ARRL FMT Results

Results - April 18, 2025 FMT

Actual Radio Frequencies (Hz):
	80m	40m
K5CM		7,064,265.37
W8RKO		7,065,131.30
K5CM	3,598,258.36
W8RKO	3,598,995.90

K5CM,W8RKO,K5CM,W8RKO All (<=1.0 Hz):
AA3I, AA6LK, AB4RS, AC9LV, AF1R, AF9A, AJ4YA, AJ5P, K0MZ, K1MU, K4PPK, K5CM, K5ND, K6LL, K9JM, KB3HF, KB4XR, KC3VNB, KD2BD, KD5MMM, KD8RV, KE2N, KF7NP, KI5EE, KN1H, N0PFE, N1IRO, N3CRT, N3FG, N4PAJ, N5TNL, N7QXB, NO6B, VE2IQ, VE3GSO, VE3PIK, VE3YX, VE3ZRK, W1QG, W2FD, W3JW, W4IVF, W5AJ, W5SSV, W7SUA, W9GR, W9INE, W9ZB, WA1SXK, WA2DVU, WA3YDZ, WA5UCW, WA7BNM, WB7ABP, WQ8T

K5CM 80 (<=1.0 Hz):
AA3I, AA6LK, AB4RS, AC9LV, AF1R, AF9A, AJ4YA, AJ5P, K0MZ, K1MU, K4CXX, K4PPK, K5CM, K5ND, K6LL, K7NG, K9JM, KA8BRK, KB3HF, KB4XR, KC3VNB, KD2BD, KD5MMM, KD8RV, KE2N, KF7NP, KI5EE, KN1H, N0PFE, N1IRO, N3CRT, N3FG, N4PAJ, N5TNL, N7QXB, N8OBJ, NO6B, VE2IQ, VE3GSO, VE3PIK, VE3YX, VE3ZRK, W1QG, W2FD, W2QL, W3JW, W4IVF, W5AJ, W5LAC, W5SSV, W6OQI, W7SUA, W9GR, W9INE, W9ZB, WA1SXK, WA2DVU, WA3YDZ, WA4FJC, WA5UCW, WA7BNM, WB2CMF, WB7ABP, WO7V, WQ8T

K5CM 80 (>1 to <=5 Hz):
KB2HSH, N7WS

K5CM 80 (>5 to <=10 Hz):
KD7KDO

K5CM 40 (<=1.0 Hz):
AA3I, AA6LK, AB4RS, AC9LV, AF1R, AF9A, AJ4YA, AJ5P, IN LIMBO, K0MZ, K0WM, K1MU, K4PPK, K5CM, K5ND, K6LL, K7NG, K9JM, KA8BRK, KB3HF, KB4XR, KC3VNB, KD2BD, KD5MMM, KD8RV, KE2N, KF7NP, KI4NVX, KI5EE, KJ7E, KN1H, N0PFE, N1IRO, N3CRT, N3FG, N4PAJ, N5TNL, N7QXB, N7WS, N8OBJ, NO6B, VE2IQ, VE3GSO, VE3PIK, VE3YX, VE3ZRK, W1QG, W2FD, W3JW, W4IVF, W5AJ, W5LAC, W5SSV, W6OQI, W7SUA, W9GR, W9INE, W9ZB, WA1SXK, WA2DVU, WA3YDZ, WA4FJC, WA5UCW, WA7BNM, WB2CMF, WB7ABP, WO7V, WQ8T

K5CM 40 (>1 to <=5 Hz):
KB2HSH

K5CM 40 (>5 to <=10 Hz):
(none)

W8RKO 80 (<=1.0 Hz):
AA3I, AA6LK, AB4RS, AC9LV, AF1R, AF9A, AJ4YA, AJ5P, IN LIMBO, K0MZ, K0WM, K1MU, K4CXX, K4PPK, K5CM, K5ND, K6LL, K7NG, K9JM, KA8BRK, KB3HF, KB4XR, KC3VNB, KD2BD, KD5MMM, KD8RV, KE2N, KF7NP, KI5EE, KN1H, N0PFE, N1IRO, N3CRT, N3FG, N4PAJ, N5TNL, N7QXB, N7WS, N8OBJ, NO6B, VE2IQ, VE3GSO, VE3PIK, VE3YX, VE3ZRK, W1QG, W2FD, W2QL, W3JW, W4IVF, W5AJ, W5SSV, W7SUA, W9GR, W9INE, W9ZB, WA1SXK, WA2DVU, WA3YDZ, WA5UCW, WA7BNM, WB7ABP, WO7V, WQ8T

W8RKO 80 (>1 to <=5 Hz):
KB2HSH, KD7KDO, W5LAC

W8RKO 80 (>5 to <=10 Hz):
(none)

W8RKO 40 (<=1.0 Hz):
AA3I, AA6LK, AB4RS, AC9LV, AF1R, AF9A, AJ4YA, AJ5P, IN LIMBO, K0MZ, K0WM, K1MU, K4PPK, K5CM, K5ND, K6LL, K9JM, KB3HF, KB4XR, KC3VNB, KD2BD, KD5MMM, KD7KDO, KD8RV, KE2N, KF7NP, KI4NVX, KI5EE, KJ7E, KN1H, N0PFE, N1IRO, N3CRT, N3FG, N4PAJ, N5TNL, N7QXB, N7WS, NO6B, VE2IQ, VE3GSO, VE3PIK, VE3YX, VE3ZRK, W1QG, W2FD, W3JW, W4IVF, W5AJ, W5SSV, W6OQI, W7SUA, W9GR, W9INE, W9ZB, WA1SXK, WA2DVU, WA3YDZ, WA4FJC, WA5UCW, WA7BNM, WB2CMF, WB7ABP, WQ8T

W8RKO 40 (>1 to <=5 Hz):
K7NG, KA8BRK, KB2HSH, N8OBJ, VE3ICH, W2QL, W5LAC, WO7V

W8RKO 40 (>5 to <=10 Hz):
(none)

K5CM 80 (>1 to <=5 Hz):
KB2HSH, N7WS

K5CM 80 (>5 to <=10 Hz):
KD7KDO

K5CM 40 (>1 to <=5 Hz):
KB2HSH

K5CM 40 (>5 to <=10 Hz):
(none)

W8RKO 80 (>1 to <=5 Hz):
KB2HSH, KD7KDO, W5LAC

W8RKO 80 (>5 to <=10 Hz):
(none)

W8RKO 40 (>1 to <=5 Hz):
K7NG, KA8BRK, KB2HSH, N8OBJ, VE3ICH, W2QL, W5LAC, WO7V

W8RKO 40 (>5 to <=10 Hz):
(none)

Entries (n=75):

Call Sign

QTH

Area

Grid

Method/Soapbox

AA3I

FN20if

	80m	40m
K5CM		7,064,265.10 -0.27
W8RKO		7,065,131.01 -0.29
K5CM	3,598,258.21 -0.15
W8RKO	3,598,995.62 -0.28

Method: TS-590S xcvr, old laptop running WSJT-x in frequency cal mode,Bodnar LBE1420 GPS disiplined OSC for freq cal. Copy WSJT data to an excel spreadsheet for avr and cal correction.

