Pot Value Double Check

[Leon Of Late]

I ordered some CTS 450G Series 250K Vintage Style Short Split Shaft Pots for my Strat, as I need to replace one of the pots. I ordered 3 just to have some spares on hand. Anyhow, it’s been years since I’ve had a 250K pot, but it doesn’t say 250K on the back. It says 25K, is that right? I thought it should be marked 250K.

I just want to be sure they sent me the right stuff. Thanks.

 

[Ace Flibble]

It should definitely say 250K. 25K pots do exist; they're used for active pickups and some Jazzmaster/Jaguar-style 'rhythm' circuits. They are not fit replacements for a common 250K pot.

 

[beaubrummels]

On CTS, the full part number tells you exactly what it is.

The first number is the base model of the pot (450 is a flat solid back, 500 is vintage dish-back)
The next letter is the lug style (T is a solder lug)
The next number is the mounting style (brass bushing, die cast, molded, etc.)
The next number is the shaft length
The next letter is the shaft type
The number after that is the resistance code (253 would be 25k, 104 is 100k, etc.)
The letter after that is the tolerance (A is +/- 10%, B is +/- 20%)
The next number is the taper (1 is Linear, 2 is 10% audio, 3 is 10% audio CCW)
The next letter is any switch actuation (A is none, B is SPST rotary, etc.)
The last number is any special features (1 is left side lug, 4 is right side lug, 5 is no locating lug, etc.)

Not all indicators may be present all the time. Some models may use a different order to those code segments, which means you really need the data sheet or the part drawing to read the model number.

The 25K is not the resistance. 25 is a code indicating the shaft length (you need the data sheet to figure out exactly what it is) and K means "knurled shaft"

The best thing to do is just measure to make sure it's 250k, if you have a doubt.

EDIT: looks like they've updated the sheets since I ordered my run.

https://www.ctscorp.com/wp-content/u...heet-Rev-B.pdf
2 is a .25" bushing length
5 is a .625" shaft length
K is split knurl

 

[Leon Of Late]

Here is a pic of the back of the pot, this should help:

 

[idsnowdog]

What does it read on a multimeter?

 

[Leon Of Late]

254A2L. 10% tolerance Linear audio taper. If 253 means 250K, I hope 254 isn’t too far off. Thank you for posting that info.

I don’t have a meter.

 

[beaubrummels]

254A2L. 10% tolerance Linear audio taper. If 253 means 250K, I hope 254 isn’t too far off. Thank you for posting that info.

I don’t have a meter.

254 is the code for 250kohms

FYI - the third number is the number of zeros, so

253 = 25000 ohms, or 25k
254 = 250000 ohms, or 250k

 

[Leon Of Late]

254 is the code for 250kohms

FYI - the third number is the number of zeros, so

253 = 25000 ohms, or 25k
254 = 250000 ohms, or 250k

I misread your value in your first post for 253. Thank you for the info. I appreciate the help. It’s like decoding secret code just to figure out the resistance value.

 

[beaubrummels]

I misread your value in your first post for 253. Thank you for the info. I appreciate the help. It’s like decoding secret code just to figure out the resistance value.

Yeah it takes a while to get it. It's an industry standard. It's so they can print the values on small components regardless of how big or small the resistance / capacitance values are.