Category Archives: moonbounce

50MHz F2 propagation and QRPP EME!

Lance, W7GJ, is well-known for his 50MHz EME exploits, both from his home location and abroad from many exotic locations expedition-style. Details of his activities along with a lot of useful information regarding 6m EME can be found on his website. When terrestrial propagation is poor, I sometimes set the 6m 6el antenna towards the setting Moon to “see” what is happening: On the 30th December 2014 I noticed that Lance was a very good and consistent signal via EME, at -19dB in JT65A. I decided, rather tongue-in-cheek, that I’d call him with the barefoot FT857D (i.e. certainly no more than 100W in the shack, and somewhat less into the antenna 150m away) – To my amazement, and thanks in no small part to Lance’s tenacity, we managed to complete a QSO! It took quite a while and required all of Lance’s skill to dig my signal out of the noise, but it just goes to show what’s possible as long as we try. I really recommend everyone to at least take a look for Lance’s EME signal and perhaps give it a go – not least because his QSL card is rather nice 😉

F2 propagation on 50MHz reached Irish latitudes on 2nd February, which can’t be a bad sign as we approach the Spring equinox. The opening could have been easily missed, were it not for the Senegal beacon 6V7SIX (50.013MHz): This was the only signal heard for a while (at a good 599), but widespread reporting on the packet cluster probably encouraged Francis, 6W7SK (aka F6BLP), to come on to the band. Francis was a good signal here, resulting in a nice contact using my barefoot FT857D to the 6el LFA2.

I made this recording shortly after our QSO, of Francis calling CQ on CW…

6W7SK
"6W7SK" from 6m F2 by ei3kd. Released: 2015.

Update…

I thought I’d better post an update, having not posted anything for a while; the reason being that not a lot has been happening!

The Eta Aquariids meteor shower peaked on the 6th of May, producing some fine, long meteor bursts: The best I heard was one from DF1JC (JO31) on 2m that apparently lasted for over 130s at S9, and there were a number more from various people lasting 20/30s. The one downside of this shower was quite a low meteor rate, so we had to be patient especially over the longer distances. We’re actually at the bottom of a twelve-year cycle for this shower, so the rates should only get better over the next six years. I didn’t work anything sensational, but was very happy to complete with the Camb-Hams DxPedition, GS3PYE/P (IO68ul) for a new square.

The much-anticipated Sporadic E (Es) propagation has started in Europe, giving a few lucky people 6m links into TEP and F2 propagation further south. The only thing of interest heard here recently was the ZD8VHF (II22TB) beacon on 50.0325MHz at around 21z on 5th May, via an Es link into evening TEP, weak but audible:

zd8vhf 6m es+tep
ZD8VHF/B on 50.0325MHz heard at EI3KD on 5th May 2014 @ 21z

East and Northern Europe have had the first Es opening of the year on 2m, on the 13th of May – one of the favourite dates each and every year!

On 2m EME I’ve worked a few new initials (now up to 114), including I3EVK (JN66) and IK7EZN (JN90) both in new squares for me. However, a highlight was a contact with the Team Athletico expedition to Senegal, 6W/PE1L (IK14jp):

6WPE1L qso EI3KD, 2m EME, JT65B

6W/PE1L qso EI3KD, 2m EME, JT65B

A lot of concentration and patience is required for this sort of EME contact, given I was trying to work a modest, albeit highly optimised, two-yagi station with my single short 11 element yagi: I missed a few opportunities at the start of the expedition because, for a few days, they had a local obstruction causing a minimum 7 degree horizon, which meant the moon was already above my ground-gain peaks by the time it “rose” for them. However, when I began to get common windows I concentrated on them at every opportunity. I heard/decoded the expedition quite a few times but was, unsurprisingly, unable to break their pileup during the very short times when my ground-gain was enough to see them – a maximum of two periods each about twenty minutes long after moonrise, with no possibility at moonset due to local noise. In the end the time spent paid off and after many failed calls and one or two near misses we finally made a fine contact. The team can’t be thanked enough for their unsurpassed dxpedition and operating skills – thanks once again guys!

Hopefully my next update will be reporting a massive 2m Es opening, or some extraordinary tropo – we live in hope!

A small milestone…

Conditions have been poor and the weather has been terrible, but I reached a small milestone: I completed a moonbounce QSO with my 100th unique station (initial), and have since gone on to work a couple more. I’m happy with that, given my ridiculously small antenna and the fact that I’m limited to moon-rise only. The low height of the antenna above ground (approximately 6 or 7m) results in only two usable ground-gain peaks (around 2.5 and 12 degrees elevation), so my windows of opportunity for EME are indeed very limited!

