136kHz DX

Despite the Dst being low, Opera8 tests by myself and DK7FC produced good results with Stefan getting several reports from Russia. I reached only one Russian station, but at the greatest distance, 2472km. He gave me a single very marginal report of -34dB signal / noise at 0027UTC. The picture below (click on it to enlarge) is from the PSKreporter web site and shows the location of all of the stations who gave me reports, including: DF2JP, DK7FC, F4DTL, G3XBM, G4MDH, G4WGT, G8ALS, GW0EZY, GW3UCJ, M0PPP and RV3APM.

DLs on WSPR

Monitored 477kHz overnight for WSPR transmissions. I started at around 1800UTC and received DL3DNR from 2012UTC until 0310UTC, peaking -6dB signal / noise. Also, DK6NI from 2254 to 2314, peaking -24dB. Full details are as follows:

120729 2012   6 -26 -1.1   0.478485  DL3NDR JN59 27          0     2    0
120729 2020   6 -26 -1.1   0.478485  DL3NDR JN59 27          0     1    0
120729 2026   3 -27 -1.1   0.478485  DL3NDR JN59 27          0    16    0
120729 2032   5 -26 -1.0   0.478485  DL3NDR JN59 27          0    46    0
120729 2042   3 -29 -1.1   0.478485  DL3NDR JN59 27          0  1007    0
120729 2128   5 -27 -1.0   0.478486  DL3NDR JN59 27          0   749    0
120729 2206   4 -26 -1.1   0.478486  DL3NDR JN59 27          0     5    0
120729 2210   5 -27 -1.2   0.478486  DL3NDR JN59 27          0     3    0
120729 2212   9 -22 -1.1   0.478486  DL3NDR JN59 27          0     1    0
120729 2224   8 -23 -1.1   0.478486  DL3NDR JN59 27          0     1    0
120729 2226   6 -26 -1.1   0.478486  DL3NDR JN59 27          0     1    0
120729 2232  13 -19 -1.3   0.478486  DL3NDR JN59 27          0     1    0
120729 2234  10 -21 -1.4   0.478486  DL3NDR JN59 27          0     2    0
120729 2238  14 -18 -1.4   0.478486  DL3NDR JN59 27          0     1    0
120729 2244  13 -18 -1.2   0.478486  DL3NDR JN59 27          0     1    0
120729 2246  13 -18 -1.2   0.478486  DL3NDR JN59 27          0     1    0
120729 2252  15 -17 -1.3   0.478486  DL3NDR JN59 27          0     1    0
120729 2254   8 -24 -0.7   0.478454  DK6NI JN59 20           1     1    0
120729 2258   5 -25 -0.8   0.478456  DK6NI JN59 20           0     1    0
120729 2258  19 -14 -1.3   0.478486  DL3NDR JN59 27          0     1    0
120729 2304  20 -12 -1.2   0.478486  DL3NDR JN59 27          0     1    0
120729 2306  11 -21 -1.2   0.478486  DL3NDR JN59 27          0     2    0
120729 2310  10 -21 -1.2   0.478486  DL3NDR JN59 27          0     1    0
120729 2314   4 -27 -0.8   0.478455  DK6NI JN59 20           0     2    0
120729 2314  19 -14 -1.2   0.478486  DL3NDR JN59 27          0     1    0
120729 2318  18 -13 -1.2   0.478486  DL3NDR JN59 27          0     1    0
120729 2322  20 -12 -1.2   0.478486  DL3NDR JN59 27          0     1    0
120729 2326  18 -13 -1.1   0.478486  DL3NDR JN59 27          0     1    0
120729 2332  18 -15 -1.2   0.478486  DL3NDR JN59 27          0     1    0
120729 2338  20 -13 -1.3   0.478486  DL3NDR JN59 27          0     1    0
120729 2340  20 -13 -1.3   0.478486  DL3NDR JN59 27          0     1    0
120729 2346  14 -19 -1.3   0.478486  DL3NDR JN59 27          0     1    0
120729 2352   9 -24 -1.3   0.478486  DL3NDR JN59 27          0     1    0
120729 2354  15 -18 -1.3   0.478486  DL3NDR JN59 27          0     1    0
120730 0000  19 -13 -1.1   0.478486  DL3NDR JN59 27          0     1    0
120730 0002  19 -14 -1.3   0.478486  DL3NDR JN59 27          0     1    0
120730 0008  19 -14 -1.3   0.478486  DL3NDR JN59 27          0     1    0
120730 0014  20 -13 -1.2   0.478486  DL3NDR JN59 27          0     1    0
120730 0018  23 -10 -1.3   0.478486  DL3NDR JN59 27          0     1    0
120730 0026  17 -14 -1.1   0.478486  DL3NDR JN59 27          0     1    0
120730 0034  23 -10 -1.3   0.478486  DL3NDR JN59 27          0     1    0
120730 0042  22 -12 -1.3   0.478486  DL3NDR JN59 27          0     1    0
120730 0048  23 -10 -1.2   0.478486  DL3NDR JN59 27          0     1    0
120730 0056  26  -6 -1.4   0.478486  DL3NDR JN59 27          0     1    0
120730 0104  22 -11 -1.3   0.478486  DL3NDR JN59 27          0     1    0
120730 0112  24  -9 -1.3   0.478486  DL3NDR JN59 27          0     1    0
120730 0122  16 -16 -1.3   0.478486  DL3NDR JN59 27          0     1    0
120730 0130  14 -19 -1.4   0.478486  DL3NDR JN59 27          0     1    0
120730 0136  10 -22 -1.3   0.478486  DL3NDR JN59 27          0     1    0
120730 0146  10 -21 -1.5   0.478486  DL3NDR JN59 27          0     1    0
120730 0156  20 -10 -1.3   0.478487  DL3NDR JN59 27          0     1    0
120730 0204  15 -15 -1.4   0.478487  DL3NDR JN59 27          0     1    0
120730 0214  17 -13 -1.5   0.478487  DL3NDR JN59 27          0     1    0
120730 0222  19 -12 -1.4   0.478487  DL3NDR JN59 27          0     1    0
120730 0228  10 -20 -1.2   0.478487  DL3NDR JN59 27          0     1    0
120730 0236  18 -14 -1.3   0.478487  DL3NDR JN59 27          0     1    0
120730 0242  16 -15 -1.4   0.478486  DL3NDR JN59 27          0     1    0
120730 0250  11 -20 -1.4   0.478486  DL3NDR JN59 27          0     1    0
120730 0300  11 -19 -1.4   0.478487  DL3NDR JN59 27          0     1    0
120730 0306  15 -15 -1.5   0.478487  DL3NDR JN59 27          0     1    0
120730 0310   8 -23 -1.4   0.478487  DL3NDR JN59 27          0     9    0

