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Excalibur Potentiometers

T

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Anyone know whether the potentiometers within the Excalibur are all the same? I have seen posts where a modified version of the 39SB-1RB-104-ND potentiometer can be used for the threshold control but I was wondering whether this same potentiometer can also be used at the other control locations. I am thinking about changing all of mine if the 39SB-1RB-104-ND can be used.
 
two different ones.. I think the other number is 103, will have to check..

one is a 10 the other is a 100ohm
 
All are 100k ohms except the Volume which is 10k ohms.
 
Mel ..... whats the advantage of the volume being a 10? Seems having them all the same would reduce having to carry that size in stock.

Dew
 
It's a function of circuit design.
 
So the VOLUME control is 10k ohm (which equates to the 39SB-1RB-103-ND). The threshhold control and remaining controls are 100K ohms (which equates to the 39SB-1RB-104-ND). If I purchase these potentiometers, it appears that the only mod I will have to make to them is with respect to the potentiometer shaft length and engagement slot (at the end of the shaft). Can anyone confirm this?
 
This might work even better.
http://www.newark.com/bourns/39sb-1rb-103/rotary-potentiometer-10kohm-20/dp/32K8299?ost=39SB-1RB-103-ND
 
thread..... so they used the 10 because of the shaft length or was there a specific reason they did use 100 on them all? Would changing the 10 to 100 have any affect on the machine operation? Obviouly thread you are interested in changing it for a reason........ just a curious mind.

Dew
 
IRT Dew - I am not interested in changing the VOLUME to 100K ohms. I am simply trying to determine which potentiometers I need to buy so that I can change out all of them in one of my detectors.
 
https://www.youtube.com/watch?v=RqOOuiUhck4

You can pick up what you need at a hobby story, brass rod and tube..I have two machines running these, both the 104 nd 103,

do not solider. I used epoxy to bind the extension on.. one has broke loose in 2 years use now..no big deal, just pulled it a part and redid...

Changing a 10 to a 100 it will not work as normal. Sometimes you can get away with a small difference but 10 to 100 is like 1 mile to a 1000 mile in difference.
 
No, 39SB-1RB-104-ND is the potentiometer for threshold control. It requires a modification to the potentiometer shaft before you can use it.
 
Which if any are audio taper? I would think the volume would be.
What about a source for the all metal/ disc rotary switch?
 
https://www.youtube.com/watch?v=RqOOuiUhck4

http://www.mouser.com/ProductDetail/Bourns/39SB-1RB-104/?qs=2npYuRPwIzFFALZVmf1U%2FA%3D%3D
 
Unless I'm not understanding this, it seems to me there's three different potentiometer's. Disc/PP is one that seems different than the others, the disc and volume seem the same and the threshold and sensitivity seem the same. Am I missing something or am I correct?
 
Mel Parker said:
All are 100k ohms except the Volume which is 10k ohms.
Click to expand...
So here is what I get out of this:
Discrimination control - no switch, 100K - 39SB-1NB-104-ND
Sensitivity control - switch, 100K - 39SB-1RB-104-ND
Volume control - no switch, 10K - 39SB-1NB-103-ND
Threshold control - switch, 100K - 39SB-1RB-104-ND
Disc/Pinpoint switch - this one has me stumped. Photos on the net show a pot with a switch. But there is no pot function. So you don't want rotation just on/off. So what is the replacement part here?
Given the option by Bourns of different resistance tapers, has anyone tried audio rather than linear for any of these?
 
Now I see there is a stop on the connect shaft on the Disc:
http://www.treasurenet.com/forums/attachment.php?attachmentid=562434&d=1332393328
 
Ok, so the disc/pp pot is the same as the sensitivity and the threshold just with a stop so only the switch part of the pot is used? That would make sense.
 
surfman said:
Ok, so the disc/pp pot is the same as the sensitivity and the threshold just with a stop so only the switch part of the pot is used? That would make sense.
Click to expand...

Yeah, I didn't know because I only have the boards. Please confirm for me the value of the Disc pot as 100K(?). I haven't found 100k pots without the switch for sale so I guess we buy with switch and disable it.
 
I have no idea what resistance value any of the pots have. I read recently that there are 10k and 100k pots. Not sure which is which. I know there are some guys here that know all about it. I actually have one I just sent down to Kellyco to have a pot or two replaced. It's not all that expensive and they have all the correct parts and the people that know how to perform the repairs. Might be worth sending it to them to have it checked out.
 
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