Soapbox: Strong signals with QSB. Always enjoy the challenge. Thankyou again K5CM and W8RKO for providing the FMT.

AA6LK

CM98kw

	80m	40m
K5CM		7,064,265.10 -0.27
W8RKO		7,065,130.70 -0.60
K5CM	3,598,258.10 -0.26
W8RKO	3,598,995.60 -0.30

Method: HP Z3805A 10MHz GPSDO, Marconi 2019 HF synth, HP 3325A LF synth, HP 54601A o'scope, FT-847 in AM/narrow mode, 5BTV antenna, Win10 laptop running SpecLab, Digipan for spotting, EZGPIB driving USBserial and Prologix USB-GPIB to control and interrogate the instruments and radio, GPSCon for monitoring Z3805A; the 2019 was set to inject a reference beat signal to produce a ~400Hz beat tone, and the 3325A was manually tuned for minimum phase slip between it and the beat tone as seen on o'scope. Each run was also recorded to a .wav file through SpecLab, though this time I just used the display as a sanity check.

Soapbox: Thanks to the ARRL FMT crew for setting up and running the event. 40m signals were strong but variable, and the 80m signals were weak but not as variable. 73, L-

AB4RS

FM18hw

	80m	40m
K5CM		7,064,265.25 -0.12
W8RKO		7,065,130.78 -0.52
K5CM	3,598,258.03 -0.33
W8RKO	3,598,995.58 -0.32

Method: Used HP3586B Selective Level Meter, locked to 10 MHz reference from Trimble Thunderbolt GPSDO. Sampled IF from the 3586B with computer soundcard and analyzed with SpectrumLab. Used HP3336C frequency generator, also locked to 10 MHz reference, to inject known signal to calibrate sound card.

Soapbox: Weak but readable signals into Northern Virginia. The waterfall spectrum plot looked like a lace ribbon spread over several Hz, but if I squinted right I think I could discern a straight line through it all. Good to get back in the game after missing several due to work travel.

AC9LV

EN52kh

	80m	40m
K5CM		7,064,266.00 0.63
W8RKO		7,065,131.00 -0.30
K5CM	3,598,258.00 -0.36
W8RKO	3,598,995.00 -0.90

Method: >>TS-590s, tapped front end into a SDRPLAY, calibrated with
Leo Bodnar LBE-1420.>

Soapbox: !!! discovered a 1.5 hz drift off ref. freq. on the SDR PLAY...AFTER the K5CM 40M TX. May be off on that one. Noise all night with the T-storms...excuses,excuses...HI...submitted anyway...Thx K5CM and W8RKO !!

AF1R

FN42jh

	80m	40m
K5CM		7,064,265.54 0.17
W8RKO		7,065,131.37 0.07
K5CM	3,598,258.15 -0.21
W8RKO	3,598,995.80 -0.10

Method: -Used FLDIGI in "Frequency Measuring Test" mode
-Measured the carrier frequency of CHU 7850 KHz and 3330 KHz to find the offsets for the frequency displayed in FLDIGI
-Used these offsets to add or subtract from the frequency shown in FLDIGI for the 4 unknown signals

Soapbox: (none)

AF9A

EM69wv

	80m	40m
K5CM		7,064,265.24 -0.13
W8RKO		7,065,130.55 -0.75
K5CM	3,598,258.28 -0.08
W8RKO	3,598,995.15 -0.75

Method: Open HPSDR Mercury recvr, WSJT-X Freq Cal mode, OCXO calibrated to WWV/CHU.

Soapbox: All signals were good. Thanks for another good FMT!

AJ4YA

FM05st

	80m	40m
K5CM		7,064,264.82 -0.55
W8RKO		7,065,132.30 1.00
K5CM	3,598,258.64 0.28
W8RKO	3,598,996.00 0.10

Method: Elecraft K3S, LDG AT-100 Ant. Tuner, Fan Dipole 40m/30m/10m
Tuned listening for the “beat”, used Excel program adjusting frequency using historical error for the tuner. All done while remembering to keep my fingers crossed.

Soapbox: I still look forward to this event each spring and fall. I always learn something. I think this year the 40 m signals were actually too strong. I should have attenuated before tuning to the beat. Thank you.

AJ5P

EM51kr

	80m	40m
K5CM		7,064,265.40 0.03
W8RKO		7,065,131.10 -0.20
K5CM	3,598,258.00 -0.36
W8RKO	3,598,995.60 -0.30

Method: IC-705, Fldigi

Soapbox: 40 meter sigs 20 dB over S9. 80 M sigs S4 with some background hum on K5CM. Voice interference on 40 M. QSB was there but strong.

IN LIMBO

EM00kb

	80m	40m
K5CM		7,064,265.30 -0.07
W8RKO		7,065,131.23 -0.07
K5CM	3,598,503.97 245.61
W8RKO	3,598,995.71 -0.19

Method: SA44B recording IQ data
> Homespun SW plotting calibrated phase versus time
> Measured slopes by hand and calculated final frequency from slope
data combined with tune freq of SA44B.
> Used Rb clock as frequency reference.>

Soapbox: I've never before seen such broken-up signals during an FMT, had a devil of a time especially at 40m.

Note: Callsign will be K8YUM again if I can ever plow through the FCC's
OnLine system successfully.

K0MZ

DM03ts

	80m	40m
K5CM		7,064,265.00 -0.37
W8RKO		7,065,131.00 -0.30
K5CM	3,598,259.00 0.64
W8RKO	3,598,996.00 0.10

Method: Local oscillator counted with a Heath IM-4100 counter clocked with an HP 10544A OCXO calibrated with WWV earlier in the day around noon local time. TR-7 receiver with Hustler 6BTV with radials and tuned CW note matched pitch by ear.

Soapbox: An amazing FMT tonight as all received signals were S-9 up to 10 over without any doppler. Great signals. A great thank you to Connie and Mike for providing all of us with an evening of fun playing with radios.

