Re: Topband: Vertical and horizontal polarized antennas
This is a very well-established fact! See http://www.w0btu.com/160_meters.html. 73, Mike www.w0btu.com On Sat, Nov 17, 2018, 5:56 AM Clive GM3POI wrote: > My take on this is that having had a low inverted vee at about 80ft and a > top loaded vertical over a very good ground system to compare against each > other. I have found the following that despite the vertical being short > 60ft > with the exception of stations within 200miles the vertical is always > better. However the vertical is about 87% efficient with a serious amount > of > long radials. > YMMV 73 Clive GM3POI > > -Original Message- > From: Topband [mailto:topband-boun...@contesting.com] On Behalf Of Roger > Kennedy > Sent: 17 November 2018 11:43 > To: topband@contesting.com > Subject: Topband: Vertical and horizontal polarized antennas > > > I think most people know I use a horizontal 160m Dipole as my main antenna > . > . . > > But my 6ft Receiving Loop is vertically polarised . . . so it's quite > interesting to see the difference in signals between the two. (I have a > pre-amp that makes local signals the same strength on the Loop) > > Most EU signals are stronger on the Dipole . . . and listening to those > wide > radar type signals (from Russia?) there is a huge difference in tone when > switching (due to phase differences) > > However . . . although SOME DX signals are stronger on the Loop, it's > interesting that most of the time, they're exactly the same strength. > > (but my S/N is usually 6 -10dB better on the Loop . . even more if there's > any local switch-mode electrical interference) > > Regarding 160m Conditions, not bad on Thursday night . . . but poor last > night - apart from a Sunset Peak sweeping across NA, after that signals > dropped right off. (my signals typically dropping 25dB on RBN sites). > > Roger G3YRO > > > _ > Searchable Archives: http://www.contesting.com/_topband - Topband > Reflector > > > --- > This email has been checked for viruses by Avast antivirus software. > https://www.avast.com/antivirus > > _ > Searchable Archives: http://www.contesting.com/_topband - Topband > Reflector > _ Searchable Archives: http://www.contesting.com/_topband - Topband Reflector
Re: Topband: Vertical and horizontal polarized antennas
On 11/17/2018 3:42 AM, Roger Kennedy wrote: I think most people know I use a horizontal 160m Dipole as my main antenna . But my 6ft Receiving Loop is vertically polarised . . . so it's quite Roger G3YRO Assuming you mean the loop is a 6 ft diameter circle, you would typically have 0.1% efficiency (-30 dBi gain), if it is TUNED, as opposed to being broadband. It is inconceivable that the loop would have more output than your low dipole. Does your loop include a preamp? In that case, then of course you could have more signal after the preamp than the dipole. But the comparison would be meaningless because it would depend on the gain of the preamp, which is an arbitrary number. What you can do, however, is to use the receiving loop, such as it is, as a reference antenna, and then reconfigure your dipole as a top loaded vertical. I think you will then notice that the vertical is much better vs the loop than the dipole was. I have directly compared a 160 meter inverted vee with the apex at 60 feet, with a 60 foot high vertical having top loading wires that sloped down (like the inverted vee wires). The vertical was easily 10 dB better. YMMV. 73 Rick N6RK _ Searchable Archives: http://www.contesting.com/_topband - Topband Reflector
Re: Topband: Vertical and horizontal polarized antennas in the same space (was Propagation improves from VK6 into Europe)
Hi Steve. You are 100 % right, the V works like a top hat for a vertical TX antenna. I it simple to detune any vertical TX antenna. Vertical TX antenna is the only way to work DX on topband! You may ask about the inverted V or low dipole, they are not 100% horizontal, actually they are 50% horizontal on the broadside and 50% vertical along the wire. Ground reflects horizontal signals -1, it means 180 degree out of phase, and the reflected signal cancels the arriving signal, The Arriving signal is maximum only near 1 1/2 wave high above ground 750ft!!!. The vertical reflected signal has +1 and add to the arriving signal producing gain, ground gain. Detuning a TX antenna is like a LC circuit, you need high impedance between the antenna and the ground. The UNIPOLE or cage antenna works very well to detune grounded towers up to 30 db, and it is easy to feed with 200 ohms, becoming a very large broadband antenna. Isolated towers or inverted V is the same, they need high isolation from ground. I sed the same configuration for over 20 years, the open line works very well 80 - 10m. Regards JC M4IS _ Searchable Archives: http://www.contesting.com/_topband - Topband Reflector
Re: Topband: Vertical and horizontal polarized antennas
My take on this is that having had a low inverted vee at about 80ft and a top loaded vertical over a very good ground system to compare against each other. I have found the following that despite the vertical being short 60ft with the exception of stations within 200miles the vertical is always better. However the vertical is about 87% efficient with a serious amount of long radials. YMMV 73 Clive GM3POI -Original Message- From: Topband [mailto:topband-boun...@contesting.com] On Behalf Of Roger Kennedy Sent: 17 November 2018 11:43 To: topband@contesting.com Subject: Topband: Vertical and horizontal polarized antennas I think most people know I use a horizontal 160m Dipole as my main antenna . . . But my 6ft Receiving Loop is vertically polarised . . . so it's quite interesting to see the difference in signals between the two. (I have a pre-amp that makes local signals the same strength on the Loop) Most EU signals are stronger on the Dipole . . . and listening to those wide radar type signals (from Russia?) there is a huge difference in tone when switching (due to phase differences) However . . . although SOME DX signals are stronger on the Loop, it's interesting that most of the time, they're exactly the same strength. (but my S/N is usually 6 -10dB better on the Loop . . even more if there's any local switch-mode electrical interference) Regarding 160m Conditions, not bad on Thursday night . . . but poor last night - apart from a Sunset Peak sweeping across NA, after that signals dropped right off. (my signals typically dropping 25dB on RBN sites). Roger G3YRO _ Searchable Archives: http://www.contesting.com/_topband - Topband Reflector --- This email has been checked for viruses by Avast antivirus software. https://www.avast.com/antivirus _ Searchable Archives: http://www.contesting.com/_topband - Topband Reflector
Topband: Vertical and horizontal polarized antennas
I think most people know I use a horizontal 160m Dipole as my main antenna . . . But my 6ft Receiving Loop is vertically polarised . . . so it's quite interesting to see the difference in signals between the two. (I have a pre-amp that makes local signals the same strength on the Loop) Most EU signals are stronger on the Dipole . . . and listening to those wide radar type signals (from Russia?) there is a huge difference in tone when switching (due to phase differences) However . . . although SOME DX signals are stronger on the Loop, it's interesting that most of the time, they're exactly the same strength. (but my S/N is usually 6 -10dB better on the Loop . . even more if there's any local switch-mode electrical interference) Regarding 160m Conditions, not bad on Thursday night . . . but poor last night - apart from a Sunset Peak sweeping across NA, after that signals dropped right off. (my signals typically dropping 25dB on RBN sites). Roger G3YRO _ Searchable Archives: http://www.contesting.com/_topband - Topband Reflector
