Monday, December 25, 2006

Phasing / Unphasing 2 yagis - Solution and benefits

Having 2 yagis at home for SO2R-contesting, I quickly realized that it was sometimes very useful to use the 2 antennas on the same band. For example, during summer, the 20m band is still open to Asia, simultaneously with North-America. Having one antenna in each direction, just switching from one to the other, was the obvious first step. Then logicaly, the idea came to feed them both... I first used a "UnUn" to match the antennas fed in parallel, but this solution although working fine was lacking flexibilty. I then decided to buy a "stackmatch" allowing to use one or the other, or the 2... Using this device, I quickly realized, that the phase relashionship between the 2 antennas was essential, and that the antennas being not identical and not in the same plane I had to be able to play on the phase relationship between the antennas. I then looked for some commercial solution or description, but could not find any(*); I then decided to quickly build something, and try it...

(click on diagram to enlarge it)The F6IRF antenna monoband phasing device: It just requires 3x2RT switches. Phase delays are obtained using 3 lenghts of coax cables 1/8wl (45degrees) 1/4(90degrees) and 1/2 (180degrees). Combining the 3 allows 0 to 315 degrees variation by 45 degrees steps. The device is inserted in one of the antenna line, after the stackmatch. I have used 5D-FB foam coax cable, and high-current switches (losses and impedance mismatch are neglectable and it was tested at 1KW without problem...)

The phasing device in service, during the 2006 CQWWDX-contest from CN2WW (SOSB20m).
From Morroco, it is a big advantage to keep one antenna toward EU, while playing with the second one, to get mults in exotic directions, or to boost the EU rate, with the second one toward states...

Potential applications and benefits

First example: The 2 antennas at 12m are in the same plane pointing at the same desired direction and spaced horizontaly by 0.8wl (my home setup to JA). As shown by the following examples, varying the phase allow some direction adjustment, which is quite useful as the horizontal pattern is quite narrow (even with the simple 2elements used for the simulation - just imagine with 2x 5 elements).

Click on images to enlarge them. Here, the 2 antennas are at 12m agl, in the same plane, perpendicular to the desired direction, spaced by 0.8wl and fed in phase (I.E. identical antennas with equal lengths of coax cable). In red is the pattern of 1 antenna, in black the pattern of the stack. The gain of the stack is 3dB compaired to a single antenna, but the pattern becomes quite narrow.

Left: the antennas are fed with 90degrees relationship (in red the pattern of a single antenna as reference). Right: The antennas are fed with 180 degrees relationship, the pattern becomes bidirectionnal, with a nul in the main direction (in blue the pattern of the antennas in phase, in red a single antenna). By varying the phase, it is therefore pssoible to adjust the pattern to any value between +/-30degrees compaired to the perpendicular axis of the antennas.

Second example: the 2 antennas are not in the same plane, and one antenna is turned by 45 degrees...

right: The pattern of each antenna fed separatly. To be noted, the backlobe of each antenna is distorted by the presence of the other one.

Left: one antenna phased out by 45degrees, the result (in black) is almost a virtual antenna pointing between the 2. Center: the phase relation is 225degrees, the bidirectionnal pattern is almost restored. Right: the phase relation is now 315 degrees, the bidirectionnal feature remains but with a substantial advantage for one of the antenna.

Third example: Here the 2 antennas are pointing at 90 degrees directions; you may think that the phase relation is less important in this case... it is, but still, it is not completly useless to play on the phase...

center: the 2 antennas are fed in phase, the expected bidirectionnal pattern is here, but with some distorsion (in red the pattern of a single antenna)The 3dB loss is normal taking into account that each antenna is fed with half of the power. Right: In black the 2 antennas are fed with 180 degrees phase relationship (in red, the antennas in phase, in blue a single antenna as reference).

Fourth example: Like in example 2, the 2 antennas are looking at 45 degrees directions, but it is the second antenna that has been turned (as shown in picture below).

Left: the patern of each antenna fed separatly. Right: the patterns obtained when phasing the 2 antennas with 0, 90, 180 and 270 degrees phase relationship.

Comments : This system was built-up for 20m band, however, it is also usable on 15 and 10 (with 90 degrees step on 10 and something in between on 15). It is also usable on 40 but then the phase limit is 315/2=157.5 degrees. Of course it is possible to add lines and switches if you are interested by multiband capability, but the spacing of the antennas will have to be somehow "compromised", especialy if you are looking for "extra gain"(as shown in example 1). All simulations have been done using MMANA203 by JE3HHT and can be verified using NEC2 engine for MMANA by UA3AVR (allows MMANA antenna files to be converted to NEC2 files).

Does it work ?: The answer is yes ! just moving one switch maybe sufficient to get a station out of the noise and QRM, and this has been verified in several contests....
(*) To be accurate Array-solutions commercializes a "180degrees-unphaser" which allows high angle radiation for verticaly stacked yagis.