K0WM

DM79jt

	80m	40m
K5CM		7,064,265.33 -0.04
W8RKO		7,065,130.56 -0.74
K5CM	3,598,138.19 -120.17
W8RKO	3,598,995.47 -0.43

Method: Set up is mostly old school; I like it because it’s paid for. Rig is a Yaesu FT-1000MP Mark V with a Rockwell/Collins 180S-1 tuner, 40-meter dipole, Fluke 8845A as an audio frequency meter. Calibrate the receiver with a Bodnar GPSDO. I have used my homebrew Excel spreadsheet to analyze several FMTs, with varying degrees of success. :-)

Soapbox: The 40- and 80-meter signal strengths were excellent. Lowest frequency variation was K5CM on 40 meters and W8RKO on 80 meters. Frequency variation for the other two stations/bands was higher and nearly equal. I like to compare my results with those of my “neighbor,” W9INE near Estes Park, about 40 miles away.

The major unknown is Doppler shift. It is possible to get Dopplered right out of the green box. It is fortunate that we avoided the chaotic propagation conditions of the previous day.

Thanks to Connie and Mike for continuing support for this interesting event. The FMT makes radio really interesting.

K1MU

FM18ju

	80m	40m
K5CM		7,064,265.06 -0.31
W8RKO		7,065,130.78 -0.52
K5CM	3,598,258.02 -0.34
W8RKO	3,598,995.58 -0.32

Method: fldigi for measurements.
bodnar mini-gps clock for reference

Soapbox: Thanks to Connie and Mike for running these tests!

I'm not super confident in my measurements as the standard deviation was pretty high. I think I may have failed to sync with the signals so fldigi had to seek for the right spot. Fun, nevertheless, to learn from your potential mistakes.

K4CXX

EL98qd

	80m	40m
K5CM		7,064,478.23 212.86
W8RKO		7,065,142.54 11.24
K5CM	3,598,258.23 -0.13
W8RKO	3,598,995.67 -0.23

Method: Experimental: Used GPSDO to read error at audio output of ordinary synthesized RCVR, and applied the correction to the test signals. Signals were good into central Florida; first 40 m run by K5CM suffered from bad antenna selection error here.

Soapbox: This was a good exercise; it’s enjoyable every time. Many thanks to K5CM and W8RKO for their commitment to this semi-annual event, and thanks to ARRL for continued national sponsorship of progressing an under-appreciated technical skill.

K4PPK

EL87pt

	80m	40m
K5CM		7,064,264.95 -0.42
W8RKO		7,065,130.85 -0.45
K5CM	3,598,257.75 -0.61
W8RKO	3,598,995.20 -0.70

Method: (none)

Soapbox: Thanks for another fun FMT event. All four signals were good here in West Central Florida.

K5CM

EM25ir

	80m	40m
K5CM		7,064,265.37 0.00
W8RKO		7,065,131.20 -0.10
K5CM	3,598,258.36 0.00
W8RKO	3,598,995.80 -0.10

Method: TX: HP Z3801 GPS frequency standard, HP-3336b. A 10 db transistor amp follows and drives a 12by7 / pair 6146. Then to the final amplifier (8877) running 800 watts out. There are no mixers or any device in the chain of amplifiers that might impact the accuracy of the GPS frequency source.
RX: K3 in AM mode with low side injection from a GPS locked HP-3336B. Audio is feed to Spectrum lab.

Soapbox: Mike had a good signal on both bands.

K5ND

EM12kv

	80m	40m
K5CM		7,064,265.24 -0.13
W8RKO		7,065,131.35 0.05
K5CM	3,598,258.44 0.08
W8RKO	3,598,995.88 -0.02

Method: IC-746PRO with CR-388 high stability oscillator. Cushcraft MA6V vertical antenna. Warmed up for two days. WSJT-X frequency calibrated one hour before the test. Measured with WSJT-X.

Soapbox: Good signals with a bit of QSB. Sometimes, there was a bit of QRM, but it didn't interfere with my measures. I appreciated the dit—dit—dit signal from K5CM before the key down.

K6LL

DM22qq

	80m	40m
K5CM		7,064,265.48 0.11
W8RKO		7,065,131.13 -0.17
K5CM	3,598,258.48 0.12
W8RKO	3,598,996.00 0.10

Method: I used an Uncalibrated K3 in AM mode. A Bodnar GPS Mini was used as BFO, about 500 Hz below the unknown signal to get a beat note. Spectrum Lab Peak Detector readings were recorded and averaged. I did a one-time measurement of 5 MHz WWV halfway through, and I was .19 Hz low on that measurement, so I added .19 Hz to all readings as a rough Doppler estimate. I hope it helps rather than hurts.

Soapbox: Signals were loud and clear on all 4 test runs. There was some MFSK QRM on 80M W8RKO, but it didn't seem to hurt anything. I don't know why, but I find these FMTs a lot of fun. Thanks for the opportunity to play!

K7NG

CN73ui

	80m	40m
K5CM		7,064,264.99 -0.38
W8RKO		7,065,130.02 -1.28
K5CM	3,598,257.95 -0.41
W8RKO	3,598,996.15 0.25

Method: IC-7610 w/ external reference, FLDIGI in Frequency Analysis mode & data reduction in MS Excel.

Soapbox: I got pretty much thru the test without Murphy's help this time. I would, however, like very much to ask that future FMTs take place outside the digimode freqs (3575 to 3600 appx) as there was what I believe was an OLIVIA qso right where W8RKO's FMT signal was. RKO's signal was actually inside the envelope of the OLIVIA signals. The digimode folks were there first... take the above accordingly.

K9JM

CM99lc

	80m	40m
K5CM		7,064,264.82 -0.55
W8RKO		7,065,131.19 -0.11
K5CM	3,598,258.22 -0.14
W8RKO	3,598,995.87 -0.03

Method: Calibrated K3s with tuning forks

Soapbox: 40m K5CM excellent signal est error = +/- .15Hz, W8RKO good signal lots of QSB est error +/- .40 Hz ... 80m may has screwed up 80m... K5CM good signal some QSB est error +/- .40 Hz W8RKO had DQRM + VARA HF ruff

KA8BRK

EN81fc

	80m	40m
K5CM		7,064,265.24 -0.13
W8RKO		7,065,129.98 -1.32
K5CM	3,598,257.99 -0.37
W8RKO	3,598,995.51 -0.39

Method: IC-706MKII, IC-7100, 80 Meter Inverted Vee, Bodnar Mini GPSDO, FLDigi, Libre Office

Soapbox: Decent but not great signals. Doppler on 40, static on 80.
Thanks to K5CM, W8RKO, and everyone that helps with the FMT.

