[SOC] MCW, again.

Bry Carling AF4K at hotmail.com
Fri Oct 12 16:42:08 EDT 2018 

>>I said that MCW is supposed to be distracting, that's modern day
purpose, it's wider than CW and makes a heck of a noise as a receiver
with BFO hears 3 tones keyed at the same time.

>>73 DR

Not if you are smart and turn the BFO off like you are supposed to, or move your MODE switch to the AM position!

However, for weak sigjnal work, it is quite often better to hear those MCW beacons (yes they are keyed albeit by a program) with the BFO on (SSB mode) and a narrower filter. I have never found any of them at all "distracting." It's all in how you adjust the receiver. Maybe an FOC op would find it annoying but I don't. (grin!)


________________________________
From: soc-bounces at mailman.qth.net <soc-bounces at mailman.qth.net> on behalf of D.J.J. Ring, Jr. <n1ea at arrl.net>
Sent: Saturday, October 6, 2018 11:34 PM
To: Second Class Operators' Club
Subject: Re: [SOC] MCW, again.

A keyed pure sine wave into a SSB radio results in A1A emission, not A2.

A2, MCW, or A2A is a carrier with modulating Morse tone, it comes in
two varieties, keyed like ships used and unkeyed like non-directional
beacons (NDB) use.

I said that MCW is supposed to be distracting, that's modern day
purpose, it's wider than CW and makes a heck of a noise as a receiver
with BFO hears 3 tones keyed at the same time.

73
DR
On Sat, Oct 6, 2018 at 11:30 PM Joseph B Cotton <cottonj at gmail.com> wrote:
>
> MCM that is generated by a SSB rig can not be differentiated from a
> standard CW signal. You are talking about an MCM generated by an AM
> transmitter. Playing a pure sine wave audio into a good SSB rig is what I
> am talking about.
> Joe W3TTT
>
> On Sat, Oct 6, 2018 at 4:22 PM D.J.J. Ring, Jr. <n1ea at arrl.net> wrote:
>
> > Keyed MCW is best received with BFO on as you then can also receive the
> > carrier as well.
> >
> > Detection of CW is much more sensitive then AM.  Detecting MCW in CW
> > receive is also better.
> >
> > 73
> >
> > DR
> >
> > On Sat, Oct 6, 2018, 15:12 g4jht <g4jht at eircom.net> wrote:
> >
> > > Remember MCW is just keyed AM,  so you  turn the CIO or BFO off, to
> > > receive it.
> > > You can even pick MCW up on crystal set, were as with CW you just just
> > > gives clicks in the phones.
> > > The Marconi Atlanta main ships receiver I have just bought (manual says
> > > 1967) has a real variable BFO and an off switch for it. Once I have it
> > > powered up I will try some experiments with local MF Aero beacons and
> > > report back what I find if anyone is interested. They sound like 800
> > > cycles without putting an audio frequency counter on it.
> > >
> > > 73, Dave
> > > EI0DB
> > >
> > >
> > > On 10/06/2018 02:47 PM, D.J.J. Ring, Jr. wrote:
> > > > You're right, Joe.
> > > >
> > > > I guess I got carried away with adding 400 Hz to 800 Hz coming up with
> > > 1200
> > > > HZ.  I'd do that on my receiver and it's not the tones transmitted.
> > > >
> > > > 400 Hz tone used to modulate
> > > > a carrier of 500 kHz, you will have carriers at 4,999,600 Hz,
> > > > 5,000,000 Hz and 5,000,400 Hz.
> > > >
> > > > I corrected the typo.
> > > >
> > > > With a wide receiver we heard three tones.
> > > >
> > > > I used bandwidth of about 8 kHz for watchkeeping.
> > > >
> > > > 73
> > > >
> > > > DR
> > > > N1EA
> > > >
> > > >
> > > > On Sat, Oct 6, 2018, 00:19 Joe Pontek Sr <v31jp1957 at gmail.com> wrote:
> > > >
> > > >> This is not completely accurate.
> > > >>
> > > >> An MCW is made up of components determined by the method of
> > generation.
> > > >> If standard AM method
> > > >> with a single tone is used, there will be the carrier and then two
> > side
> > > >> tones, ie. 400 Hz tone used to modulate
> > > >> a carrier of 5,000 kHz, you will have carriers at 4,999,600 Hz,
> > > >> 5,000,000 Hz and 5,000,400 Hz.
> > > >>
> > > >> Now, depending on your receiver's band width, you might hear a single
> > > >> carrier at each frequency, a beat
> > > >> tone od 400 Hz if you hear two carriers at the same time and further
> > > >> mixes with a wider bandwidth.  The
> > > >> beat note(s) is(are) made in your receiver.
> > > >>
> > > >> In the above example, the bandwidth only 800 Hz, not like a single
> > > >> sideband suppressed carrier voice
> > > >> signal of about 2,700 Hz.
> > > >>
> > > >> Too many times, it is a P poor receiver causing garbage you hear on
> > the
> > > >> bands or poorly used receivers
> > > >> by the operators.
> > > >>
> > > >> 73
> > > >>
> > > >> Joe
> > > >> K8JP
> > > >>
> > > >>
> > > >> On 10/5/2018 1:00 PM, D.J.J. Ring, Jr. wrote:
> > > >>> It's horribly wide and intrusive!
> > > >>>
> > > >>> It's about as wide as a SSB signal.
> > > >>>
> > > >>> About 1.2 kHz wide.
> > > >>>
> > > >>> It sounds like three carriers, say tones of 400, 800 and 1200 Hz all
> > > >>> sending the same pulses of Morse.
> > > >>>
> > > >>> 73
> > > >>>
> > > >>> DR
> > > >>> N1EA
> > > >> --
> > > >> Regards, Joe, K8JP/V31JP, Martin & Sidney Pontek
> > > >> 175 Diamond Loch Rd., Apt. 5
> > > >> Gilmer, TX 75644-9374
> > > >> U.S.A.
> > > >> or
> > > >> P.O. Box 280, Dangriga, Stann Creek District
> > > >> (Hopkins Village) Belize
> > > >>
> > > >> 903-204-2318 (My TX cellular)
> > > >> 903-884-5990 (Skype telephone number, Belize & TX)
> > > >> Also, K8JP, member FOC-1743, QCWA-LM21894, OOTC-4607, A1OP,
> > SKCC-3171T,
> > > >> NAQCC-5798, Flying Pig-2819, FISTS-7625CC951, A1C-2299, SOC 1075,
> > 10-10
> > > >> 22977, PG1915841, CW Rag chewers #21,
> > > >> Facebook: Joe Pontek
> > > >> Skype: v31joepalooka
> > > >> I am looking for Vibroplex Model X, Double lever and prefer basket
> > cases
> > > >> to restore.
> > > >> LotW
> > > >>
> > > >> ______________________________________________________________
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