[AMRadio] AM Presentation

[Rob Atkinson]

I don't think it is strange; but it is a challenge.  What to cover
about AM?  The real question is what to leave out.

I'd assume the audience is CW and slopbucket ops who wonder Why AM?
So the first thing I'd do is address that by explaining why one
operates AM:

It is a challenge given the duty cycle.

It is a technical challenge to transmit non-distorted AM audio

It is a challenge to do so and provide the other station with an
acceptable S/N ratio given the lower sideband power.  This is done by
maximizing the quality and efficiency of every part of the station, in
other words, AM demands more than a poor antenna.  I.e. how to be a
strapper.

It is a reception challenge due to natural and man made QRN and wider
passband on receive

Therefore, if one is bored with plug and play appliance operating, and
is looking for a way to further enhance and improve his radio
knowledge and skills in the practice of the amateur radio art, AM
offers a way to do that.

There is an interesting paradox about AM:  At a minimum, it is a
relatively simple way to transmit voice but that simple method
produces a most complex waveform that is harder to measure and
analyze.   But the simpler circuits afford one the opportunity to
operate equipment that can be understood, maintained and repaired
in-house rather than a sad reliance on professional repair shops.

It also allows one to study and practice the craft of punching and
building on chassis, all of which is extremely satisfying.

there's a whole dimension to ham radio that is unknown to anyone who
remains content to operate manufactured modern solid state
equipment--the missing 50% of the hobby found in magazines and books
published before around 1960.

One question many might have is "Why a carrier?"   Despite the
propaganda to the contrary, the carrier performs at least two
important  functions:   it attenuates QRN and transmits pauses, a
vital part of regular speech.

There's a lot more about AM but these are a few points--expanding them
to full explanations might take up the whole hour.

I would not sugar coat it--there is a lot of hard work involved with
setting up and putting into operation an AM station, but each little
success, from my experience, is immensely satisfying.


73
Rob
K5UJ




On Sun, Jun 16, 2013 at 5:42 PM, Bernie  Doran
<qedconsultants at embarqmail.com> wrote:
> Am I the only one that thinks it a bit strange that an amateur radio club needs a presentation of AM?   They have never listened to BC or SW BC?  And, what are those strange beeping sounds at the low end of the ham bands?   Bernie W8RPW