HobbyKing.com New Products Flash Sale
Reply
Thread Tools
Old Mar 10, 2007, 06:41 AM
Registered User
Joined Dec 2006
126 Posts
Question
can any one help me identify this part

Can any tell me what this part is. It reads (55J and has the murata logo on it.It has three pins and is approx. 2mm thick.Below are some pics of the part.
radio freak is offline Find More Posts by radio freak
Reply With Quote
Sign up now
to remove ads between posts
Old Mar 10, 2007, 07:31 AM
"MAYONNAISE"
Acetronics's Avatar
Le Treport, France
Joined Jun 2004
1,416 Posts
455 Khz Ceramic Filter ???

J grade ( = bandwidth )

Alain
Acetronics is offline Find More Posts by Acetronics
Reply With Quote
Old Mar 10, 2007, 07:35 AM
NeverAgainVolunteerYourse lf
nick_75au's Avatar
Australia, QLD, Regents Park
Joined Mar 2007
3,732 Posts
Ceramic resonator?

It may be a ceramic resonator, similar to a crystal used for timing microcontrollers etc, bit of a guess but see how you go.
just looked at the murata website quickly 55j doesnt come up in serches but it does look like a ceramic resonator.
Regards
Nick
nick_75au is offline Find More Posts by nick_75au
Reply With Quote
Old Mar 10, 2007, 08:20 AM
Registered User
Joined Dec 2006
126 Posts
Quote:
Originally Posted by Acetronics
455 Khz Ceramic Filter ???

J grade ( = bandwidth )

Alain
Can this be used as a ceramic filter in an rc receiver??
radio freak is offline Find More Posts by radio freak
Reply With Quote
Old Mar 10, 2007, 09:43 AM
"MAYONNAISE"
Acetronics's Avatar
Le Treport, France
Joined Jun 2004
1,416 Posts
Quote:
Originally Posted by radio freak
Can this be used as a ceramic filter in an rc receiver??
Of course !!!

Alain
Acetronics is offline Find More Posts by Acetronics
Reply With Quote
Old Mar 10, 2007, 10:13 AM
Registered User
Joined Dec 2006
126 Posts
Quote:
Originally Posted by Acetronics
Of course !!!

Alain

Can you please help me out with the pin identification
radio freak is offline Find More Posts by radio freak
Reply With Quote
Old Mar 11, 2007, 11:37 AM
Registered User
Joined Dec 2006
126 Posts
Is there no one who can help me identify the pins on this ceramic filter??
radio freak is offline Find More Posts by radio freak
Reply With Quote
Old Mar 11, 2007, 12:28 PM
RC Bum
Eric_N57105's Avatar
Riverside, CA
Joined Apr 2006
1,494 Posts
Quote:
Originally Posted by radio freak
Is there no one who can help me identify the pins on this ceramic filter??
From the orientation in your photo, the pins are USUALLY Input, Ground, Output. However, it doesn't always matter as they are symmetrical designs.

My guess is also that it is a 455khz ceramic filter. If you have a kilobuck spectrum analyzer sitting in a dusty corner of your garage, it is a simple matter to test it and check its response. If not there are some relatively easy test methods based on using a software audio spectrum analyzer like Spectrogram.

Here's a link to get you started. It is a procedure for adjusting filters in an Elecraft amateur radio transceiver. Most of the details will be meaningless, but it should give you an idea of the technique which you can easily adapt to testing ceramic or crystal filters.

http://www.elecraft.com/Apps/new_fil...ilter_apps.htm

Google Spectrogram as well and you will find a lot of similar articles. It's a great tool for receiver design. Cool Edit is another one that works well for me.

Eric
Eric_N57105 is offline Find More Posts by Eric_N57105
Reply With Quote
Old Mar 11, 2007, 02:23 PM
Registered User
Joined Dec 2006
126 Posts
Hello and thanks to everyone who tried to help me out. I found the part and I am attaching a PDF link for future reference for everyone.






P.S.The murata manual says filters for AM use, does this mean they cannot be used on an FM receiver??
radio freak is offline Find More Posts by radio freak
Reply With Quote
Old Mar 13, 2007, 08:16 PM
RC Bum
Eric_N57105's Avatar
Riverside, CA
Joined Apr 2006
1,494 Posts
Quote:
Originally Posted by radio freak
Hello and thanks to everyone who tried to help me out. I found the part and I am attaching a PDF link for future reference for everyone.

P.S.The murata manual says filters for AM use, does this mean they cannot be used on an FM receiver??
No. Generally, AM radios use a 455khz IF and have bandwidths of around 6 khz. FM radios normally use a 10.7 mhz IF and have wider bandwidths. Even narrow band FM is more than twice as wide as AM. You can see that in their specs.

So, generally, the AM ceramic filter is going to be more selective, i.e. better at rejecting adjacent channel interference which is a good thing for an RC receiver.

Eric
Eric_N57105 is offline Find More Posts by Eric_N57105
Reply With Quote
Old Mar 13, 2007, 09:48 PM
Registered User
vintage1's Avatar
East Anglia, UK
Joined Sep 2002
29,705 Posts
Narrow band FM such as we use uses 455KHz filters just like AM. The bandwidth is similar. Well actually in the USA the channels spacing is 10KHz whereas AM radio is 9KHz.

UK spacing is IIRC 20Khz.

10.7 MHz filters are used in broadcast FM (400 KHZ bandwidth) and the the first IF of dual conversion receivers.
vintage1 is offline Find More Posts by vintage1
Reply With Quote
Old Mar 14, 2007, 07:00 AM
Registered User
Joined Dec 2006
126 Posts
thanks for the info people
radio freak is offline Find More Posts by radio freak
Reply With Quote
Reply


Thread Tools

Similar Threads
Category Thread Thread Starter Forum Replies Last Post
Help! Help me identify this part tomskk DIY Electronics 6 Apr 10, 2006 02:49 PM
Can some one help me with this choper woodsy Micro Helis 22 Nov 16, 2004 05:10 AM
Cool Is it a P-40? Can you help me identify this aircraft temp_oct Parkflyers 1 Jan 05, 2004 12:46 AM