Sunday, August 23, 2009

FM-phaser: Fading out local FM-stations

I have had FM-phaser for several years, but this summer I had a chance to finetune it because I have now 5-6 antennas (=Triax-preamps with two outputs). With this device it is possible to fade out some local/semi-local FM-stations by phasing out the chosen signal.

This phaser is at it's best when you have certain and constant signal-level of the QRM-station, which you want to fade out. It should not be too close and strong (= if tuneable with 1 meter-wire forexample) or too far and weak (=fading in/out a lot).

HOW IT WORKS:
I do not give here any technical data, only a description how it goes.
I have two yagi-antennas for this job: Yagi-1 (vertical) is directed to the station I want to hear. Yagi-2 (horizontal) is directed to that station I want to fade-out (QRM-stn). First I adjust the signal of QRM-station from both antennas to equal levels in my receiver. Then I phase the QRM-stations's FM-signal opposite, 180 degrees, and combine them to my receiver. This means that the local station fades out and DX-station has free or almost free frequency to come up.

For example I have YLE Eurajoki 87.7 MHz (30 kW) 80 km away. I can fade it out for Es-stations (unfortunately no Es-conditions this year for results).

Here is a video-clip of how I fade-out YLE Fiskars on 97.0 MHz (3 kW) 100 km away. It is constant here and blocks the frequency. I could have chosen better example (closer/more power) because this signal is beatable by strong tropo.
However, there is a new Latvian local station to hunt on 97.0 MHz, Radio Vidzeme in Valmiera.This is the reason why I choose 97.0 MHz (vertical).
video
In this clip I show the signal-level of YLE 97.0 MHz (3 red leds shining) - then I fade it out by tuning the phaser (one led shining) - and after that I take horizontal QRM-antenna away from combiner, which shows that QRM-signal comes back with V-antenna (3 leds again), because there is no combined signal anymore.
I try later to make examples of closer stations.
This FM-phaser is built by Pertti Äyräs, living close to me. His QTH is almost impossible for FM-DX (Kaarina, 6 x 50 kWs only 3 km away).
I do not have any technical data available of this for instant delivery, but I suppose I could get it from Pertti later.
Let's see if I manage to hear this Radio Vidzeme during autumn tropos (no idea of their power)!!

Thursday, August 13, 2009

Perseids meteors 2009: No results

Again this year Perseids meteor-shower gave nothing special!! However, it seems that the best peak was at night between 12-13 August. I monitored in the morning and late evening on 12.8 some times, but mostly very short pings came up. 5-20 sec long pings is needed.
Perseids seems to have been weakening all the time comparing to 10-20 years ago!
In Finnish Perse = ass - and id = identification! That describes Perseids very well nowdays!

Wednesday, August 5, 2009

Wed 5.8.2009: Weak South France

Today very weak opening to France. However, one new station popped up even with RDS, Radio M from Montélimar (26) on 88.3 MHz.

And once again Radio Nimes and France Bleu Gard Lozere. Almost every summer I have some stations which coming up several times, which are never heard before by me. Strange why E-clouds like to take same places within one summer!

LOG Wed 5.8.2009: Weak South France

88.3 MHz - Radio M, Montélimar(26), France. RDS + DJ. - 18.15-
88.4 MHz - UNID Spanish. Unfortunately only nonsense talk. - 18.15-
92.2 MHz - Radio Nimes, Nimes, France. RDS with music. - 18.07-

Tuesday, August 4, 2009

Mon 3.8.2009: Sardinia, Toscana !

Very interesting opening to Italy. Sardinia is very rare here and also Toscana. Both areas were audible during 20 minutes opening, Sardinia 7 minutes. This was nice moment because the band was not full of stations from all around Italy.

LOG Mon 3.8.2009 (Mainly Sardinia-Toscana, Italy - First time in Finland underlined)

87.5 MHz - Radio Zeta, Caravaggio (BG). Spot to Torino (011-). Zeta seems to have local spots to 6 areas but this tx should be in Toscana??? - 17.29-
88.0 MHz - Radio Rama, Tortoli (NU), Sardinia, Italy. No ID but spot to Bari Sardo near Tortoli. Faded out just during jingle. - 16.48-
88.8 MHz - Radio Maria, Italy announced that they will start R.Vatican News. - 17.30-
89.5 MHz - Radio Mater,Italy. RDS and talking. - 17.11-
90.8 MHz - RDF - Radio Diffusione Firenze, Firenze (FI). New relay? - 17.00-
92.2 MHz - Radio Siena, Siena (SI). - 17.13-
93.3 MHz - Radio 19, Genova tentatively. Spot to Genova. 16.57-
94.7 MHz - Radio Fiesole 100, Firenze(FI). - 17.09-
95.2 MHz - Radio Italia Uno, Padova. Not listed here. - 16.51-
95.2 MHz - Radio Studio Piú,Desenzano del Garda (BS). - 16.59-
95.7 MHz - Radio Sintony, Cagliari (CA), Sardinia, Italy. - 16.55-
95.8 MHz - Radio Macomer Centrale, Siniscola (NU), Sardinia, Italy. No ID only pizzeria spot to Siniscola with tel 0874-. - 16.51-