[Elecraft] The Old Days

[Walter Underwood]

This is exactly why AM is used instead of FM. It has better weak signal performance and two signals mix linearly.

wunder
K6WRU

On Jan 29, 2013, at 1:10 PM, Nate Bargmann wrote:

> * On 2013 29 Jan 14:34 -0600, Sandy wrote:
> 
>> "Ancient AM" is still used today, but basically only for two
>> purposes.  One is AM broadcasting from about 550-1700 Khz.  A
>> holdover from "ancient times" dying but "still alive and kicking"
>> Second it is used for aircraft communication from about 108-135 Mhz
>> or so.  An ESSENTIAL to safe airborne communications and safety.
>> The military still uses it in the 225-400 Mhz band in mostly jet
>> aircraft.  WHY not SSB or FM?  well because it "does the job" and it
>> is reliable and the circuitry is much simpler!
> 
> The conclusion here may well be part of it.  A coworker who worked in
> avionics in a former life told me that the use of AM for aircraft
> communications is indeed for the ease of tuning but also because a
> weaker station can be heard under a stronger one unlike with FM and its
> capture effect (likely true for digital).  AM allows an air controller
> or other aircraft to hear an emergency call when another station is
> transmitting.  Based on my experience, I have no reason to doubt his
> conclusion.
> 
> 73, de Nate, N0NB >>
> 
> -- 
> 
> "The optimist proclaims that we live in the best of all
> possible worlds.  The pessimist fears this is true."
> 
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