Above my home setup used in 2005 in more than 30 contests (a 2elts steppIR and an OB6-3M). Here the setup used at CN2WW for the CQWW-CW 2006 (SOSB20 - 3 elts SteppIR and 3elts spiderbeam) .

The maa and nec files are available here

Une version Française est disponible ici en pdf

Tuesday, October 10, 2006

CN2WW - On the road again !

Je serais de nouveau actif depuis le Maroc avec l'indicatif CN2WW à l'occasion du prochain CQWW DX CW, en principe en catégorie SOSB20m. Le QTH sera le même que l'an passé (Dar Bouazza, depuis la station de CN2DX). Activité peri-contest du 22 au 29 Nov; QSL via EA7FTR. Plus de détails à suivre...
I will be active once again from Morroco, with CN2WW callsign for the next CQWW DX CW. In principle I will take part in the SOSB20m category.The QTH will be the same as last year (Dar Bouazza, from CN2DX location). Peri-contest activity fm Nov 22 to 29; QSL via EA7FTR. More details to follow...

Tuesday, September 26, 2006


Just for the fun I took the BCC station, DQ4W claimed score published on 3830 for reference ( see )
Although they did more QSO's (2485 vs 2321), which is quite normal taking into account their M/2 category, I was surprised to see that we managed slightly more mults (590 vs 581) despite our poor location, and quite modest antennas.
Multipliers by type... States/prov is our weak point !

Of course, it could be explained by a collateral effect of the M2 category, but what is interesting is that we managed more zones and DXCC's but less states/prov. The effect of our poor take-off toward NA is quite obvious in the following graphs: On 80m, the 8 degrees blocking does not look as a major handicap, but it becomes dramatic on 15m... Conclusion: F6KAR maybe a decent location for many contests along the year, but certainly not for an ARRL-DX all-bands !

Multipliers by band... 15m is our weak band !

States/provinces by band: The effect of 8 degrees blocking !


F6KAR 3D view toward ESE, first mountain is "le saleve"(1500m) and behind "le mont-blanc" (4807m). F6KAR station is located near the F/HB border.

Bd QSO Pts Sta DX Zones
80: 345 743 20 50 14
40: 659 1550 35 87 28
20: 970 2428 52 108 35
15: 311 731 13 83 27
10: 36 75 0 31 7
Total: 2321 5527 120 359 111
Total Score = 3,260,930

Club/Team : Cern(*) Amateur Radio Club (F6KAR)
StationHigh bands station: IC756 + Ten-tec Titan
Low bands station: IC756pro3 + Ten-Tec Titan
Ants: 80m: shunt-fed tower 40m:
40-2CD20-15-10: KT34 and 3el ECO
RX ants: 100m beverages NE and S, K9AY loop
Software: N1MM Logger V6.9.6 with MMTTY soft-terminal
MSC: ICE band-filters, microkeyer USB-conterters
station pictures here:

Operators: Nico F5VIH/SV3SJ, Phil F6IFY, Pat F6IRF
Guest ops: PM HB9DTM/F6FNL, Seb F8CMF

Condx better than expected taking into account the very low SFI
(who could expect 124 countries to be logged this weekend in TTY?)
15m opened to Eastern-states on saturday, and 20m remained open quite late.
Unfortunately the propagation deteriorated on sunday, but the E's openings allowed 31 countries and 7 zones to be logged on 10m.
Good first night with 2 hours at rate >80, but bad second night with rate droping around 20 between 2 and 5z and very few NA-stns. No major technical problem experienced, just a few glitches with PA switching and software behavior, both probably due to some RF-feedback.
Finaly a decent score for the solar minimum, thanks to DX-peditioners and all participants for creating such a huge activity on the digital bands (and even a bit outside ;-) !

F6KAR 3D view toward NW, "le Jura"(1500m) represents some 8 degrees blocking toward NA

(*)CERN is the European Organization for Nuclear Research, the world's largest particle physics center.

For Dan Brown readers see also;-)

see 3830 post for multipliers stats

Wednesday, August 16, 2006

F6KAR - WAEDC, Stats and audio-clips

waedc audio clip1.mp3 WAEDC audio clip QTC'S - 21MHZ RK9CWW, EX2M, RN9SXX 28MHZ RW9QX, RU9CK, 9M6XRO
waedc audio clip2.mp3 WAEDC audio clip QTC'S - 21MHZ UA9CDC
waedc audio clip3.mp3 WAEDC audio clip QTC'S - 21MHZ CE3BFZ, PV8DX, CN8YR
waedc audio clip4.mp3 WAEDC audio clip QTC'S - 14MHZ K6XX, VE3NE, KU8E, VE9DX
Click on the loudspeaker to listen to the clip. Click on the image to enlarge it...

qso's by time: not a contest to beat records !

qtc's by time: No good score possible without QTC's

Multipliers: hard to find, hard to work ! (multipliers are weighted 2x on 10-15-20m / 3 on 40m / 4 on 80m)

QSO+QTC by hour, the rate to look at...

