VLF Experiments in Newfoundland

The only known VLF transmitter in Newfoundland and Labrador. Others welcome!
F=8.0-8.3 kHz, Wavelength ~36 km. P ~30 watts, Efficiency < 0.000001

Authorised ERP 10 mW. Licence renewed by ISED Canada: January 2017, Sep. 2017, June 2018-2019, 31 March 2021. 31 Mar 2023.

Stations reporting reception of VLF EbNaut messages from this station: Todmorden UK, DL4YHF, SQ5BPF, IK1QFK, RN3AUS(5810km distance record),
W1VD, N4VLF, DK7FC, DL0AO (decoded by DF6NM)

Paul Nicholson VLF RX
VLF milestones
Roger Lapthorn's VLF site
VE2IQ VLF grabber
DK7FC Heidelberg sg
DL0AO VLF spectrograms
KL7L VLF spectrograms
WWLLN St. John's"
SQ5BPF details on vt setup
19 Mar. Aerial de-iced. Had very low current until 1800ut today.
9 Mar. Aerial iced. IA abt 10 per cent. (5170/8270.)**-1 * 490=784...
1 Mar. Coil doing well. It hasn't fried itself. Markus updates data and explains the attenuation of the carrier and relative amplitudes of the diurnal peaks amongst other things.

24 Feb. New coil (120 mH 60 Ω) deployed.
14 Feb, Another Cdn VLF spotted by Paul?
13 Feb SAQ 17.2 kHz 569 SM6LKM cvt, miniwhip and quiet location via showshoes. SAQ Audio

QSL Rec'd 23 Feb.
11 Feb. VLF aerial near end and its 16 splices replaced after 20 years of service following downing by ice. Raised ~1400.
22 Jan. Aerial raised and TA VLF service resumed 1900 ut. Sadly, one fir had to be felled because the wire was neatly tied to the tree top by the wind during our latest blizzard (53cm snow). Had been off since 2200 yesterday.
16 Jan. Aerial iced and on the ground and/or tangled in tree tops.
Raised 2020uc.

More data from Amberg thanks to Markus. Last month's results.


3 Dec. Right: New 9-spoke pie in the middle of the helix. 139-40-114 total 482 mH. Left xfmrs: 4:1, auto; current.

01 December. DF6NM update of Amberg data.
22 Nov. Aerial iced - off air from ~2200 to 1124 ut 23 Nov. Reception report from Riccardo IW4DXW. Raspi4 4G miniwhip and USB card. Focusrite Scarlett 2i2 USB audio.

IW4DXW using vlftools (P. Nicholson)
1 Nov. Update from Markus.

The upper diurnal peak is attenuated.
Paul's spectrogram is showing sronger sigs on 8.27 kHz.

24 Sep 22. Report from DF6NM. Plot of data Aug/Sep.
Note very weak diurnal peaks.

8 Sep 2022. Ongoing poor GPS reception. 1800 utc off air until 1800 11 Sep. in respect of QEII.
1030 19 Aug on . 17 Aug. Ongoing failure of GPS reception causing carrier loss. This has been an issue for some weeks.
2000ut off for lightning.
10 August Reception data for July from DF6NM monitoring DL0AO. Clear carrier and dirunal peaks.
Several GPS dropouts causing intermittent loss of carrier.
3 Aug. Reception experiments in Terra Nova National Park.
27 Jul. Off 1250 ut for lightning. Off for unknown period(s) until 4 Aug 2022. Loss of GPS reception?
20 Jul. Off 00-08ut Lightning threat.
2 Jul. Latest monthly update from DF6NM. Lots QRN, little visible signal.

29 June Carrier off 1230utc: mains failure. Carrier resumed 0150 1 July 10-11 Jun. WX forecast : probability of lightning. Aerial grounded 2300 10 June- ~0800 11 June. Short in helix fixed ~2130

2 June. Another update from Markus of the data from DL0AO.
Weak carrier but relatively strong diurnal peaks.
23 May. 2020ut Aerial disconnected for lightning forecast.
11 May. Normal current (0.2A) at 8.27 kHz.

9 Apr. It seems to be working. (yesterday also knocked over the tuning coil!)

8 Apr. Aerial raised 2100 after being brought down by 2" of ice.
1 Apr 2022 1730-1300 02 April. Lowered aerial as precaution for forecasted ice storm. 2 April 2022 1300ut. Current ~0.2 A. 8.27kHz GPSDO.
24 Mar 2022
vtvorbis -dn,4401 @vlf1
vtwrite -G14400 @vlf1 /media/pi/WHOPSE/vtraw
vtread -T 2022-03-23_22:00,+8hr /media/pi/WHOPSE/vtraw | vtfilter -h bp,f=8270,w=3000 | vtblank -a12 -d0 -t100 -v | vtnspec -r3.5e-5 -w0.007 -f8270 > vtnfilqt20

21 Mar. Aerial partially raised. 2120ut 22 1120 raised fully.
1330 aerial lowered for freezing rain in forecast.
13 Mar. Aerial severed by strong winds early in the morning. 2124 Raised. QRV 2124 ut.
11 March 2022. DF6NM works on data for past year.
Daily phase (top) and diurnal and lunar peaks (!) (bottom). Amazing!

8 Mar Aerial downed. Raised and QRV 8.27 kHz 1838 utc.
7 Mar. Markus plots up data for the past year. Aerial current very low due to icing.

DF6NM data from DL0AO

16 Feb. F5VLB running 50v 0.32A between 2 earth stakes 125m apart. 13 dB snr (bw?) at DL0AO . QRB 1100km
9th: 1 metre wire to lm324/4 vf -> flatmax s-c.

08 Flatmax stereo sound-card arrived yesterday -- the exciter sig:

05 Some time before 1239ut, the ice melted and the aerial current returned to normal.
04 1600 ut Aerial lowered for ice storm.
2 Feb. Markus sends the hourly DL0AO reception data. Very interesting discussion between DF6NM and AA5BW on phase at DL0AO.
F5VLB on 8.270035 kHz.

30 January.

Temp is up to 8C and the aerial current is up a bit too.

11 Jan. Yesterday put a boost xfmr in primary of matching xfmr. Sigs seem stronger at Todmorden, DL0AO and DF6NM. Markus was QRV on 8270.0025 Hz with EbNaut.
2 January
More data from Markus. Note the sign changes in the Im component... and the clear diurnal first overtones compared with last month.
Trying to record phase changes due to WX.
Maintaining constant phase by putting combinations of 1 uF caps in the line to the primary of the matching xfmr. This saves going through snow to get to the shed for tuning.


Received a few VVV VVV VVV DE SAQ SAQ SAQ using Marconi XH100,LF10 and a downed but quiet RL.

1900 22 Dec 2021 to 1400 23 Dec aerial lowered- foul WX forecast.
30 Nov. DL0AO data thanks to DF6NM. Carrier and diurnal peaks are strong relative to the noise.

18 Sep. Markus sends hourly I/Q data from DL0AO. Lots of noise
16 Sep. 1500-2130 off for lightning.
10 Sep. 2000ut-1430 11 Sep. off for lightning and mains failure associated with 11/9 hurricane.
3 Sep. lightning downtime 1530-1330 4 Sep. 16 Aug. off for lightning 2224-2300ut.
15 Aug. Maukus works up the July Amberg data.

