Re: Topband: dipole height

2012-10-30 Thread Rick Karlquist
ZR wrote: 15 and 60M and run comparisons for awhile. In areas where countries are tightly packed a dipole may be a good choice. Carl KM1H I had full size 160M dipoles (not inverted vees) up at 9 meters and 18 meters for about six months and did a lot of A/B'ing of them. On receive, there was

Re: Topband: dipole height

2012-10-30 Thread N4IS
Hi Rick I had full size 160M dipoles (not inverted vees) up at 9 meters and 18 meters for about six months and did a lot of A/B'ing of them. On receive, there was never any difference in audible S/N ratio. This result is 100% sure to happen. Any time you have more than one resonant antenna,

Re: Topband: dipole height

2012-10-30 Thread Tom W8JI
Hi it's an interesting discussion about the dipoles. I want to put up an inverted vee dipole for 160. I can put the apex at 15,30,45 or 60m and have 90 degree apex angle. The ground is very good and I am right on the magnetic equator. I'm sure what works here is different for you, but I

Re: Topband: dipole height

2012-10-30 Thread Rick Karlquist
N4IS wrote: Hi Rick I had full size 160M dipoles (not inverted vees) up at 9 meters and 18 meters for about six months and did a lot of A/B'ing of them. On receive, there was never any difference in audible S/N ratio. This result is 100% sure to happen. Any time you have more than one

Re: Topband: dipole height

2012-10-30 Thread James Wolf
RDF is the key point to improve signal noise, not gain. Vertical or low dipole has very or none directivity, so low RDF or directivity does not improve signal noise. In general, this is the case, but it is not always true. Consider that you can have an antenna with a high RDF number, but at

Re: Topband: dipole height

2012-10-30 Thread Tom W8JI
RDF is the key point to improve signal noise, not gain. Vertical or low dipole has very or none directivity, so low RDF or directivity does not improve signal noise. In general, this is the case, but it is not always true. Since I started using RDF, let me explain what it really is. RDF is

Topband: Tuning 160M Dipole

2012-10-30 Thread paul ecker
I put up a 160m dipole but now need to tune it. SWR at low end of band is abt 3 and at top end abt 5. From what I have read this means I need to shorten it. My question is how much should I take off? A foot off each end?? Any good links to sites that may explain this in some detail so I can

Re: Topband: Tuning 160M Dipole

2012-10-30 Thread Bob K6UJ
Paul, Here is a handy on line calculator to help you determine the approx wire length. You can play with putting in different freqs and see how much the wire length changes. I believe with frequency changes of 10KHZ the wire length changes by about one foot. So if it is resonant at 1.800 and

Topband: FW: Tuning 160M Dipole

2012-10-30 Thread Peter Voelpel
I would rather guess you should short it by at least 4-6 foot per side. Easiest way is to check for the resonant frequency and short accordingly. 73 Peter, DJ7WW -Original Message- From: Topband [mailto:topband-boun...@contesting.com] On Behalf Of paul ecker Sent: Mittwoch, 31. Oktober

Re: Topband: dipole height

2012-10-30 Thread N4IS
Jim high RDF number with significant lobes off the back that are only 10 dB down from the main signal There is no high RDF with lobes 10 db down, or one or another, not both at the same time. Regards JCarlos N4IS ___ Topband reflector -

Topband: feed choke

2012-10-30 Thread Bob Kupps
Hi thanks for all the replies I have decided to put the dipole up at the 45m level.  One more question - I will run the feed line up inside the tower so is a choke still needed at the feed point? Thanks and hope to be QRV on 160 for the WW CW. ___