Weekend MF Activity

On Saturday night I received Opera4 signals from PA0WMR and G4WGT on 500kHz. At 2350UTC I heard the end of a CW contact between DF0WD (449 in static) on 478kHz and PA3ABK (589) on 502kHz.
On Sunday morning, I heard the regular 500kHz CW contact beween M0JXM (599), G3DXZ (579) and G3XIZ (599+).

EI on 500kHz CW

At 0020UTC on the morning of Thursday 26 July, I heard the end of a 500kHz CW contact between Finbar, EI0CF and a station he called "John" whose call I did not hear. Finbar was 559 and "John" was 439 in the static. Finbar has subsequently informed me that he was working EI6DN in Dublin. EI is a new country for me on this band.

More 136kHz Op32

I ran another Opera32 test on 136kHz last night. Highlights were as follows:

02:51    136 G3XDV de TF3HZ Op32 1858 km -34 dB in Reykjavik

02:19    136 G3XDV de TF3HZ Op32 1858 km -36 dB in Reykjavik

01:46    136 G3XDV de TF3HZ Op32 1858 km -33 dB in Reykjavik

01:13    136 G3XDV de TF3HZ Op32 1858 km -34 dB in Reykjavik

00:40    136 G3XDV de RN3AGC Op32 2483 km -38 dB in Moscow

An offline report from Alex, RN3AUS has also been received:
00:40    136 G3XDV de RN3AUS Op32  -40 dB in nr Moscow

Sunday LF/MF

Sunday morning on 500kHz, I heard a CW contact between G3XIZ (599+), M0JXM 599+) and G3DXZ (569), and another between G3KEV (599) and PA3ABK (579).

An overnight test last night using Opera32 on 136kHz, produced reports from: DF2JP, F6CNI, G8HUH, G0KTN, G0NBD, G3XBM, G4MDH, GW0EZY, PA7EY, and TF3HZ. The Icelandic station gave me one report (-33dB signal / noise) at 0234.

DF6NM was also testing on this mode, using twice as much power as me, and he managed to reach TF3HZ and RN3AGC.

