[TenTec] Monitor (was moniter)

Thu, 25 Apr 2002 15:01:07 -0400

hhhmmm doesn't sound like a simple software upgrade. To bad. When I was
having RF problems with my mic I could hear it through the monitor.
Jeff
ve3ios
----- Original Message -----
From: <n4lq@iglou.com>
To: "George, W5YR" <w5yr@att.net>; "Larry B" <K1zw@webtv.net>;
<tentec@contesting.com>
Sent: Thursday, April 25, 2002 2:17 PM
Subject: Re: [TenTec] Monitor (was moniter)


> Speaking of CW monitoring....One of the best is the TT 13x0 series QRP
> rig which actually plays the beat note through the audio system instead
> of
> a normal sidetone. The FT-1000MP has a similar system, enabling one to
> monitor the actual keying and you can hear yourself in the Heath HW-16 if
> you rip out the neon bulb.
> For SSB, the TS-870 must be like that Kachina in that it monitors the
> digital stage and you can hear your voice response change as you adjust
> the tx audio slope.
>
> N4LQ Steve
>
>
> -----Original Message-----
> From: "George, W5YR" <w5yr@att.net>
> To: Larry B <K1zw@webtv.net>
> Date: Thu, 25 Apr 2002 12:29:36 -0500
> Subject: Re: [TenTec] Moniter
>
> > Possibly, Larry, but probably not likely.
> >
> > Monitors can range from simple audio taps off the modulating audio
> > signal;
> > to separate monitor systems which usually function to downconvert the
> > r-f
> > transmit signal to baseband and present the output through a separate
> > monitor audio amplifier system ; to - in the case of digital rigs - DA
> > converters and audio systems which emulate the second approach above.
> >
> > Usually the first type is a fair indication of what you are putting
> > into
> > the rig but no assurance of what is coming out. The second type can be
> > a
> > very good replica of your transmitted signal depending upon how good
> > the
> > monitor audio system is. The third type can range from fair to
> > excellent,
> > usually depending upon the word-length of the DA converter and the
> > quality
> > of the following audio stages.
> >
> > My IC-765 is an example of the second type and it gives a fair idea of
> > what
> > your transmitted audio sounds like. The transmit IF signal is taken to
> > baseband with the BFO signal into a special monitor mixer stage and
> > then
> > the resulting audio is amplified and mixed into the main audio output
> > system.
> >
> > My Kachina digital radio uses a separate DA converter for the monitor
> > system on the transmit digital data stream at the 40 KHz DSP-processing
> > level and takes the output to drive the monitor audio system. Early
> > Kachina
> > models used only an 8-bit DA for the monitor channel and the results
> > were
> > very poor. An update greatly improved the results with a 16-bit DA
> > converter and a better audio system.
> >
> > My Icom 756PRO uses a digital version of the approach taken with the
> > 765.
> > The main DA 24-bit output from the DSP processing feeds not only the
> > transmit IF channel - starting at 36 KHz and then mixing up through the
> > higher IF's until the output frequency is reached - but also feeds a
> > separate digital mixer which takes the 36 KHz digital data stream
> > signal
> > back to baseband audio where it is digitally filtered and added into
> > the
> > main audio output channel.
> >
> > Of the three, the PRO provides the best indication of the actual sound
> > and
> > quality of the transmitted audio signal. I have verified this by
> > observing
> > the output signals in the time domain with a scope, in the frequency
> > domain
> > with SpectroGram and by careful listening over a quality outboard audio
> > system.
> >
> > As most "audio experts" will tell you, however, do not rely upon your
> > rig's
> > monitor if you *really* want to hear what you sound like. Use an
> > external
> > receiver with a fairly wide bandpass and ensure that it is not
> > overdriven
> > and that it is tuned as accurately as possible to you transmitted
> > frequency. You will still hear only what the monitor receiver passes
> > through its IF and audio stages so it is not a perfect solution, but it
> > probably is representative of what most of your listeners are hearing.
> >
> > I don't know what system your Jupiter uses, but the block diagram will
> > probably give you a few clues and pointers to the circuit diagrams if
> > you
> > want to dig into the specific circuitry.
> >
> > Funny, but in the old days of AM and CW, we seldom gave much thought to
> > "monitoring" the actual quality and sound of our transmitted signals,
> > other
> > than soliciting on-air reports, as we still do. I used a WW2 surplus
> > BC-221
> > frequency meter to monitor my CW signal both to measure the actual
> > transmitted frequency (!) and to hear the tone of the signal.
> >
> > 73/72/oo, George W5YR - the Yellow Rose of Texas
> > Fairview, TX 30 mi NE of Dallas in Collin county EM13qe
> > Amateur Radio W5YR, in the 56th year and it just keeps getting better!
> > QRP-L 1373 NETXQRP 6 SOC 262 COG 8 FPQRP 404 TEN-X 11771 I-LINK 11735
> > Icom IC-756PRO #02121  Kachina 505 DSP  #91900556  Icom IC-765 #02437
> >
> >
> > Larry B wrote:
> > >
> > > Just been enjoying the moniter feature of the Jupiter. Kinda nice to
> > > hear ones own voice. I  assume that the other party in the qso hears
> > > just what I hear when using the moniter feature ? If there was a
> > problem
> > > in the ssb audio one could hear it using the moniter feature ?
> > _______________________________________________
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> > TenTec@contesting.com
> > http://lists.contesting.com/mailman/listinfo/tentec
> >
>
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