With reference to below, I have a question please. I put up a quarter wave inverted-L for 160 meters. My only counterpoise is the ground rods at the base of the tower. I wasn't expecting much, but it does so well I'd like to add a decent counterpoise.
If I bury a quarter wave wire, would it be best to put it under the Ariel wire, or opposite from it? Thanks in advance, Dick, n0ce On 12/29/2016 10:16 AM, Don Wilhelm wrote: > I think this is mixing up 1/2 wave radiators and 1/4 wave radiators. > To be resonant, a 1/4 wave wire needs another 1/4 wave "counterpoise" > - think of a center fed dipole - it has 1/4 wave on each side whether > one side is a monopole (vertical) and the other 1/4 wave is an > elevated radial or buried radials of indeterminate length, or whether > it is a dipole with the center in the air. > > A 1/2 wave radiator fed at the end theoretically does not need any > counterpoise, but in practice it does - but only needs to be about > 0.05 wavelength long. > > Refer to some antenna books (the ARRL has a good one) or the ARRL > Handbook for good information about basic antennas. > > 73, > Don W3FPR > > On 12/29/2016 10:30 AM, Fred Moore wrote: >> With an end fed 1/4 wave you only need a counterpoise that is about .05 >> wave length. it can be the coax or another counterpoise. Although a >> counterpoise has some effect on radiation pattern of a quarter wave >> radiator, it is minimal. You won't see much improvement in performance >> by going above .05 wave length.. it's not worth the trouble to increase >> the counterpoise length.. Fred >> >> >> On 12/29/16 9:01 AM, mjisted wrote: >>> Looking at your text message on the elecraft board. About a half wave >>> length ...here is a question for you. I'm going to put up a half >>> wavelength of wire for the 5 mhz band. ..hyendfed can I use a quarter >>> wave length of counter point as a radiator ground plane. .. >>> The. ..G0MVP. >>> >>> [email protected] >>> >>> >>> Sent from Samsung Mobile >>> >>> >>> -------- Original message -------- >>> From: Fred Moore >>> Date:29/12/2016 13:04 (GMT+00:00) >>> To: [email protected] >>> Subject: Re: [Elecraft] Small QRP antenna >>> >>> Don, >>> >>> Thank you very much, for pointing out a very common issue that gets >>> mixed up into discussions. Your point is so valid the random wire >>> always seems to get mixed into the 1/2 wave discussion for some >>> reason.. and should never be mixed together. you are absolutely >>> correct.. thanks again regards.. Fred >>> >>> >>> On 12/29/16 12:33 AM, Don Wilhelm wrote: >>>> Scott, >>>> >>>> If the radiator is not a half wave long, it is not a "half wave". >>>> Yes, a random length wire may work, but please do not call a random >>>> length a half wave - the length of a half wave is quite specific. >>>> Similarly, a quarter wavelength is a specific length at a particular >>>> frequency. >>>> >>>> 73, >>>> Don W3FPR >>>> >>>> On 12/28/2016 11:20 PM, K9MA wrote: >>>>> The counterpoise for an end fed half wave (or multiple) really >>>>> doesn't >>>>> have to be anywhere near a quarter wave long. >>>> ______________________________________________________________ >>>> Elecraft mailing list >>>> Home: http://mailman.qth.net/mailman/listinfo/elecraft >>>> Help: http://mailman.qth.net/mmfaq.htm >>>> Post: mailto:[email protected] >>>> >>>> This list hosted by: http://www.qsl.net >>>> Please help support this email list: http://www.qsl.net/donate.html >>>> Message delivered to [email protected] >>>> >>> >>> -- >>> Fred Moore >>> email: [email protected] >>> [email protected] >>> phone: 321-217-8699 >>> >>> ______________________________________________________________ >>> Elecraft mailing list >>> Home: http://mailman.qth.net/mailman/listinfo/elecraft >>> Help: http://mailman.qth.net/mmfaq.htm >>> Post: mailto:[email protected] >>> >>> This list hosted by: http://www.qsl.net >>> Please help support this email list: http://www.qsl.net/donate.html >>> Message delivered to [email protected] >>> >>> -- >>> This message has been scanned for viruses and >>> dangerous content by *MailScanner* <http://www.mailscanner.info/>, >>> and is >>> believed to be clean. >> > ______________________________________________________________ > Elecraft mailing list > Home: http://mailman.qth.net/mailman/listinfo/elecraft > Help: http://mailman.qth.net/mmfaq.htm > Post: mailto:[email protected] > > This list hosted by: http://www.qsl.net > Please help support this email list: http://www.qsl.net/donate.html > Message delivered to [email protected] -- ______________________________________________________________ Elecraft mailing list Home: http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/mmfaq.htm Post: mailto:[email protected] This list hosted by: http://www.qsl.net Please help support this email list: http://www.qsl.net/donate.html Message delivered to [email protected]
