Precision trimmers Bourns 3296 vs 3299

[Mr Simpleton]

I am currently renovating  several PTS1000 signal generators, and they use 50 (fifty) Bourns 3299 trimmers for coarse setting of VCO
Now the 3299-serise seems to be a lot more expensive and harder to find (at least "my" values) vs the 3296-series

Reading data sheets, it seems it is a drop-in replacement as the only difference seems to be a thinner housing on the 3296. But is there any advantage to keep looking for 3299-potentiometers? Key parameters are noise and keeping performance over time.

I rather do this right the first time. Not too fun replacing 50 pots.... on ten units. Leave the math for the reader

Should add: The PTS1000 comes with the 3299.. hence the query 

[Psi]

Looks identical to me, other than the size as you say.

[markce]

900VAC - 600VAC, 25 turn - 12 turn. Contact resistance variation 1% - 3%
The 3299 is more precise the 3296 more enduring (temp, vibration).

[Mr Simpleton]

@Markce Not sure where you found those specs.... I had a look at:
http://www.bourns.com/data/global/pdfs/3296.pdf
and
http://www.bourns.com/data/global/pdfs/3299.pdf
They look pretty identical except for weight and size!

I still have to make sure the 3296 is just as good as the 3299, the size is smaller and will fit the PCB, I just have to be sure it will be performing like the 3299 (or better ) BTW the 3296 seems to be MIL-listed.

Cheers

[markce]

It's in the left column under 'Electrical Characteristics'.

[Mr Simpleton]

Not trying to be a smart alec...
I see no electrical difference between these two... both are 25 turns and both shows 900VAC dielectrical strength, if looking at the PDF-links I posted.
Are there other specs available that differ the data sheet? 

[markce]

My 3269 datasheet is for the X style, which is the current product I found. Yours is for the W style, and these apparently also differ electrically. Found the Bourns trimpot catalog on the Farnell site.
http://www.farnell.com/datasheets/681515.pdf

[Mr Simpleton]

@Markce, are you aware that we discuss 3296 vs 3299 not 3269 

BTW all my docs are straight from Bourns... not a retailer 

[dacman]

I'd use them, but what I'd be concerned with is would the 3296 rock on the board due to it being narrower.  A cross for the 3299 used to be the 68 series, although its data sheet presently states that it has 20 electrical turns.

[markce]

Sorry, seems to be a typo when searching initially...

[Mr Simpleton]

Thanks for all information.... not sure it is economical viable to use the 3299 series, it seems to be 2-3 times more expensive and longer lead times. I have to settle for the 3296 and try to secure from vibrations.

Cheers