Thank you for visiting RF Cafe! Electronics World Cover,TOC,and list of posted Popular Electronics articles QST Radio & TV News Radio-Craft Radio-Electronics Short Wave Craft Wireless World About RF Cafe RF Cafe Homepage RF Cafe in Morse Code Google Search of RF Cafe website Sitemap Electronics Equations Mathematics Equations Equations physics Manufacturers & distributors Engineer Jobs Twitter LinkedIn Crosswords Engineering Humor Kirt's Cogitations Engineering Event Calendar RF Engineering Quizzes AN/MPN-14 Radar 5CCG Notable Quotes App Notes Calculators Education Magazines Software,T-Shirts,Coffee Mugs Articles - submitted by RF Cafe visitors Simulators Technical Writings RF Cafe Archives Test Notes Wireless System Designer RF Stencils for Visio Shapes for Word Search RF Cafe Sitemap Advertising Facebook RF Cafe Forums RF Cafe Homepage Thank you for visiting RF Cafe!

Building a 16Mhz Radio for Senior Design Project. have Q's - RF Cafe Forums

The original RF Cafe Forums were shut down in late 2012 due to maintenance issues. Original posts:

Amateur Radio | Antennas | Circuits & Components | Systems | Test & Measurement


donjonson
Post subject: Building a 16Mhz radio for Senior design project. have Q's Posted: Wed Sep 19, 2007 7:23 pm

Lieutenant


Joined: Wed Sep 19, 2007 6:58 pm
Posts: 3
Hello Very Happy This is my first post on this forum. I am building a 16Mhz radio for my senior design project and Have a few questions. I have been working in PSPICE and am ready to start building and testing.


1)What kind of capacitors should I use in my tuned amplifiers, oscillators, and filters? I have been looking online and there are so many to choose from. I think I should be using something with a small temp coefficient but what material should I use etc..

2)Does anyone know of a place online with low shipping costs and a good selection of components? I have been looking at mouser it seems to be pretty good any other suggestions?

3)In my transmit oscillator I am using an NFET to switch in and out a cap. I am having a difficult time trying to Find one in a TO-92 package with a good enough Ft. Does anyone know where I could go to get this? or perhaps suggest a better device for me to use than an NFET.

thank you for taking the time to read and answer my questions.

I posted this in the amateur radio forum first but I noticed it is pretty much a dead forum so I reposted it here. If a moderator wants to delete one of them please delete the other one.


Top

IR
Post subject: Posted: Sat Sep 22, 2007 2:51 am

Site Admin


Joined: Mon Jun 27, 2005 2:02 pm
Posts: 373
Location: Germany
Hello donjonson,

First of all, welcome to our forum!

To answer some of your questions:

Quote:
1)What kind of capacitors should I use in my tuned amplifiers, oscillators, and filters? I have been looking online and there are so many to choose from. I think I should be using something with a small temp coefficient but what material should I use etc..


In principle, you should use high Q capacitors. As for the material you are right there are materials with large temperature coefficient like Y5V. You should use X7R or X5R capacitros which have a low temperature coefficient.

Quote:
2)Does anyone know of a place online with low shipping costs and a good selection of components? I have been looking at mouser it seems to be pretty good any other suggestions?


You can try: Digikey www.digikey.com

Quote:
3)In my transmit oscillator I am using an NFET to switch in and out a cap. I am having a difficult time trying to Find one in a TO-92 package with a good enough Ft. Does anyone know where I could go to get this? or perhaps suggest a better device for me to use than an NFET.


While NFET is a good choice I would not limit myself to a specific type of package to allow more flexibility. Thre are many types of packages available besides TO-92.

Here are number of TO-92 NFET transistors from Vishay-Siliconix:

http://www.vishay.com/docs/70237/70237.pdf

Quote:
I posted this in the amateur radio forum first but I noticed it is pretty much a dead forum so I reposted it here. If a moderator wants to delete one of them please delete the other one.


posts with topics which are relevant to the Forum are not deleted.

I am moderating this forum for almost 2 years now and have met here people with reach knowledge from whom you can only learn.

Good luck

-IR







Posted  11/12/2012

RF Cafe Software

   Wireless System Designer - RF Cafe
Wireless System Designer

RF & EE Symbols Word
RF Stencils for Visio
Calculator Workbook
RF Workbench
Smith Chartâ„¢ for Visio
Smith Chartâ„¢ for Excel

About RF Cafe

Kirt Blattenberger - RF Cafe WebmasterCopyright
1996 - 2022
Webmaster:
Kirt Blattenberger,
 BSEE - KB3UON

RF Cafe began life in 1996 as "RF Tools" in an AOL screen name web space totaling 2 MB. Its primary purpose was to provide me with ready access to commonly needed formulas and reference material while performing my work as an RF system and circuit design engineer. The Internet was still largely an unknown entity at the time and not much was available in the form of WYSIWYG ...

All trademarks, copyrights, patents, and other rights of ownership to images and text used on the RF Cafe website are hereby acknowledged.

My Hobby Website:
 AirplanesAndRockets.com

Try Using SEARCH
to Find What You Need. 
There are 1,000s of Pages Indexed on RF Cafe !

height-line