Carrier very weak in the summer noise but diurnal components are getting through. They were much weaker in June.
Spectrograms at DF6NM, DK7FC not showing much signal on 8.27. Paul's spectrograms sometimes show sigs in the QRN.
6 Aug 2021. Opened a short which developed in the coil. Normal operation resumed 1700ut. Had been intermittent.
26 Jul Aerial earthed 1030 ut- risk of thunder showers.
04 July. SAQ not heard at 1200ut. SM6LKM cvt, PA0RDT mw, FT817 in back yard quite spot but a strong harmonic heard on 16.54 kHz.
07 July. Weak traces seen on DL0AO 47 uHz grabber in the summer QRN. Stefan's tree shows sigs vanishing in static (below).
Phase and aerial current are stable compared with winter.
More consistent reception in Todmorden. Continuing with 0.2A to 100mx15m RL. Carrier from neo7 set to 8270 Hz.

06 June 2021 Aerial disconnected for lightning 1600-1830ut.

(Thanks to Environment Canada)

DF6NM IQ data from DL0AO for May. Freq. is offset from 8.27 kHz DGPDO carrier.
28 Apr. Carrier restored 2011 ut. Accidentally left off 1930ut 27 May.
01 DK7FC on 8270.005. Aerial current up a bit.
22-23 Apr. Mucking about with aerial/coil. Reduced L, raised aerial a bit and increased L to previous settings. DL0HOT seems to be on 8270.01.

DL0AO data from Marku DF6NM.

DF6NM analysis of DL0AO data.

17 Apr. Aerial current rebounded after low values for past 2 days, Probably due to environmental effects. GSTQ 11 Apr. Wire raised. Carrier on at 1806 ut.
10th. Aerial lowered for ice storm. Working on maths with info from df6nm. March
31. Replaced shattered pyrex insulator, raised aerial. On air at 1430 otc.
27th. Aerial down. Other sigs on band: DL0HOT/DL7NN
7th Peak at B=0.11fT; E=26nV/mx on PN spectrogram at 0700
Spectrum for past week: -12uHz 0.6 central 1.0 + 12 uHz 0.8
1 March. Spectrograms at P.N. DL0AO and DK7FC showing sigs about 10 dB above noise on 47 uHz spectrograms.
17th. Wire raised 1253ut. Lots of current at 8.27 kHz.
16 Feb. Freezing rain in forecast. Wire lowered ~3pm.
12 ~0.2 A. 8.27 kHz ~50 cm snow on gnd. 09 raised again. Current ~0.1A to iced wire.
08 Wire lowered to minimise ice damage.
03 Feb wire down again.

Phase, mag, noise.

Mag and noise. Plots thanks to DF6NM. Data from DL0AO Amberg, 6 hr mean.

January phase and mag.
31st. Aerial raised agn after removing 2 cm ice.
27th. Aerial raised again following downing by 5mm radial ice. 1947 ut:nominal current, phase lagging 9/60 cycle.
26. Current at 5/30 nominal. Phase -19/60 cycle. It was good 30/-9 AT 0600. T=0 , RISK IF ZL THIS AM. Wire down!
25th. 1653 QSY to 8270 Hz. 23rd:put a shield over GPS module to deflect draughts from the window.
22nd. 30 cm new snow. I_A down 30 per cent, radiation phase lagging by 100 degrees. F=8270.0075 kHz.
20th. Mains glitches. Carrier on 2148 ut.
19th. 1724 move to 8.2700075 kHz. Testing new coil. Peak: current, 8 kHz squeal; phase shift, dip blue glow, ozone odour and hissing sounds.
19th am: Marco IK1HSS reported a carrier on 8270 kHz but this was a PPS harmonic unfortunately.
18. Frying a new coil until 2130 utc then unmodulated carrier 8.270 kHz.
17th. Aerial icing changes the phase of the radiation. A query on the LF reflector yields insights from OH3MA, SM6LKM, and DF6NM.
φ = -arctan(X/R) = -70° for X=18k and R =100V/0.2A=500.
16 Jan. Aerial current about 0.2 amps, 8.270 kHz. Unmodulated carrier.
15 Jan. Antenna icing. Phase now lagging by 60°. Ice increases capacitance of the aerial and reduces capacitive reactance
so that there is excess inductive reactance from the tuning coil. Resonance was restored and phase shift nulled by reducing the coil's
inductance by 23 mH. With no ice, L=461mH. XL=24 kΩ corresponding to a capacitance of 800 pF. This seems high for the 15x100m RL.
14 Jan.

Impreissive copies by Stefan (top) and Markus before the aerial iced up. Note the blue colour indicating NE direction.
13 Jan. Strong sigs reported bt DK7FC.
12 Jan. ARRL report on the 50 char reception Thanks Rick WW1ME
Wire raised and QRV again at 1700. The ice diameter was 2 cm.
SF72 SN0 A10 K1 11: Antenna wire broken ~25m from feedpoint. Halyard frozen. QRT UFN.
10th. Aerial current at 10% at 1130 local. 'Freezing drizzle.. T steady near 0' From pn s.g. it seems the radiation dropped quickly after 0800ut.
Consistent with onset of freezing drizzle wx report at 6.30am local. 7 Jan. 0.12 fT peak in pn spectrogram this morning.
6 Jan 1600 ut : unmodulated carrier 8.27 kHz. Aerial current about 0.22 A to 10x30m RL.

50 Character message received by DK7FC 6-Jan-2021
Thanks to Stefan for these plots and to Markus for his efforts with the data from DL0AO.


31 Dec. Back on the air with 50 char EbNaut message.
30 December: Lightning at 7/5 mile. Aerial earthed today.

Map tnx Environment Canada
18 0100 ut. Ia at 30%. Freezing drizzle on aerial.
16, 17, 18 EbNauts, Ia nominal
14 16K21, 6s symbols, CRC-16, 50 character message, 2230 ut 14 Dec 2020 8.271 kHz
13 20 char message decoded by Stefan (3 stacked) and DF6NM (DL0AO recording)
09 20-char message 2230ut on 8271 Hz 16K21 15 s symbols CRC-16
09 Dec. Stefan decodes again! 1st time a 10 char message from here is decoded in Germany.
08 Tonight's message delayed: 2300 instead of 2200
07. Decodes by DF7fC an at DL0AO (by DF6NM) of 4 char message. A 10 char message is set for tonight.
06 No decode of the last message but Markus, using data from DL0AO at a 7.5 µHz offset decoded the 4/5th and 3rd/4th Dec transmissions.
The former was on 8270.0075 using the divider which was suspected in causing phase glitches. The phase was in fact flat and
the divider was working properly. 05 Dec. Stefan decodes the 3 char message. A 4 char message is schedulled for 2200 ut.
8.2700000 kHz, ~10 µW, 200 mA to a 100x10m RL.
16K21A, CRC-16, 4 chars, 960 symbols, 40 s each, 2200ut 05 Dec 2020
TX details: NE07M gpsdo set to 8.27, XOR keyed by Rasip running P. Nicholson's ebnaut.c piped to ebkey.c, AF amp, 5:1 xfmr, 0.47H, 100m aerial.
Report from DK7FC. "With 12 uHz offset:
found rank 3 ber 4.0394e-01 Eb/N0 1.8 M -1.675551990e-03 ph 85 -150,-120,180,-150 [JNC]
carrier phase: -5.3 deg
carrier Eb/N0: 1.2 dB
carrier Es/N0: -15.84 dB
carrier S/N: 13.53 dB in 28.9 uHz, -31.86 dB in 1Hz, -65.84 dB in 2.5kHz"

