Tww

Not sure I got what tww is (looked it up, some domino thing so I guess I get it if so) but 0402 are significantly worse, a lot more than twice worse. And I have not yet done any 0201...

I highly recommend a good set of curved jaw tweezers, with a tiny binder clip on the hinge end. That lets you micro-adjust the tension by sliding the clip, so that they open when you squeeze them edgeways, and close very gently when you release.

Good Medicine.

Cheers

Phil Hobbs

When I first saw 1206's, I thought they were tiny. Ha!

I refuse to use 0402's. I default to 0805s.

I'm tuning the tempco of a 50 MHz triggrered Colpitts oscillator. What a nuisance. It should have a 3.3 pF N4700 0805 cap, but the layout guy used all 0603s, so some engineer (who shall not be named) substituted an 0603 NP0. "NTC" does sound a lot like "NPO" I guess.

The proper 0805 cap was custom brewed for us by Capax.

This sounds interesting, would you please post a photo? I manage with my normal tweezers, two of those I have are good enough to get me through placing placing a lot of 0402-s, not too hard especially if the paste has not begun to dry so they stick. But yours might be helpful on less standard operations...

I often do it the other way around,the 0805 pads I make can also hold

0603. Took me a while to grasp I could do it the first time I could not find the 0805 I needed...

The temp compensations I typically have to deal with are resistor tracking. Meanwhile I know which batch of which supply I have does not track too well with which other.

Yes. It uses a SAV551 phemt as a source follower driving the usual two caps back into the tank.

Here's my temp chamber.

I blast it with a heat gun or freeze spray to evaluate tempco. This gadget has a pretty narrow pull range PLL to lock the triggered LC oscillator to a crystal oscillator, and it will fail lock if temperature changes the LC osc frequency more than maybe 1000 PPM.

We use a digital capacitor to center the frequency to close to 50 MHz at powerup, but then it's usually cold, and can't drift more than the

1000 PPM after that.

Tedious.

DOGBERRY: But truly, if I were as tedious as a king, I would find it in my heart to give it all to you, your Worship. LEONATO: All thy tediousness on me, ah?

I assume that board has an MCU and with many now including on chip temperature measurement can you use the digital capacitor to do the temp compensation in software?

piglet

Something like these:

. You take off the silver handles and just use the black spring part. That and a little jar of acetone for cleaning flux off the tweezers makes an excellent combination that reduces the tiddly-wink problem by a lot.

Cheers

Phil Hobbs