Re: Topband: RDF for Transmit 4 Square vs 8 Circle Array
I've had a full size four square on 160 for about 15 years. I still always put up Beverages. They heard well but usually did not out perform the TX array. That said, they hear "differently" as one might expect. Several years ago I put up a Hi-Z 8 circle array optimized for 160. That was the end of the Beverages as they did not perform as well (they were only about 600' although I did have an end-fire Bev array but the 8 circle still out performed it). That said, having had the 8 circle array for six of seven years, it only "out hears" the four square maybe 20% of the time. That said, it is helpful to have it in diversity with the TX array. Having really high RDF RX antennas is not that significant of a benefit here as I have low noise levels (although they continue to creep up with distant new housing, various digital junk, etc.). YMMV. . .73. . .Dave, W0FLS -Original Message- From: Chuck Dietz Sent: Monday, October 16, 2017 1:26 PM To: topband@contesting.com Subject: Topband: RDF for Transmit 4 Square vs 8 Circle Array I was always told that, if one had a 4 square, there would be no need for a receive array. I am finding this to be untrue when looking at the list of RDFs. (Receive Directivity Factor) I have snooped through the archives reading about RDF. Can anyone verify this from actual experience? Can you actually hear stuff on an 8 Circle that can't be heard on the transmit 4 square? I would think the difference might be more than marginal with the difference in RDFs of 2.48 db. I'm not sure of the difference in takeoff angles. That could be important too. As a practical matter, the 8 Circle is huge and expensive for a single band antenna... Chuck W5PR _ Topband Reflector Archives - http://www.contesting.com/_topband --- This email has been checked for viruses by AVG. http://www.avg.com _ Topband Reflector Archives - http://www.contesting.com/_topband
Re: Topband: RDF for Transmit 4 Square vs 8 Circle Array
To add to Dennis' comments: you can never have too many antennas (very important exception: unless they interfere with each other). Very large arrays such as 8 circle arrays form their deep nulls in the far field which may be many hundreds of yards away from the array. Very large arrays are not as effective for suppressing very close RFI sources., they're fantastic for more distant RFI sources and especially for ionospherically propagated interference of all kinds. Small receiving antennas such as the K9AY or SAL may be more effective for suppressing nearby RFI. 73 Frank W3LPL - Original Message - From: "Dennis" To: topband@contesting.com Sent: Monday, October 16, 2017 6:43:20 PM Subject: Re: Topband: RDF for Transmit 4 Square vs 8 Circle Array Chuck Having used both at a number of stations, I can speak with some experience here. The biggest virtue I have found of an 8 Circle array is the ability to put a bothersome station or noise in a null. Most of the time, you can hear a station in the 4-square beamed direction as well on the 4-square as on the 8 Circle. You might even be able to put a bothersome station or noise in a null with the 4-square, but now he doesn't hear you either. The 8 Circle allows you to steer the null and maybe find a spot where the SNR is better, and I've found both as valuable as the direction of maximum gain. So, yes, you can hear things on an 8 Circle that you might not hear on a 4-square, but to me its more a question of nulls (of both other signals and noise) rather than a stronger signal. Dennis W1UE On 10/16/2017 2:26 PM, Chuck Dietz wrote: > I was always told that, if one had a 4 square, there would be no need for a > receive array. I am finding this to be untrue when looking at the list of > RDFs. (Receive Directivity Factor) I have snooped through the archives > reading about RDF. > Can anyone verify this from actual experience? Can you actually hear stuff > on an 8 Circle that can't be heard on the transmit 4 square? I would think > the difference might be more than marginal with the difference in RDFs of > 2.48 db. I'm not sure of the difference in takeoff angles. That could be > important too. > As a practical matter, the 8 Circle is huge and expensive for a single > band antenna... > > Chuck W5PR > _ > Topband Reflector Archives - http://www.contesting.com/_topband _ Topband Reflector Archives - http://www.contesting.com/_topband _ Topband Reflector Archives - http://www.contesting.com/_topband
