Re: Topband: NCC-2 antenna pattern?
On 12/27/2023 7:35 AM, Jon Zaimes, AA1K via Topband wrote: Spacing is 1/4 wave. I haven't looked at spacing for verticals, but optimum spacing for VE3DO loops worked out to be 5/8 wavelengths, which I am lucky to have. 73, Jim K9YC _ Searchable Archives: http://www.contesting.com/_topband - Topband Reflector
Re: Topband: NCC-2 antenna pattern?
Hi Jon, thanks for your input. So I guess the antenna pattern is simply the spacing of the antennas and the phase you dial in, but you would need the antennas aligned so the null was in the correct direction? 73 and HNY Kenny K2KW On Wed, Dec 27, 2023 at 10:35 AM Jon Zaimes, AA1K wrote: > I use NCC-1 and NCC-2 boxes for phasing numerous receive antennas, mostly > on 160. My property is heavily wooded, with antennas among loblolly pines, > oak, maple, gum, etc. > > For in-band listening while transmitting on 160, I have a pair of 34-foot > verticals (self-supporting aluminum elements) placed about 1000 feet from > my nearest transmit array, roughly on a line toward Europe (the RX antennas > are closer to Europe). Spacing is 1/4 wave. To get maximum end-fire null, > they are lined up on a heading of 29 degrees. The beamwidth is broad enough > to hear many Eu signals while transmitting. Equal RG6 feedlines run to an > NCC-1 in the shack, and I am able to listen within a few kHz of my transmit > signals > > The quality of the transmitter signal and the receiver are major factors > allowing in-band listening. There was a quantum leap years ago when I > upgraded my K3's to the newer synthesizer boards (or a K3S). > > When I change directions of the transmit array, I usually have to tweak > the null on the NCC-1. > > I also have used a broadside/endfire set of 560-ft Beverages that have the > TX array off the rear for in-band listening and their null is deep enough > for this to work. I use an NCC-1 to phase the two pairs of Beverages. The > closest feedpoint is about 550 feet from the nearest TX array. > > I have two sets of broadside-endfire short verticals (four 34-foot wire > elements hung from trees). These have the two forward and rearward element > feedlines coming together at tees (no matching) and then separate feeds run > to an NCC-2 in the shack. Performance of these can equal or exceed that of > the numerous phased Beverages we have. > > A few of my stagger-phased Beverages have separate feedlines going to an > NCC-1. This allows adjusting the rearward null for optimum. > > While the exact phase setting isn't known, the settings achieved > experimentally are repeatable. I use several BC stations in the 1600-1700 > range for reference.; An S-9 plus signal often will drop out entirely when > I reverse the phase on the NCC-1 (or -2). > > The charts of phased arrays in the ARRL Antenna Book and ON4UN's Low Band > antennas book are useful in positioning of the various arrays for placing > the null in a desired direction. > > 73/Jon > > Jon P. Zaimes, AA1K > Tower climber for hire > Felton, Delaware > http://www.aa1k.us/ > > > Reviews of AA1K tower work on eham website: > http://www.eham.net/reviews/detail/12922 > > Hug your favorite tower every day, and always stay connected to it. > > On Saturday, December 16, 2023 at 10:05:41 PM EST, Kenny Silverman < > kenny.k...@gmail.com> wrote: > > > Rick, my application is for an in-band RX antenna, but on a higher band. I > just thought the guys here might know more about the NCC-2, MFJ or QRM > eliminator than most others. > > One thought was to create a 2 ele phased vertical array for the RX antenna > with a known pattern and put the null towards the TX array, along with > physical separation to allow in-band receiving. > > But I was thinking an adjustable phasing system may produce a better null. > But I wouldn’t want the adjustable unit to create a clover leaf pattern > for > example. One null might take out the interference but another null towards > the desired receiving direction might be created and is not desired. > > I hope I’m explaining this well. > > Regards , Kenny K2KW > > > On Dec 16, 2023, at 9:47 PM, Rick Kunath wrote: > > > > What's your application Kenny and what would you be feeding the antenna > > output of the phaser into? > > > > Rick Kunath, K9AO > > > > _ > Searchable Archives: http://www.contesting.com/_topband - Topband > Reflector > _ Searchable Archives: http://www.contesting.com/_topband - Topband Reflector
Re: Topband: NCC-2 antenna pattern?
