Gotta reply to this ... A 1/4 wave radiator DOES NOT radiate straight up. As a matter of fact, this is where *minimum* radiation takes place. Any antenna handbook will easily bear me out on this. The amplitude-pattern of a simple 1/4 wave (really - a dipole, since the 'ground' plane proivdes a reflection or image of the other half of the antenna ) antenna follows the cosine of the angle (from a line straight out or normal to the antenna wire/long axis) and the cosine of 90 degrees is, of course, zero. There are antennas that exhibit maximum 'radiation' along their long axis, but the 1/4 wavelength (Lamda) monopole/dipole is not one of them. Jim ----- Original Message ----- From: "Alan B. Pearce" To: Sent: Thursday, August 02, 2001 2:42 AM Subject: Re: [EE]: VHF and UHF mini modules >I don't know if this is relevant to your app, but a 1/4 wave radiates a >significant amount of energy straight up. (along the long axis) A 5/8 wave >flattens this out. >Depends on wether talking to spacecraft is what you're into :) I agree with this, the lower angle of radiation is of benefit to ground communication. A 5/8 wavelength whip also has another advantage, in that it's resistive component of the impedance is very close to 50 ohms, and so you need to only tune out the reactive part of the impedance, although this is a larger reactive impedance than a quarter wave whip. At the end of the day it can be a simpler aerial to use. -- 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.