136kHz Op8 to Iceland and Russia

Transmitted an Opera8 beacon again overnight on the 136kHz band and got reports from RN3AGC, RX3QFM and TF3HZ (-32dB). The Icelandic station produced five decodes between 0022 and 0202. Best distance was 2681km to RX3QFM. Highlights were as follows:

02:02    136 G3XDV de TF3HZ Op8 1858 km -35 dB in Reykjavik

01:37    136 G3XDV de TF3HZ Op8 1858 km -31 dB in Reykjavik

01:12    136 G3XDV de TF3HZ Op8 1858 km -32 dB in Reykjavik

00:47    136 G3XDV de TF3HZ Op8 1858 km -32 dB in Reykjavik

00:47    136 G3XDV de RX3QFM Op8 2681 km -33 dB in KO91OO

00:22    136 G3XDV de TF3HZ Op8 1858 km -32 dB in Reykjavik

00:22    136 G3XDV de RN3AGC Op8 2483 km -34 dB in Moscow

23:57    136 G3XDV de RN3AGC Op8 2483 km -31 dB in Moscow

RN3AUS (2448km) provided this off-line report later:
00:22    136 G3XDV de RN3AUS Op8  -32 dB in nr Moscow

Opera8 Overnight

DK7FC ran high power on Opera8 on 136kHz (dial), 137.6kHz (actual). This resulted in a lot of listener interest and a few transmitting stations, including myself. He reached Iceland and several western Russian stations at distances up to 2848km.

My 400mW ERP was received by DF2JP, F4DTL, F6CNI, G0TKN, G4MDH, G4WGT, G8HUH, GW0EZY, PA0A, PA0LCE, PA0LPN, PA7EY, and TF3HZ who was my best DX at 1858km. The decode at 0119 was as follows:

01:19    136 G3XDV de TF3HZ Op8 1858 km -30 dB in Reykjavik

01:19    136 G3XDV de G8HUH Op8 199 km -9 dB in IO81mg

01:19    136 G3XDV de G0KTN Op8 158 km -11 dB in Bath, UK  IO81

01:19    136 G3XDV de PA7EY Op8 347 km -29 dB in Amsterdam

01:19    136 G3XDV de DF2JP Op8 487 km -31 dB in Duesseldorf

01:19    136 G3XDV de F4DTL Op8 400 km -24 dB in JN18FP

TF3HZ also received G0HUH.

Opera (and other mode) reception can be displayed on the "PSK Map". Last night's reports on my signals look like this (click on the picture to enlarge):

Overnight 136kHz test

Last night, I transmitted my callsign in QRSS120 (two minutes dot length) from 2000 to 0830UTC. DK7FC (top) and PA3CPM (bottom) were also active in the same 2Hz slot between 136.1702 and 136.1722kHz. Propagation was better than the previous night and my transmission was just visible for most of the night. The picture below shows the best part. It is actually two screen shots stitched together from TF3HZ's Iceland grabber (click on the image to enlarge). It is interesting to see the slow fading which not only takes out the end of my callsign, but also affects the German and Dutch stations at the same time. Often this fading can affect different stations at different times, indicating more complex propagation paths.

DX Test on 136kHz

I re-tuned my antenna to 136kHz and ran some extremely slow CW tests on 136.171kHz. This started at QRSS30 (30 second dot length) at 1830UTC, then changing to QRSS120 at 1850 until 2130. I made a later test from 2245 until 2345. DF7FC (1Hz above me) and PA3CPM (1Hz below) were also active at this speed, aiming at reception in the southern hemisphere. Conditions were not good, but I could see traces of my signals on TF3HZ's grabber during the evening session, with a solid "V" from the end of my callsign at 2330 (see below). W1VD monitored overnight but received nothing.

WSPR test on 500kHz

Monitored for G3XBM's WSPR transmission on 501.5kHz (500.0kHz dial frequency) yesterday evening. I received his signal from 1826 to 2134UTC at signal to noise ratios peaking -8dB. I had the usual interference from my plasma television.

Opera4 on 500kHz

Yesterday, during daylight, I received the following strong Opera4 signals on 500kHz, in chronological order: PA0A (+5dB signal/noise), PA3ABK (+1), G3XIZ (+7), PA0WMR (+5).

Three Germans on 477kHz WSPR

Yesterday evening, I monitored for WSPR signals from 1700 to 2130UTC. I received DF0WD between 1804 and 1848 at -23dB signal to noise; DL3DNR 2014 to 2124 peaking -15 S/N, and one call from DK6NI at 2102. This brings my total of stations received on this band (so far only licensed in Germany and Monaco) to eight (see my main site for callsigns).

German CW and Op4 on 472kHz

Last night, I heard a CW ident from DJ5BV (521km) on about 476kHz at 2310UTC. He was a good 579 - the best CW signal so far heard on this new band.

Also saw decodes on Opera4 all night from DK7FC (681km), peaking at 0dB signal/noise around 2300 to 0300, decreasing to -20dB during daylight. The last decode was at 0833, presumably when his radio station closed down.

500kHz Opera

Lots of Opera4 activity on 501-504kHz on Monday (9th) evening. Decoded signals on my laptop from G0ROJ, G4WGT, PA3ABK, G3XIZ, M0FMT and PA0A.

MF Activity 8 July

Yesterday morning I heard a CW contact between G3XIZ (599+) and M0JXM (599), but little else on this band.
Later, I monitored 472kHz and received WSPR transmissions from: DF6NM from 2056 to 0252 UTC, peaking at -9dB signal to/noise and DK6NI from 2134 to 2318 peaking -26dB S/N. Static levels on my receiver were the lowest for a couple of weeks.

