| From: Claudio Maracci
[mailto:cmaracci{zavináč}gmail.com] Sent: Saturday, October 17, 2015 5:44 PM To: Vladimír Petržílka Subject: Re: 3cm IARU contest log and report Hi Vlada, thanks for your fast reply. I think that we need (not only us but in Europe) to improve the output power up to 30-50W on 10 GHz to test troposcatter on that band. In some case our tx power is enough but you must take in account that on 23 cm the power run about 300-1000 W at present. I think that 10 db down of output power (with higher gain dishes but also higher path loss) it's really a must to test stable tropospheric conditions. Really I don't have experience on tropo on 3cm band but I think that: like on 2m band the best tropo to Germany from my location occur into intermediate seasons (warm days but not too dry) like on 2m band the best tropo to Czech, Slovakia, Hungary (and to directions where I cross 150-200 Km of sea path) from my location occur in summer season with an extended high pressure in the whole area. Mine are only hypothesis because I made only few tropo QSOs on 3 cm above 500-600 Km of distance and also because (you know!!) 144 MHz band is far away to the 10368 MHz band! I think also that dishes under 1.2-1.5 m of diameter are the best to test tropo condx and I don't have any digital experience because (shame me!) I still use an arcaic IC202 on 3cm band hi. Without any serious mod of our systems I think we must try and retry several times with the same stations (in contest) to have some more info about tropo, even if there is a great waste of time (due to unsuccesfully tests). We'll see in the future but next step is a power improving from the actual 10W standard to a 6db more standard....maybe... 73 - Claudio 2015-10-17 10:39 GMT+02:00 Vladimír Petržílka <ok1vpz{zavináč}seznam.cz>: Hi Claudio it's nice to see your report. TNX!. We will put it on the web soon. I think it is quite good result from EU perspective. Congrats! Unfortunately we were not QRV on 3cm due to failed rotator controller, so our 10GHz gear we left home. Propagation in our area on 3cm were poor, no RS, high attenuation due to fog - the other guys reported lost of many usual QSOs on 47GHz. However our 70 and 23cm results were quite OK and the OK2A contest report will be show soon. Here is for comparison few pics of us and DL0GTH achievements in attachment. Good news is, that the 23cm activity in Italy is going up! "Normal tropo" condx on 3cm: we need to discover, how to make a regular airplane scatter QSOs similarly, like on 23cm. Tests, which we made resulted in a very short reflections, uneffective for finalizing of QSO. Maybe less sharp antenna or use some fast digital transmission may help. Have you some positive results? 73 Vlada -------------------------------------------------------------------------------- From: Claudio Maracci [mailto:cmaracci{zavináč}gmail.com] Sent: Friday, October 16, 2015 9:14 PM To: Vladimír Petržílka; ok1teh Petrzilka Subject: 3cm IARU contest log and report Hi friends, I know that's a bit late to send my results of last IARU SHF contest to be published on ok2kkw site anyway you can do like you want, I'm always glad to send you my links: log report Two more words: wx was variable with sunny and light rain for the whole contest but was a warm day and in the last hour I've worked 3 DL stations (odx DL0GTH) with real troposcatter low signals! No burst from airscatter, really amazing for me. I made many tests with OK, OM and HA stns without success. Finally I think that for the "normal tropo" we must increase the power with GaN devices (30-50W CW) but at present their cost is too high for me hi! 73 - Claudio I4XCC |