Clipperton Island TX5K on 6m



Background information on Clipperton Island can be found here:

As you may be aware, there is another serious DXpedition to activate Clipperton Island under the callsign TX5K at the beginning of March of 2013:

The TX5K team says they are pleased and very excited to have W7GJ join the team to ensure that the DXpedition is active and successful on 6m.  I am very grateful the TX5K for their support and encouragement.  It is their understanding and consideration that will make the 6m operation a success.  The appreciate that I need to be far away from the HF group so I can be assured a very low noise floor and a location with excellent ground gain - at least on moonrise.  I am planning to take my portable 6m EME station, to activate TX5K on 6m.  This is only possible, thanks to the generous support of many dedicated 6m enthusiasts, and I am greatly in your debt!  Rest assured, I will do everything in my power to put Clipperton on 6m and contact you one way or another:

There may be a chance of some F2 propagation by next March, and I certainly am committed to spending an inordinate  amount of time trying to work it!  However, even if there is no F2,  there are some good EME windows with everyone around the world (especially during the first few days of the trip) and I have the proven ability (E51SIX, 3D2GJ, 5W0GJ, E6M) to work single yagi stations on JT65A mode when the moon is near their horizon by using my portable 6m DXpedition station.  So anybody who is seriously interested in 6m should have a good opportunity to work Clipperton Island one way or another.  I have been assured that I will be able to operate 6m full time, so am very hopeful that many people will be able to add Clipperton to their 6m DXCC totals.


The 6m station is essentially the same as that used on my other 6m EME DXpeditions, except that I am also taking a paddle for CW, and I also will use the computer keyboard for sending and logging CW.  The 6M-1000 has been modified by M2 for overseas use, and provides a solid KW output on JT65A mode with under 3 watts of drive.  The transceiver this time will still be the reliable K3 and PR6 preamp. The K3's flat, wide bandwidth is ideally suited to copying multiple JT65A mode callers spread out every 200 Hz from about -800 Hz to +800 Hz.    The antenna again is my 6M8GJ yagi fed with LMR600 low loss cable and home-made manual elevation mount.   I also have purchased a Honda EB3000c  125 VAC 3kw generator for operating 6m at TX5K (and built a shipping crate for it), and a MeanWell RSP-2000-48 power supply that runs off 120 VAC so I can use it with the generator to power the 6M-1000. 

Thanks to the generous support of RF CONCEPTS, I also will be using an ALPHA 8406 as the primary amplifier.  Although limited by my 125 VAC generator, tests here have demonstrated that it is capable of a solid kw output on JT65A mode (and more on SSB and CW).  If anything, this configuration will give me a bit more output than on my previous 6m DXpeditions.

As you can see from reviewing the trip reports from my previous 6m EME operations from E51SIX, 3D2LR, 5W0GJ and E6M, many contacts were made with single yagi horizon-only stations.  The smallest station contacted from all four of those places was N3CXV with his single 6M5X yagi.   If you have a good yagi, good ground gain, good power and lots of patience, we should be able to complete via EME, although the Degradation will be higher at the time of the Clipperton operation.  If there is ionospheric propagation, the EME station should be very effective on F2!

Operating Location

The actual 6m operating site was not be finalized until the landing site was selected after a day of circling the island and several failed landing attempts by the Shogun crew.   Although the most southern tip of the atoll had been my first choice for the 6m station location, with the most northern tip being my other choice, my tour around the island convinced me that the final site actually was much better for ground gain.  Note that the entire island is in main Maidenhead grid locator DK50, and most of the atoll is in subgrid DK50jh; only the southernmost tip of the island is in DK50jg.  So, as far as WSJT modes are concerned, either grid locator adequately worked with callsign TX5K.  As you can see from the map below, the actual final 6m site was in southern DK50jh.

As you can see from the above map, there will be very little need to aim between 150 and 220 degrees azimuth.  There also is a "dead zone" between 310 degrees (toward JA) and 340 degrees (toward W6).  Therefore, ideally, efforts will be made to locate the station so that the generator and operating tent are at an azimuth of 325 degrees from the antenna, while still affording shots over the ocean on moonset and moonrise.  For that reason, the 6m station, sleeping tents and generator were set up at along an angle of 325 degrees from the antenna.

