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 Thank you for visiting RF Cafe!

16bit / 48KHz PCM Audio Recorder? - 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


HazyWinter
Post subject: 16bit / 48KHz PCM Audio Recorder? Posted: Sat Jan 27, 2007 2:23 am

Captain


Joined: Sun Jan 21, 2007 4:57 am
Posts: 6
I'm trying to build a PCM (wav) audio recorder that would have some basic controls like record (duh), play, pause, next track, previous track and have the ability to start a new file for each recording. I'm looking for the absolute lowest noise floor possible, that's why I'm not hacking an mp3 recorder or some such consumer device.

The main goal here is to have the smallest recorder possible because of limited space inside the housing of a wideband radio receiver.

If anyone can give me some pointers on where to start, schematics, parts, a rough block diagram, it'd be nice.


Top

fred47
Post subject: PCM recorderPosted: Tue Jan 30, 2007 1:37 pm

General


Joined: Wed Feb 22, 2006 3:51 pm
Posts: 104
Hi!
OK, physical size is important. How do:
1. Cost (per unit)
2. Cost (to develop)
3. Power consumption
4. Volume
5. Total recording time
rank in importance to you?

Do you need stereo/5.1/7.1/other multi-channel recording?

Do you need analog playback, or does the signal get out of the recorder in digital form (for example, SPDIF)?

What about monitoring what's recorded?

Are there any available resources in the receiver that you don't have to implement for your recorder? (I assume power supply, but there might also be program storage space, so that a flash EPROM wouldn't be necessary - a program could be downloaded onto a single-chip microprocessor or DSP).

Good luck!
Fred


Top

HazyWinter
Post subject: Posted: Tue Jan 30, 2007 4:10 pm

Captain


Joined: Sun Jan 21, 2007 4:57 am
Posts: 6
Hi Fred,

Power is supplied by three AA 3000mAh batteries for a total of 3.5v - 4v.
Volume is not really a factor since the output from the receiver will be soldered directly to the recorder's input. In other words, this is going to be a straight line level (about 200mV) audio connection. As far as channels are concerned it doesn't have to go beyond stereo, so 2 channels should be enough.

Analog playback will not be nessecary. In fact, a mini USB connection would be ideal for file transfers to a PC.

The receiver uses a Mitsubishi M38267M8L-256GP CPU and an Asahi Kasei Microsystems (AKM) Serial CMOS EEPROM model AK93C10A along with a Rohm DTA144EE Digital Transistor.

Some other components of note are: TI Differential Opamp & M35017-001FP On Screen Display.


Top

fred47
Post subject: RecorderPosted: Tue Jan 30, 2007 9:17 pm

General


Joined: Wed Feb 22, 2006 3:51 pm
Posts: 104
Oops, my fault in not asking the questions clearly.

When I said "volume" I meant like "cubic inches", not dB!

How long does it need to record for? If it's seconds, some chips have enough memory on-board. Minutes implies external RAM, hours implies Flash - so it's important to know the size of the records.

sounds like power efficiency is critical, too - at 11 Watt-hours battery, you couldn't use a 1W DSP, for example.

Good Luck,
Fred


Top

HazyWinter
Post subject: Posted: Tue Jan 30, 2007 9:59 pm

Captain


Joined: Sun Jan 21, 2007 4:57 am
Posts: 6
I'm aiming for 4 hours of storage, so a flash based storage system is a must, either NAND, SD, or CF. If space becomes an obstacle then I can make the housing a little taller and wider to accommodate all the components. It's a cast magnesium alloy and I have a place that can do that from a 3D CAD file.

Volume wise, I can only think of a rough figure right now, something in the neighborhood of 6 cubic inches; 3L x 2 W x 1H.



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