The bandwidth of an AM receiver might be 10khz, the QMX strips out all but 3.2khz of that AM signal.
While it is harder to tune in with the QMX, if there are interfering signals within the 10khz AM signal
then this can often be filtered out using the QMX receiver.? What's more, you can choose to use either
the upper sideband or the lower sideband of that AM signal, whichever has less interference.
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It should be possible to add normal AM reception to the QMX through a firmware update,?
but that would be a very low priority for a rig meant to be used on the ham bands.
Especially since using the QMX as an SSB receiver often gives better results.
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Jerry, KE7ER
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On Mon, Mar 24, 2025 at 03:38 AM, Chris wrote:
The current QMX SSB receiver can receive AM because what is transmitted is the two sidebands and a carrier but it's not receiving it as AM, it's receiving as SSB using one sideband of the AM signal and ignoring the other sideband and the carrier.? You don't get the advantages of true AM reception where precise tuning is not required, and you have thrown away half of the data.
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Try it with a rig that can receive SSB and true AM on a broadcast AM signal.? You will see that the AM signal can be received as SSB but you need precise tuning to get the correct tone, with AN you don't need precise tuning and the signal to noise is a little better.
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Chris, G5CTH