Operating Schedule & Frequencies

A tentative 6m Operating Schedule in UTC is shown below. However, I am anticipating very difficult operating conditions, and the schedule is subject to weather, landing and unloading delays.  So there may be periods when I am unable to follow the schedule exactly as planned.  I also have to sleep sometime and/or go off to get food/water/fuel, so please be patient with me!  I am hoping to set up by myself far from the HF operations in order to achieve a low receiver noise floor.  I will be trying to dodge crabs and rats during all the moonrise periods when I am out trying to adjust the antenna but fortunately,  JT65A will continue to operate while I am outside moving the lines on the antenna to aim it.  Please be patient with me if we have to frequently disconnect and go off the air....there are plenty of tropical storms down there, and my antenna (and even my backpacking tent) will be the highest thing for 1/2 mile.

Anticipated EME operations during my MOONRISE and MOONSET are shown.   Times shown during MOONRISE periods start with my moonrise and end with moonset in Europe.  Times shown during MOONSET periods start  with the moon at 20 degrees elevation in New England, and end with my actual moonset at TX5K (which is also often very similar to moonset along the west coast of North America).  Note that the last moonset is also during sunset, so there may be solar noise and/or ionospheric propagation during that period (although I have very successfully operated 6m EME during such times in the past anyway).  If you wish to contact me by 6m EME and you don't see that I have shown an EME operating time that works for you, please let me know - I will do my best to accommodate everyone's needs to the best of my ability.

NOTE: If you are in North America and have the choice to contact me on either your moonrise or moonset, please consider your moonset first (unless you are in western USA and your moonrise is after the EU moonset).  It is true that my moonrise windows will be in total darkness, and will undoubtedly be free from any interference from ionospheric activity.  However, notice that my MOONRISE periods will probably be very busy with EU callers.  There will be no windows with EU on their moonrise, so I will normally give priority to any EU stations I decode (at least if they are copying me).

Expected EME operation will take place on 50.190 and TX5K will always TX FIRST sequence JT65A mode.  Anyone seriously interested in completing via EME is encouraged to call during the first few days of operation, as the Degradation becomes excessive during the middle of the trip.  EME operation during the times shown during the first half of the trip will take priority, because these times are the only windows with eastern Europe, and little chance of ionospheric propagation is anticipated then.   The EME operation shown during the latter days of the trip is contingent on there not being any ionospheric propagation at those times, which will take priortiy on those days.   Continued EME operation during the second half of the trip also will be contingent on the amount of activity - especially after European moonset.  Similarly, the amount of EME operation between the EU moonset and the beginning of NA moonset (times shown with an asterisk *) will be contingent on the amount of continued EME activity seen during those periods.  Especially after March 6, if you hear me calling CQ on JT65A via some ionospheric mode, please call me on JT65A or try to answer me on some other mode.

Anticipated ionospheric operation (and beaconing) is planned to take place on 50.117.  Beacon operation in most cases will be an attended "breakable beacon" so please make noise on whatever mode you have available to "break" it.  I suspect it may be necessary to lower the power during beacon operation in order to save on generator fuel.  Therefore, signals may not be strong enough for you to hear.  Please use an aid such as Spectran or SpecJT (the waterfall display in WSJT) to LOOK for weak JT65A or CW signals that can be 10 to 15 dB too weak to actually hear.  When the beacon is not running and I also am not transmitting somewhere, I will be monitoring 50.110 for signs of activity.














Feb 27

Feb 28

Mar 1

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Mar 11





0040 MS





0410 MR



0500 MR


0600 MR


0700 MR


0800 E MS

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0900 E MS





1000 E MS

1000 MR

1045 MR


1000 NA MS

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1130 MR


1200 NA MS

1245 NA MS

1230 MR


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1430 E MS




1545 E MS


1620 MS

1600 NA MS




1705 MS

1730 NA MS


1700 E MS


1800 MS
1800 MS

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2150 MS

2100 NA MS


2250 MS

(New Moon)


2350 MS

(New Moon)


(New Moon)


EME Operating Tips

 I urge you to gain experience with JT65A and especially review the QSO PROCEDURE that I use most effectively on these DXpeditions  I look forward to contacting you on 6m EME. which very well may be the ONLY way that many stations outside the TEP Zone will be able to contact TX5K on 6m, given the low solar flux!  Please use the ON4KST EME CHAT PAGE page to coordinate your transmit frequency with other callers, so you do not create QRM with another caller - ideally, stations should be spread out every 200 Hz.  Please also keep calling me even if you copy me working someone else.  As long as you are not on the same frequency as the other station, you will not be interfering with them.  I try to decode all callers every receive sequence, and I make a note of each caller and their and frequency so I can reply to you as soon as I am able.  Therefore, NEVER change your transmit frequency after you start calling - pick a clear frequency nobody else is using and stay on it!  I will try to contact any callers I can copy, but first priority will be given to contributors and stations with shorter common moon windows.  

