Geoffrey S. Mendelson wrote:
Bob Dobbs wrote:
When there is audio (modulation) present, there most certainly is a carrier,
otherwise it's suppressed and therefore problematic for sync-det.
If someone were to modulate their SSB signal with anything close to a steady
tone the sync-det could possibly get a lock.
note* - there isn't a way to engage the sync-det in either of the SSB modes on
the only radio I have that has it.


No. Most ham rigs made since 1980 don't actually produce an AM signal, they
produce a double sideband reduced carrier signal. Ham rigs produce a signal
by taking an AM signal and running it through a filter to remove
the carrier and the other sideband.

Their "AM" mode signal is made by recombining the the upper and lower sideband
signals, with only a tiny residual carrier.

Most AM receivers can receive this signal, but there is no carrier to lock
on to, so I doubt that a sync detector can lock onto them.

Geoff.



With only a tiny residual carrier, any AM receiver with an envelope
detector would see this as a overmodulated AM signal and the reception
would be quite distorted.