K5CM FMT June 6, 2012 (9 PM CDT)
K5CM 20 - 14140003.754 with a reference of 14120000.000 (20 Khz delta)
WB6BNQ, and K7HIL continue their streak of "zero error" readings, with W8XN joining in this week. I have to say pretty impressive considering the 20 KHz delta. Lots of close readings continue to point to the fact that a reference signal can be use to great advantage. It will be interesting to see if we will see a gradual loss of correlation or there might be a sharp knee as we continue to a higher delta.
Take a look near the bottom of the page, at the pdf from K7HIL, and the spectrograph from W3JW.
Assuming various transmitter problems can be solved, the next planned delta will be 200 KHz.
K5CM 20 Meters (9:00 CDT)
|Call||Section||Grid||TX Frequency||Measured Freq||Error in Hz||Error in PPX|
|K7HIL||AZ||DM42ph||14140003.754||14140003.754||0.000||0.00E+00||Was able to reduce three antenna directions. Average was 14,140,003.753998. Individual measurements were ESE=14,140,003.753881, WNW=14,140,003.754092 and S=14,140,003.754020. Apparent Doppler was worst seen yet, variations of up to 300 mHz and was pleasantly surprised after reducing the data. Great job Connie, appreciate all the effort you are making.|
|WB6BNQ||SDG||DM12||14140003.754||14140003.754||0.000||0.00E+00||To do the 20KHz spacing had to use my IC-765ProII and main computer which have no temperature or frequency stability. Based upon the recorded error differences from Sunday and Monday’s tests, I applied a correction factor of 14 milli-hertz to my derived 14,140,003.740 from Wednesday’s run for the reported value. The only usable part of the run was the last, i.e., South direction signal.|
|W8XN||MI||EN82DG||14140003.754||14140003.754||0.000||0.00E+00||I let the computer guess the frequency this time -- no human intervention -- so I could be way off. Large Doppler spread with very ragged looking peaks, but near zero shift over my averaging time. Thanks for another fun test, Connie. On to 200 kHz!|
|N7AIG-ESE||AZ||DM42||14140003.754||14140003.752||-0.002||1.41E-10||Lots of differential Doppler dispersion across 2-5 Hz bandwidth|
|NF6Z-W||NV||DM26||14140003.754||14140003.752||-0.003||1.77E-10||Recorded n USRP controlled with gnuradio companion. Programmed a receiver with 2 channels separated by 20kHz. Looked at delta-f between the two. Got much more variation than at 2kHz separation. Averaged over interval when separation was nearly constant.|
|W3JW-ENE||VA||FM17TN||14140003.754||14140003.757||0.003||2.12E-10||The data from the ENE run was my second best data set. There was a significant amount of doppler shift during this run however. The traces look like a snake. They have high level of correlation though.|
|W3JW-ESE||VA||FM17TN||14140003.754||14140003.757||0.003||2.12E-10||The ESE transmission produced the "Best" data at this QTH. This result is the average of all data points produced by the SL export file tool during the ESE portion of the test. There was a noticable amount of "wiggle" in the waterfall trace. Tnx fer the gud test.|
|NF6Z-NNW||NV||DM26||14140003.754||14140003.750||-0.004||3.18E-10||Same as NF6Z-W|
|N7EP||WWA||cn87uk||14140003.754||14140003.763||0.009||6.36E-10||My equipment was a ICOM 746 Transceiver and Spec. Lab. Software. No WWV or Sound card calibration. The Doppler shift averaged about 1 Hz but I didn’t measure it. I set the two FMT frequencies for receive tones of 1000 and 1002 Hz in memory. Then eve|
|NF6Z-ESE||NV||DM26||14140003.754||14140003.763||0.009||6.58E-10||Same as NF6Z-W. This one was pointing away from me. Much better signal than those near 90 degrees.|
|ve3dnl_run3||ON||FN03||14140003.754||14140003.743||-0.011||7.78E-10||Run 3 at about 10:08 p.m. EDT. Signals are a little weak, but still decent SNR. 22050.02 s/s. 262144 FFT, no decimation. Average of about ten FFTs with 50 % overlap.|
|ve3dnl_run2||ON||FN03||14140003.754||14140003.740||-0.014||9.90E-10||This is second run @ 10:05 p.m. EDT. Strongest signal of all the runs. Still am not confident in Spectrum Lab's peak-finding setup. 22050.02 s/s . 262144 FFT, no decimation. Average of about 15 FFT's. Used 14120000.0 as a reference for lower peak. I have no locked, stable references (yet).|
|ve3dnl_run1||ON||FN03||14140003.754||14140003.721||-0.033||2.33E-09||From first run @ 10:00 p.m. EDT. Receiver is direct conversion homebrew with 25 Khz. bandwidth. L.O. placed at 14.13 Mhz. Two audio peaks near 10Khz. processed by SpectrumLab. Am not confident that soundcard is calibrated, or that peak-finding is accurate. Have WAV recorded files.|
|K6BZZ||AZ||DM33xb||14140003.754||14140003.809||0.055||3.89E-09||WNW strong, W stronger. Reading from W. Hetrodyne method.It gets more and more interesting, hi. Thanks Connie.|
|KM6QX-W||EB||CM87||14140003.754||14140003.699||-0.055||3.89E-09||Delta-F didn't work out with the Flex-1500 MultiRX VFO-B, so this guess is a single frequency measurement with SpecLab. I picked a somewhat consistant peak about 10 dB below the main smear of Doppler shifted signals. This peak, measured on the W run, did not appear on the NNW run.|
|N4AU||AL||EM62vp||14140003.754||14140003.840||0.086||6.08E-09||ESE signal weak and in local noise. Used Spec Lab and made guess.|
|N4AU ESE||AL||EM62vp||14140003.754||14140003.840||0.086||6.08E-09||Weak signal in local noise. Made a guess using Spec Lab and spread sheet. Measured the REF signal, then the Unknown and calculated the difference.|