KB2HSH

FN03na

	80m	40m
K5CM		7,064,261.75 -3.62
W8RKO		7,065,127.23 -4.08
K5CM	3,598,256.22 -2.14
W8RKO	3,598,993.59 -2.32

Method: Radio: Xiegu G90...Antenna: AN-131-A manpack whip. Software: fldigi

Soapbox: Conditions weren't great but still able to copy the RKO and CM just fine. Always fun to do the FMT with my old friend Chuck, N3CRT. Have a great summer, everyone and we'll see you in November. 73 from Gateway Harbor!

KB3HF

EM48qt

	80m	40m
K5CM		7,064,265.44 0.07
W8RKO		7,065,131.23 -0.07
K5CM	3,598,258.04 -0.32
W8RKO	3,598,995.22 -0.68

Method: TS-890, 80-40 Dipole, WSPR FMT software

Soapbox: Good signals on all 4 runs. Thanks for the FMT.

KB4XR

FM18hw

	80m	40m
K5CM		7,064,265.27 -0.10
W8RKO		7,065,130.82 -0.48
K5CM	3,598,258.04 -0.32
W8RKO	3,598,995.54 -0.36

Method: ICOM 725 fitted with TCXO, FLDIGI FMT, Bodnar GPSDO for ref, spectral analysis of audio recording using Matlab tools. Attic G5RV.

Soapbox: Clean signals on both K5CM & W8RKO. Thank you for your time and effort - always a challenge.

Hope I'm not overcompensating for Doppler. Still getting discrepancies FLDIGI & Spectral analysis

KC3VNB

FN00dl

	80m	40m
K5CM		7,064,265.57 0.20
W8RKO		7,065,130.96 -0.34
K5CM	3,598,258.53 0.17
W8RKO	3,598,995.56 -0.34

Method: ICOM 7300 set to AM, with a nearby GPSDO referenced signal source added as carrier approx 1K below test frequency. Spectrum lab used to analyze resulting signal. WWV 5MHz measured after test to get an idea of Doppler shift.

Soapbox: Quite a bit of what I interpreted as multipath propagation on both bands. Made discerning how much Doppler shift to add mostly guesswork. Assumed would be shifted low in evening - used upper readings from spectrum lab and added .1 to .2 Hz to yield submitted values. Many thanks as always to K5CM and W8RKO!

KD2BD

FN20xd

	80m	40m
K5CM		7,064,265.17 -0.20
W8RKO		7,065,130.90 -0.40
K5CM	3,598,258.10 -0.26
W8RKO	3,598,995.60 -0.30

Method: All homebrew equipment including a carrier phase tracking receiver, a WWVB referenced frequency standard, an electrically small vertically polarized loop antenna, and a frequency counter. Method involved phase locking the receiver's DDS LO to the frequency of the unknown carrier minus a 1 kHz offset, measuring the frequency of the receiver's LO over several 10 second integration periods and taking a selective average of the readings (leaning on the high side to compensate for Doppler Shift) after factoring in the 1 kHz offset. More info at: https://www.qsl.net/kd2bd/fmt-methodology.html

Soapbox: The Kp-Index was around 3. RSTs were 599 except for K5CM on 80 which averaged 579. K5CM experienced deep fades on 40. There was a lot of short-term phase instability on W8RKO on 80 resulting in a measured pk-pk frequency deviation of 0.55 Hz during the keydown period. The Kp-index was increasing by this time as well. WWVB was rock-solid on 60 kHz.

KD5MMM

EL19ds

	80m	40m
K5CM		7,064,265.40 0.03
W8RKO		7,065,131.30 0.00
K5CM	3,598,258.50 0.14
W8RKO	3,598,995.70 -0.20

Method: FT-847, Speclab, Spreadsheet. CHU for reference.

Soapbox: good strong sigs on all 4 runs & a bit of interference.

KD7KDO

DM54hc

	80m	40m
K5CM		7,064,283.51 18.14
W8RKO		7,065,131.76 0.46
K5CM	3,598,268.10 9.74
W8RKO	3,599,000.47 4.57

Method: Elecraft K2 & FLDIGI

Soapbox: Much more difficult with handbuilt Elecraft K2
with BFO that drifts with temperature
Enjoyable test... always learning
GL MARCA club members W7MOT

KD8RV

EN82mj

	80m	40m
K5CM		7,064,265.40 0.03
W8RKO		7,065,130.50 -0.80
K5CM	3,598,258.20 -0.16
W8RKO	3,598,995.10 -0.80

Method: Spot the callup with my K3. Use the DSB synchronous amplitude modulation mode PLL offset measurement in SDRUno software with a GPSDO'd RSPdx to hone in the final number at key down and also provide a sanity check.

Soapbox: Good signals up in Michigan, but I felt like I was just riding the waves on an agitated lake. Doppler spread was especially significant on 80 meters at this QTH. Wish I could be more confident with my results.
Thanks, once again, for the challenge, everyone! 73, Greg, KD8RV

KE2N

FM18ew

	80m	40m
K5CM		7,064,265.10 -0.27
W8RKO		7,065,130.90 -0.40
K5CM	3,598,258.10 -0.26
W8RKO	3,598,995.60 -0.30

Method: GPS-locked IC7610, direct measure using Spectrum Lab via USB conn. Checked by using recordings from rig's SD card.

Soapbox: First try after many years.
Signals were quite good on both stations

KF7NP

DM33wp

	80m	40m
K5CM		7,064,265.26 -0.11
W8RKO		7,065,130.58 -0.72
K5CM	3,598,258.00 -0.36
W8RKO	3,598,995.41 -0.49

Method: My main system is an RSP2 SDR using the external reference clock input. The reference clock input is driven by a homebrew GPSDO. The backup system is an Icom IC-7610 also driven by the same GPSDO. Both of these systems drive copies of WSJT-X using virtual audio cables. WSJT-X is running in the frequency calibration mode. This data is logged to a file which is then imported to excel.

Soapbox: Things went well during the 40m session with good signals. Just as the 80m callup began the entire band was filled with broadband noise overloading the input to the RSP2 even when set to minimum gain. The 80m signals were barely readable on the IC-7610 but at least it was not overloaded. I have seen this broadband noise come and go over the last few days and have not located the source.

