A friend (who is a mechanic at heart) threw together a 4 element quad for 2 meters, along with a moxon for 2 meter sat work. The feed for the 4 element quad is *straight* coax. To an ugly balun below the antenna.. It feeds at 50 ohm rather nicely. And easy to build. (Spreaders are just fiberglass driveway markers...wire simple 12 gauge wire. It has survived 3 ice storms, and a near miss by a tornado. Superb directionality and all that. About a 3-4' long piece of pvc for the central beam that holds everything. Portable. And lots of gain. The moxon gets used with his hand held for sat comm work. In front of the moxon, a 5 or 6 element yagi for 440. Next experiment for him? I've heard he is working on a quagi. That is a quad reflector, quad driven element.. then a boat load of directors made up of copper wire on a piece of light wood. More gain than a 6 element quad... and lighter.
KK4QDZ - Now with Extra Class Priv's, and a tiny KX3 to enjoy them! ________________________________ From: Robert G Strickland <rc...@verizon.net> To: elecraft@mailman.qth.net Sent: Friday, April 4, 2014 1:09 PM Subject: Re: [Elecraft] OT: application of directional Quad in UHF Johnny... I have no experience with UHF quads, but I modeled, used and modified an HF quad for over 15 years. I now use a SkyHawk HF triband yagi. Based on that experience, quads require more mechanical effort for construction and maintenance. The form factor for a yagi is two-dimensional, while for a quad it is three-dimensional. Thus, packing, storage and transport is potentially simpler for the yagi than for the quad. Feeding a yagi is simpler than for a quad, because the yagi can use a solid driven element, while the quad generally requires a break in the driven element; this can complicate construction. Adding elements to a yagi antenna is mechanically simpler than adding elements to a quad. So, based on my HF experience - and thinking about UHF quads - I think mechanical issues might be a significant difference. At UHF a 4/5 element yagi might be easier to deal with than a 3-el quad. My opinion. ...robert On 4/4/2014 03:05, Johnny Siu wrote: > Hello Elecrafters, > > It is off-topic and you can press 'DEL' now. > > Hong Kong is quite a hilly place in the rural areas. Local ham > societies are often providing radio communication support services to > charity organisations having fun raising sports activities in these > areas. We have to set up UHF repeaters at the hill tops. Purely > from the radio text books, a 3 element quad gives better performance > than a 3 element yagi. However, I seldom see using directional Quad > in the UHF repeaters. > > Apart from performance, are there any disdvantages (or advantages) of > using directional quad instead of yagi in UHF repeaters? Could you > share with me your experience in US? > > Thanks for your help in advance and please reply off-the-list to > reduce the traffic in the mail listing (oh, yes, not forum!!) > > 73 > > Johnny VR2XMC > ______________________________________________________________ > Elecraft mailing list Home: > http://mailman.qth.net/mailman/listinfo/elecraftHelp: > http://mailman.qth.net/mmfaq.htmPost: > mailto:Elecraft@mailman.qth.net > > This list hosted by: http://www.qsl.net/Please help support this > email list: http://www.qsl.net/donate.htmlMessage delivered to > rc...@verizon.net > -- Robert G Strickland, PhD ABPH - KE2WY rc...@verizon.net.usa Syracuse, New York, USA ______________________________________________________________ Elecraft mailing list Home: http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/mmfaq.htm Post: mailto:Elecraft@mailman.qth.net This list hosted by: http://www.qsl.net/ Please help support this email list: http://www.qsl.net/donate.html Message delivered to billblomg...@yahoo.com ______________________________________________________________ Elecraft mailing list Home: http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/mmfaq.htm Post: mailto:Elecraft@mailman.qth.net This list hosted by: http://www.qsl.net Please help support this email list: http://www.qsl.net/donate.html Message delivered to arch...@mail-archive.com
