Crock Pot Surgery!

[tedmich]

Hobbit finding expedition to 89° 41' W to 94° 42' W CANCELLED!

[Joe Gwinn]

Rival model 3100/1 Crock Pot may be controlled with a lamp dimmer

There is a reusables area at the local dump, where I found an old Rival crock pot (Model 3100/1). The barrel is 8.5 inches in diameter, and the unit is about as high as it is wide. The nameplate stats 120 volts, 60 Hz, 70-140 watts, AC only. I took the unit apart. It has two nichrome-wire windings in grooves in the crock, cemented down using furnace cement. One winding is 205 ohms at room temperature, and the other is 208 ohms, all controlled by a three-position switch. There are no electronic components, not even a diode, so the part about AC Only mystifies me. My guess is that the issue is corrosion over time from leakage currents, a big issue with DC power systems.

The switch has three positions, Off, Low, High. In Off, nothing is connected.

In Low (70 watts), the 208-ohm winding is connected and the 205-ohm winding is not connected.

In High (140 watts), both 205 and 208 ohm windings are connected in parallel, for an overall resistance of 105 ohms.

An ordinary lamp dimmer would work well with such a crockpot. Most convenient would be the in-line 300-watt lamp dimmer made by Lutron; this costs about $20 and can be installed in the power cord. Hardware stores often carry this unit.

Lutron Attaché® Lamp Dimmer Overview

[Steve A.]

An ordinary lamp dimmer would work well with such a crockpot. Most convenient would be the in-line 300-watt lamp dimmer made by Lutron; this costs about $20 and can be installed in the power cord. Hardware stores often carry this unit.

Thanks for the information. I was wondering if they have come up with a dimmer that doesn't cause single coil guitars to hum and buzz. I removed all of the dimmers in my condo and added diode switches to the line cords of my light bars. Unfortunately my neighbor's huge wide screen TV is about 3 feet from our common wall and makes my single coil guitars unusable when it is on. (Previous neighbors had the cable company move the outlet from the wall adjoining the garage to our common wall- there oughta be a law against that in condo CCR'S! There are rules against aural noise but not the noise from damn TV's.)

Another question: I understand how old CRT TV's would cause hum and buzz in single coil pickups, but why does my neighbor's 52" flat screen TV do that? When I switched my CRT computer monitors to flat screen LCD it eliminated all of the noise. (I will post more information about their TV since they still have the box in the garage we share.)

Steve Ahola

[Joe Gwinn]

Thanks for the information. I was wondering if they have come up with a dimmer that doesn't cause single coil guitars to hum and buzz. I removed all of the dimmers in my condo and added diode switches to the line cords of my light bars. Unfortunately my neighbor's huge wide screen TV is about 3 feet from our common wall and makes my single coil guitars unusable when it is on. (Previous neighbors had the cable company move the outlet from the wall adjoining the garage to our common wall- there oughta be a law against that in condo CCR's! There are rules against aural noise but not the noise from damn TV's.)

Higher quality dimmers cause less noise. But, it sound like you need to shield the cavity where the singlecoil lives, including the pickguard. And ground the strings and other hardware.

A Lutron lamp dimmer controlling a Crock-Pot is unlikely to cause your singlecoil any problems, because the total dimmed circuit is so small.

Another question: I understand how old CRT TV's would cause hum and buzz in single coil pickups, but why does my neighbor's 52" flat screen TV do that? When I switched my CRT computer monitors to flat screen LCD it eliminated all of the noise. (I will post more information about their TV since they still have the box in the garage we share.)

At 52", and the noise problems, I'd guess it's a plasma unit. These use fairly high voltages and power levels.

Again, guitar shielding is most likely needed. The problem is most likely electrostatic interference, against which a humbucker is useless if not shielded.

But, do unshielded humbuckers have the same problem?

[Steve A.]

Higher quality dimmers cause less noise. But, it sounds like you need to shield the cavity where the singlecoil lives, including the pickguard. And ground the strings and other hardware.

Most of my guitars and lap steels are shielded with copper foil tape but some of them aren't. The shielding doesn't seem to make as big of a difference as the HB vs single coil issue. With lap steel the pickup is facing up and for some reason that is the direction that picks up the most hum. With regular guitars you can usually rotate 180 degrees and find a spot where the noise is minimized; I don't really have that option with a lap steel. However, one of the projects I am working on is a floor mounted dummy coil for console steels and pedal steels. If the basic test unit works then I will wire one up as per the Suhr/Chiciachi design.

An unshielded guitar with a humbucker will pick up a little bit of crap here but nothing like the SC's. I have a personal grudge against light dimmers because two of the bars I play at thought it would look really great to hook up all of their lights to dimmers without considering the effect it might have on guitarists using single coil pickups. (On the bright side those "bars from hell" have given me the opportunity to test out my dummy coil designs. )

Thanks!

