[Elecraft] An interested link

[Dave G4AON]

Fortunately the K3 is quite good on AM transmit, unlike legacy equipment
often used. I don't know about elsewhere, but here in the UK there are
80m AM nets where some of the stations run original AM gear without any
additional audio filtering, one was measured at +/- 12 KHz by a fellow
ham with an SDR receiver. The operator seemed indifferent to the fact
his transmission was excessively wide and carried on regardless. The guy
who measured the wide signal used home built AM gear himself, but had a
multi-pole active filter of a similar specification to that used by
broadcast stations to achieve their "skyscraper" envelopes as seen on a
panoramic adapter or SDR receiver.

The UK license has the clause "The bandwidths of emissions should be
such as to ensure the most efficient utilisation of the spectrum".

73 Dave, G4AON
K3/100 #80

Joe, W4TV wrote:

Similarly, AM - except for legacy equipment - should be
limited to 6 KHz bandwidth. In other words, the maximum
modulating frequency should be set at 3 KHz - or no more than
3200 Hz.