TX5K is a standard type of callsign, so no "special prefix" has to be added in the WSJT SETUP/OPTIONS screen.  However, you may want to add TX5K in grid DK50jh to your call3.txt file if you plan to use the Deep Search option and/or have my moon position shown when you click on the tab to "VIEW/ASTRONOMICAL DATA"..  You do this from the main JT65 screen.  If you have any question on how to do this, please either contact me, or ask any experienced 6m EME operator on the ON4KST EME CHAT PAGE.

Ionospheric Operating
I did take a 10m dipole and made a number of calls on 28.885 MHz,looking for 6m stations, but never heard anyone on that frequency.  When not on aimed at the moon, the beam was aimed at South America for TEP or North America, beaconing for terrestrial propagation.  In addition at mid day each day, CQ was called for an hour or more on JT65A mode on 50.190 toward North America, but there were no replies.

The 6m operating site was too far from main HF camp for the Wi-Fi to reach, so it was not possible to use Wintest along with all the HF stations.   Therefore, it was not possible to view the DX Cluster spots through Wintest.   Wintest was used for most of the terrestrial contacts, and "synchronized" with the main log at the end of the trip.  All the EME contacts were logged by hand, and later typed into the Wintest log, along with a number of TEP contacts.

QSL Information
Please follow the directions on the main TX5K page:

6m EME QSL cards were mailed direct to each station.


 I worked very hard to be QRV on 6m and set up at a location far from the HF operations.   The 6m band was absolutely quiet at the remote location.   Below is an aerial photo, courtesy of LouPhi Locke, showing the TX5K 6m  operating site, looking northeast toward the HF sites, 1000' and 2000' away.  The reef and infamous surf surrounding the island is shown on the right.  The landlocked interior lagoon of the atoll is shown on the left.  The 6m operating tent is the gray 8'x8' tent with the open end away from the prevailing winds, and a blue tarp toward windward to hold down the tent and keep rain out of it.   Two sleeping tents  are shown to the left of the operating tent.   The small blue tent 50' to the northwest of the operating tent housed the generator.   The 6M8GJ 6m yagi  is 35' to the southeast of the operating tent.                                                                                             

 As of the third week in January, all 5 boxes of my equipment and tent,  plus the two boxes for the Alpha 8406 and its transformer, plus my generator, have all been received down in California for transfer to the Shogun.
Feb 14.2013 - Equipment is being loaded onto the Shogun at the port in San Diego, California.  Great to see the little wooden crate with W7GJ  and the UP arrow on the side - that is my 3kw generator on the boat ;-)

There was no internet access from leaving the dock in San Diego on February 18 to return to the dock on March 18, 2013.

Mar 29, 2013 - Summary.   Thanks to the generous contributions from many 6m DXers, I was able to join the TX5K team to add a serious, dedicated 6m operation to that DXpedition.  Unfortunately, the period scheduled for the Clipperton operation was over the worst week of the month for 6m EME.  Of that time, the better EME days at the beginning and end of the operation were eliminated by our reaching the island a day later than expected, and our having to tear down earlier than expected. However, as expected, there was TEP to South America every evening, which provided most of our 6m contacts, and KF4ZZ made many of those.  And half of the EME contacts were made on the first night, so I sure am glad I was able to get everything going for that first moonrise!

The 92' Shogun sportfishing boat was to transport the gear and team members to the island.  Some of us boarded the Shogun in San Diego but the boat picked up  most of the European team members in Cabo San Lucas.   The Shogun was comfortable, the crew was great, and the food was plentiful and surprisingly good.  However, the 10 day trip from San Diego to Clipperton, and the 7 day return trip, became rather tedious.   The highlight of the trip for me was the magical approach to Clipperton Island on the evening of Wednesday, February 27.   The full moon was rising over the calm sea, and porpoises were escorting us next to the bow as the faint outlines of scattered palm trees loomed on the dark horizon.