|N4AU||AL||EM62vp||14140003.754||14140003.640||-0.114||8.06E-09||ESE signal very weak and in the local noise. Lot of guessing here. Used SpecLab and spreadsheet calcs.|
|N4AU S||AL||EM62vp||14140003.754||14140003.639||-0.115||8.13E-09||Slightly better signal in local noise. Made a guess using Spec Lab and spread sheet. Measured the REF signal, then the Unknown and calculated the difference. Considerable difference in the S and ESE signals.|
|W6IHG||VA||FM09tb||14140003.754||14140003.610||-0.144||1.02E-08||Flex5000, HP3336, Tbolt. Used two receivers, AM on unknown sig (my first time to try that technique) and CWL on known sig. Measured sigs direcly in two instances of SL, then had to use the delta because of strong beat note in freq. ESE and ENE gave me same answer for a change. Thanks Connie for keeping us amused. Jerry|
|NO5K-W||STX||em10CM||14140003.754||14140003.546||-0.208||1.47E-08||Not sure about direction. This is from data taken at 02:15 until 02:16, I could not pull out the directional ID, Key-down was strong then a deep fade - gone. The CW that I was able to fish out was at 02:26 which was the sign off.de NO5K|
|W6OQI||LAX||DM04vf||14140003.754||14140003.536||-0.218||1.54E-08||Doppler was the least when K5CM beamed East and South. K5CM beaming West had the strongest signal and the most Doppler. It was as if the frequency changed when K5CM beamed south, 14140003.428 Hz compared to 14140003.536 Hz while beaming East. I measured the pilot signal but did not use it in my calculations.|
|N05K-S||STX||EM10cm||14140003.754||14140003.305||-0.449||3.18E-08||The usual poor signals and High Noise level here, a real antenna would help. The SSB in the middle was interesting, no problem just 20 dB stronger than FMT. I think this entry is for 'South' it was at the end and 2-6 db over the NF. This time I used the 1500, John's DBM method and included a small amp, narrow BPF and LPF. Sure looks/works great with two sig gens! FMT Signals I could see were in the noise and usualy moving Hz. Thanks for the effort.|
|K6IQL||KS||EM28nq||14140003.754||14140003.267||-0.487||3.44E-08||Did not use 14.120 reference. Submitted Data is NNE based upon a measurement of unknown frequency only. Noted WNW to be higher in frequency by perhaps 200 mHz, but did not use that info in arriving at my solution. Solution based upon straight numerical data reduction. Crystal Ball battery dead. Thanks Connie -73 john k6iql.|
|W7FU||WWA||CN87xo||14140003.754||14140003.201||-0.553||3.91E-08||K5CM-WNW GPDSO, SDR with second receiver to translate REF signal into passband of UNK signal. Thank you John, K6IQL, for such a straightforward design. Worked like a charm. Recorded I/Q stream and analyzed at AF. Experimented with "pattern drift" frequency analysis using an O'scope and function generator. Fraught due to phase shifting of propagated signals. Goal for this test is to experiment with alternative and potentially more accurate analysis method. Can only hope.John, W7FU|
|John||WWA||CN87xo||14140003.754||14140003.194||-0.560||3.96E-08||K5CM-WNW Same equipment line up and acquisition method as W7FU. AF analysis with direct count using 150 sec gate times. Average of three readings. Goal for this test is to achieve reasonable accuracy, with basic equipment and minimal interpretation ambiguity. Total analysis time: 10 minutes. Thanks for a great test. John, W7FU|
|KG0HY||NE||EN20||14140003.754||14120000.000||Signals were -110db, with a slight echo. Used a WinRadio G313 and a HF vertical. Spectrum Lab was showing a steady tone on all six transmissions.|
This from Michael, K7HIL
This from Jeff, W3JW. A 20 KHz delta practice run. Despite the noise, notice the correlation in the two signals which are 20 KHz apart.
Transmitting equipment used by K5CM for this FMT:
A HP Z3801 GPS frequency source clocks a HP-3336B and a PTS-250. The outputs are combined and feed to a 10 db transistor amp which drives a 12BY7 / pair 6146. Then to the final amplifier, a Dentron 2500 running 300 watts out. Each signal was first set to 150 watts out. There are no mixers or any device in the chain of amplifiers that might impact the accuracy of the GPS frequency source. As a reality check, I periodically log the frequency source against WWV and other GPS referenced sources. I monitor each transmission with a completely separate receive system to look for any instability or short term drift.
I typically see considerably less than 1 mHz difference at 10 Mhz when comparing two Z3801's or a Z3801 and a Thunderbolt, over a 10 to 10,000 second period.
160 - Vertical
80 - New Sloping dipole. Sloping down from 140'. (favors West, North, East)
40 - Standard Dipole hanging between two 80 foot towers. (favors East, West)
20 - 4el SteppIR at 70'
Current W6OQI FMT transmitting equipment for this FMT:
My Transmitting setup consists of a HP Z3801 clocking a HP 3336B which drives a Johnson Viking I transmitter, the output of which is attenuated by a 6 db attenuator, to then drive an Icom PW-1 amplifier to about 500 watts. The antenna is an inverted Vee which favors north and south from the Los Angeles area.
Note: Because I put the results up quickly, there will be mistakes, so don't hesitate to point them out quickly.
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