Thanks to all for the suggestions. On RTTY AFSK (basically a constant
carrier)I do get about 80-90 watts out on second measurement, with Navigator
set to max outputs. The Navigator still seems to be a bit light on drive for
an Orion however. Now, looking at PSK on a scope, I see that it is not exactly
constant amplitude when idling, as I had assumed erroneously previously - seems
to have a slow sine modulation envelope on it. I assume that's normal (?).
This could account for the lower average power reading on the wattmeter in that
mode. When I set the wattmeter to peak/hold, it shows close to 90 watts (by
capturing the peak). Of course that's too much, but I think that explains some
of the discrepancies.
N4BE
---- Ron Castro <ronc@sonic.net> wrote:
> I observed the same things in my O2 regarding the power output readings.
> While the meter only seems to be accurate at the 100 Watt level, the power
> setting control is amazingly accurate. Using both a Bird 43 and a Telepost
> LP-100 the settings agree with the true output power within 2% to 5% from
> about 20 Watts to 100 Watts CW out.
>
> Ron N6IE
> www.N6IE.com
>
> ----- Original Message -----
> From: "Merle Bone" <merlebone@charter.net>
> To: <tentec@contesting.com>
> Sent: Wednesday, February 11, 2009 9:49 AM
> Subject: Re: [TenTec] O2 output level with PSK aux
>
>
> >I think it is very hard to know what the "power readings" of the Orion
> >meter
> > really mean. Actually, most,
> > if not all, of the Orion meter readings are "relative." The power meter
> > description says"
> > ----------------------------------------------------------------------------------------------------------------------------------
> > ANALOG METER
> > In transmit, the meter shows approximate output power (+/- 5%). The power
> > meter is
> > a sampling-type meter and will stay more or less constant when sampling
> > power output,
> > particularly when the transceiver is used in CW mode."
> > ----------------------------------------------------------------------------------------------------------------------------------
> > I take from this description that the meter is "some form" of average
> > reading meter. All Orion/Orion II
> > meter readings are really from "calculated" numbers from the DSP and then,
> > through a Digital to Analog
> > converter, drive the analog meter. "Average" meter readings are always a
> > function of the "averaging time constants"
> > in the meter and the "time varying levels" of the waveform being measured.
> > These are almost never the same
> > and, unless you are using a "very high sampling rate meter" - like the
> > LP-100- that then does the math to
> > compute an average, the readings are - at best - relative and approximate.
> >
> > I never use the Orion meter to give me power readings, except on CW,
> > because
> > I have never figured out what
> > they really meant. I think on "time varying signals," you are better off
> > to
> > use an external "peak reading meter"
> > to set the Orion peak power and then accept the average power that results
> > from the time varying input signal.
> > If there is concern for "intermodulation distortion," then you can reduce
> > the peak Orion RF power to a level where
> > you believe the Orion will be "most linear," - maybe down 3dB to 6dB below
> > the Orion's rated RF power output.
> > Of course, this doesn't ensure a clean output signal. You can reduce the
> > Orion RF peak power output and still have
> > an audio overdrive situation - creating signal distortion in the audio
> > before it gets to the RF drive of the Orion.
> > In the case of signals that are very sensitive to distortion, such as
> > PSK31,
> > an external monitor - such as the
> > "PSK31 Meter" display monitor may be more useful then power meters to
> > assure
> > a good output signal. If you
> > have a time varying signal like voice, then you can use the Orion
> > compression, with a high sampling rate, - which
> > is some of the best I have ever seen for voice (See
> > http://lists.contesting.com/archives//html/TenTec/2009-02/msg00075.html )
> > - to increase the average RF Orion output power. The Orion meter still is
> > only giving a "relative" power measurement.
> > 73, Merle - W0EWM
> >
> >
> > _______________________________________________
> > TenTec mailing list
> > TenTec@contesting.com
> > http://lists.contesting.com/mailman/listinfo/tentec
> >
>
> _______________________________________________
> TenTec mailing list
> TenTec@contesting.com
> http://lists.contesting.com/mailman/listinfo/tentec
_______________________________________________
TenTec mailing list
TenTec@contesting.com
http://lists.contesting.com/mailman/listinfo/tentec
|