Radio: Difference between revisions

Latest revision as of 16:55, 8 April 2010

Outputs a logic high and logic low. What is the best way to convert this to a co/sine wave (multiplex?)
What value are we looking for?

FM is most likely too high to create
AM radio (car stereo) is about right. Find a station you want to tune to. KFBK 1530?
AM is allowed +- 5kHz
96kHz of bandwidth (due to what the audio card can sample)
SI570 can create a number of frequencies

Switching Regulator
SI570, KN9YIG
Johnson counter
Jumper selectable band pass filter?
http://www.sdr-kits.net/USB/USB_Description.html
Softrock is taking up about 40mA, USB provides 100mA for USB2, and up to 500mA for a high-powered USB 2.0 bus.
Pick a logic family and stick with it: CMOS?
Quad Analog switch for the multiplexer (Sine/Cosine). 74(V)HC4066 is one of them
The 74VHC4066 doesn't go high enough. We need to use a Frequency Mixer instead, http://yu1lm.qrpradio.com/HF-VHF%20SDR%20receiver-part1-YU1LM.pdf

Example 9.12, work through the math please
Can oscillators produce sine waves without needing a square wave? Do we need to have potentiometers instead of resistors to make sine waves not clip?

@@ Line 32: / Line 32: @@
 :*Pick a logic family and stick with it: CMOS?
 :*Quad Analog switch for the multiplexer (Sine/Cosine). 74(V)HC4066 is one of them
+:*The 74VHC4066 doesn't go high enough. We need to use a Frequency Mixer instead, http://yu1lm.qrpradio.com/HF-VHF%20SDR%20receiver-part1-YU1LM.pdf
 *Book questions