If you have access to a ARRL antenna book, there is much to be learned from reading about phase shift versus capacitive coupling, many times more is not better - the current from lightning has bad effects on capacitive coupling - it is very tedious for a home builder to construct phase shift coils that have equal 52 ohm impedance and reactance but that should not stop you only slow you down. If you change the coil length you can change the angle of radiation to suit your location to the users, what angle of downtilt do you need to reach your users? The phase shift method will produce a wider bandwidth, changing the cap values is quicker but very narrow bandwidth and very likely to fail with wind corona and especially sparks from the sky. Once you decide on the electrical characteristics then overcome the mechanical stress choices and loading factors and you are on your way to making a antenna that can solve your problem, many work great on paper, keeping it upright and stable in the air is the final chapter.
samsoncr wrote: > > Clark, I've heard about angles and gain of an antenna (6 grades-10dB, > 17 grades-6dB, 30 grades-3dB) but I don't understand what they are > and how they work. I wanna stack two 5/8 wave elements vertically > using collinear model or stack array. Thank you. > --- In [email protected], Virden Clark Beckman > <[EMAIL PROTECTED]> wrote: > > What angle of radiation are you measuring gain in? What method of > > coupling are you using between the radiating elements? > > > > samsoncr wrote: > > > > > > Hi. I wanna make an antenna stacking two 5/8 elements, it's for > my > > > GMRS radio. Which one will have more gain, 40,5 cm over 40,5 cm > > > element with 2 cm of space between them or 40,5 cm over 40,5 cm > with > > > 64,8 cm between them? > > > > > > Thank you. > > -- 73...Clark Beckman N8PZD 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/
