[ICOM] Tone squelch operation, "uniformed" question - REPLY

[Steve Peterson]

Wow!  Congrats on the new hams...  Yay Rorge.

--
Steve Peterson
(630) 901-6962 (mobile) | sjpete75 at gmail.com
On Feb 14, 2012 9:44 AM, "George J. Nixon Jr." <n9ejs at yahoo.com> wrote:

> Thanks to all who responded.  The reason for the question is that my
> daughter and her husband (both relatively newly licensed amateur radio
> operators) are getting involved in a local emergency response program in
> their area, heard discussion of using the tone squelch feature from another
> local ham and didn't understand it.  I explained setting the
> transmit/receive tones, but had this question to throw into information for
> them. 73 - George, N9EJS = = = = = = = = =
>
> --- On Tue, 2/14/12, C.Whitaker <whitaker at pa.net> wrote:
>
> From: C.Whitaker <whitaker at pa.net>
> Subject: Re: [ICOM] Tone squelch operation, "uniformed" question
> To: icom at mailman.qth.net
> Date: Tuesday, February 14, 2012, 8:11 AM
>
> de WB2CPN
> Good thoughts, Dick.
> A clearer picture is this.  Only A or B is transmitting at any one time,
> so it doesn't matter which one it is.  So that means the one that is
> not transmitting will hear whatever happens.
> Then, same for C and D.  Only one is transmitting at a time, so it
> doesn't matter which one is a source of interference.
> Let's keep C, and discard D.
> Now, if B is listening to A, and C starts a transmission, what B hears
> will depend on the relative strength of A and C, as heard by B, and
> the carrier frequencies of A and C.  If they are not synchronous,
> exactly,  what B hears will depend on all the factors Dick mentioned.
> FM is not like AM in receiving a signal.  AM will sum + and -, but
> FM won't do that.  Shades of higher math, such as FM sidebands.
> Who said "clearer"?
> 73  Clete
>
>
> On 2/14/2012 3:35 AM, Dick Flanagan wrote:
> > Yes.  In my experience the two encoded tones will mix and you will hear
> > the audio products (sum/difference) and the stronger of the four RF
> > carriers will capture the others.  Depending on the tone filtering and
> > other characteristics of the radios, the tonal grunge can be either
> > minimal or overwhelming.  It is one of those things that just has to be
> > tried as there are too many variables to give a definitive answer.
> >
> > Is this just an academic question or are you actually trying to create a
> > useful application?
> >
> > Dick
> >
> > --
> > Dick Flanagan K7VC
> > dick at k7vc.com
> >
> >
> > On 2/13/2012 11:25 PM, George J. Nixon Jr. wrote:
> >> Suppose that operators A and B have IC-W32a or equivalent ICOM VHF
> >> capable radios, and are having a QSO with  normal settings on a VHF
> >> simplex frequency.
> >> Suppose that operators C and D have similar rigs, get on the same VHF
> >> simplex frequency, and set the same subaudible transmit and receive
> >> tones.  When operators C and D start a QSO at the same time when A and
> >> B are in their QSO, will they hear (be QRMd) by the QSO of C and D?
> >> 73 - George, N9EJS
> >>
> > ----
> > Your Moderator: Dick Flanagan K7VC: icom-owner at mailman.qth.net
> > Icom Users Net: Sundays, 1700Z, 14.316 MHz
> > Icom FAQ: http://www.qsl.net/icom/
> > To support QSL/QTH.net: http://www.qsl.net/donate.html
> >
> >
>
> ----
> Your Moderator: Dick Flanagan K7VC: icom-owner at mailman.qth.net
> Icom Users Net: Sundays, 1700Z, 14.316 MHz
> Icom FAQ: http://www.qsl.net/icom/
> To support QSL/QTH.net: http://www.qsl.net/donate.html
> ----
> Your Moderator: Dick Flanagan K7VC: icom-owner at mailman.qth.net
> Icom Users Net: Sundays, 1700Z, 14.316 MHz
> Icom FAQ: http://www.qsl.net/icom/
> To support QSL/QTH.net: http://www.qsl.net/donate.html
>