KI4NVX

EL96bn

	80m	40m
K5CM		7,064,264.60 -0.77
W8RKO		7,065,130.40 -0.90
K5CM
W8RKO

Method: QRP-LABS QDX Low Band.
Chelegance MC-750 Portable Ground Mounted Vertical
Leo Bodnar LBE-1420 GPS Locked Clock
Fldigi 4.2.04 - Win11 Pro

Soapbox: Good strong signals from both. Some fading. Interesting note: perceived frequency samples during Key Down from K5CM drifted down about 0.4 Hz and from W8RKO drifted up about 0.4Hz.
80 M band just dead for me, but then the antenna only configures down to 40 M. (HI HI)
THANKS AGAIN FOR RUNNING THESE TESTS. LOTS-O-FUN AND HAVE HELPED ME LEARN A LOT ABOUT FREQUENCY ACCURACY/STABILITY AND PROPOGATION EFFECTS.

KI5EE

EM30jd

	80m	40m
K5CM		7,064,265.08 -0.29
W8RKO		7,065,130.68 -0.62
K5CM	3,598,257.79 -0.57
W8RKO	3,598,995.49 -0.41

Method: I used my Kenwood TS-850s and my Dell desk top computer using Spectrum Lab V2.95b8. The day before the test, I zeroed the TS-850 to WWV.

Soapbox: All signals were strong with the signal doppler shifting the frequency +/- about 1 Hz.

KJ7E

DM04sq

	80m	40m
K5CM		7,064,265.24 -0.13
W8RKO		7,065,131.55 0.25
K5CM
W8RKO

Method: Kenwood TS-990 with GPSDO external 10MHz ref, USB to FLDigi, averaged WWV 5MHz and 10MHz for Atmospheric Doppler shift correction.

Soapbox: Had dinner plans so could not stay for 80m test, but noticed 2.5MHz WWV had nearly zero Doppler Shift.

KK4KAZ

EL88qn

	80m	40m
K5CM
W8RKO		7,064,655.84 -475.46
K5CM	3,597,999.78 -258.58
W8RKO	3,598,516.57 -479.33

Method: BG7TBL & Bodnar GPSDOs, RSPdx SDR locked to 24 MHz from Bodnar, Synchronized RIGOL 2-Channel Signal/Waveform Generator for Upper & Lower Frequency Markers (+25Hz & -25 Hz) injected into RSPdx, and HP53131A Counter to confirm accurate Reference Frequencies. Audio was recorded via RSPdx, and FFT post-processed in Spectrum Lab for accurate peak readings of Marker and Target Frequencies. Also recorded screen video of Spectrum Peaks, GPS Time, and RSPdx Local Oscillator to minimize mistakes.

Soapbox: Again, I totally missed the first of the four tests - maybe next time!

KN1H

FN33sg

	80m	40m
K5CM		7,064,265.29 -0.08
W8RKO		7,065,131.16 -0.15
K5CM	3,598,258.02 -0.34
W8RKO	3,598,995.64 -0.26

Method: IC-7300, SW facing EWE. Audio into Spectrum Lab. Averaged about 50 samples, applied corrections figured out ahead of time for each band, crossed fingers.

Soapbox: Thanks for another fun FMT. K5CM and W8RKO 599 on both bands, although a Spanish-speaking SSB QSO on 7065 made a bit of a mess on this end.

N0PFE

EM00ul

	80m	40m
K5CM		7,064,265.00 -0.37
W8RKO		7,065,131.00 -0.30
K5CM	3,598,258.50 0.14
W8RKO	3,598,995.50 -0.40

Method: Equipment: Elecraft K3 with P3 (built in 2009), AV640 vertical antenna, AMD PC with Spectrum Lab. No separate antenna for 80m; Just using the AV640 vertical with significant attenuation on that band. Let the receiver warm up for a few hours. Tuned WWV at 5 MHz around 7:30 PM local time, used 600 Hz tone to zero beat the LO. Tuned to the FMT signals by ear, then refined using Spectrum Lab audio spectrum to estimate the center of the tone.

Soapbox: This was fun as usual. I used the zero-beat-by-ear method again, same as past FMTs. It still seems to give decent results, at least for 40m where the signal was strong enough to make fine adjustments. (I did try the W1JT method once before but it failed miserably for me so I went back to the zero beat method). 80m was more difficult—signal was audible but buried, and I estimate maybe ±1 Hz (or worse) uncertainty just trying to catch a steady carrier. I didn’t do anything fancy, no math, no hardware references. Just ears, Spectrum Lab, and, hopefully, a stable setup. Noise was higher on 40m than usual, but signals held up.

N1IRO

FN33qw

	80m	40m
K5CM		7,064,265.21 -0.16
W8RKO		7,065,130.40 -0.90
K5CM	3,598,258.97 0.61
W8RKO	3,598,995.66 -0.24

Method: KiwiSDR remote receiver, Frequency measurement program on PC using the free Daqarta program.

Soapbox: Thanks for doing this and particularly improvements to data entry web page. Also, thanks to whoever sent out the announcement on the fmt-nuts list. I missed the last one because it wasn't announced and I didn't poll the ARRL page.

N3CRT

FN20qv

	80m	40m
K5CM		7,064,265.20 -0.17
W8RKO		7,065,131.24 -0.06
K5CM	3,598,258.25 -0.11
W8RKO	3,598,996.12 0.22

Method: Flex 6400, wire dipole, FLdigi Freq Analysis mode, spreadsheets (36 of them over the event) and math. Spot check of WWV and CHU on multiple frequencies before during and after the test runs.

Soapbox: Great signals on all runs, S9+10-30 here into NNJ. Thanks to my friend John KB2HSH for reminding me about the test and for teaching me that FLDIGI macros for quickly changing to WWV/CHU etc takes a lot of trouble out of spot tuning. Thank you to the organizers for another great test.

N3FG

FM29hw

	80m	40m
K5CM		7,064,265.21 -0.16
W8RKO		7,065,131.08 -0.22
K5CM	3,598,258.29 -0.07
W8RKO	3,598,995.80 -0.10

Method: K3, vertical dipole, Spectran, WWV, CHU

Soapbox: Good copy on all signals. MNY TNX to both stations for another fine event.

N4PAJ

EM95lr

	80m	40m
K5CM		7,064,264.67 -0.70
W8RKO		7,065,130.54 -0.76
K5CM	3,598,257.59 -0.77
W8RKO	3,598,995.37 -0.53

Method: Icom 7851 + homebrew FFT Python audio peak detector, live capture only

Soapbox: That was fun! All four signals were easy copy in western North Carolina. Both were over S9+20 on 40m off of a 33 foot wire.

N5TNL

EM25ui

	80m	40m
K5CM		7,064,264.78 -0.59
W8RKO		7,065,131.71 0.41
K5CM	3,598,258.22 -0.14
W8RKO	3,598,996.11 0.21

Method: RX888, ka9q-radio, pcmrecord, SDR Console to demod, Fldigi to measure. Compare to CHU and WWV for Doppler estimates.