Re: Topband: RDF for Transmit 4 Square vs 8 Circle Array
I might suggest some flags or pennants as receiving antenna alternatives with a broader beamwidth. Easy to throw up. I used one for all receiving in V3M lowbands and high bands and was impressed. W0MU On 10/16/2017 2:28 PM, donov...@starpower.net wrote: Hi Chuck, I have both a full size transmitting 4-square and a W8JI BSEF 8-circle array using 25 foot low impedance passive umbrella verticals. There are no active electronics in the W8JI's BSEF 8-circle array, unlike the Hi-Z array. While the transmitting array is an excellent receiving antenna, I can verify that the 8-circle is superior in some situations apparently because of its much narrower beamwidth. I'm sure the Hi-Z array would provide similarly excellent performance. I have completed QSOs with very weak DX stations that could not have been completed with the 4-square or my Beverages. For a contester its very important to have an alternative antenna to the 8-circle array. Its 3 dB beamwidth is so narrow (about 45 degrees) that you won't hear some off-azimuth callers. Normally I use the Beverages for receiving and switch to the 8-circle array only when needed. 73 Frank W3LPL - Original Message - From: "Chuck Dietz" To: topband@contesting.com Sent: Monday, October 16, 2017 6:26:41 PM Subject: Topband: RDF for Transmit 4 Square vs 8 Circle Array I was always told that, if one had a 4 square, there would be no need for a receive array. I am finding this to be untrue when looking at the list of RDFs. (Receive Directivity Factor) I have snooped through the archives reading about RDF. Can anyone verify this from actual experience? Can you actually hear stuff on an 8 Circle that can't be heard on the transmit 4 square? I would think the difference might be more than marginal with the difference in RDFs of 2.48 db. I'm not sure of the difference in takeoff angles. That could be important too. As a practical matter, the 8 Circle is huge and expensive for a single band antenna... Chuck W5PR _ Topband Reflector Archives - http://www.contesting.com/_topband _ Topband Reflector Archives - http://www.contesting.com/_topband _ Topband Reflector Archives - http://www.contesting.com/_topband
Re: Topband: RDF for Transmit 4 Square vs 8 Circle Array
If you browse back through the Topband archives, you'll see a common thread: "You can never have too many RX antennas!". Incoming angles vary. Sometimes a Beverage is best, other times it's a certain phased vertical array, and once in a great while it's the TX antenna or even a dipole. 73, Mike www.w0btu.com _ Topband Reflector Archives - http://www.contesting.com/_topband
Re: Topband: RDF for Transmit 4 Square vs 8 Circle Array
Hi Chuck, I have both a full size transmitting 4-square and a W8JI BSEF 8-circle array using 25 foot low impedance passive umbrella verticals. There are no active electronics in the W8JI's BSEF 8-circle array, unlike the Hi-Z array. While the transmitting array is an excellent receiving antenna, I can verify that the 8-circle is superior in some situations apparently because of its much narrower beamwidth. I'm sure the Hi-Z array would provide similarly excellent performance. I have completed QSOs with very weak DX stations that could not have been completed with the 4-square or my Beverages. For a contester its very important to have an alternative antenna to the 8-circle array. Its 3 dB beamwidth is so narrow (about 45 degrees) that you won't hear some off-azimuth callers. Normally I use the Beverages for receiving and switch to the 8-circle array only when needed. 73 Frank W3LPL - Original Message - From: "Chuck Dietz" To: topband@contesting.com Sent: Monday, October 16, 2017 6:26:41 PM Subject: Topband: RDF for Transmit 4 Square vs 8 Circle Array I was always told that, if one had a 4 square, there would be no need for a receive array. I am finding this to be untrue when looking at the list of RDFs. (Receive Directivity Factor) I have snooped through the archives reading about RDF. Can anyone verify this from actual experience? Can you actually hear stuff on an 8 Circle that can't be heard on the transmit 4 square? I would think the difference might be more than marginal with the difference in RDFs of 2.48 db. I'm not sure of the difference in takeoff angles. That could be important too. As a practical matter, the 8 Circle is huge and expensive for a single band antenna... Chuck W5PR _ Topband Reflector Archives - http://www.contesting.com/_topband _ Topband Reflector Archives - http://www.contesting.com/_topband