I’m sure there are people with similar systems to mine that have never considered EME, perhaps thinking their antenna is too small. Please do give it a go! As an incentive, here’s a few statistics from my 102 unique EME stations:

  • Number of EME DXCC: 34 (15 are unique to EME)
  • Number of EME Squares: 88
  • Number of EME Fields: 22
  • EME best dx: ZL3TY, RE57OM, 18956km

I’ve also heard quite a lot more stations that I’ve not yet worked, including a better ODX, so there could be more to come…

I arbitrarily chose the 100th initial as a target to reach before making any changes to the system. Now that’s done I can think about what to do – current plans are to add 70cms, and perhaps add elevation and/or a second 2m antenna.

A good start to 2014 (apart from the weather)

Firstly, I’d like to wish everyone a very happy new year – all the best for great 2014.

The weather over the last few weeks has been dreadful, so thoughts are with anyone adversely affected. As I type, we have yet another storm (“Christine”) passing through with 125km/h winds just offshore to the south of us, thunder and lightning, local flooding and damage… We could do with a break now, please!

On the radio side, things have started off a little better. I’ve worked a couple of nice EME initials, i.e. ZS9MADIBA, commemorating the life and recent passing of Nelson Rolihlahla Mandela, and RA22AL, one of the 2014 Russian Winter Olympics special event stations.

The Quadrantids meteor shower was predicted to peak at around 19:30z on January 3rd and is one of my favourites, with a reliably strong peak, albeit usually fairly short-lived. I concentrated on long-distance skeds (e.g. > 2000km), especially with stations that I’ve tried and failed with before (special thanks to Dule, YU7TRI, and Zdravko, E77AR, for many previous attempts), and chased a few new squares that were closer in.

I was delighted with the results this year, completing with the following (bold = >2000km, red = new locator):

02/01/2014 09:56 S58M JN76JC 1794km
02/01/2014 12:43 IK2DDR JN55GN 1544km
03/01/2014 09:47 I3MEK JN55SJ 1619km
03/01/2014 13:21 SM7THS JO76WU 1647km
03/01/2014 15:03 LY2BUU KO15XH 2141km
03/01/2014 15:27 LY2R KO15VS 2128km
03/01/2014 16:39 OH1MN KP10FO 2104km
03/01/2014 17:37 OH2NHP KP10RN 2157km
03/01/2014 18:25 OH4LA KP20LG 2232km
03/01/2014 21:30 DL8II JN49GP 1205km
03/01/2014 21:39 DH0LS JO51UA 1383km
03/01/2014 21:41 DL2RMC JN59IF 1369km
03/01/2014 21:53 S57VW JN76HD 1780km
03/01/2014 21:54 OK1TEH JO70FD 1596km
03/01/2014 21:57 DL3YEE JO50LX 1333km
03/01/2014 22:23 IW5ECS JN53GQ 1670km
03/01/2014 22:58 YU7TRI KN04KV 2272km
03/01/2014 23:35 E77AR JN94AS 2088km
04/01/2014 09:48 DG0JMB JO60LV 1472km
Quadrantids 2014 QSO map

Quadrantids 2014 QSO map from EI3KD, IO51vw

There were several exceptional contacts, including Dule, YU7TRI (KN04kv/2272km), who’s bursts can be heard in the links below:

Note 1: The second clip (with “RRRR”) was not automatically decoded by WSJT, probably due to significant doppler on the signal. It required a lot of manual mouse-clicking around the burst!

Note 2: There are a number of very short breaks in the audio, which were caused by a poor internet connection to the remote rig.

Reflections from Pasi, OH4LA (KP20LG/2232km) were also good, with eight bursts similar to this one:

Top burst prize goes to Timo, OH2NHP (KP10RN/2157km) for a great burst peaking S9, containing finals – a nice way to complete a QSO!

Links to the .wav files that can be opened directly in WSJT are here: YU7TRI_140103_223700.wavYU7TRI_140103_225200.wavOH4LA_140103_180300.wavOH2NHP_140103_1737001.wav

Using the Graves radar to check elevated antenna lobes on 2m

By now, most VHF-ers have heard of the Graves radar on 143.050MHz in JN27si, France. The radar transmits very high effective radiated power (ERP) CW towards the southern sky at various azimuths switched in sequence and, apart from its intended purpose of tracking satellites for the French Air Force, provides a very useful beacon for radio hams. More details can be found on PE1ITR’s excellent webpage, here.

