The MVUS FMT:
October 2007 Results
These are the results of the Midwest VHF/UHF Society Frequency Measuring
Test held on 13-14 October 2007 (UTC).
(Updated 10 Dec. 2007)
The Winners
Nineteen people submitted measurements, and they show just how well it's possible to measure HF frequencies if you're slightly crazed. As described in more detail in the results section below, we chose winners based on the average offset of their measurements, divided by the number of measurements submitted.The clear winner was Connie, K5CM, who had the lowest average offset by almost two orders of magnitude, submitted fifteen measurements and thereby ended up with a weighted offset an order of magnitude lower then any other entrant, and tied for having the single best measurement. Only one of Connie's measurements was more than 1x10-9 in error. Connie wins the grand prize, a certificate for any TAPR time and frequency product. Congratulations, Connie!
We awarded four runner-up prizes to Jeff, W3JW, Bill, VE2IQ, Brad, Wb9FIP, and Martin, VE3OAT, who all had weighted offsets in the low 10s. All four did a great job.
Finally, we wanted to recognize that folks west of the Rockies had a special challenge receiving our modest signals from Ohio. So, we are giving the "DX" award to Richard, W5UFZ, who managed to turn in an average offset in the 9s despite the weak signals heard in Arizona.
Jeff, Bill, Martin, and Richard all win certificates for an ARRL Handbook or equivalent value from the ARRL store.
Thanks to ARRL and TAPR for their generous prize donations.
The Frequencies
The "W8KSE Calculated" frequencies shown below are the official results; the "N8UR Measured" frequencies serve as a cross-check.Details of the frequency generation/transmission system, and the N8UR monitoring system, are at the 2007 FMT Description page, and here's a photo gallery showing the hardware.
Below the chart are some comments about the transmissions.
W8KSE Calculated |
N8UR Measured |
Difference (N8UR-W8KSE, Hz) |
Offset (N8UR-W8KSE) |
|
Afternoon Run | ||||
3 554 412.014 889 | 3 554 412.014 670 | -0.000 218 | -6.145E-11 | |
3 554 412.014 889 | 3 554 412.014 890 | 0.000 002 | 4.478E-13 | |
3 554 406.014 889 | 3 554 406.014 819 | -0.000 070 | -1.957E-11 | |
7 056 588.029 559 | 7 056 588.029 183 | -0.000 376 | -5.329E-11 | |
7 056 588.029 559 | 7 056 588.029 596 | 0.000 037 | 5.235E-12 | |
7 056 577.029 559 | 7 056 577.029 556 | -0.000 003 | -3.859E-13 | |
10 114 763.742 369 | 10 114 763.742 435 | 0.000 066 | 6.552E-12 | |
10 114 763.742 369 | 10 114 763.742 445 | 0.000 076 | 7.541E-12 | |
10 114 767.542 369 | 10 114 767.542 444 | 0.000 075 | 7.429E-12 | |
Evening Run | ||||
3 561 316.014 881 | 3 561 316.014 850 | -0.000 030 | -8.512E-12 | |
3 561 337.014 881 | 3 561 337.014 816 | -0.000 065 | -1.825E-11 | |
3 561 294.014 881 | 3 561 294.014 880 | -0.000 001 | -2.465E-13 | |
7 060 586.029 502 | 7 060 586.029 604 | 0.000 102 | 1.450E-11 | |
7 060 607.029 502 | 7 060 607.029 690 | 0.000 188 | 2.659E-11 | |
7 060 569.029 502 | 7 060 569.029 533 | 0.000 031 | 4.352E-12 | |
10 111 367.542 250 | 10 111 367.542 305 | 0.000 056 | 5.519E-12 | |
10 111 388.642 250 | 10 111 388.642 286 | 0.000 036 | 3.571E-12 | |
10 111 348.642 249 | 10 111 348.642 289 | 0.000 040 | 3.912E-12 |
Here is a spreadsheet showing the raw data and the calculations done to reach the final numbers:
XLS | ODF (OpenOffice) |
We had a few glitches with the transmissions:
- In the afternoon run, the frequencies did not change between
the first and second transmissions.
