De Matthieu si je comprends bien, c'est probablement une perte de puissance et de temps de jouer dans 2 polarisations lorsque je cherche des contacts.
Au contraire: En cherchant selon des polarisations différentes, tu peux trouver une combinaison qui va donner un résultat meilleur que tous les autres.
Ce que je disais précédemment, c'est qu'il est impossible de prévoir ce qui arrivera sans faire d'essai.
En ce qui concerne la propagation sur 2 mètres, je te recopie ce qu'en dit le dernier Handbook de l'ARRL:
144-148 MHz (2 m)
Ionospheric effects are significantly reduced at 144 MHz, but they are far from absent. F-layer propagation is unknown except for TE (trans-equator), which is responsible for the current 144-MHz terrestrial DX record of nearly 8000 km (5000 mi). Sporadic E occurs as high as 144 MHz less than a tenth as often as at 50 MHz, but the usual maximum single-hop distance is the same, about 2300 km (1400 mi).
Multiple-hop sporadic-E contacts greater than 3000 km (1900 mi) have occurred from time to time across the continental US, as well as across Southern Europe. Auroral propagation is quite similar to that found at 50 MHz, except that signals are weaker and more Doppler-distorted. Auroral-E contacts are rare. Meteorscatter contacts are limited primarily to the periods of the great annual meteor showers and require much patience and operating skill. Contacts have been made via FAI on 144 MHz, but its potential has not been fully explored.
Tropospheric effects improve with increasing frequency, and 144 MHz is the lowest VHF band at which weather plays an important propagation role. Weather-induced enhancements may extend the normal 300- to 600-km (190- to 370-mi) range of well equipped stations to 800 km (500 mi) and more, especially during the summer and early fall. Tropospheric ducting extends this range to 2000 km (1200 mi) and farther over the continent and at least to 4000 km (2500 mi) over some well-known all-water paths, such as that between California and Hawaii.
Un autre facteur important est le mode que tu choisis... pour les modes habituels de QSO, excluant les modes 'mathématiques' ne permettant pas de QSOs conventionnels comme le JT65, l'efficacité est médiocre en FM (signal trop large), meilleure en BLU/phonie (SSB)... et optimale en CW/PSK.
