10.7MHz quartz filters needed!

[plane_spotter]

Hi all I am looking to buy very small quantity of 10.7Mhz crystals for diy d/c rx. I am UK based so needs to be someone who will deal with the public.
Have tried one company and they quoted me 9quid. Seems a little steep.

cheers

[Dan Baldwin]

Are you looking for something like this?

http://www.mouser.com/index.cfm?handler=displayproduct&lstdispproductid=469555&e_categoryid=29&e_pcodeid=64807

Dan

[plane_spotter]

No sorry 2 pole monolithic crystal filters, not ceramic.

[JMP_blackfoot]

Hi all I am looking to buy very small quantity of 10.7Mhz crystals for diy d/c rx. I am UK based so needs to be someone who will deal with the public.
Have tried one company and they quoted me 9quid. Seems a little steep.

cheers

These people have what you need, I suppose :

http://www.lextronic.fr/Composants/HF/PP.HTM

Look for : Filtre à quartz "10,7 MHz"

Price : 5.34 Euro including purchase tax.

Good luck.

[vintage1]

6 pole ceramics may be more suitable than quartz.

[hadihf]

Here are to catalogue reference from Digikey and Mouser. Mouser is cheaper :) .

Regards

[ZagiArt]

Hi Plane spotter,

Here is a company who is selling crystal filters of various kinds for narrow banding two way radios. I replaced a bad filter in a Futaba receiver with one of the CF-1's and have had no problems with interference or short range. It seems to be like new. They will also sell in small quantities for a reasonable price. Good Luck Zagiart

Oops, I forgot the URL http://www.com-spec.com/narrow.htm
[URL=http://www.com-spec.com/narrow.htm]

[vintage1]

The only function of the 10.7 filter is really to reject the image frequency of the second IF,so provided it ias flat over a 5khz pass band (almost impossible not to achieve) the only thing it has to do is knock out the frequency 950Khz off the center by at least 40dB.

Almost any filter will do that.

[JMP_blackfoot]

The 10.7 MHz crystal filter not only eliminates the image frequency, it has another beneficial effect :
It strongly attenuates all neighbouring frequencies which made it through the first mixer, letting pass only the useful intermediate frequency signal. This practically eliminates any risk of intermodulation in the second mixer.
It would not be the case if a cheap common wide-band (200 - 300 khz) ceramic filter were used, which would be unable to stop adjacent channels.
Dual-conversion is an improvement over single-conversion, on the condition that a crystal filter be used, failing which it is no better and in some cases worse.

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