From Stefan (he doesn't recall the source at the time) to explain the 10 uHz offset.
04 Dec. Following email exchanges with DF6NM, DK7FC, the TTL/RTL divider chain is removed. An XOR had previously replaced the
reversing relay. Paul's ubx.c is used to set the NEO7M to 8270 and another EbNaut is sent.
01,02 December: 8.2700075 kHz, ~10 µW, 200 mA to a 100x10m RL. 16K21A, CRC-16, 3 chars, 864 symbols, 40 s each, 2300ut 01 Dec 2020

29 Stefan: no decode from Paul's data. Much QRN.
28 Nov DK7FC decodes but not correct. Try again 2300.
27 Nov. 2300 EbNaut again. DK7FC and IZ7SLZ attempt decodes
16K21A, CRC-16, 3 chars, 864 symbols, 40 s each, 8.2700075 kHz, 2300ut 26 Nov 2020. EbNaut but carrier failure after 0200ut 27 Nov.
22 Nov. EbNaut transmission completed. Aerial current down about 30% for the last day, but now near normal. Stefan has 200 Gb of data to analyse.
14 Nov: EbNaut experiment suggested by Stefan. cat text|ebnaut -et -N6 -p16K21A| sudo ebkey -S600 -m rp,gpio=23 -T '20201114 2000' -r 653400 -vv
14 Nov: Stefan's reception S/N: 16.78 dB in 1.5 uHz, -41.46 dB in 1Hz, -75.43 dB in 2.5kHz from > 1 week .

13 Nov. Stefan reports reception in Heidelberg 'better than 15 dB in 1.5 µHz.' Plans are made for EbNaut transmissions.
02 Nov. Paul spots the sigs on the Heidelberg RX.
30 Oct. Markus notes 'brighter pixels' on the DL0AO 47 µHz spectrogram
24 Oct SAQ 569 using a PA0RDT eprobe, SM6LKM converter and FT-817 at a scenic and quiet spot.

19 Oct off 1407. On 1153 20 Oct.
16 Oct 20200 500utc 0.07fT in Todmorden. 15 Oct 2020. Switched off from approx. 1200 to 2320 ut while using pegelsender.
Sun 11 Oct 2020 20:20 UTC off- Mon 12 Oct 2020 05:55 UTC on. 20 Sep TX off 1850-2246ut, 1859-1947 21 Sep.,
1521-1654ut 22 Sep. 07 Sep 2130 ut. aerial and mains earths connected. Relative aerial current increases from 27 to 28.
05 sep 2020 aerial earth only. ~1630ut
04 Sep 2020. Connect mains and aerial earths 1655 utc.
28 Aug JXN 16.4 kHz on again. < br> 23 Aug Off 1130-1140 24 Aug.
13 Aug Off ~1830 - 0100 ut 14 Aug in anticipation of electrical storm.
30 Jul Off 1115-1637 ut - lightning.
24 Jul Off 1200-2300 ut (lightning forecast)
30 Jun Carrier restored 0750 following mains glitch some time yesterday pm.
27 Jun 1344 67 0 4 1 Nice peak Paul's spectrogram yesterday.
22 Jun 2306 67 0 5 1
19 Jun 0027 SF67 SN0 A5K1. Continuing 200mA to 100m RL @ 10m.
29 May 2038 67 0 4 0
27 May 2240 68 0 4 0
24 May 0033 SF68 SN0 A4K1
15 May: Paul's Todmorden Spectrogram showing several strong sigs (0.4fT 100 nV/m) including IW4DXW DL7NN I1RFQ.
11.6 uHz sidebands reported by DF6NM. 8.2699975, 8.269980, 8.270006, 8.270010, 8.270020 kHz. Tnx info from vlf groups.io
Aerial raised. GPSDO derived carrier (÷ 400) -> 0.2A to 100m wire ~15m mean height.

23 Jan. Wind chafing severed the halyard, bringing the aerial down to the snow. The TX is QRT UFN.
9th. Paul concludes there is a problem with the transmission of EbNaut. DF6NM tries decode, but does not get what was intended
to be sent. The sound card has been misbehaving and so the carrier is now generated by a less elegant method, GPS disciplined
but without phase stabilisation by sampling radiated signal.
6th. Stefan attempting decodes. Aerial survives big storm.
2300, 1100 utc, 16K23A, CRC-21, one character, 784 symbols, 30 seconds each, 8.2700075 kHz starting 3 Jan 2020 at 2300 ut
02-Jan:0100-1400 carrier off for unknown period. Restored ~1500ut.


27 Dec. Strong sigs from DF6NM on Paul's spectrogram. 29 Dec. Aerial current down to 1/4 nominal due to snow.

IW4DXW(left) makes a brief appearance on 8270.003 Hz. Note the sideband structure consistent with with diurnal
ionospheric changes.
Thu. 5 Dec. 2 new peaks in Todmorden: DK1IS and DF6NM at .000 and .005 7 Dec. Snow on aerial 1730ut --
current is very low. 2200 ut closer to normal current.
Sun. 24 Nov 2019 Sefan confirms reception for the first time: "carrier S/N: 12.05 dB in 83.3 uHz from a segment
starting at 2 UTC, taking 200 minutes. This is quite a good peak from you here for just 200 minutes! The EW loop
was mixed with the E field." Meanwhile, still trying to eliminate glitches in the gps disciplining. A ground
loop between the pc and NEO7 was removed. This helped a lot.
21 Nov. IW4DXW QRV on 8270.003 Hz 0.6A 23kV. Clear sigs on Paul's spectrogram at 3 and 7.5 mHz offsets.
The date is set. 16 Nov. Strong (relatively) signals received in Todmorden.
24th. Stefan, DK7FC noting a good copy in Todmorden, detected the carrier for the first time.
5 Nov. Return to 8270.0075 Hz from 8270.000 Hz after tinkering with Spectrum Lab and the NEO-7 pps/data
output scalers to the soundcard. Hopefully this will continue.
20 Sep. Brief ac mains failure. SL restarted - aerial current normal and phase lock indication on sl good but no sigs at
Todmorden until 9 Oct when mucking about With feedback network restored phase control. SF 66 ssn 0. Sigs back
on PN Spectrogram briefly. More tweaking with SL and patch cables. Carrier seems to be on since 12ut 13 Oct. 15 Oct.
Now using ad9851+DOCXO. 2110ut.
16 Oct 19 0024ut SF67 SN0 A6 K0. Earnestly seeking sigs in Todmorden. Peak yesterday 0.1 fT, 36nV/m. 0300-0400ut.
2317 sf66 ssn 0 a6 k0 NEO7 8270 Hz now.. 21 Oct. 8.27 kHz sigs on PN spectrogram though weaker than usual. sf64 sn0 16 k2. 22Oct sf64 sn0 a6k2.
31 Oct. Still doing well with NEO-7 gps on 8.27 kHz with transatlantic graffitti appearing on Paul's VLF spectrogram. 0.24A RF to 100m wire.
01 July ~2330 ut 0.1fT 65 nV/m peak in Todmorden. TNX PN spectrogram.
16 July: ~0000-2100ut. Aerial earthed due to lightning.
16 June. Notepad pc & SL restarted 2300 ut following malfunction.
Signal is weak wrt noise on PN spectrogram but seems to show return of central carrier.
10 May. The carrier is split into 2 sidebands at 12uHz with a strong attenuation of the central peak. It seems the diurnal phase shifts have returned.
26 May central peak seems to be returning. Aerial current increased 25% by boosting drive.
27 May aerial icing-- 0700ut Aerial current 1/2, 1200ut 1/8 nominal value. 1955 ut Back to nominal. (meter reading 30 uA=>240mA on rf probe.)
April. There seems to be some evidence of diurnal phase shifts near the spring equinox. The central peak is less intense than the one 12 uHz lower and
sometimes less than the one above on Paul's spectrograms. The intermediate tower was no longer used after a day or so. Aerial current fluctuates with wx.
12th. Paul Nicholson reports to the Long Wave message board that the carrier is regularly seen in Todmorden at 5-9nV/m daytime.
16th. Aerial grounded with 10mm ice overnight. Raised at 1830 ut after chopping down a tree to recover wire.
23 1630ut ice in forecast - aerial lowered. Missing signals noticed by Paul the same day.
After an climbing adventure to replace a halyard, the 100m aerial was raised again and transmissions resumed at 1400 utc 6 March 2019 on 8.2700075 kHz.
An intermediate tower is now 17' shorter so the average height is a bit lower. It is good to see the traces on P. Nicholson's spectrograms. 9th Mar.
Carrier still on. Announced to LWCA message board. No sign yet on the DL0AO VLF grabber.
13 Feb Garry K3SIW is nearly convinced of reception. 15th Aerial halyard failure. Off air.
30 Jan Aerial lowered for ice. Raised again 4:42 local 31 Jan. No trace on Paul's spectrogram whilst lowered. Aerial current was 20-30% nominal.
26 Jan. Unmodulated carrier. 27th: 0.14fT, 47nV/m on paul's spectrogram 2000ut

