The industry rule of thumb is that the hole has to be 1/10 the wavelength to have any effect.
These small drainage holes (normally called "weep holes") have no effect if we're talking AM band frequencies. Chuck -----Original Message----- From: [EMAIL PROTECTED] [mailto:[EMAIL PROTECTED] On Behalf Of Craig Healy Sent: Wednesday, August 22, 2007 4:48 PM To: Mailing list for the International Radio Club of America Subject: Re: [IRCA] Metal matching transformer box > One thing that you could do, is to drill the holes in the bottom of the > box, thread them and put a bolt or screw into the holes and take them > out to drain the box and put them back in when done. You would have to > fiqure out how often to drain the box though. That would compremise the > box letting stray signals in. A small hole will absolutely not let AM signals in. It's just too small in relation to the wavelength. Even at the much shorter FM wavelength, the hole used to pressurize the coax doesn't let any of the FM signal out. Given the 100x wavelength of AM, it's not going to happen. Craig Healy Providence, RI _______________________________________________ IRCA mailing list IRCA@hard-core-dx.com http://montreal.kotalampi.com/mailman/listinfo/irca Opinions expressed in messages on this mailing list are those of the original contributors and do not necessarily reflect the opinion of the IRCA, its editors, publishing staff, or officers For more information: http://www.ircaonline.org To Post a message: irca@hard-core-dx.com _______________________________________________ IRCA mailing list IRCA@hard-core-dx.com http://montreal.kotalampi.com/mailman/listinfo/irca Opinions expressed in messages on this mailing list are those of the original contributors and do not necessarily reflect the opinion of the IRCA, its editors, publishing staff, or officers For more information: http://www.ircaonline.org To Post a message: irca@hard-core-dx.com
