coaxial ceramic resonator oscillator

CCR_600/CCR_600.JPG

CCR_600/CCR_600.zip

I remember seeing product announcements decades ago. Or maybe "this'll be great -- someday" press releases.

Do you have any fielded, or at least on boards? How are they after you pull the frequency to exactly where it needs to be?

Another one of Larkin's "I need to pimp my ego" posts of the day.

If there's any _real_ interest I can pull up some of my designs from many years ago at AZM... Harold Muller has retired. ...Jim Thompson

Am 01.08.2016 um 21:56 schrieb John Larkin:

OMG. I have seen users of these in REALLY bad mood recently. Never 2 oscillators on the same frequency on 1600 MHz. They had to get lots of capacitors in the 0.3 pF range to tune, all space qualified and you really are not supposed to solder twice in the same location. Takes a lot of paperwork.

I have the fun to wrap the PLL around these.

regards, Gerhard

CCR_600/CCR_600.JPG

CCR_600/CCR_600.zip

I suppose if you were forewarned you could have several parallel cap locations, and a process (i.e., put a small cap on, measure the frequency change, do some math, put the next cap on, repeat, and hope that the third time's a charm 'cuz that's your last open pad).

Or some bizarre adjustable cap on a probe, to establish the correct value...

Can you laser-trim caps on a space qualified board? Get one of the old ESI trimmers (or a new one if they're still made) and just keep zapping until the frequency's up to snuff?

We have one product that uses them. It's over 10 years old but we still sell some. In that case, we didn't pull the frequency... we just lived with whatever it was.

These things are used a lot, in bandpass filters and diplexers and such, mostly in the low GHz range. Those resonators are much smaller than my 600 MHz guy, which is about 3/4 inches long.

They are available at 2% and 1%. Plus, you can theoretically tune them by scraping off silver plating with an x-acto knife.

We've used 1400 so far. The only problem was finding the right solder, that wouldn't dissolve the silver plating. Like those old Tek terminal strips.

On my next project, I'll coarse-tune them with an SPI digital capacitor.

Am 01.08.2016 um 23:01 schrieb Tim Wescott:

An empty 0603 location is already in the 0.3 pF region. You cannot have many of them.

They have a capacitor-on-a-stick set from ATC, that helps a lot, but not with such small values. That is not really repeatable.

Nevertheless I have made some of these sticks for my own lab from Qtips and Erie RedCaps etc, epoxy glue and shrink-hose(?). Then I measured the final exact value on the bridge. They can be a tremendous help, at least at a few 100 MHz, for quickly tuning filters...

If one finds somebody who characterizes the process and does all the paperwork, reviews, and then somebody willing to pay for it.. So, the short answer is NO.

regards, Gerhard

I think you mean heat-shrink tubing.