20 Jan. Another announcement to the LF reflector:
VLF: 8.2700075 kHz 2300, 1100 utc, 16K23A, CRC-21, one character, 784 symbols, 30 seconds, 30 watts to a 15x100 metre RL.
13 Jan. Report from Jacek, but no decode yet.
12 Jan 2019. No sign of diurnal phase inversions since Sept 2018. Try Ebnaut again: 2300, 1100 utc, 16K23A, CRC-21, one character, 784 symbols,
30 seconds each, 8.2700075 kHz starting 12 Jan 2019 at 2300 ut and continuing until further notice or unforeseen natural catastrophe.
30 watts TX output, 10 uW ERP to a 100m rotated L at 15 m mean height. Spectrum Lab configured to do psk and generate gps disciplined carrier
(TNX DL4YHF, DF6NM and DK7FC). Aerial tuning 1:5 xfmr, 456 mH series inductance wound with 24 copper 0.08mm conductors in parallel.
9th Jan. Aerial partially lowered as precaution for freezing rain in forecast. ERP will be much lower than the usual 10 uW.
Unmodulated carrier 8.2700075 kHz GPS Disciplined 0.25 Amps to 100m wire at 15m average height as of 2130ut 10 Jan. No sign of phase
inversion has been found on Paul's spectrogram data other than Sept. 2018.


December: reports from Paul of EbNaut reception but not confirmed.
6th: Start EbNaut.
14th system reset.
18th aerial grounded by wx.
19th. Put a few more splices in the low RL and raised it, but a bit lower than before. Retuned by reducing the inductance and carrier back on 1500 ut.
23rd VLF Pileup at Todmorden.

DJ8WX DK7FC VO1NA left to right. Paul reports strong sigs.
IW4XDW joins the pileup.

22 Dec. Markus annotates Paul's spectrogram: a large congregation on 36km.
24 Jacek SQ5BPF reports a carrier on 8270.0075 Hz for the past few days.
27 DF6NM reported spectrogram obs at DL0AO. 29th. Clearly seen on DL0AO site along with diurnal frequency shifts.
The carrier is still idling. Strange stuff with SL notepad last night: put a 3.3 ohm across the sound card input to correct pps overdrive.

28 Oct. Strong peak on Paul's spectrogram: 0.12fT 33nV/m around 03-05 ut today.
16 Oct. Mains out for few hrs in evening. Carrier resumed ~2300 ut. (8.2700075 kHz, ERP 10 µW) Getting quite clear on Paul's spectrograms
with weaker signals during day and the peaks due to diurnal phase shifts seen at 1.5 µHz resolution. Lately the
carrier peak has been visible between the peaks.

12 Oct. Aerial earthed for lightning forecast this evening,.
21 Sep. Finally getting some work done for a new and improved coil.
13 Sep. 1000 tx off until 14 Sep. 0040 for lightning.

17 Sep 0700. Start mucking about with the phase.

24 Phase inversion between 07-22ut daily since 17th. 25,26: CW reception trials up to 3 km.
11 Sep. Conditions were good during the closing weeks of summer or perhaps the dry back yard helped reduce losses. Calculating a spectrum
from Paul's spectrogram showed the line had split. Broadening of the carrier peak had been seen before and was thought to be associated with
Doppler shifting by apparent diurnal ionospheric motion. Markus, having made similar
observations of Paul's data concluded that it was due to a 180o phase shift from the difference in the ionospheric height at day and night
based on the +-12 uHz departure from the carrier. This makes more sense; Doppler
fluctuations would distribute the frequencies over a band corresponding to the ionospheric velocities rather than
create 2 discrete values. 12 uHz fits well with a diurnal phase change but poorly with a reasonable speed for the ionosphere i.e.:
v=12*10-6 *c/2 = 1.8km/s This value is significant with respect to the escape velocity.

Markus' spectrum from Paul's spectrogram.

Markus also provided tantalising spectrograms from DL0AO and his own with hints of sigs from here but just a few dB too weak to confirm.

Jim plotted the phase variation and used the flipflop analogy to account for the pase inversion.

11 Sep. Meanwhile on this side of the pond, following an unsuccessful attempt to copy the sigs across 30 km of
ocean to the remote site of Frank VO1HP in Freshwater (30km), sigs were copied on Signal Hill (20 km)
using the PA0RDT eco-miniwhip variant and a bias T from the USB of a macbook running bootcamp/win10 and
DL4YHF Spectrum Lab with a configuration deck from Stefan DK7FC. Note the E field antenna atop the summit cairn.
The carrier is generated using spectrum lab and is phase coherent against GPS and corrected for phase changes
with aerial environment monitoring via feedback from a sense antenna.
The amp is a G1/SC and the aerial is 100m of 2mm copper at an average height of 15 metres. 30 watts yields an ERP of 10 µW.

9 Sep. Report and spectrogram from Paul showing good reception. Wx has been quite dry recently.

01 Aug. Helix blaze (flashover). Off air for a few hours. Did some work on aerial insulators but still getting TVI from time to time.
22 Aug. Possible detection of carrier at 3.5 λ using SL. More details to follow.