Steve Ahola

[J M Fahey]

*Excellent* idea, but rather than a "floor mounted" one which might be too far away to pick exactly the same that's bothering you why not a dummy coil on the guitar itself?
Same coil and magnetic circuit but of course no magnet.
If ceramic, simply omit it; if Alnico, replace it with some SAE 1010 iron.
This will guarantee they are identical twins and can be place quite close to each other, since one of them is string deaf.
jm2c

[Steve A.]

*Excellent* idea, but rather than a "floor mounted" one which might be too far away to pick exactly the same that's bothering you why not a dummy coil on the guitar itself?
Same coil and magnetic circuit but of course no magnet.
If ceramic, simply omit it; if Alnico, replace it with some SAE 1010 iron.
This will guarantee they are identical twins and can be place quite close to each other, since one of them is string deaf.
jm2c

Been there. Done that. All of my previous experiments used dummy coils made from pickups like a P-90 with the magnets removed- like my LP Jr:

http://www.blueguitar.org/new/articl..._revisited.pdf

An identical coil wired in series does alter the tone- to my ears it makes it a little darker and more compressed. The Suhr system using the Chiliachi patent uses a low impedance coil of a heavier wire, such as one 250 ohms/39GA to match a sensing coil that was 8k/42GA:
http://www.blueguitar.org/new/misc/p...chiliachki.pdf

I got a 1/4lb roll of 38GA magnet wire from eBay and wound a 570-turn coil on an aluminum can which worked out to 330 ohms and dipped it in wax in my Little Crock Pot to hold it together when I removed the can. It doesn't quite fit in the control or pickup cavity of its intended host, a 1960 Valco Alkire 10 string E Harp...

... so I decided to try putting it in a floor box (a project that is on hold right now as I am moving everything around in my condo- I figured that I might as well put my test bench on the wall next to their TV hoping that the hammering and drilling and routing will encourage them to move their TV elsewhere, like another state. )


The Chiliachi patent has the low impedance dummy coil mounted in series with the sensing coil, using two pots, one to change the intensity of the effect by bypassing the dummy coil and the other wired up to that pot as a tone control is wired up to a regular volume control (however its effect is the opposite as it will brighten the sound as you turn it down.) I had to rewire the output jack by using a stereo jack and connecting the signal return of the pickup to the ring (with a mono cord plugged in the signal return is connected to ground for normal operation.)

Evidently one of Suhr's partners has started his own company using a different approach. While the Suhr system mounts a small dummy coil on the spring cover of a strat, the new company uses a much wider coil that goes around the pickups in a strat which supposedly works better than the smaller coil. Which got me thinking- a much larger coil could be mounted in a small channel routed underneath the fretboard on practically any steel guitar (although it would look better if the fretboard was opaque.) Trim pots could be added in the control cavity, or replaced with fixed resistors once the optimal settings were determined.

Not wanting to be rudely off-topic I think I will use my Little Crock Pot to heat up some soup for lunch.

Steve Ahola

[big_teee]

I'm the OP and we have covered so much ground it Don't Matter No More!
Why not just use Humbucking pickups, instead of all the trouble to make the dummy coil.
I have recently been making the mini blade pickups, for strats and Tele's and I just love them.
They are 2-3 times more hum free than regular sized humbuckers.
I was told it is because the coils are different on full sized humbuckers.
One having screws, and one having slugs.
But, that doesn't seem to be the case because I have humbuckers with double slugs, and double screws.
They are working ok, but the rail type P/Us for a strat are much quieter in the same noisy environment!
So If I was making lap steel P/Us, I would sure recommend trying the Rail Buckers.
Maybe they are not Vintage Politically correct?
T

[Steve A.]

Why not just use Humbucking pickups, instead of all the trouble to make the dummy coil.

I don't make pickups- I molest them!- but sadly enough there is no Pickup Molesters forum here.

I have used SD Hot Rails pickups in modern lap steels that use a strat-sized pickups and they work great (especially with a series/parallel switch) but there are very few drop-in replacement pickups for 8 or 10 string steel guitars, or for many of the 6 string models that use non-standard pickups. Hence the need for an add-on dummy coil (the only alternative for most lap steel players would be to have a custom double coil pickup built for them.)

There is one very popular steel guitar pickup built by George L using rails so it can accommodate different string spacings. While the Emmons style E-66 is the most popular, I really like his 10-5 which has six leads from two tapped coils. The wiring possibilities are amazing. Here is a little trick for rails pickups: instead of linking the two coils in series insert a small ceramic capacitor between the two coils. George L calls it the inductive-capacitive linkage. He uses a small 110pF cap for a thinner tone but I am using a 220pF cap which gives a really nice humcancelling tone in addition to the series and parallel linkages. One more trick if you use tapped coils-his are 8k (Bk) and 6k (Red) with White being the hot for the 1st coil and the ground for the other: connect the Bk wire of Coil #2 to ground and the BK wire of Coil #1 to the Red wire of Coil #2. It has a little "quack" in there but is only partially humcancelling.

