Thanks, John, and good idea! I like the suggestion of the analog meter. I may try to put it in a box or something; it would be awfully unwieldy without one!<div><br></div><div>73,</div><div><br></div><div>Kyle<br><br><div class="gmail_quote">
On Sat, Sep 15, 2012 at 6:38 PM, John Klingelhoeffer <span dir="ltr"><<a href="mailto:wb4lnm@aol.com" target="_blank">wb4lnm@aol.com</a>></span> wrote:<br><blockquote class="gmail_quote" style="margin:0 0 0 .8ex;border-left:1px #ccc solid;padding-left:1ex">
<font color="black" size="5" face="Arial, Helvetica, sans-serif">Nicely done!
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<div>Allow me to make a suggestion based on experience: It is *extremely* difficult for the human ear to hear a 'peak' or a 'null' in an audio tone's amplitude. Two possible extensions to your project to overcome this:</div>
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<div>The first is to take the audio output of the HT from the earphone jack, run it through a precision rectifier (op amp with diodes in the feedback loop) and then drive an analog meter movement with the filtered DC output. </div>
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<div>Or, use the same precision rectifier to drive a voltage to frequency converter, so the output is a varying frequency audio tone rather than a varying amplitude (sort of like a theremin!). Either should provide a better (and faster) null or peak indication than the ear.</div>
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<div>73</div>
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<div>John...</div>
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<div style="font-size:10pt;font-family:arial,helvetica"><div><div class="h5">-----Original Message-----<br>
From: Kyle Owen <<a href="mailto:kylevowen@gmail.com" target="_blank">kylevowen@gmail.com</a>><br>
To: k4ry <<a href="mailto:k4ry@eng.auburn.edu" target="_blank">k4ry@eng.auburn.edu</a>><br>
Sent: Fri, Sep 14, 2012 9:36 pm<br>
Subject: [K4RY] Direction Finder<br>
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<div>
<div>Hi all, </div>
<div>I just finished my 555-based direction finder. It works too! It draws a constant 8.5mA during operation. I may increase the RC time constant, as the pitch is a bit high. On the other hand, it's very easy to hear. </div>
<div>Attached are a few pictures. Let me know if you have any questions about it! </div>
<div>Kyle </div>
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