30 Aug. 2300 off for lightning.

01 July 2018. Carrier on except for some brief CW today to test an SM6LKM converter (5 mH T1, 10 MHz LO). New distance record for 8 kHz CW: 3.3 km.
Lots of QRN and no trace on PN spectrograms. Excellent copy of SAQ on 17.2 kHz using mobile RX comprising
PA0RDT miniwhip, SM6LKM converter and FT-817 away from mains lines.
9 July off for a day. A bit of TX off thanks to mains company doing line work.
03rd. A slight hint of sigs on Paul's spectrograms. 4,5 and 7th: Clear line on PN Spectrogram.
12th Aerial earthed. 13 on 15 off 16 2035 carrier on.

1 June 2018 continuing with carrier 8.2700075 kHz 10uW to the low RL.
13 June carrier off at 0008 utc. The carrier could be seen each day on Paul's spectrograms.

29-30 June Carrier on but sign of it on PN Spectrogram.

13 May. Raised the aerial again. Started carrier 2300 ut. 15th,18th Announced operation on RSGB LF reflector. Evidence of carrier on PN spectrograms.
20 May. DK7FC reports 10dB+S/N carrier. Try EbNaut:
One character, 8.2700075 kHz, 2300, 1100 utc, 16K23A, CRC-21, 784 symbols, 30 seconds.

21 Mar. Fouled halyard and insulators were removed from guys with aid of fishing rod as other more normal residents took to ice-fishing. Aerial
was repaired and missing portions replaced as required. Raised again. Carrier on 8.2700075 kHz ~2100 utc. 10 uW. 24th.
Aerial current decreasing and by morning it's on the ground with a thick coat of ice.

01 Mar. Aerial downed by freezing drizzle. TX off.

February. A new message and encoding is started. And now for something completely different:
0000, 1200 utc, 16K23A, CRC-21, one character, 784 symbols, 30 seconds each, 8.2700075 kHz.
Starting 1200 ut 6 Feb 2018. The traces on Paul's spectrogram are longer between the EbNaut transmissions. 7th: PN receiving the new message.
12th Paul reports good reception day and night but no decodes since 9th. The TX is running but the aerial current is very small due to icing.
It is back to normal (1/4A) by evening with T=7C today.
16-17th. Aerial icing but back to normal current 2100ut 17th.
23rd. BPSK to resume 2400ut.
27th. ¬0000 the aerial current is down to 0.5 nominal. Not enough for phase correction by SL. WX effect? 28th: Morning BPSK message not sent. Current normal.

Unmodulated carrier 21-22 Feb. to look for structure caused by ionospheric Doppler effects. The spectrum (from Paul Nicholon's spectrogram)
seems to show shoulders on the 8.2700075 kHz peak.

January. Continuing with single letter message at 2100 utc. Paul provides reports of very consistent decodes in Todmorden
and variable at other sites. 9th. A daytime transmission is added for tomorrow at 0900.
15 2100 ut. Aerial lowered in anticipation of ice and raised 24 hrs later. The carrier remained on. Paul reports daytime receptions.
17 Another good decode by Alex RN3AUS: Stacking procedure of files from 30 Dec to 10 Jan. Paul sends reception details from the remote receivers.
20th Jay W1VD finally gets a decode. He suspects terminator effect may have been the culprit preventing an earlier decode.
It was discovered today thanks in part to Paul's spectrograms that the daytime transmission was missing on or after 14 Jan. Restored today.
So far this month, there have been influences from Mother nature: unintended and intended lowering of the aerial and mains outages but
EbNaut still gets across the pond.


December. W4DEX is welcomed to 8270.0 and makes a good showing on Paul's new and more sensitive spectrogram.
DF6NM makes a brief appearance on .0025 completing a VLF pileup on the 3rd. There is snow on the
ground and wx changes so coil current is peaked and power are adjusted to keep the aerial current near 0.25A.

VLF Pileup.

Dex and yours truly on Paul's spectrograms.
12th. Letter S sent to Stefan is received by Paul instead. This is the fist EbNaut message transmitted using SL here.
Syntax: " echo 'S' | ./ebnaut -et -N1 -p 16K21A -k 8 > psk.txt " and put it column format for Spectrum Lab. Paul copies the S but not Stefan.
15th. peaked -20.2 dB S/N in 1 Hz at 0440 on pn spectrogram but no trace after 0830. Dex was there too.
16th. Phase inversions at 6m40s (period) 0000 - 1000 ut.
17th. Phase inversion at 5 min intervals (period =10m). 1400ut. Problem with notebook operating system or soundcard.
Since 1500 ut. using ne07m in frequency mode instead of SL to generate carrier on 8.2700075 kHz.
but uint32_t limits set to integral frequencies??
but "double freq = atof( ARG_f);
if( UBX_set_frequency( h, 0, freq, 0, 0, 0, 0, 0.5, 1))
printf( "set output frequency %.6f Hz\n", freq); "
suggests uHz resolution so leave it for a while!
18th. No trace of sigs seen on Paul's VLF spectrogram.

21st Dec. EbNaut transmission. Following morning Paul sends report. Summary: Station, km, Eb/N0 (dB), S/N in 1 Hz (dB).
Todmorden 3575 +11.1 -26.52
DL4YHF Bielefeld 4302 +4.7 -32.91
SQ5BPF Warsaw 5097 +1.0 -36.58

22-23 Dec. (reports thanks to P. Nicholson) Todmorden +10.3 -27.3 phase -167.2 *Decoded*
Bielefeld +1.4 -36.2 phase -35.3, *Decoded*
Warsaw -4.2 -41.8 phase 172.2;
IK1QFK Cumiana 4533 km +1.6 -36.0 phase 39.2, *Decoded* First Canada to Italy VLF message!

Forest, VA (2415.3 km KE4RJQ)
21/22 Eb/N0 -0.4 dB, S/N -38.0 dB in 1Hz, phase 62.5;
22/23 Eb/N0 -3.8 dB, S/N -41.3 dB in 1Hz, phase -15.8;
Despite valiant efforts at DF6NM, no reception yet. The SL ALC and phase disciplining are working well thanks to DF6NM and DK7FC.
28. Lots of reception reports to follow. Over the past week, P.N. in UK, DL4YHF SQ6PBF IK1QFK KE4RJQ RN3AUS DF6NM.
Tonight a new message. 2100 utc, 16K21A, CRC-8, one character, 544 symbols, 1 minute each, 8270.0075 Hz.

1st. Continuing with carrier GPS controlled via SL. ~250 mA RF. Paul sends several reports noting absence of signal during daytime and
4th. Aerial raised at far end again. From Paul:
4th/5th H-field 10.46 dB 0.09 fT -106.5 deg
E-field 10.34 dB -107.8 deg
Combined 14.62 dB EbNaut transmission started 16K19A 2300 utc and decoded by Paul with 1.8 dB Eb/N0 and 40 % BER.
5-6th. 5 Character message sent and received by Paul. Eb/N0 = +1.8 dB, BER 40.5%
8th-9th. 8 character message sent. Received by P. Nicholson: Eb/N0 = -0.5 dB, constant reference phase, BER 41.1%
9th (~1800 utc) : A pickup wire is connected to the soundcard to correct phase for aerial/coil fluctuations with SL.
12th. Peaked I_A by increasing L a bit. Heard CW sigs at 1.7 km using the crude DC RX.

