Dittel radio squelch

On 10/5/2016 10:20 AM, Martin Gregorie wrote:

Short wave AM broadcasting, is still there, since its in the band that's
strongly reflected by the ionosphere, so has beyond the horizon range
Many government stations still use AM these band, e.g. Voice of America.

True enough.

The Marine VHF band (156-162.025 MHz) used for much the same purposes as
the Air Band, i.e. ship to shore, ship to ship, port operations...

I suspect these are likely to remain AM for a very long time since they
can work well on much narrower channels than FM and are certainly
unlikely to get more band allocation in the forseeable futu just look
at the way that mobile phones snarf up any frequencies they can get.


Actually, the Marine VHF channels use FM. Also, FM can be very narrow
band these days.

Vaughn