EMRFD Message Archive 11019

Message Date From Subject
11019 2015-04-29 08:58:32 winston376 Current Source(s) for High Q Crystals

In doing research on a custom design crystal filter a couple years ago, finding a manufacturer that could cut custom crystals with high Q  (greater than 200,000  at 10.7 MHz) was challenging.  ICM was the only provider that could get close to these specs.


If anyone could provide some current sources/manufacturer  for custom cut high Q crystals, it would be much appreciated.


Thanks in advance.


Alex

11020 2015-04-29 09:21:16 bobtbobbo Re: Current Source(s) for High Q Crystals
JAN Crystals in Florida can do all that if they are still in business. In years past they were my go-to crystal manufacturer.

Bob, K1AO
11021 2015-04-29 10:11:09 Garey Barrell Re: Current Source(s) for High Q Crystals
Not any more.

73, Garey - K4OAH
Rome, GA
Drake 2-B, 2-C/2-NT, 4-A, 4-B, C-Line
and TR-4/C Service Supplement Files












11022 2015-04-29 10:41:18 Dana Myers Re: Current Source(s) for High Q Crystals
11023 2015-04-29 11:38:33 Garey Barrell Re: Current Source(s) for High Q Crystals
Dunno...  Saw a 'news item' somewhere that said they had closed up.  Perhaps a 'future'? Closing.

73, Garey - K4OAH
Rome, GA
Drake 2-B, 2-C/2-NT, 4-A, 4-B, C-Line
and TR-4/C Service Supplement Files












11024 2015-04-29 13:12:45 Lasse Moell Re: Current Source(s) for High Q Crystals
Quarztechnik in Daun Germany should be able to help!
http://www.quarztechnik.com/contact.html

They produced the roofing filter crystals for the PA3AKE receiver... average of  Q > 130 000
http://martein.home.xs4all.nl/pa3ake/hmode/roofer_ssb.html

/Lasse SM5GLC

29 april 2015, winston376@yahoo.com [emrfd] skrev:

 

In doing research on a custom design crystal filter a couple years ago, finding a manufacturer that could cut custom crystals with high Q  (greater than 200,000  at 10.7 MHz) was challenging.  ICM was the only provider that could get close to these specs.


If anyone could provide some current sources/manufacturer  for custom cut high Q crystals, it would be much appreciated.


Thanks in advance.


Alex

11026 2015-04-29 19:58:11 Ashhar Farhan Re: Current Source(s) for High Q Crystals
Andhra Elec was a defence contractor to the local defense industry (joke, joke). they sell in small quantities too. shipping may be slightly painful. but they do deliver quickly and they are inexpensive. i have used them before. the only catch is that they are a little old fashioned. you have to write to them, probably talk over the phone. but they can deliver the crystals you need.


- f

11045 2015-05-01 08:52:02 winston376 Re: Current Source(s) for High Q Crystals
Ashhar,

I looked at the Andhra website.

My primary parameter for selecting a custom crystal source is the quartz  Q (> 200,000). 

Once I drilled down and asked for hard test data on crystal Q, many of the sources that I contacted, were unable to provide or otherwise substantiate their claims with this regard.  

 Do you know or do you have experience with this source when it comes to delivering a high Q crystal?

Alex
11055 2015-05-01 21:57:58 Ashhar Farhan Re: Current Source(s) for High Q Crystals
Alex,
 
I never got around measuring the Q of those crystals. We mostly used them for local VHF handies' crystals. The guy we contacted was sastry@andhraelec.com. They delivered in a week's time. Charging around Rs.150 (three dollars) per crystal. I have some lying with me. I will run a sweep and get back to you? Let's take this offline from the group.

- f