20th Far end of low RL increased 50 percent.
22 Nov. The pickup wire (for SL phase stabilisation) was disengaged earlier today
23 Spectrogram of signals reported by Paul who suspects they might be from here. http://abelian.org/vlf/fbins.shtml#p=1511402400&b=100&s=sp
DF6NM reminds the op on correct SL usage ie: it will correct phase shifts whether they are intentional or not!
24th. Mains was out so there was no carrier from morning to 2200 utc today. Continuing with carrier 8.2700075 kHz.
25th. Phase stabilised by E field feedback to Spectrum Lab starting ~2200 ut.
The notebook pc is synchronised by GPS NMEA and 10 mS PPS. TNX to DF6NM,DK7FC
for SL tips and Paul's UBX code for the NEO7M. 8270.0075 Hz, 10 uW + a little bit due to the aerial being raised on 1 Nov.
4-6th Good reception of carrier on 8270.00709 Hz by P. Nicholson. 10 µW to low RL with new xfmr (1:5) 144,70,100,17 mH coils. 30 watts from G1/SC amp.
Exciter: DDS60 (AD9851 + 8088 amp). Paul's field strengths and S/N were 0.06, 0.084 and 0.042 fT and 13 14 and 11 respectively in
34.72 uHz "(8 hours 23:00 to 07:00 UT) using combined E-field and H-field."
7th. Heard VLF CW beacon at 1km using homebrewed rx.
Report from P. Nicholson:
Overnight signals 23:00 to 07:00 UT:

8th/9th 0.046 fT S/N 9.1 dB, noise 0.016 fT;
9th/10th no signal detected, high noise;
10th/11th no signal detected, high noise;

Daytime 10:00 to 18:00 UT:

8th: 0.033 fT S/N 15.1 dB very low noise: 0.0057 fT
9th: 0.022 fT S/N 8.8 dB noise 0.0083 fT
10th: no signal detected, noise 0.012 fT

Reports of spectrogram traces on right frequency from Laurence KL7L and Markus reporting on DL0AO in Amberg also on the 10th.
These traces were unlikely to have originated from here.

More reports from Paul: Overnight signals 23:00 to 07:00 UT:

8th/9th 0.046 fT S/N 9.1 dB, noise 0.016 fT;
9th/10th no signal detected, high noise;
10th/11th no signal detected, high noise;

Daytime 10:00 to 18:00 UT:

8th: 0.033 fT S/N 15.1 dB very low noise: 0.0057 fT
9th: 0.022 fT S/N 8.8 dB noise 0.0083 fT
10th: no signal detected, noise 0.012 fT

After much mucking around with a NEO7 and using SL ini files from Stefan and Markus, Paul reports a "nice sharp line on 8270.0075 " and "
Night: 19th/20th 13.9 dB phase 3.0 deg 0.065 fT H-field only
Day: 20th 10.5 dB phase 101.4 deg 0.034 fT H-field only
Night: 20th/21st 12.1 dB phase 8.0 deg 0.058 fT H-field only
10.8 dB phase 0.0 deg E-field only
14.4 dB E-field and H-field combined
Day: 20th 12.3 dB phase 104.8 deg 0.038 fT H-field only
10.1 dB phase 100.3 deg E-field only
15.2 dB E-field and H-field combined

Daytime phase and amplitude repeats very well."
And so our quest (for coherence, stability and accuracy) is at an end.
21 October. Start periodic phase inversions at ~2100 utc on 8.2700075 kHz. Neo7m gps module pps to notebook running SL with DF6NM vlf ini,
vo1fr audio preamp, vo1bl rca patch cord, vo1na cw key cord to back of group one/sc amp, birch breadboard with knurled nuts,
shunt resistor, meter, lamp, DPDT reversing relay keyed with raspi3, etc. then to helix hut via 2 pairs of 3 parallel wires
to the new 1:5 xfmr, ammeter in ground lead, helix with 24x0.08mm wires, 100m RL at 12m high and much help and coaching from DF6NM and DK7FC.
22 constant phase 0750 ut, EbNaut starting 2300, 3 characters, 55 second symbols, 8K25A, 8.2700075 kHz, repeating every 12 hours.
23 October Email from P. Nicholson:
" CRC was 16 bits.
Copied 'VLF' with constant reference phase.

H-field: Eb/N0 = +1.4 dB, phase 155.7 deg
E-field: Eb/N0 = -0.2 dB, phase 152.5 deg (new RX)
Combined: Eb/N0 = +3.0 dB, phase 154.4 deg

First sub-9kHz message Canada to UK."
25th. Aerial raised a bit. tx still running.


7th The aerial is earthed following lightning threat forecast. Paul again overcomes the instability and weakness (8uW) of signal...

"a non-coherent average over 8 days of 10:00 to 20:00" is posted to the RSGB reflector.
26 DK7FC provides advice on SL and NEO7M which recently arrived.
27 Carrier on 2245 utc 8269.9975 kHz (note f*400/239 is prime) 8 uW ERP but not a hint seen by Paul the following morning.
The DST took a major dip and there could be trouble with the carrier.
28 replaced pc and running sl+rsntp. Some fizzling sounds heard around the coil but no blue glow was seen.

Thanks to Dave G3YXM who mentioned the work in his LF column, p66 RadCom.
0.25 amps to the 10x100m RL (8 µW) unmodulated and undisciplined (DOCXO) 8270.00709 Hz +- a few ppb. (24 Aug)
Amazingly, the signals are copied by P. Nicholson who reports: ...two daytime signals, 25th and 26th 10:00 to 20:00,combined coherently,
bin width is 27.8 uHz. S/N of the combined days is 16.0 dB.
Adding the two days non-coherently gives only 9 dB." Nothing useful was extracted from the night signal.

0.3 Amps to the 10x100m RL via 3 pies and a solenoid wound with 24 strands of 0.08mm copper (~2 kg)
03. Detected using SL and DK7FC VLF E probe at airport(10km) and possibly at Signal Hill (20 km).
Paul's report: Nothing detected overnight 3rd/4th but a nice signal 4th/5th at 0.13 fT, S/N poor due to high noise - only about 10.3 dB in 46.3 uHz. 14th.

Tuned aerial with 2 large and one small pie: Total 487 mH 148 ohm DC. 0.33 amps till flashover. Spectrum peaks at 8270.0070865 +/- 0.5 uHz.

