easiest route to take... and it will only be a bit more expensive than the spray adhesive.. but will be a lot cleaner and I can work directly on the cavity without having to 'setup' beforehand.
Any further thoughts?
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Post by D2o on Oct 6, 2008 11:39:09 GMT -5
Hi oz, I have used aluminum duct tape numerous times with good results - actually you can see and hear the reduction in hum for yourself right here. Scroll down the post about half way and you'll see a picture - that's your first big clue about how effective shielding is. You will also see a link to a recording and, assuming that link is still active, you can hear the reduction in hum for yourself (there are four sounds - the first sound is an unshielded strat with stock wiring and the last sound is a shielded strat with stock wiring). It is not as good as copper, nor is it as beautiful - on the other hand it's cheap, easy to find, and easy to use. Good luck, D2o
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Post by ozboomer on Oct 10, 2008 5:22:50 GMT -5
I've been doing a bit of research on the shielding thing this past few days... and have a couple of thoughts.. but first: I have used aluminum duct tape numerous times with good results - actually you can see and hear the reduction in hum for yourself... Yup, it's certainly noticeable.. although, I don't have any of the broadcast issues you seemed to have in that experiment... Anyway, referring back to another article... ...All the pot and switch cases will contact the foil, but they are not on the signal path. Ideally, you then have just one place where the whole shielding system is grounded. Now, referring to 'Figure 1' in JA's article Shielding a Strat, he mentions about connecting the tremolo ground wire with a screw into the cavity. So, I can see how that will get some sort of grounding between the shielding and the bridge, etc... but that means the 'explicit' connection between the bridge and the 'circuit ground' isn't there anymore. Should I 'force the issue' and 'guarantee' the signal ground and bring another wire from that screw up to a circuit ground point (say, on a pot shell)? Otherwise, it seems we're relying on the cavity foil 'overflow'/pickguard shield/pot connection to get the bridge at 'signal ground'...? In any event, if you look at some of the previous photos of the guitar body, I assume I should at least bring the shielding up out of the cavity and over the pickguard screw holes, so that will help guarantee the shielding in the cavity AND on the pickguard are joined, and effectively complete the 'Faraday Cage', hmm?? ...or is this simply introducing another ground loop, thereby sort of defeating the purpose (again)? Another trivial question, too: I've only seen it done rarely... but is there any point to shielding the cutout for the output jack? ..or is that really overkill? Apologies for my crazy writing - my brain is a bit addled from crazy work things today...
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Post by D2o on Oct 10, 2008 9:14:49 GMT -5
Hi oz, EDIT: re: I think you could do just that - it seems to me that someone here did it recently, but I can't remember who. Angelodp, maybe? At any rate, Angelo has given us some really good pics of the QTB mod and shielding, have a look at his work (the pics at the bottom of the thread). D2o P.S. re: Output jack cavity - no real advantage, and has led to regrets via shorting out more often than anything else.
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Post by newey on Oct 10, 2008 9:19:53 GMT -5
Oz-
The QTB mod calls for using shielded cable to the out jack, if you go that route shielding the jack cavity becomes superfluous. By all means, you should run the foil up under the pickguard, as you want the foil on the guard to contact the cavity.
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Post by ozboomer on Oct 10, 2008 20:35:25 GMT -5
12:29 pm, MEL time 11/10/2008 While trying some 'dry run' examples of applying the shielding foil, I realized something...
The new pickguard is a little bit of a different shape to the one that was originally fitted. So, I tried it out on the guitar and found most of the screw holes are a bit off or non-existent. So, the first thing I'm going to do is fill the 6 holes that are off-alignment with some wood filler and drill some small 'guide holes' for the new pickguard. Then, when I apply the shielding, I'll be able to extend some of the foil into the correct place to coincide with the pickguard screws.
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Post by ozboomer on Oct 11, 2008 4:04:32 GMT -5
7:33 pm MEL time, 11/10/2008 I've started applying some self-adhesive aluminium foil tape to the cavity, viz: Using a narrow strip to go around the curves with minimal buckling, I place one end of the strip on the top surface of the guitar and then bend it down along the vertical wall of the cavity. The end section of the strip is doubled-back on itself underneath, so that subsequent strips make electrical contact with the previous strip. Now, as I hope you can see in the photo, I've done a few layers around one of the cavity openings... and if I use a meter to measure resistance on the lowest ohm scale, when I touch one strip with each of the meter probes, I read 0 ohms, as you'd expect. However, if I place one probe at one end of the 'run' of strips and the other probe at the other end, the meter doesn't read 'infinity' but it might read, say, 30 ohms or a bit more. Seeing we're still getting a current through Ok, I assume this is Ok? Given the amount of aluminium metal there is around the cavity, I'd expect to get some resistance in there... but is this going to be a problem and prevent the shielding from working? Heh... I feel like I'm asking a question on MythBusters or something(!)...
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Post by JohnH on Oct 11, 2008 5:19:45 GMT -5
Its interesting to see what continuity you get through the joins. I reckon a few Ohms is probably OK, say if everywhere on the foil is connected to everywhere else with less than say 100 Ohms (my guess).
Where do you get the foil tape?
cheers
John
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Post by ozboomer on Oct 11, 2008 7:13:40 GMT -5
Its interesting to see what continuity you get through the joins. I reckon a few Ohms is probably OK, say if everywhere on the foil is connected to everywhere else with less than say 100 Ohms (my guess). Yup, that's about what it's running at. I'll keep workin' at it then, if we think it's Ok... Found the foil adhesive tape at Jaycar - 25mm or 50mm x30m length for about A$10/$15. -John
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