Soapbox: Thanks for putting this on! Really appreciate the hard work that goes into it.

N7QXB

DN40cq

	80m	40m
K5CM		7,064,265.68 0.31
W8RKO		7,065,130.32 -0.98
K5CM	3,598,258.17 -0.19
W8RKO	3,598,995.34 -0.56

Method: Elecraft K4D, Leo Bodnar GPSDO, WWV, and Spectran software

Soapbox: Thanks to W8RKO and K5CM for hosting the FMT. Lots of QRM this time.

N7WS

DM42jh

	80m	40m
K5CM		7,064,265.20 -0.17
W8RKO		7,065,130.80 -0.50
K5CM	3,598,260.00 1.64
W8RKO	3,598,995.70 -0.20

Method: Bodnar GPSDO through stepped attenuator to directional coupler to SDR-IQ RX input. Bodnar set to ~600 Hz below received signal. Record AM demodulated spectrum via SpectraVue S/W for later analysis. Extract keydown portion of audio with Audacity S/W. Analyze with Spectrum Lab S/W.

Soapbox: I lost my recording of K5CM's 80-meter signal. So I scaled an approximation off screenshot of SpectraVue display. This is not green box accuracy but submitted anyway. Propagation was as usual awful with 20-30 dB QSB on 40-meters. W8RKO's 80-meter signal seemed rather broad and was up against some digital garbage. Eyeball averaging and a SWAG in all cases.

N8OBJ

EN91fh

	80m	40m
K5CM		7,064,265.11 -0.26
W8RKO		7,065,129.99 -1.31
K5CM	3,598,257.77 -0.59
W8RKO	3,598,995.27 -0.63

Method: FLEX6500 w/HP Z3801A freq ref, running SmartSDR Ver 1.12.1, LB GPSDO cal std for radio tuning, FLDIGI Ver 4.1.18, 80M OCF dipole antenna facing E-W

Soapbox: A very challenging and turbulent night - LOTS of TID's [Traveling Ionospheric Disturbances]. Good strong signals on all 4 runs

NO6B

DM14ca

	80m	40m
K5CM		7,064,265.08 -0.29
W8RKO		7,065,130.93 -0.37
K5CM	3,598,258.35 -0.01
W8RKO	3,598,995.78 -0.12

Method: Airspy R2 SDR w/Mini-Circuits ZFM-150 mixer as upconverter; HP8640B LO source set to 130 MHz. Bodnar GPSDO set to ~200 Hz below test signal (to minimize soundcard sample rate errors) coupled into SDR. SDR set to AM mode, 1 kHz BW. Recorded with Audacity, played back through Spectrum Lab.

Soapbox: Leaking signal from the GPSDO to SDR in the shack resulted in a lot of 60 Hz IMD on the GPSDO signal. Didn't affect the measurement but was disconcerting to hear so much 60 Hz; will use a coaxial coupler next time.

VE2IQ

FN15nt

	80m	40m
K5CM		7,064,265.35 -0.02
W8RKO		7,065,131.14 -0.16
K5CM	3,598,258.31 -0.05
W8RKO	3,598,995.52 -0.38

Method: E-probe > TS850(OCXO) > soundcard FFT. Immediately after each keydown, measured CHU Doppler (near vertical incidence here). Some serious negative shifts noted, even after adjusting for frequencies, paths. All submitted readings are without Doppler correction.

Soapbox: Thanks to Connie, Mike - excellent signals S9 + 10. Still don't have the confidence to apply Doppler estimates. Much easier entering readings in same order as the transmissions, thanks.

VE3GSO

EN92ix

	80m	40m
K5CM		7,064,265.47 0.10
W8RKO		7,065,131.05 -0.25
K5CM	3,598,258.29 -0.07
W8RKO	3,598,995.45 -0.45

Method: Receiver Icom 7610 in Am mode 1kHz bandwidth. Bodnar GPSDO set to 400~500Hz below carrier during callup, and beat measured with Spectrum Lab. The two frequencies are then added, and a small guesstimate on how much Doppler is present

Soapbox: Fourty meters was pretty good with strong signals. Eighty meters was very noisy with QRN at this location. Signals still reasonable. Thanks go to Connie and W8RKO!

VE3ICH

FN25bg

	80m	40m
K5CM		7,064,280.00 14.63
W8RKO		7,065,130.00 -1.30
K5CM
W8RKO

Method: Yaesu FT-450D transceiver.

Soapbox: First time participating!

VE3PIK

EN93ka

	80m	40m
K5CM		7,064,265.80 0.43
W8RKO		7,065,132.10 0.80
K5CM	3,598,258.10 -0.26
W8RKO	3,598,996.10 0.20

Method: SDRPlay RSPdx with QRP-Labs GPS-locked VFO reference clock. Sanity check and Doppler guess from CHU and WWV. Measurement in SDRuno with the cursor, like a caveman.

Soapbox: Good signals for all four received at VE3LON LARC club station QTH. First crack at this. Great fun.

VE3YX

FN16fd

	80m	40m
K5CM		7,064,265.26 -0.11
W8RKO		7,065,131.32 0.02
K5CM	3,598,258.20 -0.16
W8RKO	3,598,995.29 -0.61

Method: TS-870 with Bodnar GPSDO replacing the reference osc. FLdigi in FMT mode using just the UNK, no separate Ref.

Soapbox: All 4 signals were quite strong this time, S9+10 to 20. However, Doppler on WWV 5 and 10 MHz before and after the FMT was very high. I have never tried to correct for Doppler before but this time I will. We shall see how that works out! Thanks again to Connie and Mike.

VE3ZRK

FN25di

	80m	40m
K5CM		7,064,266.00 0.63
W8RKO		7,065,131.00 -0.30
K5CM	3,598,258.00 -0.36
W8RKO	3,598,996.00 0.10

Method: Comparison method.
GPSDO to HP 3335A Level generator.
Yaesu FT-897.
Used a coax relay to switch between off air and the level
generator.
Rx audio out to PC-based AF SA app. (Visual Analyser 25.5)

Soapbox: Good signals on all four transmissions
Good FMT
Many thanks Dave Green VE3TLY for his help

W1QG

CM87xg

	80m	40m
K5CM		7,064,265.06 -0.31
W8RKO		7,065,130.36 -0.94
K5CM	3,598,258.18 -0.19
W8RKO	3,598,995.48 -0.42

Method: HP 3585B selective level meter GPIB controlled with MATLAB.
Simulink used to create a tracking PLL for fine freq estimator.
Freq std is Datum GPS RX.

