SWLing Post Message Board

The first thing which popped to my mind was the "Luxembourg effect", but I sincerely doubt it may be the case, although it can't probably be excluded; a secondo cause may be due to some "manteinance" performed on transmitters, in such a case during a tuning/alignment/testing proc...

Forgot, the "9:1 transformer" isn't a magical object, the transformation ratio may be appropriate for some antennas but totally unappropriate for others, keep in mind that if the antenna wire is near (or below) 1/4 wave at a given frequency, the impedance will be very low so dividing that ...

Regarding the impedance transformer, an easy to build one is shown here http://www.kk5jy.net/LoG/ http://www.kk5jy.net/LoG/images/transformer-schematic.png http://www.kk5jy.net/LoG/images/thin-transformer-inside.jpg it's a "galvanic transformer" (that is, the antenna is electrically isolat...

thanks to both of you, I'll try my hand at building it and I'll tell you...unfortunately my conditions are what they are as a space for antennas...the best is a balcony practically closed on 3 sides...I have an active loop similar to ala1530 that up to 2 meters is fine, @Andrew I'm also looking for...

hello .... a curiosity .... how does it behave towards the high portion of the HF? like in 15 and 10 meters amateur radio?...thanks and congratulations for everything! Hi there, Martyn, welcome on this forum. Regarding your question, I hope 13dka answer included the infos you were seeking for, I'll...

here's a partial list https://it.m.wikipedia.org/wiki/Emittenti_radiofoniche_italiane_in_onde_medie no english version, sorry. but the table should be easily readable even w/o a translator Fact is that, after the switch off of RAI MW transmitter, the government changed the laws/regulations and nowad...

I wonder if the jungle job could be assembled using replacement telescoping antennas that are sometimes available for shortwave radios? Three telescoping antennas, a bit of wood and some wire? well, yes, if the antennas are long enough they will fit as a reflector, add two pieces of wire for the di...

Another easy to build and quite efficient antenna is the H-DoubleBay by W4GRW, the antenna can be built for the HF or for the V/UHF bands, the original website disappeared in the internet limbo, but luckily was archived so a good copy is still available here http://web.archive.org/web/20210216050430...

which antenna did you use ? The belka whip or an external one ?

as for the Jungle-Job, in case someone is interested, here's the 4NEC2 model for the antenna, feel free to play with it as desired :D CM G4ZU "Jungle job" antenna (2 element compact beam) CM https://www.essexham.co.uk/gordon-dick-bird-g4zu-information CM feedpoint impedance around 50 Ohm, ...