The ERP from Graves is high enough that it’s easy to receive moonbounce signals from it. In the past I have had excellent results using just a small 2m antenna, with enough signal to noise margin to suggest even smaller is possible – shown below is a 25 minute waterfall of signals captured from IO91wv in 2008, using just a 4el yagi fixed at around 100 degrees azimuth:

Signals from Graves radar

Signals from Graves radar using 4el yagi, as received in IO91wv.

Graves’ moonbounce signal is reliable enough that, by tracking the Moon’s azimuth with an antenna fixed at, or near, zero elevation, it’s possible to get some idea of what that antenna’s pattern looks like at higher elevations. There are (at least) a few caveats: Firstly the earth-moon-earth path is not 100% reliable or stable, so there will be signal variations that are unrelated to antenna performance; Secondly, 143.050MHz is some way away from the design frequency of a 2m yagi, so the antenna pattern will probably be skewed slightly; and Thirdly, Graves’ antenna pattern appears to be focused between 15 and 40 degrees elevation, so measurements need to be made when it sees the Moon within that window, which might preclude being able to test one’s own antenna at all (especially low) elevations. I decided to have a go at measuring it anyway, and was quite pleased with the results…

A quick run down of how my system is configured:

    • My 2m antenna is an 11el F9FT, rotatable but with a fixed elevation of about 10 degrees. The rotator is computer-controllable, with an Easy Rotator Controller fitted to its control box.
    • The antenna can track the Moon’s azimuth, using F1EHN’s superb free EME System software.
    • Audio from my FT857D is fed to a Windows XP PC, via an isolated interface (bought from ebay, cheaper than I could have built it for).
    • The audio is analysed, in this case, using DL4YHF’s excellent free Spectrum Lab software.

Spectrum lab isn’t necessarily the easiest thing to set up but it does provide powerful audio analysis features, which, incidentally, were hardly touched during this test! For this measurement I used Spectrum Lab’s plotting feature (Main menu->View/Windows->Watch List & plot window), with “watches” set for finding the peak signal (amplitude and frequency) within a small range of audio frequencies, targeted at where the signal from Graves was expected to be. Watches were also set to measure the base audio noise amplitude, and the peak-minus-noise amplitude.

With Spectrum Lab running as described above, I set the antenna tracking the Moon and started logging results from 15:26z on 13th November 2013. At this time the Moon was at 14 degrees above the horizon at JN27si, i.e. almost within the antenna pattern at Graves. Having to wait for the Moon to enter Graves’ beam pattern meant that the Moon was already almost 5 degrees above my horizon, already above my first ground gain peak: I don’t see that as a problem because I already know that the antenna works fine at very low elevations, I’m more interested in what happens higher up!

Running the measurements through to a little beyond 18:30z, when the Moon’s elevation at Graves went above 40 degrees, gave the following result:

Graves moonbounce signal

Graves radar moonbounce signal plotted against time

The top graph shows the peak amplitude of the Graves moonbounce signal (green) and the average base noise amplitude (red) against time. The bottom graph shows the audio frequency of the Graves moonbounce signal with dial set to 143.049MHz USB, within a few tens of Hz (blue) and the difference between the two signals from the top graph (mauve). The slowly changing doppler as the Moon rises can be clearly seen on the blue trace, with a few “spikes” where the signal is too weak to get a lock.

As previously mentioned, I already know that I get a good ground-gain peak between 0 and 5 degrees, which is not shown on the above graphs. However, the graphs do show two clear strong peaks, between approximately 16:05z-16:35z and 17:03z-17:32z, with a later insignificant peak. At my location on 13th November, these equate to elevations of around 10-15 degrees and 19-23 degrees respectively. The lower window is no surprise to me, agreeing well with previous results off the Moon. What is surprising is the higher window which appears to be equally as good: In the past I’ve always assumed that I might as well stop looking when the Moon’s gone above 15 degrees, but this shows that it might be worth looking again a little higher up! I shall certainly give it a try 🙂

New ODX on 2m

Moonrise today was in a very favourable position for this location, in a direction I know from past experience provides good ground gain. It was also at a conveniently sociable time, which is always a bonus!

I saw on the N0UK EME chat that Bob, ZL3TY (RE57om) was active and he was kind enough to set up a sked for 07z, at which point my Moon was just starting to rise and his was setting: We had a little over ten minutes of common window.

Almost exactly on cue, Bob’s signal appeared and the QSO ended up being quite easy. I had a nervous moment when Bob continued to send “RO” after I’d sent a period of “RRR”, but signals were back up in the next period and all was ok.

So that’s my longest distance QSO (ODX) on 2m, at 18956km (or 18984km, it depends on how it’s calculated?) – many thanks to Bob for making my day. It’s going to be a difficult one to beat!

