EMRFD Message Archive 5937
Message Date From Subject 5937 2011-03-21 17:58:38 kilocycles Custom crystals 5 or 6 years ago, I bought some crystals for a Drake R-4B special order from QuartSlab.com. 35 years in business under "the 3 Daves", who are hams. They are in the UK, so prices in USD depends on the exchange rate.
6284 2011-05-14 12:00:26 rcbuckiii Custom crystals Has anyone ordered custom crystals from any of the manufacturers? I have looked at the websites of several (Crystek, ICM, JAN, etc) and they do not mention price. They all want you to submit a request for quote.
I only need 2 crystals for 2 different frequencies and 1 of another frequency. I wonder if the low quantity will make them $50 crystals. Or will the price range be a more reasonable $15-$20?
I realize they have setup costs involved. But I do not know the process for manufacturing crystals. Possilbly it is a computer controlled process where they just enter numbers for etching times so setup is minimal. Or it may be more involved than that.
I've considered using programmable oscillators similar to the Epson SG-8002 but the noise figures look too bad to be used as a local oscillator.
6285 2011-05-14 12:07:15 bobtbobbo Re: Custom crystals 6286 2011-05-14 12:16:32 w4zcb Re: Custom crystals ICM runs about $22 each, special ones, (cut for low phase noise or
specific overtone operation) adds 5-6 bucks to the tab.
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6287 2011-05-14 12:19:31 bobtbobbo Re: Custom crystals 6288 2011-05-14 14:22:09 dave Re: Custom crystals You can get a Si598 good to 260 MHz for $9.98 or an Si570 for about $16
that's good to 160 MHz. Phase noise is good, though not as good as a fixed crystal.
Dave - WB6DHW
6289 2011-05-14 14:34:29 Tim Re: Custom crystals I haven't priced out crystals but most custom ones will be in the $30 ballpark and up these days in small quantities, and lead time will be a few weeks. The one less expensive source that I know of, is Quartslab (which gives prices in UK Pounds): http://www.quartslab.com/
Not quite custom but many "common" ham radio frequencies are stocked and sold by AF4K for reasonable prices e.g. $14 at http://www.af4k.com/567MHz_crystals.htm
Otherwise most of us are picking through the microprocessor/standard crystals in the Mouser/Digikey catalogs and designing the rig around those frequencies for IF etc.
6290 2011-05-14 15:03:19 n7net Re: Custom crystals I ordered a couple from JAN a long time ago. The prices were different, hinging 6291 2011-05-15 08:36:41 rcbuckiii Re: Custom crystals Thanks everyone for the comments. Quartslab pricing puts them just under $20. I will have to check out their shipping charges to U.S. and see what total cost would be.
Dave, I've thought about playing with the Si598 before but have not had much luck in finding a distributor to the part.
6294 2011-05-15 10:02:55 AD7ZU Re: Custom crystals I've thought about playing with the Si598 before but have not had much luck in
finding a distributor to the part.
6296 2011-05-15 11:47:01 dave Re: Custom crystals Ray:
You can buy Si598 from the Silab web site. I ordered 10 for the club build.
Took about a month to get them.
Dave - WB6DHW
6297 2011-05-15 12:01:12 dave Re: Custom crystals Randy:
Sadly, Silabs no longer provides free samples of the Si598 or the Si570.
That happened shortly after I started selling the UHFSDR, which is based on a
grade A Si570! You can buy samples starting from the page you referenced.
You can get free samples of the non-programmable oscillators. We got free
samples of the Si595 and the Si550 for our BFO's.
Dave - WB6DHW
6298 2011-05-15 13:52:09 AD7ZU Re: Custom crystals bummer ..
I wanted one each Si514/Si570/Si598 to eval for a project i was working. but had
6299 2011-05-15 20:32:44 Darrell Bellerive Re: Custom crystals Our club has ordered custom crystals for our repeaters from
Not sure what their current prices are, but they were reasonable a few
years ago when we ordered them.
Amateur Radio Station VA7TO
6301 2011-05-16 04:02:43 drmail377 Re: Custom crystals Last time I looked (fairly recently), Tom Hoflich (KM5H) was selling Si570's off the shelf in small quantities and at reasonable prices.
His newer site:
If you want to experiment with the Si570, I suggest you read the latest data sheet carefully (www.silabs.com). I also suggest you use a micro-controller development environment that supports double-precision out of the box (unless you want to write your own extended precision routines!) If memory serves, for sub-Hertz control you need be able to calculate the value of a 38-bit register.
There's a nice working example of a USB Si570 controller in the ATMEL ATtiny85 8-bit 8-pin based controller for the latest Softrock Ensemble-II SDR's. The documentation, binaries and source code is available on Fred's (PE0FKO) web site. This software includes the Si570 "slow tune" algorithm.
If you need to program the ATtiny, go to ATMEL's web site and download AVR Studio (free, not crippled, Windows, not open-source) and buy yourself and ATMEL AVR Dragon programmer/debugger. Don't buy an el-cheapo AVR programmer from the likes of Adafruit Industries! These crummy programmers can't program the fuse bits on the AVR's, that means you can't program (or reprogram) the ATtiny85. The AVR Dragon is $50 - well worth it, trust me!
The schematic for the Ensemble-II SDR's is available on Robby's (WB5RVZ) Builder's Notes site. The ATtiny85 controlled Si570 in the latest Softrock SDR has isolation from the USB port (finally). This helps ensure a single grounding point, which eliminates ground loops which often result in spikes in the center of the SDR bandpass.
There is another USB Si570 controller that is similar to the one for the Softrock SDR's (the source code may be the basis of Fred's code - I'm not sure though). But last time I looked, this one did not have USB isolation. I think these are also sold through Tom's (KM5H) Web site (link above).
If you dig around on this site you can find a little application to change the Si570's frequency in Windows. I think this application works with Fred's firmware too.
I think you're better off building a stand-alone version of the Softrock Ensemble-II Si570 circuit with Fred's latest firmware.
Dave Brainerd (WB6DHW, who has replied in this thread) may still have a nice Si570 breakout board for sale that you can use with your own Si570 controller design. Check his site.
73's, David WB4ONA