Re: Topband: RDF for Transmit 4 Square vs 8 Circle Array
Chuck, I don't have the experience with both that Dennis has but I have had the same beneficial results with the HI-Z 4-8Pro Rx antenna which I'm using 8 active short antennas. Sometimes I can null another station almost totally out of the picture. There's not that much gain compared to the sloper but the S/N is far better on the HI-Z. I consider it essential. I understand you're talking about Tx as well but I wanted to share my similar Rx results as Dennis has had. 73, Gary KA1J > Chuck > > Having used both at a number of stations, I can speak with some > experience here. > > The biggest virtue I have found of an 8 Circle array is the ability to > put a bothersome station or noise in a null. Most of the time, you > can hear a station in the 4-square beamed direction as well on the > 4-square as on the 8 Circle. You might even be able to put a > bothersome station or noise in a null with the 4-square, but now he > doesn't hear you either. The 8 Circle allows you to steer the null and > maybe find a spot where the SNR is better, and I've found both as > valuable as the direction of maximum gain. > > So, yes, you can hear things on an 8 Circle that you might not hear on > a 4-square, but to me its more a question of nulls (of both other > signals and noise) rather than a stronger signal. > > Dennis W1UE > > On 10/16/2017 2:26 PM, Chuck Dietz wrote: > > I was always told that, if one had a 4 square, there would be no > > need for a receive array. I am finding this to be untrue when > > looking at the list of RDFs. (Receive Directivity Factor) I have > > snooped through the archives reading about RDF. Can anyone verify > > this from actual experience? Can you actually hear stuff on an 8 > > Circle that can't be heard on the transmit 4 square? I would think > > the difference might be more than marginal with the difference in > > RDFs of 2.48 db. I'm not sure of the difference in takeoff angles. > > That could be important too. As a practical matter, the 8 Circle is > > huge and expensive for a single band antenna... > > > > Chuck W5PR _ Topband Reflector Archives - http://www.contesting.com/_topband
Re: Topband: RDF for Transmit 4 Square vs 8 Circle Array
Chuck Having used both at a number of stations, I can speak with some experience here. The biggest virtue I have found of an 8 Circle array is the ability to put a bothersome station or noise in a null. Most of the time, you can hear a station in the 4-square beamed direction as well on the 4-square as on the 8 Circle. You might even be able to put a bothersome station or noise in a null with the 4-square, but now he doesn't hear you either. The 8 Circle allows you to steer the null and maybe find a spot where the SNR is better, and I've found both as valuable as the direction of maximum gain. So, yes, you can hear things on an 8 Circle that you might not hear on a 4-square, but to me its more a question of nulls (of both other signals and noise) rather than a stronger signal. Dennis W1UE On 10/16/2017 2:26 PM, Chuck Dietz wrote: I was always told that, if one had a 4 square, there would be no need for a receive array. I am finding this to be untrue when looking at the list of RDFs. (Receive Directivity Factor) I have snooped through the archives reading about RDF. Can anyone verify this from actual experience? Can you actually hear stuff on an 8 Circle that can't be heard on the transmit 4 square? I would think the difference might be more than marginal with the difference in RDFs of 2.48 db. I'm not sure of the difference in takeoff angles. That could be important too. As a practical matter, the 8 Circle is huge and expensive for a single band antenna... Chuck W5PR _ Topband Reflector Archives - http://www.contesting.com/_topband _ Topband Reflector Archives - http://www.contesting.com/_topband
