How can I make this switch usable?

[Mike_J]

Purchase this switch to put in a box. Will connect the thing to a couple of wires with alligator clips on them. Supposedly 250VAC. Supposedly 12 positions but I am only counting 11 which probably isn't the end of the world.


Want to use it to test caps from 47pF to 130pF in case I get a fuzzy overdrive and/or ice picky amp. Apparently the cure for these syndromes is to increase the value of the capacitor across the plates of the PI. Apparently once you get near 100pF you start to get into audible territory so this and probably a combination of something else up the chain may be needed. Explanation I saw is it is best to make adjustments like this as far back in the circuit towards the power section as possible for the sake of the amps tone and the PI is fairly far back. Don't know how true it is but I am certainly willing to test it.


Problem I am having is how are you supposed to connect the pF caps to these things sticking out of the switch. They have no loops in them to solder to. You can get some with solder tabs if you are willing to order a million of them or some quantity that might as well be a million. Any suggestions would be greatly appreciated.


Thanks
Mike

[thetragichero]

remember that there's no designated "off" so fully clockwise and fully counter-clockwise are positions (I've done the same thing with 6 position rotary switches, thinking i only had 5)

[Mike_J]

remember that there's no designated "off" so fully clockwise and fully counter-clockwise are positions (I've done the same thing with 6 position rotary switches, thinking i only had 5)

Thanks thetragichero. Any idea on how to get a silver mica cap soldered to it. Suppose I could get a little solder on the end of the cap lead then heat the pin up and stick them together. Bought two of the switches thinking I might burn up the first one experimenting with it. Didn't think I could also burn up the silver mica caps experimenting with it. Going to have to develop a good system because I am confident this will be a better than average tool to have if it is made correctly.


Thanks
Mike

[jjasilli]

how are you supposed to connect the pF caps to these things sticking out of the switch.
First tin both the lug, and end of in the lead of the cap.  Hold the end of the tinned lead touching alongside the tinned lug.  Touch with the hot tip of your soldering iron.  They will melt together.  Don't overheat, or the molten solder will take too long to cool.  You'll get a feel for this.  Don't move the parts while the solder cools, as this risks a bad (cold) solder joint.  To speed cooling you could use a damp sponge.


If you must, you could wrap and crimp the cap lead around the SW lug before soldering.  Shouldn't be necessary.


You may wish to consider shrink wrap around the cap leads if there's a danger they will touch ea other.


BTW: some vintage electronic devices had rows of straight lugs, no holes, etc.


EDIT:  you could a small alligator clip, or forceps, near the body of the cap as a heat sink to protect the cap. 

[Mike_J]

how are you supposed to connect the pF caps to these things sticking out of the switch.
First tin both the lug, and end of in the lead of the cap.  Hold the end of the tinned lead touching alongside the tinned lug.  Touch with the hot tip of your soldering iron.  They will melt together.  Don't overheat, or the molten solder will take too long to cool.  You'll get a feel for this.  Don't move the parts while the solder cools, as this risks a bad (cold) solder joint.  To speed cooling you could use a damp sponge.


If you must, you could wrap and crimp the cap lead around the SW lug before soldering.  Shouldn't be necessary.


You may wish to consider shrink wrap around the cap leads if there's a danger they will touch ea other.


BTW: some vintage electronic devices had rows of straight lugs, no holes, etc.


EDIT:  you could a small alligator clip, or forceps, near the body of the cap as a heat sink to protect the cap.

Do you think I could use forceps to hold them together, after they have both been tinned. As you suggested, hook a small alligator clip near the body of the cap as a heat sink to protect the cap. Also agree should either use some excess Teflon or shrink wrap to keep the leads from touching. This definitely can be done.


Waiting on my neighbor to get his new metal roof put on. Am taking a box from this cheap tester I bought years ago. Need to replace the top though where the switch would be connected. Tried the flashing I used to keep the squirrels out but it is much too thin for what is needed. Hopefully they will get started on the roof pretty soon. All the materials are lying in his driveway. Need so little to make a cover for the box. Think I have another of those cheap boxes around. Need to make sure I get material for a cover for it as well.


Thanks
Mike 

[thetragichero]

if i order the wrong part (i consider lack of holes for components the wrong part) I'll bend the bottom into a little J and bend the component into a J so that i can crimp them together and get a decent physical connection before soldering

[jjasilli]

I wouldn't use forceps to hold them together- would probably interfere with the soldering.  Find a way to hold the SW steady.  In a vise or mounted somehow on a plate or chassis, held steady, with easy access to the lugs.

[Mike_J]

if i order the wrong part (i consider lack of holes for components the wrong part) I'll bend the bottom into a little J and bend the component into a J so that i can crimp them together and get a decent physical connection before soldering

I would generally agree with you if it was in an amp that could be thrown around going to gigs. This is going to be placed in a small box and used very infrequently. I was more concerned with the voltage it could handle than anything else. Think using the method jjasilli suggests will be adequate for its purpose.


Thanks
Mike

[Mike_J]

I wouldn't use forceps to hold them together- would probably interfere with the soldering.  Find a way to hold the SW steady.  In a vise or mounted somehow on a plate or chassis, held steady, with easy access to the lugs.

I can do that.


Thanks
Mike

[HotBluePlates]

... how are you supposed to connect the pF caps to these things sticking out of the switch. They have no loops in them to solder to. ...

That switch was made for a printed circuit board.  The straight tabs went through matching holes in the board.

Yes, you can still make it work, but as others say you have to be creative.

[Mike_J]

... how are you supposed to connect the pF caps to these things sticking out of the switch. They have no loops in them to solder to. ...

That switch was made for a printed circuit board.  The straight tabs went through matching holes in the board.

Yes, you can still make it work, but as others say you have to be creative.

I am willing to be creative even considering its limited use. Will build a board with 3/32" eyelets. If I am reasonably precise both the outside lugs and the pF caps will fit it the same hole. Will use a 1/8" eyelet for the center lug on the switch so there is room for a wire to connect it to a first alligator clip. Will make a second board for the other side of the cap leads to enter. Will use 1/8" eyelets here since they all have to come together into one point to connect to a wire that will go out to a second alligator clip. If I had a bigger eyelet I would certainly use it. Will use the ink pen method of spacing this whole thing in the box so it fills the entire depth of the box.


Thankfully, some of my daughters are coming home for Easter, one of whom is a mechanical engineer. I will ask her what she thinks of the adequacy of my plan. As for me I am pretty sure it would survive an atomic blast but that is just guessing. All for something that may be used a half dozen times.


Thanks
Mike

[Mike_J]

Now I am going to need to add rubber feet so the screws I will use to hold the contraption and the spacers to the bottom of the box won't accidentally scratch my wife's table. Would have more trouble than I want or need if that happened.

[Mike_J]

Thought of a possible option to the rubber feet, a third board. Its only purpose would be to keep anything on the bottom from touching anything conductive which it wouldn't because the box is plastic. No rubber feet or third board needed. Will need to find some ink pens to use for spacers and for the next door neighbor to get his roofer on the ball so I can get the metal I need for this thing. Around here if the fish are biting you may not see those fellows for weeks.

[Mike_J]

Spent a couple of minutes making the boards for the pF tool I am making. The board that will hold the switch is shown below. The other board just has four 1/8" eyelets in it which will hold the other end of the caps. Kind of glad I did this. Didn't take long and will be significantly more substantial than what was planned before.


Thanks
Mike