- Due to a communications error, the 80 and 40 meter synthesizers
were not run in low phase noise mode. While the increased phase noise
was probably not visible by the time the signals got to you, as a
consequence the generators on those bands had 1 Hertz rather than
0.1 Hertz resolution, and the signals on those bands were transmitted with
a nominal .0 Hertz as the last digit (but that .0 turns into something
else after correcting for the frequency standard offset).
- We had an Ameritron AL-1200 amplifier in line on the 80 meter station.
During the afternoon run, RF interference issues in the keying matrix
caused transmitted power to drop be 2 to 3 dB from nominal levels.
- Because of crowded band conditions and a desire to minimize QRM, we did not use the amplifier for the evening run.
We averaged the offsets of all the measurements submitted by each entrant;
that is the "Average Offset" column in the table below. To give credit
for those who were able to take multiple measurements, we then divided the
average offset by the number of measurements. That result is the
"Weighted Offset" column, and is what we used to rank the entries.
We felt that those west of the Rockies had a special challenge in
measuring our modest signals, so in addition to the top four winners, we
selected the lowest weighted offset from the Mountain or Pacific time
zones for a special award.
Here is a spreadsheet showing the data and formulae used to generate the
results:
The Minimum and Maximum Offset columns show the absolute value (i.e.,
ignoring the sign) of the best and worst measurements submitted. One of
the things we learned in the process of putting these results together is
that Excel sorting and min/max functions don't deal well with negative
numbers...
The Results
Our goal in scoring the entries was to recognize both absolute accuracy in
frequency measurement, and the ability to measure as many as possible of
the eighteen transmission segments. To do that, we first converted each
submitted measurement to a fractional frequency offset using the formula:
Frequency(transmitted)
MVUS FMT October 2007 Results
Absolute
Average
Number of
Weighted
Minimum
Maximum
Name/Call
Offset
Measurements
Offset
Offset
Offset
Connie, K5CM
-1.648E-11
15
-1.099E-12
3.131E-11
1.213E-9
Jeff, W3JW
2.146E-9
13
1.651E-10
3.131E-11
1.815E-8
Bill, VE2IQ
-2.609E-9
13
-2.007E-10
2.043E-10
5.005E-8
Brad, WB9FIP
-2.155E-9
9
-2.395E-10
2.500E-10
2.720E-10
Martin, VE3OAT
1.949E-9
8
2.436E-10
4.319E-10
2.516E-8
John, WA1ABI
3.002E-9
3
1.001E-9
1.999E-9
4.461E-9
Paul, KB8MOU
-1.084E-8
8
-1.355E-9
9.879E-10
3.782E-8
Jay, N5PWG
-6.496E-9
3
-2.165E-9
2.732E-9
2.989E-8
Richard, W5UFZ
-7.359E-9
3
-2.453E-9
1.388E-8
3.738E-8
John, KD2BD
-9.109E-9
3
-3.036E-9
2.687E-9
1.631E-8
Burt, K6OQK
-2.413E-8
7
-3.447E-9
2.732E-9
8.561E-8
Marvin, W6OQI
-4.452E-8
6
-7.421E-9
1.834E-8
1.390E-7
Jim, K6APW
-2.396E-8
1
-2.396E-8
2.396E-8
2.396E-8
Wally, W0PHD
3.677E-7
8
4.596E-8
4.189E-9
3.057E-6
Phil, W1PW
-2.280E-7
3
-7.600E-8
2.204E-7
2.318E-7
Mike, AA8K
8.163E-7
9
9.070E-8
2.001E-8
8.169E-6
Richard, WA2IKL
2.313E-5
1
2.313E-5
2.313E-5
2.313E-5
Henry, W2HV
7.777E-5
3
2.592E-5
4.697E-5
1.113E-4
Roberta, VA3RMW
3.818E-5
1
3.818E-5
3.818E-5
3.818E-5
PDF
XLS
ODF (OpenOffice)