Soapbox: Always the shortest minute in the day.
Time flies when your having fun.
Keep up the good work.

W2FD

EN91wx

	80m	40m
K5CM		7,064,265.15 -0.22
W8RKO		7,065,130.30 -1.00
K5CM	3,598,258.00 -0.36
W8RKO	3,598,995.45 -0.45

Method: IC7100--TEK 535 OSCILLOSCOPE/HP 205AG AUDIO GENERATOR/HP5385A FREQUENCY COUNTER--Measure near 600 Hz. CW/CW-R audio output using scope trace synched with audio generator and generator frequency measured with counter.

Soapbox: Thanks for another good job, Connie and Mike. Both bands were noisy with rapid phase changes but good signal strengths from both stations on both bands.

W2QL

FM18iu

	80m	40m
K5CM		7,064,255.00 -10.37
W8RKO		7,065,127.00 -4.30
K5CM	3,598,258.00 -0.36
W8RKO	3,598,996.00 0.10

Method: Wellbrook FLXN1500 with 10' circumference LMR400 element
SDRPlay RSPDuo
Bodnar GSPDO freq reference
FLDigi

Soapbox: (none)

W3JW

FM17tq

	80m	40m
K5CM		7,064,265.24 -0.13
W8RKO		7,065,130.91 -0.39
K5CM	3,598,258.17 -0.19
W8RKO	3,598,995.70 -0.20

Method: Icom 7610 (external xtal reference osc) into Spectrum lab for hundreds and tens of millihertz measurement. Separate application of Spectran used to set transceiver dial to nearest 1 Hz. Audio offset is 1500 Hz.

Soapbox: Tnx to Connie, Mike and all who make this event possible. Kudos! Signals were very good if not exceptional. On 40M Connie was 20 over nine and Mike was 15 over nine. On 80M both Connie and Mike were 15 over nine. Doppler and multipath made things interesting, but were not excessive.

W4IVF

EM96to

	80m	40m
K5CM		7,064,264.89 -0.48
W8RKO		7,065,130.80 -0.50
K5CM	3,598,258.11 -0.25
W8RKO	3,598,995.58 -0.32

Method: GPS phase-locked reference injected into receiver input. Frequency delta measured with Spectrum Lab software.

Soapbox: Some use of the dart board was required. Thanks to all for making the test possible.

W5AJ

DM82va

	80m	40m
K5CM		7,064,265.18 -0.20
W8RKO		7,065,130.84 -0.47
K5CM	3,598,258.03 -0.34
W8RKO	3,598,995.54 -0.36

Method: RF Zero GPSDO, FTdx10 with 12Khz filter in AM. Spectrum Lab.

Soapbox: For 12khz filter, the conditions seemed good. Good signals. Some qrm with that wide filter.... My first time trying the GPSDO/AM method. Many thanks to K5CM and W8RKO.

W5LAC

EM51hh

	80m	40m
K5CM		7,064,265.00 -0.37
W8RKO		7,065,130.00 -1.30
K5CM	3,598,257.50 -0.86
W8RKO	3,598,994.70 -1.20

Method: Flex3000 calibrated with Leo Bodnar GPSDO, Spectrum Lab

Soapbox: Good signals all around here in MS, some QRM from SSB station on 40

W5SSV

EL39ax

	80m	40m
K5CM		7,064,265.20 -0.17
W8RKO		7,065,130.60 -0.70
K5CM	3,598,257.80 -0.56
W8RKO	3,598,995.50 -0.40

Method: HP 3586 selective level meter in count mode on multiband inverted V at 50 ft. Also tried freq beat counting with Leo Bodner and Yaesu FT-301 on AM.

Soapbox: Another fun project at our club station in Nederland, Texas. Impulse noise was S9+ but confident in our readings on the HP. The attempt to directly count the beat note on the Yaesu was disturbed by the noise and a Spanish conversation on freq. Thanks again guys!

W6OQI

DM04vf

	80m	40m
K5CM		7,064,265.20 -0.17
W8RKO		7,065,130.70 -0.60
K5CM	3,598,258.30 -0.06
W8RKO	3,599,093.80 97.90

Method: HP 3586 selective level meter, GPS locked, was used for the measurements.

Soapbox: K5CM 80 and 40 signals were good in Los Angeles area. W8RKO 40 meter signal was also good. However, the w*RKO 80 meter signal was in the middlof a warbling digital signal which made the measurement difficult

W7SUA

DM34rs

	80m	40m
K5CM		7,064,265.38 0.01
W8RKO		7,065,131.12 -0.18
K5CM	3,598,258.40 0.04
W8RKO	3,598,995.84 -0.06

Method: GPSDO stabilized K4, GPSDO stabilized SIGLENT SDG2042X, fldigi 4.1.27 FMT modem using the FFT view to center the reference and unknown signals. Also used SpectrumLab with 50 or 100 Hz span to check for Doppler splitting which I did see. Hard to decide which signal to pick. Check runs on CHU and WWV before and after resulted in consistent low measurements by on CHU so added 166 and 332 millihertz for 40 meters and 189 and 378 millihertz on 80 meters. Based on before and after CHU cal runs assuming 1 hop to Connie and two hops to Mike and CHU. Will see if this helps me offset the Doppler shifts! Fun!

Soapbox: Thanks Connie and Mike for providing the test signals. Fun! Strong signals on both bands. Contestia QRM on 80m. Looked like Doppler spreading and multi-path resulting in some signal splitting on the SpectrumLab waterfall. Measured WWV and CHU before and after the FMT then calculated an estimated Doppler shift as was reading CHU consistently low by 300-400 millihertz. Fun! Will be interesting to see if adding in the correction will be correct. Have not done that in years.

W9GR

CM99mg

	80m	40m
K5CM		7,064,265.27 -0.10
W8RKO		7,065,131.29 -0.01
K5CM	3,598,258.17 -0.19
W8RKO	3,598,995.72 -0.18

Method: FlexRadio 6500 locked to Trimble GPS. DDS errors calculated and corrected. Audio tone sent to Denon digital recorder along with a GPS locked 2 kHz reference tone to calibrate out Denon's sampling rate error. Homebrew GNU Octave code provides envelope weighted average frequency estimate.

Soapbox: There was a nasty multilevel FSK signal with energy just 5 Hz above W8RKO on 80 meters, but I was able to filter it out in post processing. Otherwise good signals (with QSB) here in Tahoe National Forest. Always fun, thanks to K5CM and W8RKO.