Dave G3YXM includes a quick mention on p66 of RadCom.
07 0.24 amps carrier 8270.007 Hz. Reports from P. Nicholson: night 13th/14th: average 0.11 fT, freq 8270.0070925 +/- 0.5 uHz;
Daytime 14th: average 0.085 fT;night 14th/15th: average 0.082 fT;
16th. Continuing with 0.24 amps while working in the back yard and winding workshop.
More reports from Paul: Daytime 15th: No signal detected; Overnight 15th/16th: Good signal, average 0.12 fT, S/N poor;
Daytime 16th: Down in the noise at about 0.05 fT; Overnight 16th/17th: No signal visible, E-field down for some hours;
Daytime 17th: 0.075 fT, S/N 12 dB in 23uHz, 8270.007080 +/- 0.5 uHz Overnight 17th/18th: 0.13 fT, S/N 12.7 dB in 46.3 uHz,
8270.007085 +/- 0.5 uHz
A note from Alan G3NYK showed a dip in the DST was timed with poor reception at Paul's. The tuning system comprised
a pie (24 0.08mm conductors) 0.265 H 94 Ohm, solenoid (24 wire) ~70 mH and a 6 wire 100 mH 160 ohm pie.
On the 19th, the solenoid and lossy pie were replaced with a 139 mH 57 Ω pie (24 wire) and the aerial current increased to 0.34A.
Sadly, the 0.265 H pie started hissing, sparking and spewing ozone. Efforts to bring it back to life were not efficacious;
a rewind is in order. The carrier is off for now.
21st 11:40 am carrier 0.34A. 139mH pie, 70mH solenoid, 120 mH pie. Announced on RSGB reflector. 23rd: tried new coil.
0.4 Amps. Back to previous arrangement and 0.34 amps. Carrier on tfn.
28 June 1108 utc tx off, aerial earthed. WX: Risk of thundershowers this afternoon.

23-29 EbNaut 2300 and 1100 utc 0.32A RF. There was no daytime psk on the 27,28th and 3 phase glitches. No 1100 psk 26 May,
but fsk CW with groups of 5 numbers was heard on the portable VLF rx at around 1900 ut.
23rd. Paul decodes "VO!" at Eb/N0 -0.5 but BER 43% and 'PV4' at +0.9 dB, BER 39.6% but sadly, neither is correct. Jacek SQ5BPF
spots a doubtful signal a bit off frequency.
21-22 Carrier. 22-23 Ebnaut starting 2300.
20-21 Ebnaut TA attempt. ERP up 2.5 dB with new helix: 123 µ Ω * (0.32A)2 = 12.6 µW
19-20 EbNaut TA trial again. Wound a new coil (186 mH 70 ohm) and got 60% more aerial current. Then a stench of O3
and a pffft sound. =Dead coil. Now back to the lossy 6 wire 100 mH, 12 wire 80 mh and big 140 mH 59 ohm coil
30 watts 0.25 RF amps.
Paul Nicholson's reports for 16-18th, 17th/18th avg 0.045 fT and the noise was very low. The carrier 'decoded' to '***' at
Eb/N0 = +1.2 dB The carrier decode registered best Eb/N0 +1.6 dB at a frequency ... of 8270.0070925 Hz [offset] + 9 uHz.
Spectrum peaked at 8270.007101 Hz +/- 0.5 uHz.
16th/17th. night peak 0.05 fT average was about 0.035 fT, poor S/N. Daytime 17th was weak too, only averaging 0.025 fT but S/N
was fairly good.
14 May. Ice melted in sunshine. Just under 0.3 amps EbNaut starting 2300.
13 May 2300 Ebnaut transmission. 3 Chars, 8K25A, 464 symbols, 55 seconds each. Antenna iced by morning and Paul's
valiant efforts did not yield a decode.
13 May. Antenna iced. Low ERP overnight. Nil across pond. Paul's analysis shows the Forest reception to be doubtful. It has
not been seen since the 8th.
12 May. QRV on EbNaut. 2 dB added to ERP. Calibrated ammeter. Reading 0.28A
Best report from Todmorden: 0.085 fT. 11/12 May.

Paul's spectrum with the Fourier transform bins aligned to 8270.0070625 Hz +/- 0.5 uHz.

Matching transformer,current probe and tuning helix used for VLF transatlantic transmission 7-8 May 2017.

08 May. Paul Nicholson reports a peak in Todmorden 46.3 uHz above the posted frequency. The maths puts
the carrier high by 92.6 and the ref osc is likely low by 5-6 ppb. Paul's LWPC models FS as 0.069 fT,(0.021 uV/m) in agreement with
his measurement, and verifies that the signal was from the west.
It looks like the sigs crossed the pond.
Paul's info: signal peak 8270.0070625 Hz +/- 0.5 uHz. (about 3.6 ppb low) S/N 13.9 dB in 46.296 uHz. r=3545 km.
Daytime (08:00 to 11:00 8 May 2017) 0.04 fT.
A peak is detected in Virginia on the RX operated by Mike KE3RJQ at r=2442 km.

07 May. ~10 uW carrier on 8270.007 Hz. Watching VE2IQ grabber. Using new big pie: 128 mH 59.3 ohms and
2 smaller ones 80 mH, 116 mH L=470 mH. Heard at 1 mile with portable dc receiver.

24 Apr. 2130 Crossband VLF-CW/VHF-FM QSO on 8.277 kHz/147.77 MHz.
VO1RL TX at VO1NA VLF, VO1NA/1 TX on 147.77 MHz. QRA~1000'.

18 Apr. Detection of anthropogenic 36 km Fraunhofer photons (r=7km)

Coloured lines are 'flexible curves' with inverse cubic roughly fitted to data. Note the anomaly between 1 and 2 km.

Remote reception site. Note the small iceberg behind the DK7FC VLF e-probe. Looking towards England, 3500km away.

SL config file Tnx to all! Helix at 200 mA since 1000 utc. P_rad=123µΩ*(0.2A)^2= 5 uW

16 Apr. 100x12m(h) aerial is up again. Current probe reading:22 (about 1A of primary current, 0.2A secondary). Running
vlf8277_2b.usr/SL/pan pc at r=1km then helix arced!

15 Apr. Both aerials are on the ground or treetops thanks to ice and wind. Experimenting in the shack with DL4YHF SL, PA0RDT
MW and DK7FC VLF probe and a carrier generated by a DDS60.

14 Mar. Higher current to the new coil. Primary current: 12 on probe (~.25A) secondary = 0.25/5 = 0.05 ma. Prad=123 * (0.05)**2= 0.31 uW,
assuming the probe is 2A full scale. Amp o/p was 'dirty'. Heard at 1.5km using dc rx.

8 March. Repaired Traynor amp. QRV again. 6 uA probe primary (uncalibrated). {10 uA probe reading for speakers
or 16 ohm loads, 20 v p/p. (3 watts)} i=v/r = 7/16; primary= 6/10 * 7/16 = 0.3A ; secondary = p/5= 0.06A Aerial 10h x 100m
Rotated L (RL). H_eff~10m assumed uniform current distribution.
R_rad=(40Heff/ λ)2=123.4567890 µΩ. P_rad=0.4 uW. Heard with dc rx + mw at 0.93 km.

Feb. 2017. On the air ~20 ma with new coils (0.5 H 12x0.08 mm Cu wire)

13 Jan. 2017 VLF licence renewed by Innovation, Science and Economic Development Canada.

14 Jan. Tests with uno/ad9850 module sq out/tc4426. 8277 Hz. Range 1 metre. XH100 tone: 553.3 553.8 (using Argo on win xp pc)


24 Dec. 2016 Excellent reception of SAQ on 17.2 kHz CW at 0800-0804 with 100m Rotated L ~20m high,
LF10 and XH100 with SRA8 mixer. Audio clip

10 Nov. 2016 IEEE NECEC 2016 Paper: "On VLF radiation from an extremely small aerial"

7 May. Checked RF ammeter. OK. Low current was due to short in the helix. Corrected with a few pokes.
L=0.37 H. 5:1 n:n xfmr primary 4.24 mH Secondary 0.1H. Primary current 0.034x14=0.471A
Off air due to short in upper helix which must now be rewound.

