[OZAPRS] Concerned about 10.151Hhz LSB

[Hamish Moffatt]

On Wed, Dec 03, 2003 at 01:09:25AM +0800, Chris Hill wrote:
> Recipe for HF APRS happiness;
> 1.  Look up the specs on required spectral purity for out of band
> transmissions (varies from one country to another, but at least -40dB or
> better)

Well, are you sure that your USB signal is entirely below 10.150 MHz?
When you're on 10.151 LSB your suppressed carrier is out of band, but
your audio signal is more likely to be within the band.

> 2.  Estimate (or measure) the Signal to Noise ratio of the audio you are
> feeding from your TNC into your HF rig.  Don't forget to add power
supply
> noise, alternator whine, keying spurii from the modem chip, etc etc

Key clicks are likely to extend out of band from your USB signal..

Hamish
-- 
Hamish Moffatt VK3SB <hamish at debian.org> <hamish at cloud.net.au>
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