W9INE

DN70gi

	80m	40m
K5CM		7,064,265.34 -0.03
W8RKO		7,065,131.13 -0.17
K5CM	3,598,258.30 -0.06
W8RKO	3,598,995.53 -0.37

Method: FLEX-6700 and FLDIGI in Frequency Analysis mode

Soapbox: S/N was 50 dB with W8RKO 80MTR at 40 dB (strong signals).

W9ZB

EM69xp

	80m	40m
K5CM		7,064,266.00 0.63
W8RKO		7,065,131.00 -0.30
K5CM	3,598,258.00 -0.36
W8RKO	3,598,996.00 0.10

Method: IC706MKIIG into WSJTX Freq Cal function. Checked against WWWV & CHU

Soapbox: All four signals very strong here. Enjoyed it very much. Thanks guys.

WA1SXK

EM95lf

	80m	40m
K5CM		7,064,264.70 -0.67
W8RKO		7,065,130.67 -0.63
K5CM	3,598,257.76 -0.60
W8RKO	3,598,995.47 -0.43

Method: Icom-7300 using Bodnar GPSDO ref. signal. Record FMT test signal data using FLDIGI into FMT mode.

Soapbox: I always did the FMT with my Elmer Mike W9MDB/SK, now his key is silent. There is not a day that goes by that I don't miss Mike and our fun together playing in our ham radio sandbox. Thanks, Mike, for all your training!
Good Signals from both stations on both bands in NC. Doppler effects were mostly on K5CM signals, both on the 40m and 80m bands. K5CM had the most data outliers and the highest standard deviations. Thank you both for another fun evening with FMT, Best of 73 Eric/wa1sxk

WA2DVU

FM29nc

	80m	40m
K5CM		7,064,265.10 -0.27
W8RKO		7,065,130.75 -0.55
K5CM	3,598,258.02 -0.34
W8RKO	3,598,995.70 -0.20

Method: (none)

Soapbox: (none)

WA2USJ

FN30bq

	80m	40m
K5CM		7,064,155.56 -109.81
W8RKO		7,065,765.49 634.19
K5CM
W8RKO	3,599,099.75 103.85

Method: KENWOOD TS 570S OCF DIPOLE

Soapbox: (none)

WA3YDZ

FM29hw

	80m	40m
K5CM		7,064,265.00 -0.37
W8RKO		7,065,131.00 -0.30
K5CM	3,598,258.00 -0.36
W8RKO	3,598,995.60 -0.30

Method: FT-991A, wsjt-x in FreqCal mode.

Soapbox: Realized my first entries needed to be corrected by 1500 Hz offset setting of wsjt-x.

WA4FJC

FM08lf

	80m	40m
K5CM		7,064,265.10 -0.27
W8RKO		7,065,130.70 -0.60
K5CM	3,598,258.10 -0.26
W8RKO	3,598,665.30 -330.60

Method: HP SLM, 80 M dipole, GPS 10 Mhz reference

Soapbox: Thanks for this event.

WA5UCW

DM65sd

	80m	40m
K5CM		7,064,265.25 -0.12
W8RKO		7,065,131.04 -0.26
K5CM	3,598,258.27 -0.09
W8RKO	3,598,995.79 -0.11

Method: DIY direct conversion receiver, stabilized by Leo Bodnar GPSDO, with horizontal loop antenna. WSJTX and SpecLab to measure and log data, Scilab and Excel to analyze and plot results.

Soapbox: Strong signals (S/N ratios 40-50 dB) with significant multipath effects. Discrete frequency components scattered across 0.5 Hz or more.

Thanks to Connie, Michael, and ARRL for conducting this event.

WA7BNM

DM04td

	80m	40m
K5CM		7,064,265.21 -0.16
W8RKO		7,065,130.91 -0.39
K5CM	3,598,258.18 -0.18
W8RKO	3,598,995.63 -0.27

Method: Receiver: Icom R-8600
Antenna: SteppIR DB-36 at 70 ft - used 40m setting for both bands
Software: Fldigi 4.1.26 in Freq Analysis mode
Used GPSDO as external frequency reference for R-8600.
Averaged Fldigi measurements associated with strongest signals

Soapbox: Considered using Fldigi FMT mode for measurements, but need more practice so reverted to the Freq Analysis mode.

WB2CMF

FN30lu

	80m	40m
K5CM		7,064,264.97 -0.40
W8RKO		7,065,130.48 -0.82
K5CM	3,598,258.17 -0.19
W8RKO	3,599,365.60 369.70

Method: Kenwood TS-2000, Cushcraft R8 Vertical for 40Meters, End Fed Dipole for 80 Meters, HP Win 10 Desktop, Rigblaster PC Interface, Fldigi software v4.1.20 in frequency analysis mode.

Soapbox: 40 meter signals were good, K5CM had QSB. 80 meter signals were strong. A little QSB on W8RKO.

WB7ABP

CM88ok

	80m	40m
K5CM		7,064,265.04 -0.33
W8RKO		7,065,130.90 -0.40
K5CM	3,598,257.95 -0.42
W8RKO	3,598,995.58 -0.32

Method: Anan100D Active antenna Thunderbolt GPSDO Fldigi4.2.04

Soapbox: Signals were generally good. QRM 80m

WO7V

CN92eg

	80m	40m
K5CM		7,064,265.23 -0.15
W8RKO		7,065,129.93 -1.37
K5CM	3,598,257.78 -0.58
W8RKO	3,598,995.10 -0.80

Method: (none)

Soapbox: Good signals all S9. There was some interference from data on 80m however it didn't really affect the measurements.

WQ8T

EN84gh

	80m	40m
K5CM		7,064,265.46 0.09
W8RKO		7,065,131.59 0.29
K5CM	3,598,258.33 -0.03
W8RKO	3,598,995.54 -0.36

Method: Equipment:
HF9V antenna, an HP 3586B with an external GPSDO, an RSP1A and a computer running SDRuno and DL4YHF's Spectrum Lab software to analyze the 1.850 kHz signal from the HP 3586B.

Method:
The RSP1A is used to find the frequency of the call-up signal and then the HP 3586 is tuned to this frequency with an offset of 15 Hz. The tracking generator output of the HP 3586 is coupled to the antenna input signal. SpecLab is used to determine the frequency difference of the unknown signal and the 15 Hz offset signal which are both in the audio output of the HP 3586. This difference is subtracted from the HP 3586B frequency setting to determine the received frequency. The sound card is calibrated using SpecLab’s continuous calibration using a 2 kHz reference signal.

Soapbox: Thank you K5CM and W8RKO.

Frequency Measuring Tests

Results - April 18, 2025 FMT