TKD 2CP-2511 measurements?

[bazelio]

So I have a new TKD 50k 2CP-2511 and I'm seeing very strange measurements on the meter. Starting from the fully counterclockwise position, it measure 42k. As I slowly turn it clockwise, the resistance increases to 60k, then starts to gradually decrease. When it gets back to 42k, it's about about the 1/2 mark, and the last 1/8" or so drops rapidly from about 13k to almost 0.

This seems defective. I see no taper profile on the TKD datasheet that looks anything like this. Also, I just replaced the batteries in the DMM, and the measurements are repeatable.... so I don't think I'm out to lunch.

Is there anything to do other than return this?

 

[cwtim01]

I got a few 10k CP-2511 from Japan more than a year ago, and they had very similar behaviors.

I concluded that they're either rejects or fakes, so I disposed them and declared total loss. If you could still return it, it's probably a good idea.

 

[bazelio]

This one came from Michael Percy, and I've sent him a note. Based on the measurements, it's totally worthless.

 

[bk856er]

I believe that is how these TKD pots measure out of circuit and is normal for their design. I recall also getting some goofy measurements and worrying about it, but it worked beautifully in the application!

BK

 

[ErikdeBest]

Hi, have a look at this link
http://www.diyaudio.com/forums/parts/140241-faulty-tkd-potentiometers-video-link.html

 

[bazelio]

Michael Percy sent me this:

 

[popchops]

There is a warning on the TKD website that might be relevant:

http://www.tkd-corp.com/otherpdf/Important_points_LADDER.pdf

Pops.

 

[Technical Petting]

Wow, I feel really bad for Tim here. I hate it when all the evidence points one way clearly, then it turns out you were misinterpreting everything from the start. I might have done the same.

The correct info is on the German distributor's website, but why should you have to see it there? They should really make this more clear. Who installs things without testing them?

I got a few 10k CP-2511 from Japan more than a year ago, and they had very similar behaviors.

I concluded that they're either rejects or fakes, so I disposed them and declared total loss. If you could still return it, it's probably a good idea.

 

[Refugee1]

I would never call that component a pot at all.
It is more like an attenuater as would be found on the output of a signal generator but without discreet steps.
Selling it as a pot is just plane confusing.
It should work fine as a volume control.

 

[soulmerchant]

Wow, I feel really bad for Tim here. I hate it when all the evidence points one way clearly, then it turns out you were misinterpreting everything from the start. I might have done the same.

The correct info is on the German distributor's website, but why should you have to see it there? They should really make this more clear. Who installs things without testing them?

It's on partsconnexion website that sells them as well, and I think a few ebay sellers note it as well.

I got a few of these when I was in Japan, and the seller there had a little note (in Japanese only though).

I find them really quite decent btw.

 

[starcat]

Just found this thread and as I was researching this matter, just wanted to warn you that with the same number 2500, there is a pot *and* an attenuator.

2500 Potentiometer
2500 Attenuator

and there is also a 2511 as well.

 

[EUVL]

The difference between ladder circuit (attenuator) and true potentiometer can be seen in the part number.

For the potentiometer types, there is an alphabet specifying the type of taper, for example
2CP2500-B10k
means it is 2 gang, 25mm size, 300° rotation, taper B (potentiometer), 10k resistance.

The ladder type has no alphabet before the resistance, e.g. 2CP2500-10k

2511 means the rotation is 315° instead of 300°.
http://www.tkd-corp.com/products/att/pdf/cp2511as-e.pdf

There is also a 2P2511 (without the C), which is a switched (series) potentiometer with discrete resistors.
http://www.acoustic-dimension.com/tkd/2P2511.pdf

It is a potentiometer (not ladder circuit) but no choice of taper.

I have to admit that they have not made it easy for the end users to choose the right type,
One has to watch every alphabet / number with care.


Patrick