[Elecraft] P3: Can the Panadapter be used with a Ten Tec Orion 1?

[Lu Romero]

Hi Don:

Thanks for the response.  

Maybe Im not clear regarding what Im trying to do.

I have a dozen TenTec Orion 1's at a multi multi operation I
play at.  Im tasked with "standardizing" the audio
parameters for this operation in regards to compression and
frequency response before CQ WW SSB.  We want to make sure
that all the rigs sound as good as they can sound and have
consistent levels.  People play with these radios over the
ensuing months, so they are usually diddled to death by the
time I get there.

I have done this in the past "by ear".  That is, I have
plugged a given rig into a dummy load and diddled with the
audio settings until I got it to sound "right".  I wrote
down all the settings and went to another radio.  I set that
radio on a dummy load and input all the settings I wrote
down on the first radio.  I used the same microphone, the
same audio path and made sure the radios were at the same
software revision.  Lo and behold, the second radio sounds
different than the first with exactly the same numbers in
the software!  I have found in practice that no two Orions
sound the same, using exactly the same numbers and exactly
the same microphone and exactly the same voice (mine).

What I want to do is inject pink noise from a Flash Memory
WAV player that has a track from the NAB Audio Reference
disk.  I have the WAV player set to loop the file forever. 
Feeding it through a Radio Design Labs line level to mic
level amplifier block, the level coming out is 0 VU mic
level at a nominal 600 ohms impedance.  I want to feed this
into the mic input of the Transceiver under Test and, with a
"spectrum analyser" looking at the output of the audio
monitor circuit (yes, not ideal, but it gets me in the
ballpark) "see" where Im at.  I trust my ears, but it would
be nice to be able to see the waveform on the SA.  Knowing
where I am at, I can then adjust the rig's settings and even
"pre-distort" the audio input from external processing
(several transceivers are driven through W2IHY processors)
to optimize drive, punch and inteligibility.

As I said, I have done this "by ear" in the past.  But now I
have a P3.  I can do exactly the same thing on my personal
K3 by disconnecting the serial connection.  I can then see
the output of the rig in the P3 via IF leakage, and I was
able to look at what pink noise looks like at my personal
station and the effect of applying EQ to the pink noise
VISUALLY on the P3. I could do what I have to do faster on
the Orions if I could SEE the waveforms.  It would save me
time I can use otherwise at this station. 

What I would like to know is if the P3 can, using any IF
leakage from the Orion's IF out, do the same thing as I can
do on my K3. Im not looking for any laboratory grade results
here, Im just looking for a ballpark image of the modulation
envelope that includes frequency domain information so I can
judge the "flatness" (or lack thereof) of the audio
frequency response of a given Orion rig.  This way, I can
twiddle the knobs and "match" the rigs as closely as
possible to a "consistent" starting point since the same
identical numbers dont seem to have indentical results 
across Orions as they do on K3's.  If the numbers gave
repeatable results across several Orions, I wouldnt have to
do this! I would just input the numbers into all the rigs
and have a consistent starting point for tweaking.  

I want to use what I have on hand, I dont want to go out and
spend money or time building things.  If I was still at my
old TV station, I would borrow the Tek Spectrum Analyser at
the transmitter, or the Anchor audio analyser at the studio
and be done with it, but I dont work there anymore and dont
have access to these tools, so I wanted to use what I had on
hand.  

Guess I will just have to try it and see if it works!  Or
maybe I will look on the web for a freeware or shareware
audio baseband spectrum analyser which runs on a PC laptop
which I can then plug into the headphone output of a given
Orion and observe the waveform there.  

I was just curious if someone had used the P3 for something
like this in the past.

-lu-w4lt-

Message: 17
Date: Sun, 23 Oct 2011 23:40:35 -0400
From: Don Wilhelm <w3fpr at embarqmail.com>
Subject: Re: [Elecraft] P3: Can the Panadapter be used with
a Ten Tec
    Orion 1?
To: elecraft at mailman.qth.net
Message-ID: <4EA4DE33.6020402 at embarqmail.com>
Content-Type: text/plain; charset=ISO-8859-1; format=flowed

Lu,

I don't like to discourage list members away from Elecraft
products, but 
I do not know if the P3 will do the task you are asking
about - it 
depends on what other equipment you have to use along with
the P3.  Yes, 
the P3 can do the job IF you have the other equipment to run
it for your 
immediate purposes.

I would suggest that you also investigate the "Simple
Spectrum Analyzer" 
by G4AON used in conjunction with Spectrogram or SpectrumLab
or other 
computer based FFT audio spectrum analyzer.
You can find information on the resistive tap and the mixer
at 
http://www.astromag.co.uk/ssa/.  This is an adaptation of
the 40 dB 
resistive tap from the W7ZOI Power Meter along with a mixer
to bring the 
signal down to baseband where it can be analyzed with an
audio FFT 
spectrum analyzer.

73,
Don W3FPR