Steve Ahola

[big_teee]

My new Rails I put in a Loaded PickGuard are less DCR than that.
I deguass the magnet some, and have the rails tapped for Single coil type operation.
With the mini down, It is like 3 single coils, SSS with hum canceling in Pos. 2 & 4.
With Mini up you have 2 Rails and on SC, RSR.
I've had lots of fun messing with them.

T

[Steve A.]

My new Rails I put in a Loaded PickGuard are less DCR than that.

I was sure that the DCR resistances of your pickups were less than George L's*** but you could use the same ratio if you wanted to tap your coils. But whenever you get a chance try inserting a 220pF ceramic cap between the two coils for what would have been the series linkage. Try it, you'll like it! I'm hooking my 10-5 up to two push pull pots so I can get the normal series linkage, the normal parallel linkage plus the series cap linkage and a single coil (the one closest to the fretboard. 4 very distinctive sounds- all killer, no filler! (I'd need to use a 2P6T rotary switch to get the series/parallel linkage described previously using the Red wire/lower DCR tap- I'm not crazy about the other tapped options.)

Steve Ahola

P.S. Your pickguard looks great! I was wondering why there was a phillips head screw on top of the tone control but then I figured out that it was my mouse cursor! So what does RSR mean in your post? Amd did you use a regular 5 way strat switch or some sort of mega switch?

*** I don't usually like pickups with a 16k DCR- too dark and muddy for my taste- but the George L pickups are not like that at all. His 10 string pickups are 3 7/8" long so you would expect the DCR to be higher but not that high. Perhaps his magnets are weaker than usual- I dunno.

[big_teee]

I was sure that the DCR resistances of your pickups were less than George L's*** but you could use the same ratio if you wanted to tap your coils. But whenever you get a chance try inserting a 220pF ceramic cap between the two coils for what would have been the series linkage. Try it, you'll like it! I'm hooking my 10-5 up to two push pull pots so I can get the normal series linkage, the normal parallel linkage plus the series cap linkage and a single coil (the one closest to the fretboard. 4 very distinctive sounds- all killer, no filler! (I'd need to use a 2P6T rotary switch to get the series/parallel linkage described previously using the Red wire/lower DCR tap- I'm not crazy about the other tapped options.)

Steve Ahola

P.S. Your pickguard looks great! I was wondering why there was a phillips head screw on top of the tone control but then I figured out that it was my mouse cursor! So what does RSR mean in your post? Amd did you use a regular 5 way strat switch or some sort of mega switch?

*** I don't usually like pickups with a 16k DCR- too dark and muddy for my taste- but the George L pickups are not like that at all. His 10 string pickups are 3 7/8" long so you would expect the DCR to be higher but not that high. Perhaps his magnets are weaker than usual- I dunno.

SSS (Single, Single, Single) RSR (Rail, Single, Rail)
Which would be Same As HSH.
My rails are wired with 4 wire hookup for Coil Tapping.
My Question, Who is a George L?
The options you mentioned are getting too complex to do everytime, I sell one in the Local Guitar Shop.
It takes me a while to build one of these Loaded Pickguards, since I make the Pickups, drill cut a wire everything.
I buy a regular American Strat PickGuard, then go from there.
I do extra shielding and have to enlarge the bridge and Neck P/U Holes to get the larger bobbins in the holes.
The Flatwork doesn't fit the magnets and bobbins so a lot of dremel work on that.
I have a cheapie test Strat guitar Arriving tomorrow.
It will be to leave at the Guitar Store to test the RSR, SSS arrangement, to encourage Pickguard sales.
Keep Rockin!
T
**edit
I found the George L website.
Looks like lots of stuff for Steel guitarist!

[copperheadroads]

I'm either waiting for a wax chunk to melt or a molten pot of 200 degrees wax to cool down ...too many late nights what's the next step to keep it at a desired temp 148f

[Steve A.]

I'm either waiting for a wax chunk to melt or a molten pot of 200 degrees wax to cool down ...too many late nights what's the next step to keep it at a desired temp 148f

You are referring to the tiny one that holds 16 oz- right? Best suggestion I have heard so far is to hook it up to a light dimmer. You could mount it in a 4x4 box with the dimmer on one side and a duplex outlet on the other. I would have one of the outlets full voltage and the other connected to the dimmer... and would forget which one was which all of the time!

Steve Ahola

[copperheadroads]

You are referring to the tiny one that holds 16 oz- right? Best suggestion I have heard so far is to hook it up to a light dimmer. You could mount it in a 4x4 box with the dimmer on one side and a duplex outlet on the other. I would have one of the outlets full voltage and the other connected to the dimmer... and would forget which one was which all of the time!

Steve Ahola

I USE A smallish sized crocpot
I made a light dimmer when i built my amp I might have to experiment