Transcript of JT65B sequences:

065700  Transmitting: JT65B   ZL3TY EI3KD IO51                         
070400  2  -24  1.9  100  3 *      EI3KD ZL3TY RE57          0  10 
070500  Transmitting: JT65B   ZL3TY EI3KD IO51 OOO                     
070600 10  -25       102  4   RO                                   
070700  Transmitting: JT65B   RRR                           (Shorthand)
070800  2  -30       103  3   RO                                   
071000 10  -24       104  1   73                                   
071100  Transmitting: JT65B   73                            (Shorthand)
071400  2  -26  2.1  108  4 *      CQ ZL3TY RE57             1  10

9X0EME

Hermann, DL2NUD and René, PE1L have made it to Rwanda and are active on EME as 9X0EME. After moonrise last night I decided to listen/watch on their 2m frequency for a bit of fun and immediately saw about 12 stations calling in the opposite period.

Unfortunately the frequency the 9X0EME team were using, 144.112MHz, has a couple of noisy spurious carriers here within the JT65B passband. I could see the sync tone from them at around -26, but was failing to get decodes because of the QRM. It was obviously time to kick back and watch the action, rather than join the QRO pile…

The expedition’s signal faded after the Moon went above about 6 degrees elevation, as is usual at this QTH. I knew from past experience that signals normally reach a second peak at around 12 degrees elevation and also that, by then, the mutual doppler would bring 9X0EME’s signal to a better frequency relative to my QRM.

I wasn’t disappointed! True enough, from about 11 degrees up the signal started to appear again and when I saw that a previous QSO was coming to an end I started calling. From the previous traces I’d seen from other callers, I reckoned a lot were calling with their TX set more or less exactly on 144.112MHz, so I decided to set my TX with a shift of -300Hz to put my feeble signal in “clear air” 😉

This is the resulting sequence (9X0EME in bold, EI3KD in italics):

234400 1 -31 199 3 RRR
234500 Transmitting: JT65B 9X0EME EI3KD IO51
234600 2 -25 2.5 194 3 #
234800 2 -30 191 4 RRR
235000 1 -26 2.4 188 3 # EI3KD 9X0EME KI58 OOO 1 10 
235100 Transmitting: JT65B RO (Shorthand)
235200 0 -27 2.4 188 3
235400 0 -29 2.5 186 2
235600 0 -27 0.9 183 3
235800 3 -29 182 5 RRR

The first two “RRR” received were for the previous contact. Although I was struggling to get decodes through the QRM every period indicates a decent sync detection, as shown by the DT of 2.4 or 2.5 seconds (equating to how long it takes for the signal to get to the Moon and back) and the constant DF of around 188Hz.

There was some confusion at the end because the team were operating a policy of “two periods of report and if no reply move on”, which is very reasonable for a much sought-after expedition during the initial pile-up. At 23:58 a message appeared in the N0UK EME chat asking me to try again later because they hadn’t seen my reply – but at the same time I was receiving a clear “RRR”? It turned out that they’d typed the message and in the time it took to send to the chat had seen my “RO” – they had already started sending “RRR” which I then received straight away! So the QSO was completed by the skin of my teeth, for what is probably an EI-9X first on 2m (completed at 25/06/13 23:59z).

Thanks again to “The Team” for a brave and adventurous expedition – best of luck and safe journey home.

Not quite an average day on 2m…

The 18th of May turned out to be interesting, and reminds me why I’ve always found 144MHz to be so fascinating!

The day started with an early Es opening to Italy, resulting in the following QSOs:

18/05/2013 09:00 I2PY JN55NB 59 59 SSB ES 1609km
18/05/2013 09:01 IW4ARD JN64FD 59 59 SSB ES 1754km
18/05/2013 09:07 I2ARQ JN55NA 59 59 SSB ES 1612km
18/05/2013 09:19 IW2BNA JN45ON 59 59 SSB ES 1455km
18/05/2013 09:21 IZ4MAO JN54GQ 59 59 SSB ES 1597km
18/05/2013 09:23 IW2NNZ JN45SN 59 59 SSB ES 1476km
18/05/2013 09:27 I4TSB JN64DA 59 59 SSB ES 1752km
18/05/2013 09:30 IW4BET JN54PG 59 55 SSB ES 1672km

2m Es QSO Map 18/05/13

2m Es QSO Map 18/05/13

A bit later I was QRV for moonrise, and managed to work a new initial:

18/05/2013 13:43 JR3REX PM74LQ RO RO JT65 EME 9735km

After the Moon had risen too high for my fixed-elevation antenna, I tried a tropo test with Jerome, F8GGD, in IN95: Unfortunately this didn’t work, but as we were trying Dom, F6DRO, said he could hear me weakly. Dom and I then tried and we could both hear continuous signals right on the noise floor, in fact enough to complete a contact on CW with a bit of “brain averaging”. I was very surprised, because Dom is in JN03TJ and 1201km distant! It’s really too far for troposcatter, but I suspect there was some tropo enhancement (i.e. ducting) on the path.

