Dimitris, The basics of radio line of site propagation such as VHF and UHF the lower the frequency the better and stronger pentration through an object/medium. So VHF will pentrate a wall better than UHF.
When it comes to going thru openings such as windows the higher the frequency the better. Even though there are holes in a wall depending on the size and frequency used the holes will look more like a wall or shield to lower frequencies, but openings to higher frequencies. This is why a UHF HT with rubber duck will often work better than a VHF in a car or building. The higher the frequency a hole will look more like a hole. If you had a metal enclosure made of typical window screen it will look like a solid wall to RF until the frequency becomes high enough so the holes are large in wavelength. So with the ship I suspect the VHF would work best since you are trying to pentrate walls. However, since made of enclosed steel I bet about any frequency would be blocked. Sounds as if you have tried VHF. Would be interested to see UHF, but due to few holes probably would be worse, but I have never tried it on a ship. 73, ron, n9ee/r --- In [email protected], "Velissaris Dimitris" <[EMAIL PROTECTED]> wrote: > We already tryied tests inside a big ship of our navy force. > > Frequencies on vhf band (140-170 MHz) and we had contact until 6 heavy and > closed door on the same horizontical level , after that nothing at all.. > > Tranceivers was tk-2160 by Kewnwood company with a power output 5 Watt. > > > > Best regards > > > > > > Dimitris Velissaris > > Technical Support > > RadioCommunications Dpt. > > ANCO S.A > > 44 Syngrou Ave > > 117 42 Athens - Greece > > Tel : +0302109209217 > > Fax : +302109209345 > > URL : www.anco.gr > > e-mail : [EMAIL PROTECTED] > > > > -----Original Message----- > From: [email protected] > [mailto:[EMAIL PROTECTED] On Behalf Of hussien reda > Sent: Wednesday, August 24, 2005 4:57 PM > To: [email protected] > Subject: [Repeater-Builder] whats is the differ between the VHF & UHF > > > > Hi > > > > can anyone please tell me which the best VHF or UHF to select it to > communicate inside the big ship ,,,,, i think the UHF best to select it > ???????? thanks > > > > Best Regards > > > > > > > > > > > _____ > > YAHOO! GROUPS LINKS > > > > * Visit your group "Repeater-Builder > <http://groups.yahoo.com/group/Repeater-Builder> " on the web. > > > * To unsubscribe from this group, send an email to: > [EMAIL PROTECTED] > <mailto:[EMAIL PROTECTED] subject=Unsubscribe> > > > * Your use of Yahoo! Groups is subject to the Yahoo! > <http://docs.yahoo.com/info/terms/> Terms of Service. > > > > _____ Yahoo! Groups Links <*> To visit your group on the web, go to: http://groups.yahoo.com/group/Repeater-Builder/ <*> To unsubscribe from this group, send an email to: [EMAIL PROTECTED] <*> Your use of Yahoo! Groups is subject to: http://docs.yahoo.com/info/terms/
