[Milsurplus] TCS-12 was main Buff commo system???

[Grif]

I think for hams the main attractions are that it's fun, it connects with
our past, and it's easy to do. See the GloBug (GB) discussion group on
Yahoo. They're devoted to keeping tube equipment alive and building circuits
from the past. There is apparently an active AM group that meets on the
weekends on the top end of 40 (7296?). As long as the heterodynes and
squeals are confined to a very small portion of the band I don't think
they're hurting anybody. Besides, a modern rig with digital processing can
do away with the heterodynes. I may even join them some morning.

Grif, KF4JG
----- Original Message ----- 
From: <mstangelo at comcast.net>
To: <w8au at sssnet.com>; <milsurplus at mailman.qth.net>
Sent: Monday, March 14, 2005 3:04 PM
Subject: Re: [Milsurplus] TCS-12 was main Buff commo system???


>
> It's been interesting following the discussion about the introduction of
SSB.
>
> That got me thinking. For voice (or music ) modulation and demodulation,
AM modulation, was first used because it was the transmitter and receiver
circuits
> were easy to construct.
>
> SSB was used by ATT for transatlantic voice communications in the 1920's
and came into commonplace usage in the 1950's.  It is now the most effective
analog
> mode for medium to long range utility communications.
>
> FM was patented by Armstrong in the early 1930's and is now used for short
range utility communications and high fidelity broadcasting.
>
> Let's disregard digital modes for the moment. Since SSB is optimum for
long range
> communications and FM for short range is there any reason for AM
modulation today? I hope this isn't too far off-topic.
>
> 73,
>
> Mike N2MS
>
>
> -------------- Original message -------------- 
>
> > At 08:15 AM 3/14/05, Grif wrote:
> >
> > >I wasn't aware that the FCC had any jurisdiction over what the military
or
> > >the government did with their frequencies. Perhaps the military just
chose
> > >to also stop using AM?
> >
> > You are correct. FCC has no jurisdiction. Each service has their own
> > "Frequency management office" under DOD. DOD established their own rules
> > about bandwidth and that was what ended AM. Typically their biggest
> > bandwidth allocation is 2.5 kHz, the minimum for SSB.
> >
> > Perry w8au
> >
> >
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