Welcome on the “best of” page of F6IRF blog

(updated 29/09/2009)

 

The blog F6IRF " Hamradio contesting "  is on line for about 3 years and a half.

On these pages you will find articles in English, French or bilingual, who go from the historical files (25 years of ham-radio this year) to contests summaries, while passing by technical ideas and descriptions. The archives not being always very easy to use, here is a selection of the articles which I think are the most interesting. They are presented by reversed chronological order with a small content summary.  When the original article is not available in English the hyperlink brings you to a “Alta-Vista babelfish” translation (click on the (F) if you prefer the original in French  (the automatic translation is often very confusing and the links do not always work !) or use the French index .

 

I have not included contest and expedition reports. A few of them are covered by videos:  You may go to “you tube” and use the search engine with “f6irf”  keyword.

 

 

Low-band DX’ing the high angle mode hypothesis (November 2008)

 

- part 1 – statiscal study using WSPR and 2 RX-antennas on 80m

- part 2 -  Another test on K1JT 80m beacon, showing the evidence of an high angle mode on greyline

- part 3 -  Low-band DX'ing: The high-angle mode hypothesis - G0KYA contribution   

 

 

VOACAP, the end of the myth ? (April to November 2008) - English

 

- VOACAP vs WSPR reports part 1 (study of a 30m transatlantic path)
- VOACAP vs WSPR reports part 2 (study of a 30m transatlantic path)
- VOACAP, the end of the myth ? part 1 ( study of a F<>ZL 40m path)
- VOACAP, the end of the myth ? part 2 ( continuation of the study of the F<>ZL 40m path)
- VOACAP, the end of the myth ? part 3 (study of a 40m long path F to VK7 + my temporary conclusions)
- VOACAP, the end of the myth ? part 4 (back to F<>ZL short/long path, OH6BG calculations and opinion)

- VOACAP mystic, an interesting comment   (AB7E comments and suggestions)

 

 

Using WSPR to evaluate propagation, TX, RX antennas and site performance (March to November 2008) - English

 

- A statiscal method to evaluate TX antenna performance using WSPR Part 1  Part 2

- 160m spots analysis, or how to evaluate a station performance.  Part 1  Part 2

- Is my K9AY working as expected ?  verification of the K9AY  pattern using a statiscal method

- Is the propagation always bilateral ?   a 30m transatlantic path analysis

- 80m tests fm IN87  Another path analysis showing what may look  “asymmetrical propagation”

- 160m: A good example of an asymmetrical path  Once again, something that could be taken  for unilateral propagation (who knows?)

 - Low-band DX'ing: The high-angle mode hypothesis  Near Sunrise/Sunset strange phenomenas occur on low bands…

 

Recent antenna ideas (May-November 2008)

 

- A vertical half-moxon for the 40m band

- back to "another low band vertical"

- A multi-turns magnetic-loop for the top band.

 

 

 

The " Cizirf special " (January 2008) - Bilingual

 

http://mangafight.free.fr/cizirf_eng.htm the complete and detailed description of a receiving antenna optimized for short and medium distances. All the options from the simple NVIS to the most advanced version which can provide up to 30dB F/B ratio.

http://f6irf.blogspot.com/2008/01/cizirf-spciale-une-version.html  addendum1  (F). A simple bidirectional version requiring only one coaxial relay, 2 coaxial "T " and a UNUN 25/50.

http://f6irf.blogspot.com/2008/01/un-unun-5025-ohm-in-5-minutes.html  addendum 2 (F). Construction of a UNUN 25/50 ohms in 5 minutes  

http://f6irf.blogspot.com/2008/01/une-alternative-trs-simple-with-unun.html addendum 3 (F) an alternative to the UNUN. A Resistive combiner to improve isolation between dipoles when they are out of phase.

http://f6irf.blogspot.com/2008/01/alternative-with-unun-a-good-solution.html addendum 4 (F) The BB2, a better solution than the resistive combiner to improve the isolation between dipoles.

 

 

Versions using the phasing box MFJ-1025

http://f6irf.blogspot.com/2008/01/cizirf-special-as-qrn-killer.html  (F/ENG) The Cizirf special as a QRN killer. Audio clip recorded on a ZL/DL QSO.

http://f6irf.blogspot.com/2008/01/radio-sloboda.html - (F/ENG) Radio-Sloboda; may be the most spectacular demonstration, carried out on a broadcast Bosnian station in the 40m band in the morning. The spectrum-display of the IC756pro2 shows some 30 dB attenuation when "reversing the phase".

http://f6irf.blogspot.com/2008/01/petit-bench-dssai-of-the-mfj-1025.html  (F) a test of the MFJ-1025 used in the  following videos and recording

http://f6irf.blogspot.com/2008/01/castres-in-the-81.html Video. (F) Visualization on the spectrum-display of the IC756 pro2 of back immunity provided by the antenna.

http://f6irf.blogspot.com/2008/01/cizirf-special-report-before-arrire-sur.html Audio-clips (F) : Demonstration of the Front to back ratio of the antenna

http://f6irf.blogspot.com/2008/01/va-to make-mal.html Video.  (F) Splatters cancellation on a  semi-local QSO.

http://f6irf.blogspot.com/2008/01/no-comment.html :  Video. (F) How it is possible to "notch" an undesirable station.

