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| Joined: | Mar 3rd, 2008 |
| Location: | Muskogee, Oklahoma USA |
| Posts: | 349 |
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Noise types, in my opinion are 'whatever works best' for the results you obtain. For a field unit, battery based, i'd say White would be the easiest and least power hungry. Couple of good transistors type of method. Or, quite often with the Dollar Tree $1 radios I use, you can get the reception negated and they output the white noise anyway ! 3V operation at a few milliamps can't be sniffed at. Joe's 7088 methods are quite similar and he goes much further than I have with the circuits
It might be worth exploring such a chip to use its output with no radio reception coil etc. That way you negate any false radio transmission pickup on the output.Unfortunately I haven't the means right now to get hold of a Rat Shack radio, but the click on the Dollar Tree ones was stopped by using a 10uf capacitor. Basically, being as the normally used 555 chip controls the rate of reset of sweep, connecting the capacitor smoothes the output. 555's are quite the strong switching device and their output gives that click effect. If it's the same sort of situation, that's how I quietened things lol
Couple of my threads might hopefully help for a field unit:
http://www.itcbridge.com/forum/view_topic.php?id=647&forum_id=32
http://www.itcbridge.com/forum/view_topic.php?id=444&forum_id=9
http://www.itcbridge.com/forum/view_topic.php?id=634&forum_id=31
and possibly the Anrede build thread, being as it's a field unit build
http://www.itcbridge.com/forum/view_topic.php?id=448&forum_id=19
Last edited on Nov 22nd, 2008 12:33 PM by Slider2732