"A simple monopole needs more careful matching and tuning than a dipole" Practical experience in the real world will not bear this out ... ever seen or used the classical Motorola 19" whip on 2 Meters? No matching network, mates up directly to RG-58 50 Ohm coaxial cable and deleivers reasonable preformance for the simplicity and size ... "A vertical 5/4 lambda will outclass it" You *might* be alluding to a "5/8 wavelength antenna" - and you would be closer to corect ... "a lambda/4 whip probably costs them 6dB in transmitted power" Again, practical experience will not quite bear this out ... Jim ----- Original Message ----- From: "Peter L. Peres" To: Sent: Tuesday, May 14, 2002 3:41 PM Subject: Re: [EE]: RF modules > On Tue, 14 May 2002, Michael Luvara wrote: > > >As for antenna orientation, design, they are all good for different > >things. Take a look at the aarl handbook as suggested by another list > >member. The linx technology app note is good too for starters. Coils, > >loops, etc run into certain constraints, like matching, etc. Most of the > >time these layouts are used for space reasons, and can give lesser > >results than a simple monopole. > > Why ? I thought the maximum possible gain of any antenna is related to its > size vs. lambda. when viewed from the corresponding station. A simple > monopole needs more careful matching and tuning than a dipole, and an > eggbeater or discone antenna will probably outclass these two in all > respects for the same lambda-related size, for example because it will > leave no nulls in the horizontal or vertical plane. > > A simple lambda/4 whip has only one advantage: simplicity. A vertical 5/4 > lambda will outclass it and give significantly more horizontal gain (and > still require base tuning but less exact). > > For the 'lot' of matching amateurs can achieve at 433 and 900MHz a > lambda/4 whip probably costs them 6dB in transmitted power (30% > less possible range). This is just my limited experience. > > A oriented dipole > > Peter > > -- > http://www.piclist.com hint: The PICList is archived three different > ways. See http://www.piclist.com/#archives for details. > > -- http://www.piclist.com hint: The PICList is archived three different ways. See http://www.piclist.com/#archives for details.