1 May 2016. Brief test: ~20 watts to the 100m wire up ~12 metres. Poor range. Not heard at 1 km but FSK from NAA
and CW from RDL were heard clearly on the direct conversion RX.

8 April 2016. Licence renewed until December.

20 Mar 2016: VE7SL is interested in getting on VLF. German and English amateurs are sending EbNaut back and forth on 8.270 kHz.


20 Dec 2015: VLF test. About 30 watts were fed to a 1:5 XFMR and a 0.47H tuning coil then to the 100m wire at 10m height.
CW signals were heard clearly at 2 km using a homebuilt DC RX and a PA0RDT miniwhip. The sigs could not be heard on the
DC RX at 2.7 km and were much weaker though audible on the XH100/LF10 with 20m of wire strewn in the trees.
This is a new distance record for audible reception at 8.277 kHz.

I_a=0.17A R_rad=1579(10/36000)^2=122 uOhhm; P_rac=I^2R=3.5uW

08 Nov 2015. Best DX so far 5 km (Spectrum Lab, PA0RDT Miniwhip and DK7FC E-probe. Today using
homebrew DC receiver, heard sigs clearly at 0.5 km on 8.277 kHz.

09 Jun 2015 awaiting renewed licence.

dB on SpecLab QRSS120 vs r in km.

31 May 2015 Licence expired. Renewal requested.

09 May testing DK7FC design VLF preamp circuit.

05 May '15. Tried QRSS100 but best range 3.8km (10 dB). Nil at 4.3, 6.6 km. MW + Spectrum Lab.

29 Apr. Rewound another pie. 6*0.08mm Cu wires. 276 mH 279 ohm and put about an inch above another pie 98 mH 159 ohm. ~ 0.45H.
Sigs detected at 5.2 km(0010) but not at 5.9 km(0015). (CW instead of QRSS100 was used with spectrum lab (DL4YHF) in dot 60 mode.

The sigs appear at 8277.2 Hz due to a sound card calibration error.

21 Apr 15. Wound 2 new pie tuning coils using a drill press. Very quick and convenient. Now to get past the 5764.58277 m boundary....

15 Apr. Weak 8.277 kHz CW sigs copied at 1 km with xr2206/4066/lm386 VLF homebrew DC RX and PA0RDT Miniwhip antenna.

12 Apr detection of 12 WPM cw sigs using Spectrum Lab QRSS60 and mw antenna at 4.67 km.

5 Apr. Using same setup as below -- Weak but readable CW at 2.15 km.

4 Apr 2015. XH-100 & LF10: Audible CW reception at 1.25 km. Amp set at 5 (~30 watts). New tuning coil (0.1H) wound on wc paper roll to
replace old one that apparently arced. Used with XBT spool (.17H) coaxial for L=.426H 1:5 ferrite match + variac (1:2).
Nature Magazine Vol 226 20 June 1970 reports on VLF reception in NL during eclipse. It was foggy at Marconi Place 7 March 1970.
Rycroft & Reeve from U Southhampton. Spectra 1-10 kHz. 3m square loop, filters for 16 17.8 100 112.6 kHz ("GBR NAA Loran and a
local navigation station..") The latter presumably Decca in Shoe Cove.

14 Mar Wound 2 more secondaries on the ferrite xfmr 30-32 turns 3.5 mH per winding. Juiced 1 winding and put the other 5 in series.
One end to the .35 H coil, the other to gnd. Was able to measure aerial current for first time... about 6 mV across the 50 uA current probe
meter/multiplier. Heard the CW ID on 8277 Hz at 0.75 km. A hawthorn tree (PA0RDT method) could not be
found so used a fir tree instead to test the MW and home-brew VLF RX...

DC VLF receiver & Miniwhip: CW on 8.277 kHz

9 Mar 2015 Volume level 4. Trouble measuring Iae; reception at 0.66 km. 10th procured coil.

Posted to the RSGB reflector 8 March 2015:
Yesterday an old XR2206 was discovered in the shack and it seemed this might make a nice LO for a DC RX. A 4066 was used as a mixer
and an LM386 as the audio stage. The PA0RDT MW fed the mixer. A crude design for sure, not even a diplexer to follow the mixer so the
8730 Hz LO was quite loud in the speaker. It was a lovely sunny but cold day so I put the contraption against my ear held the MW above
my head with the other hand and began walking. The VLF CW beacon could be clearly heard at 0.5 km but disappeared at 0.7 km. There were
all sorts of strange noises heard including the Alphas For TX, about 10 watts were fed to a 1:4 xfmr and tuned to the 100m wire
(15m mean height) with about 0.35 H of very lossy inductance.
DL4YHF Spectrum Lab in the DC RX mode was used in earlier experiments but it seems the computer makes much QRM. For todays test,
I took the computer battery pack to power the RX and left the noisy part the shack. This the best VLF DX so far from here. It is hoped to get
a few km of wire for an improved tuning coil.


27th Dec. 2014 Set up TX again on 8277 kHz. Heard it on 3 different receivers.

24 Dec. Good reception of SAQ on 17.2 kHz CW at 4:30 AM local. Used 100m wire, LF10 and XH100 with SRA8 mixer.

17.2 kHz Christmas Eve 2014 0806 utc

23 Dec 2014. A developmental licence is now in hand, valid for 6 months. Presently tinkering with a divider circuit to get high precision
8277 Hz signal. Getting noise from 7493 chip when something is connected to the output. Tried filtering the input with ferrite choke, bypass
cap. which took out the ~10% noise. Tried shunting 0.01 uF across the 100 uF across Vcc of chip. now have a mar-3 amp to boost the
docxo to 4 v p/p (2vp/p 50 ohm). Maybe feedback ?

SAQ on the air tomorrow morning.

Date: Mon, 23 Jun 2014 17:03:31 -0230 (NDT)
From: xxxxx
To: rsgb at ba_ba_blacksheep.org
Subject: VLF in Canada

Dear Group, I tried again to get an LOA for VLF. This time, the response from Industry Canada was favourable: 10 mW 8.0-8.3 kHz.
Yesterday, after a few slight rf burns, and thanks to PA0RDT's miniwhip design and DL4YHF's Spectrum Lab and advice, VLF sigs on
8.277 kHz were heard at 200m from the 100m wire aerial. This was a reception outside my back yard! 10 watts from an 1970's keyboard
amp (volume control set on 3) were stepped up with an xfmr to a lossy 500 ohm tuning coil peaked with a ferrite rod for maximum squeal at L=0.35 H.
Is it possible for someone who is not especially enthralled by winding a mile of 0.7mm wire to use an iron core to make a VLF tuning coil?

73 Joe VO1NA

Outside the back yard

Canadian Table of Frequency Allocations:
Below 8.3 kHz is unallocated, but footnoted:
C1 (CAN-14) Users of frequencies below 8.3 kHz shall ensure that no harmful interference is caused to the services to which the bands
above 8.3 kHz are allocated.
C2 (CAN-14) Scientific researchers using frequencies below 8.3 kHz are urged to advise the Department in order that such research may
be afforded all practicable protection from harmful interference.