[time-nuts] ARRL 2006 Frequency Measuring Test

Mike Suhar msuhar at woh.rr.com
Thu Oct 19 08:55:16 EDT 2006


I have participated the past few years mostly with the N8UR multi-op group.
My setup is as follows:

1. Receiver: Icom IC-745 or the Yaesu FT-100D (I threatened to use a
Hallicrafters SX-25 one year)
2. PC with sound card running DL4YHF's Spectrum Lab for the FFT work. The
receiver audio feeds the soundcard so it can be displayed using Spectrum Lab
3. HP 8657A signal generator using external 10-MHz reference from GPS and
Z3801 or Rubidium 10-MHz oscillator
4. Home made splitter connecting antenna, receiver, and signal generator
5. If multi-op a home made amplifier buffer is used ahead of the splitter to
prevent my signal generator from back feeding the antenna system to the
other participants.


The process is to locate the W1AW signal on the receiver and Spectrum Lab
waterfall display.  I then bring the signal generator online and insert a
carrier near the W1AW signal.  I measure the difference between the signal
generator audio tone and the W1AW audio tone as observed by Spectrum Lab.
Spectrum Lab is setup to record a WAV file so I can post-process the data if
needed.  I also have Spectrum Lab set to output the readings to a text file.
This way I can pull them into a spreadsheet to do the calculations and
average the readings.  Since I know the frequency of the signal generator I
can calculate the carrier of W1AW using the difference in audio tone between
my generator and W1AW. If they want us to measure an audio tone as last year
the same setup applies.  When doing the calculations you just have to
remember if the receiver was in LSB or USB and which side of the W1AW signal
the signal generator was on.  

I participated last year but ended up messing up the data files so I did not
make a submission.  In the tests I participated my readings were within the
same range as N8UR's.

I have used the same setup for measuring signals on HF, TV carriers and the
HDTV pilot signals.  It is amazing how many TV signals I can detect using
the ICOM R-7000 receiver, Discone antenna up 60-feet, and Spectrum Lab to
dig the carriers out of the noise.  In the case of channel 3 I can detect
three analog TV carriers because of the carrier offsets (+/-/0).  I think
they are from Huntington, WV, Louisville, KY, and Cleveland, OH.


Mike
WB8GXB


W4wj at aol.com wrote:
>  
> In a message dated 10/18/2006 12:26:09 A.M. Eastern Daylight Time,  
> kb7nie at arrl.net writes:
>
> The  November QST has an announcement for the "2006 Frequency Measuring
Test"
> (  www.arrl.org/w1aw/fmt - though the 2006 announcement has not made it to
> the  website yet).  The object is to determine as accurately as possible
the
> carrier frequency of a signal sent from W1AW on the 160m, 80m and  40m
> bands.  There will also be a signal sent from the west coast on  the 40m
> band.  A lot of time nuts are hams.  Who plans on  participating?
>
> Henry
>   


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