Oh, and I also heard DK1FG’s (JN59op/1384km) complete QSO with M0BAA/P, which I suspect was via Es-enhanced meteor scatter, just to add another propagation mode into the mix 🙂

Poor EME conditions, but MS is ok

EME conditions have been poor for the last few days, and remain so. A quick look at F1EHN’s EME planner (part of his free EME System V7 software), shows why:

emeplan130513

 

Todays data (13th May 2013) is on the very left of the graph. All the lines, except declination, are down in the darker area, indicating significant degradation of the ideal path loss. The next reasonable opportunity looks to be in a few day’s time.

I tried a few calls this morning at moonrise and just about made it onto LiveCQ, about 9dB worse than ideal. Unfortunately, I struggled to copy an answer from Sergej, RN6DJ, and we consequently failed to complete… Next time Serge!

Meteor Scatter remains good now that the summer showers have started to kick in. A try with Moma, YU1EV, was successfully completed at around 09z, at a very reasonable distance of 2246km (IO51vw-KN04cn). A later attempt with Peter, SM2CEW, failed – but some reflections were heard at a distance of 2293km, so there’s definitely a chance in the next major shower.

A first on 144MHz, EI to 9G

After two weeks of trying, I finally managed to work 9G5EME on 2m, via moonbounce (EME)! The contact was completed at 23:00z on 26th April 2013, for an EI-9G first.

I have to admit I hadn’t really tried too hard at the start of Team Athletico’s expedition, presuming that it wouldn’t be possible to work them with my system (see below). However, after I’d heard the first signals I became seriously motivated! I can only use EME at moonrise, because I have no elevation control on the antenna and moonset is always obscured by a very electrically noisy building, but I listened at every opportunity.

My system is very marginal for EME, with an 11el F9FT at only 6m a.g.l., a fixed elevation of 10 degrees, 400W from a Beko HLV600 sspa, and an SSB Electronics SP-2000 masthead preamp. Past experience has shown that the best signals often occur for me when the Moon is at around 3 or 4 degrees elevation, and then again at around 12 or 13 degrees. Due to the local topography, my largest ground gain occurs when the Moon rises over the north-eastern horizon: I thought the early days of the expedition (when the Moon had a high northerly declination) would be my best chance because of this, but it turned out that I effectively had no common window with 9G at that time because trees were attenuating the moonrise path at their end.

So, apart from a few periods of signals from 9G5EME some days earlier, I had no success up until the final day of the expedition. Even on the final day, with the Moon passing through my first antenna null at 5 degrees elevation, there was nothing other than fleeting (and then lost!) signals both ways. Tom, EI4DQ, was also QRV, and had exactly the same experience. Stress!

I knew that I had one, final, chance. As the Moon starting rising up towards my second antenna peak, there it was – a trace! And then a decode!

225000  1  -26  2.4   57  3 *      CQ 9G5EME IJ95            0  10

Ok, quick, get into gear and start calling them. Next period:

225200 0 -26 2.6 54 4

No decode, damn! Still seeing a good sync at -26, keep going… Next period:

225400 1 -27 2.5 54 3 #

Gah! Still no decode, sync is ok but getting weaker, could be disaster… Next period:

225600 1 -26 2.6 54 3 # EI3KD 9G5EME IJ95 OOO 0 7

Yes, a great decode!!! But the QSO is not yet complete: Next, I have to send a R-Report. I start transmitting “RO”. Next period:

225800 0 -27 3.2 51 12

This isn’t easy… again, no decode… come on! Next period:

225800  0  -27  3.2   51 17

It’s not looking good, signals are getting weaker and the QSO is still not complete. But if I look hard enough, I can convince myself that I can see, visually on the trace, what looks like the tones for “RRR”. It’s not decoding but stick at it! Next period:

230000 2 -30 52 3 RRR

There it is! The QSO is complete, although I start transmitting “73” as a formality. On the next period I visually see the tones for 73 coming back on the trace although it doesn’t decode, but it doesn’t matter. Here is one very happy ‘3KD 😀

Many thanks to Team Athletico: Eltje PA3CEE, PE9DX Johan, and PE1L Rene for a fantastic expedition, and for knocking 2 years off my life expectancy…