 

 

Simple versions using a single dipole,  phased dipoles or coaxial lines delays

http://f6irf.blogspot.com/2008/01/une-antenna-in-rception-nvis-vido.html   Videos (F) Tests with a NVIS version (wide spacing and low height) the 2 dipoles being in phase, or out of phase with the means of switched line lengths.

http://f6irf.blogspot.com/2008/01/une-antenna-of-rception-nvis-the-cizirf.html audio clips (F) and audiograms of the NVIS version (dipoles in phase)

http://f6irf.blogspot.com/2008/01/quelle-antenna-for-the-cut-of-ref_06.html   (F) First tests using a single broadband dipole at 4m AGL. Comparison with the vertical.

 

 

Which antenna for the REF championship ? (December 2007) - French

A series of 4 articles in French, dealing with the particular problems which the short distance contacts pose on the 40 and 80 bands in these times of minimum solar index.

http://mangafight.free.fr/Antenne%20CDR%20part1.htm   (F) A fast introduction to VOACAP simulations, with a comparison of the performances of dipoles at various heights versus the distance.

http://mangafight.free.fr/Antenne%20CDR%20part2.htm   (F) A more detailed study, with tables indicating the optimum angle of radiation of an antenna according to the distance. Also a study of some basic antennas based on NEC2 simulations using the Sommerfeld-Norton model.

http://mangafight.free.fr/Antenne%20CDR%20part3.htm  (F) More sophisticated transmitting antennas (Wire-yagis, phased dipoles) with performances comparisons versus a Cushcraft 40-2CD.

http://mangafight.free.fr/Antenne%20CDR%20part4.htm  (F) Deals more specifically with receiving antennas. In addition to the traditional Beverage and K9AY, an introduction to the “Cizirf special”, an original receiving antenna concept using two broadband dipoles.

 

 

Report CQWW-CW TM6A @F6CTT (November 2007) - English

http://f6irf.blogspot.com/2007/11/tm6a-f6ctt-cqww-CW-2007.HTML In addition to the usual contest summary, a short description of a  "diversity receive" system using two receivers and a SO2R box.

Audio recordings are also available

http://f6irf.blogspot.com/2007/11/cqww-CW-CONTEST-TM6A-AUDIO-CLIPS.HTML and

http://f6irf.blogspot.com/2007/12/tm6a-cqww-CW-2007-FEW-MORE-AUDIO-CLIPS.HTML

 

Another vertical for the bands 80, 40 and 30m (and 160m) (Septembre/Octobre 2007) - Bilingual

http://mangafight.free.fr/another%20low%20band%20vertical.htm  A 18m vertical using a LC circuit and a UNUN (1 relay needed to switch from 40 to 80).

 

The CN2WW wire-beam (February 2007) - English

http://f6irf.blogspot.com/2007/02/cn2ww-80m-wire-beam.html Description of the 80m antenna used at CN2WW in the ARRL-DX CW 2007 which enabled us to beat the African record in M/S category (3rd place world).

 

IC7000 review - The good the bad and the ugly (January 2007) - English

http://f6irf.blogspot.com/2007/01/ic7000-review.html  An IC7000 review with the good and bad points.

 

Phasing/Unphasing 2 yagis - Solution and benefits (December 206) - English

http://f6irf.blogspot.com/2006/12/phasing-unphasing-2-yagis-solution-and.html How to phase/unphase 2 horizontally spaced yagis (system used at CN2WW during CQWW-CW 2006 in SOSB 20m category).

 

Training material for the WAEDC CW (July 2006) - Bilingual

http://f6irf.blogspot.com/2006/07/training-material-for-waedc-cw.html   Real audio-recordings made during the 2005 edition. Enjoy !

 

With low-cost 2 elements for 40m (February 2006) - English

http://f6irf.blogspot.com/2006/02/low-cost-2-elements-for-40m.html  My first wire-yagi prototype used in the ARRL-DX CW 2006.

 

A few details  about my SO2R-setup (February 2006) - Bilingual

http://f6irf.blogspot.com/2006/02/f6irf-few-details-butt-my-so2r-setup.html  Description of a low-cost SO2R system not using any SO2R box (just the PC and the N1MM software).

 

F6IRF: REF-CW SO2R-DEMO audio-clip (January 2006) - Bilingual

http://f6irf.blogspot.com/2006/01/f6irf-ref.-CW-SO2R-DEMO-AUDIO-CLIP.HTML A demonstration of SO2R traffic, recorded during the REF championship 2006, with the explanations allowing the neophyte to follow what occurs on the recording.

 

Audio RTTY-SO2R clips (January 2006) - English

http://f6irf.blogspot.com/2006/01/rtty-so2r-audio-clips.html   RTTY SO2R demo, recorded during the ARRL "roundup" 2006 with some explanations and the log allowing to follow... (stereo file requiring MTTY or MMVARI TTY decoders)

 

SO2R,  a minimal setup (August 2005) - English

http://f6irf.blogspot.com/2005/08/so2r-minimal-setup.html Description of my RTTY SO2R setup which providedd quite a few successes in this mode.

 

Logbook of The World (September 2004) - Bilingual (on the site of the CDXC)

http://www.cdxc.org/LoTW/f2LoTW.htm presentation of the ARRL LOTW