Improving IC-706 on LF/MF

Icom's old IC-706 (I use one of the first Mk1 models) is a good, cheap radio for receiving on 136kHz and 472/500kHz. Its sensitivity is not good enough for a poor antenna, but if you have a decent size tuned Marconi suitable for transmitting, it is more than adequate. The receiver pre-amplifier even works at 136kHz.

One advantage is its impressive frequency stability - after a few tens of millihertz warm up, my 706 stays within 10mH forever! Tuning steps, and readout are 1Hz. These features make it very suitable for the extremely slow Morse (eg QRSS60) used for intercontinental working on 136kHz.

The main drawback is its intermodulation performance, especially in view of the very weak amateur radio signals found at LF/MF compared to the strong signals out-of-band signals received by the antenna. In my case the principle problem is the medium wave broadcast transmitters located at Brookman's Park, just 10km or so away (LF guru M0BMU is less than 1km from this station), and these can cause problems on 500kHz and 1.8MHz. To improve the suppression of unwanted signals, I use a G3YXM tuned preamplifier for 136kHz, and have just added a parallel-tuned circuit across the antenna coax when using 472/500kHz.

Polish NDB "SA"

The 472-479kHz amateur band (available only in a few countries so far) has several aircraft beacons (see my main web site). One of the most prominent transmits "SA" in Morse on AM. The carrier is on 474.5kHz, and the Morse callsign sidebands can be heard approximately 1kHz above and below that frequency. It is quite loud after dark, but here is a Spectrogram (set to QRSS3) of the carrier during the daytime here. The straight line is "SA", and the big wobbly ones are from my plasma TV.

DL3ZID WSPR Received

I finally received WSPR transmissions from DL3ZID on 477.0kHz (dial frequency), despite huge static crashes. He is my best DX so far on this band at 800km. The software produced the following info:

120705 2036   3 -29  0.1   0.478585  DL3ZID JO53 23          0     8    0
120705 2048   5 -28  0.3   0.478585  DL3ZID JO53 23          0     3    0
120705 2058   7 -24  0.2   0.478585  DL3ZID JO53 23          0     1    0
120705 2110   2 -30  0.4   0.478586  DL3ZID JO53 23          0  5002   -1
120705 2120   7 -26  0.4   0.478583  DL3ZID JO53 23          0     1    0

DL3ZID on WPSR

DL3ZID ran a WSPR test on 477kHz this afternoon. Nothing seen here, however. Very bad storm static from France and Belgium did not help.

Now equipped to receive WSPR

I have installed the WSPR datacomms software on my computer, so am ready to receive this mode on 136kHz, 472kHz and 500kHz. I cannot transmit WSPR because it needs a linear transmitter and my 136kHz Tx is Class-D. You can download software and documentation for WSPR and other modes from here.

Opera / CW on 500kHz

Received Opera 4 signals on 502kHz from PA0A (+3dB signal/noise at 465km), and PA3ABK (+1dB S/N at 338km). CW ident fom PA3ABK was audible at 579.

Summer LF Radio Conditions

Low frequency activity tends to fall off during the summer. Some of this is due to holidays and the need to spend more time working out of doors. But some is also due to a perception that propagation is poor in the summer months.
In fact, sky-wave propagation is still available but, because long distance contacts require darkness over most of the path, the number of hours of propagation in reduced. DF7FC is carrying out an exercise to demonstrate that he can be received in the US during every month of the year. He has succeeded so far, even in June.
Availability of medium distance sky-wave (eg UK-Moscow) is also reduced but contacts are still possible. Local contacts are often easier in the summer, with less multi-path fading.
A major summer issue is QRN - static from thunder storms - which can carry hundreds of kilometres (for current storm maps see: Americas , Europe/Africa  or East Asia/Indonesia 
for a continuously updated map of storms worldwide). There are some days without storms, so daily checking is worthwhile, and the static levels are usually greatly reduced in the mornings.
Choice of mode is important. For instance QRSS will outperform CW in high static conditions..
So why not dust off the LF transmitter and try out some summer activity? You may well be surprised.

500kHz CW

Heard an 'armchair copy' three-way CW contact this morning betwen G3XIZ (59+9), G3DXZ 569) and M0JXM (589) on 502kHz.

Activity on 30 June

I called CQ using QRSS3 on 137.7kHz at 0850 and 1630UTC, but no reply. Static was bad on that band.
I retuned the antenna to 500kHz and received the following stations using Op4 (best signal/noise in brackets): G3XBM (-13dB), M0FMT (-1), PA3ABK (0), PA0A (0).
Listened on 477kHz but no amateur signals heard.