[TenTec] OMNI VI Transmit IMD [6+]

[George, W5YR]

Well, Mike, I think that you are exaggerating for the sake of humor. <:}

Some of the simple things that I have done with the PRO, as well as my
other radios, are

1. measure the transmit power bandwidth - r-f power output vs audio
frequency

2. measure and plot the spectral responses of the audio/DSP section for all
filters and    modes

3. measure the transmit harmonic and intermodulation distortion for single
and multiple    audio frequency inputs

4. measure the actual PSK31 IMD performance

All these measurements have given me a much better idea of what MY radio
can do - not the sample tested by ARRL or the generalized spec radio quoted
by Icom. With this information, I have been able to do a better job of
designing and matching the audio equipment I use for transmit and receive
with the PRO since I avoid using any of the internal analog audio
circuitry. Result: broadscast quality receive audio and the best sounding
audio I can achieve in the transmit bandwidth with out creating any
splatter or spurious signals. I also use a modest amount of outboard audio
control and processing equipment. Not the massive overkill of the 14178
guys, though . . .

And - you will like this! - I monitor all audio into and out of all the
radios on a scope at all times, as well as monitoring the r-f output
envelope of the transmitters whenever I am transmitting - and that on all
modes. I have constant info as to what the rig is putting out and a good
look at what the receiver is putting into the speaker or headphones. Why?
Just curious and want to ensure that what comes out with my call on it is
as good as I can make it.

Again, Mike, the difference is between buying something in a box, plugging
it in and using it and knowing what your specific something will do and
making best use of its capabilities. As an engineer I am always wanting to
try new things with the radio and having knowledge of its specific
characteristics is necessary.

The appliance operator, like the CBer, takes it out of the box and fires up
and talks to people. Fine - I do the very same thing. But, most of the
time, I also have a pretty good idea what is happening inside that box and
know that I am using it in the best possible manner for my needs.

When I get around to building my TenTec 30-meter QRP transceiver, you can
bet that it will get exactly the same treatment!   <:}

I know - curiosity killed the cat!   <:}

Again, each to his own . . .

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


Mike Hyder -N4NT- wrote:
> 
> I just had visions of a guy buying a television set, hauling it home,
> taking it apart and running endless tests to see if it does as Consumer
> Reports said it does.  Or buying a car and setting it up to test its
> horsepower, compression ratio, etc.  There is nothing wrong with doing
> these things -- it's just sorta amusing for me to think of it.
> 
> 73, Mike N4NT