The last day of February was spent circling the island, searching for the most suitable place to land.   The dangerous surf was high all around the island, and changed with the tide, which was extreme due to the full moon.  By afternoon, a sit was selected and zodiac shipments to shore were begun at dawn Friday.  I was able to go ashore with my 6m gear late morning on Friday, March 1.   I immediately began carting all my equipment (along with the generator, operating tent, sleeping tent, table, chairs, water and gasoline, etc.)  360m south of the main camp and landing zone, trying to gain enough distance from all the other generators, radios, computers, lights, fans, etc. of the main HF camp to get a location quiet enough for weak signal work.  I first selected a spot for the antenna, just 50m from the pounding surf.  Then, I marked out a place for the operating tent at an azimuth of 325 degrees from the antenna, a direction between JA and W6, where I would never be aiming the antenna.   The generator tent was located an additional 50' beyond the operating tent in the same direction. in order to minimize any electrical noise.    I started out setting up the 8'x8' 6m operating tent so I would a safe place for all the equipment, which was sitting out in the open, surrounded by hundreds of masked boobies.   I was very grateful for the assistance of LouPhi Locke, who came by to help me stand up the frame and install the cover over the tubular metal frame of the small structure.   I then proceeded to set up the generator tent and the generator. Late in the afternoon, I rushed to assemble the 6M8GJ before sunset, and finally got it set up just as night fell.   I had packed an LED Coleman lantern, and was able to set up the equipment, including installing the transformer in the Alpha 8406 amplifier, by headlamp and lantern light.   I tied down the antenna securely aimed at moonrise and began calling OH2BC, whose moon was just about to set.   I never copied anything from Kari, but at 0536Z March 2,  completed the first contact from the 2013 Clipperton Island DXpedition by working G8BCG.   I stayed up all that night working stations under the rapidly degrading EME conditions.  My last contact of that 25 contact session was 9 hours later with N6BBS as my moon was setting.  The photo below by LouPhi Locke shows the 6m site while I am tying down the antenna to hold it aimed at the moon.

I was incredibly fortunate to be able to visually aim the antenna on all but the very last days (after the sun rose and the faint sliver of a moon was no longer visible in the daylight).  Although I did have my calibrated aiming circle installed at the base of the rotating mast, it was always reassuring to be able to confirm that the elevation was also correct and that the antenna was right on target!   We also were very lucky in only having three VERY brief rain episodes, each lasting only a few minutes.  And the effort to establish the remote 6m operating site so far to the south of the HF camps really paid off - we had absolutely NO noise at all!  At least not ELECTRICAL noise.   KF4ZZ measured the ambient audio levels from the constant wind and hungry boobies as being between 75 and 80 dB.   To give you some idea of the din, we had trouble hearing the generator rev up when we went into transmit mode. But the boobies were great neighbors, and stayed away from the antenna.   The rats (except for one stubborn one that had to be eliminated) usually scampered away as you approached them to tie down the antenna.   And our totally sealed sleeping tents provided more than adequate protection from the  the ubiquitous crabs.

However, the continuous salt spray from the pounding surf did take its toll on the antenna and equipment.  The antenna receive performance seemed to degrade a bit every day.  On March 7, I went back to hand logging TEP contacts when I found that I could no longer type numbers on my laptop computer.   And on the next to last day of operation, March 8, the 100w module in my K3 stopped working between EU moonset and the start of NA moonset.   No longer being able to drive the Alpha 8406, I quickly dismantled the Alpha amp and packed it up to make space on the operating table for my switching power supply and 6M1000 solid state amp, which fortunately only requires 3w of drive.    The open antenna relays in the 6M1000 were not as reliable in the salt air as the vacuum relays in the Alpha amp, but did provide a couple more EME contacts and a number of additional TEP contacts.

The final 6m results were 317 overall contacts (212 SSB, 53 CW and 52 JT65A).  JT65A was used to contact XE2AT on D layer scatter and LU5FF on TEP; the other 50 JT65A contacts were EME.  The EME contacts with 21 countries were broken down as follows: One contact each with ES, F, FK, GM, GW, I, LA, OH, SP and UT.  Two contacts with HA, OK, SM, VE and ZL,  Three contacts with G, ON, S5, and OZ. There were seventeen contacts with USA stations.  23 additional stations were copied on EME but unfortunately not worked.

Eleven additional DXCC were added via terrestrial mode, bringing the total DXCC count up to 32.   TEP and Es added CE, CP, CX, HC, HK, LU, OA, PY, XE, YS and ZP.  I worked only one station in the USA on Es, and that was with K5RK during an Es opening with a very small footprint.  I did complete with K9SM on what sounded like a meteor burst, but the only locations close enough for meteor scatter were in Mexico, so I am assuming he was either operating portable there or via a remote station.

I will post a final complete report with photos and lists of contacts on my web page in the coming weeks.  In the meantime, some photos are posted on my FACEBOOK page, which is open to the public.

We all of course were deeply saddened by the passing of Luis, XE1L, when he arrived at the hotel in San Diego after getting off the Shogun at the end of the trip.   I asked him on the boat during the return from Clipperton Island what his favorite thing was about the DXpedition and he said he was very happy to have been able to work the SSB pileups on 75m.  It really brought joy to him to work the pileups "by the numbers". At the beginning of the trip, I fixed a broken connection on his keyer paddle for him.   VY 73, Lance
Revised 3 April, 2013