Continents all bands: another contest where working NA is the key to success.

Continents by band: 80m tfc is trusted by NA statons...

Tuesday, August 15, 2006


WAE DX Contest, CW
Station: F6KAR
Class: M/S HP

Band QSOs QTCs Mults
80: 86 2 21
40: 381 367 56
20: 390 714 64
15: 175 218 39
10: 52 24 19
Total: 1084 1325 496
Total Score = 1,194,864

High bands station:IC756 + Ten-tec Titan - Low bands station:IC756pro3 + Ten-Tec Titan
Ants: 80m: shunt-fed tower and sloper -40m: 40-2CD - 20-15-10: KT34 and 3el ECO - RX ants: Unterminated 100m beverages NE/SW and NW/SE, K9AY loop
Software: WIn-Test
The Weather has been extremely bad all weekend, with frequent showers and lowtemperatures (almost a CQWW-CW weather !)
With the Jura (8deg toward west horizon), our KT34 and a low 3el trap-yagi, wecould not expect to be really competitive on high bands, and this was confirmedby the difficulties we experienced in several pile-ups.
On low bands, it seems that we had a good signal but the WX strongly affected our receiving performances, especially on 80m.
Anyway, those details apart it has been a great weekend, without major technical problem, and we are more than happy with the score.
The conditions: Surprising! Based on the few days before, we did not expect 15mto open toward states, not to mention 10m. The strong multiple hops E's, really helped, resulting in 31 five-banders, 5 U.S call-areas on 10m and 7 on 15m.
The traffic: On a total of 44 DXCC entities worked, more than 2/3 of the QSO'swere achieved with NA. A few "interesting" entities were there. Just to mentiona few: 3W, 4K, 9K, 9M, 9V, A6, CN, FP, HP, VP9, P4, V31, VP8/h, VQ9...
The activity: Obviously being on the Eu-side and working only DX stations can't generate high hourly rates when you are at the bottom of the solar activity. Maybe the rules are still not yet understood, or is it the fact that north hemisphere summer does not stimulate HF contesters but getting new stations to work became quite a challenge on Sunday - we counted as much as 46mn between 2 consecutive QSO's... fortunately the QTC's were there ! On the other hand, it was not too hard to find a clean frequency...
The QTC's: The world may also be divided in 2 by the ones who deal with QTC'sand the ones who don't !!! (revised version of the famous Clint Eastwood sentence, in a Sergio Leone movie!) OK I understand the casual participant only responding to CQ's, but it is quite surprising to hear stations calling CQ-WAE, and refusing to send QTC's, even when the rate gets very low... Not to mention the "?" (meaning : what are you talking about ?) when you ask for QTC's ! A bit like running a KW in a QRP-contest !
Apologies to the stations we annoyed with repeated "QTC?", but for a EU competitor, the spontaneous offers are so rare, that there is no alternative strategy to aggressive search...
It has been a great pleasure for me for me to join the CERN RC(*) team - my first multi-op for quite some time -
Thanks to all for the QSO's and QTC's andto the DARC for organizing this nice event...
(*)CERN is the European Organization for Nuclear Research, the world's largest particle physics center.

Friday, July 28, 2006


3rd world place, 1st EU and new EU record for TM6A in the SOAB LP category. See the contest story at:

3eme monde, et 1ere place EU avec un nouveau record d'Europe pour TM6A dans la catégorie SOAB LP. Voir le CR du contest à

Thursday, July 27, 2006

Monday, June 05, 2006


The antennas used for this contest: Optibeam OB6-3M, SteppIR 2elements

PJ2T grabs the plaque for the DX SOAB LP category, but with the 2nd place, I established a new EU LP record. The contest story, and a few audio clips demonstrating the SO2R technique:

roundup 2006 results ARRL RTTY 2006 results

PJ2T enlève la première place, pour la catégorie DX SOAB LP, mais avec la seconde place de la catégorie, j'établis un nouveau record Européen. Le contest-story et des clips audio du contest (demontrant la technique SO2R) sont la

Sunday, June 04, 2006

F6IRF: Rien de neuf... ou presque

Bienvenue à Axel et Mael, déjà à l'entrainement avec Morse-Runner... La maman Suzy se porte bien, mais le père PM(HB9DTM/F6FNL) montre qqs signes de fatigue !
Welcome to Axel and Mael, already training at Morse-runner. The mother Suzy is OK, but the father PM(HB9DTM/F6FNL) looks tired.
F6IRF/CN2WW actuality is on WPX and peri-contest activity... you'll know everything about my last trip to Morocco...
Kevin en 1988 avec mon transceiver fabrication maison...
Kevin in 1988, with my homebrew transceiver...

Toute l'actualité du moment se trouve sur : WPX-contest et peri-contest activité, vous saurez tout sur mon dernier séjour au Maroc.