August 29, 2007 RESULTS
17M run 6:00PM CDT 20M run 6:30PM CDT 40M run - 9:00 PM CDT 80M run -9:30 CDT
West coast run - 10:00 PM CDT
K5CM TX Frequency :
80 Meters A - 3555801.5 Hz
80 Meters B - 3555905.224 Hz
Difference - 103.724 Hz
40 Meters - 7055443.864 Hz
20 Meters - 14055246.439 Hz
17 Meter - 18073707.747 Hz
W6OQI TX Frequency:
40 Meters - 7065374.586 Hz
Sort by best 80 meter difference reading (103.724 Hz)
Sort by best 40 meter reading ( 7055443.864 Hz)
Sort by best 20 meter reading ( 14055246.439 Hz)
Sort by best West Coast 40 meter reading ( 7065374.586 Hz )
|AF9A||IN||Great signal on 40, 9+20. Your signal on 20M was down in the noise on your east antenna, didnít hear you at all on the west.|
|K5CM||OK||Marvin's signal was strong at times, but the Doppler looked like a snake crawling up the screen. Thanks for doing the WC run and giving me a chance to copy an FMT also|
|KC0VSJ||MO||New equipment tonight. Learning to use a 3586 is like starting over, but it has major advantages (stability) over the Corsair. First time I could ever really see Doppler and know it wasn't receiver drift|
|K6APW||CA||3.5 in noise, both 7 good S8|
|K6YAZ||CA||Nothing heard at all on 17 meters. I am using a dipole, oriented in favor of your QTH. Very weak on 20; using 3 element beam. Best guess is 14.055, 242.2, but too weak with QSB to really pin it down.|
|KD2BD||NJ||Very weak signals were copied using a 'solid-stated' Hammarlund HQ-140-X receiver in AM mode. An audio oscillator tuned with a multi-turn pot was compared to received audio on aTektronix 465 scope until a somewhat stable Lissajous pattern was generated. The audio generator's frequency was measured using a homebrew frequency counter using WWVB as a timebase. Almost continuous Doppler shifting was observed.|
|N5PWG||TX||No signal heard on 17 and 20 meters, but I had the 80 meter antenna on, oops. Good WC signal, even with the 80 meter antenna.|
|N8OB||OH||I wasn't able to copy anything on 17 ot 20 meters. I couldn't stay up late enough to try the WC|
|VE2AZX||QC||80m sig was 57,40m was 59+,No copy on 20m and 17m. Thanks for running the FMTs.|
|W0PHD||MN||did not know about the 17 meter I was going by earlier release. did not Hear anything of you on 20 meters. found the A" Signal on 3555801.825 but never heard the B signal so no difference to report"|
|W1PW||AZ||Sorry I missed your 18 MHz and 14 Mhz tests. The remaining test results are included, but the WC signal was so weak as to be nearly imaginary. 40 Meter skip from CA to AZ must have been nonexistent at that particular time.|
|W3CSW||MD||We tried the AM mode on the 2-tones this time and leaned a lot more about SL tks agn Connie|
|W3JW||VA||Conditions were average with moderate to low QRN. Doppler effects were moderate but quite noticeable (both on the test signals and WWV). The cleanest display of the evening was for the 8o meter two signal test, using the AM mode.|
|W5UFZ||AZ||Thanks again for running the FMT. Lots of fun.|
|W6OQI||CA||In Southern California K5CM signals were good on 80, 40, and 20 but nothing was heard on 17 meters. I copied and measured K5CM on 20 meters when Connie was beaming east but his signal improved a lot when he beamed west. Sorry about the CW keying problem from W6OQI this evening. The old Viking 1 transmitter did not want to key with the AC line voltage down to about 98 volts due to hot weather. At nine PM it was still 90 degrees this evening|
|WB9FIP||WI||The effect of selective fading was easily seen on the two tones. Thanks for combining propagation study with the FMT.|
|WA1ABI||RI||My first K5CM FMT. I used a WJ-8718A receiver and a laptop to record audio tones for all the tests. For the 80m test, I had the rx in AM mode with a 300 Hz filter. I tuned to the center of the two carriers to get the most recovered audio. All freqs were measured using Spectran on the audio recordings. The receiver was slaved to a rubidium 5Mc external reference, which I discipline manually every now and then to an HP GPSDO. I disciplined the Rb about two weeks ago, so it should be within a few parts in 10E-12. The 80m recovered audio was rock solid on Spectran, probably because any Doppler affected both carriers in the same direction. The other tracks were quite wobbly, though. Those freqs are best guesses. Thanks very much for running these tests. 73 John|
See a screen shot of W6OQI's signal as copied by K5CM. The reference marker (7065368 Hz) is at zero on the ruler. Hear a short clip of W60QI.
Jacques, VE2AZX, put together some very interesting graphs of my 80 meter difference run and my 40 meter run. His perfect reading of the difference frequency was done with AM mode and Spectrum Lab. Here is a screen capture generated by Jacques wave file, but I increased the FFT/Decimate to 32K/64. Almost the entire file is required to generate the first FFT. Notice the straight line. (hit f11 for best view).
John, WA1ABI, shows that almost all Doppler is canceled by measuring the difference of the two 80 meter signals in AM mode. This was John's first FMT with the group. He had a great start with a sub 10 mHz reading of the difference frequency.
No one was able to copy the 17 meter signal. Then again, were at the bottom of the sunspot cycle and still in summer time conditions so this is not surprising.
It was interesting to see how important soundcard calibration becomes when measuring the difference frequency. Being off only 1 mHz (.001 Hz) causes a 10 part per million error at the audio frequency. When most of the Doppler is removed from the equation, calibration becomes paramount.
Stations copying K5CM 80 meter difference run to .01Hz or better
VE2AZX*, WB9FIP*, W3CWS, W3JW, WA1ABI
Stations copying K5CM 40 meter run to .1Hz or better
W0PHD, W3JW, W1PW
Stations copying K5CM 20 meter run to .1Hz or better.
Stations copying W6OQI "West coast run" to .1Hz or better.
Transmitting equipment used by K5CM for this FMT:
A HP-Z3801 GPS clocks a HP-3336B and a PTS-250. A small 10 db transistor amp follows and drives a 12BY7 / pair 6146. Then to the final amplifier, a Drake L4B at 300 watts output except on 30 and 17 meters where the power is 75 watts. There are no mixers or any device in the chain of amplifiers that might impact the accuracy of the HP-Z3801. As a reality check, I periodically log the HP-Z3801 against WWVB.
80 - Cage Dipole (favors East, West, and North)
40 - Dipole (favors East, West)
20, 17 - 4 element SteppIR (First beaming 70 degrees then another run beaming 280 degrees)
Current W6OQI FMT transmitting equipment:
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.
Thanks to all that participated, and have a great Labor day weekend.
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