[aprssig] Using a TNC as a CW Beacon Only

[scott at opentrac.org]

Without any modulation at all, the MR6 puts out a signal of roughly the same
amplitude as the fundamental 12 MHz up.  On the spectrum analyzer I was
using, it actually appeared to be 1 to 2 dB HIGHER.  If you're not using the
standard crystal, I'd make very sure that it's not putting out anything on
121.5.  Of course, that's the most likely way to make sure it DOES get
found, but it's likely to be an expensive find!
 
Scott
N1VG


  _____  

From: aprssig-bounces at lists.tapr.org [mailto:aprssig-bounces at lists.tapr.org]
On Behalf Of Jason Winningham
Sent: Sunday, February 19, 2006 5:13 AM
To: TAPR APRS Mailing List
Subject: Re: [aprssig] Using a TNC as a CW Beacon Only



On Feb 18, 2006, at 11:16 PM, <scott at opentrac.org> <scott at opentrac.org>
wrote:


I made an MR6 clone plus OT in one board, and actually launched one example

on a few party balloons, but it's got really awful spurious emissions. And

that's not just my clone - it's just as bad on the genuine Ramsey board.



I added a large (1M, IIRC) resistor between the PIC and the MR6 to keep it
from splattering so bad.

Those spurs can be useful, if your APRS payload fails and you're locating
via DF...

-Jason
kg4wsv


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