Wow Jon - what an excellent setup you have there. However, I think it is unfair that your RX antennas are 1000 feet closer to Europe. Given the fact that you are so close to Europe (compared to us on the West Coast), that is a significant difference and seems unsportsmanlike. :-) All kidding aside - your setup certainly demonstrates your commitment to the band and congratulations on your lifetime achievements. Hope to work you (again) in the Stew Perry this weekend. 73 Tree N6TR On Wed, Dec 27, 2023 at 7:35 AM Jon Zaimes, AA1K via Topband < topband@contesting.com> wrote: > I use NCC-1 and NCC-2 boxes for phasing numerous receive antennas, mostly > on 160. My property is heavily wooded, with antennas among loblolly pines, > oak, maple, gum, etc. > > For in-band listening while transmitting on 160, I have a pair of 34-foot > verticals (self-supporting aluminum elements) placed about 1000 feet from > my nearest transmit array, roughly on a line toward Europe (the RX antennas > are closer to Europe). Spacing is 1/4 wave. To get maximum end-fire null, > they are lined up on a heading of 29 degrees. The beamwidth is broad enough > to hear many Eu signals while transmitting. Equal RG6 feedlines run to an > NCC-1 in the shack, and I am able to listen within a few kHz of my transmit > signals > > The quality of the transmitter signal and the receiver are major factors > allowing in-band listening. There was a quantum leap years ago when I > upgraded my K3's to the newer synthesizer boards (or a K3S). > > When I change directions of the transmit array, I usually have to tweak > the null on the NCC-1. > > I also have used a broadside/endfire set of 560-ft Beverages that have the > TX array off the rear for in-band listening and their null is deep enough > for this to work. I use an NCC-1 to phase the two pairs of Beverages. The > closest feedpoint is about 550 feet from the nearest TX array. > > I have two sets of broadside-endfire short verticals (four 34-foot wire > elements hung from trees). These have the two forward and rearward element > feedlines coming together at tees (no matching) and then separate feeds run > to an NCC-2 in the shack. Performance of these can equal or exceed that of > the numerous phased Beverages we have. > > A few of my stagger-phased Beverages have separate feedlines going to an > NCC-1. This allows adjusting the rearward null for optimum. > > While the exact phase setting isn't known, the settings achieved > experimentally are repeatable. I use several BC stations in the 1600-1700 > range for reference.; An S-9 plus signal often will drop out entirely when > I reverse the phase on the NCC-1 (or -2). > > The charts of phased arrays in the ARRL Antenna Book and ON4UN's Low Band > antennas book are useful in positioning of the various arrays for placing > the null in a desired direction. > > 73/Jon > > Jon P. Zaimes, AA1K > Tower climber for hire > Felton, Delaware > http://www.aa1k.us/ > > > Reviews of AA1K tower work on eham website: > http://www.eham.net/reviews/detail/12922 > > Hug your favorite tower every day, and always stay connected to it. > > On Saturday, December 16, 2023 at 10:05:41 PM EST, Kenny Silverman < > kenny.k...@gmail.com> wrote: > > Rick, my application is for an in-band RX antenna, but on a higher band. > I > just thought the guys here might know more about the NCC-2, MFJ or QRM > eliminator than most others. > > One thought was to create a 2 ele phased vertical array for the RX antenna > with a known pattern and put the null towards the TX array, along with > physical separation to allow in-band receiving. > > But I was thinking an adjustable phasing system may produce a better null. > But I wouldn’t want the adjustable unit to create a clover leaf pattern > for > example. One null might take out the interference but another null towards > the desired receiving direction might be created and is not desired. > > I hope I’m explaining this well. > > Regards , Kenny K2KW > > > On Dec 16, 2023, at 9:47 PM, Rick Kunath wrote: > > > > What's your application Kenny and what would you be feeding the antenna > > output of the phaser into? > > > > Rick Kunath, K9AO > > > > _ > Searchable Archives: http://www.contesting.com/_topband - Topband > Reflector > > _ > Searchable Archives: http://www.contesting.com/_topband - Topband > Reflector > _ Searchable Archives: http://www.contesting.com/_topband - Topband Reflector
Re: Topband: NCC-2 antenna pattern?
I use NCC-1 and NCC-2 boxes for phasing numerous receive antennas, mostly on 160. My property is heavily wooded, with antennas among loblolly pines, oak, maple, gum, etc. For in-band listening while transmitting on 160, I have a pair of 34-foot verticals (self-supporting aluminum elements) placed about 1000 feet from my nearest transmit array, roughly on a line toward Europe (the RX antennas are closer to Europe). Spacing is 1/4 wave. To get maximum end-fire null, they are lined up on a heading of 29 degrees. The beamwidth is broad enough to hear many Eu signals while transmitting. Equal RG6 feedlines run to an NCC-1 in the shack, and I am able to listen within a few kHz of my transmit signals The quality of the transmitter signal and the receiver are major factors allowing in-band listening. There was a quantum leap years ago when I upgraded my K3's to the newer synthesizer boards (or a K3S). When I change directions of the transmit array, I usually have to tweak the null on the NCC-1. I also have used a broadside/endfire set of 560-ft Beverages that have the TX array off the rear for in-band listening and their null is deep enough for this to work. I use an NCC-1 to phase the two pairs of Beverages. The closest feedpoint is about 550 feet from the nearest TX array. I have two sets of broadside-endfire short verticals (four 34-foot wire elements hung from trees). These have the two forward and rearward element feedlines coming together at tees (no matching) and then separate feeds run to an NCC-2 in the shack. Performance of these can equal or exceed that of the numerous phased Beverages we have. A few of my stagger-phased Beverages have separate feedlines going to an NCC-1. This allows adjusting the rearward null for optimum. While the exact phase setting isn't known, the settings achieved experimentally are repeatable. I use several BC stations in the 1600-1700 range for reference.; An S-9 plus signal often will drop out entirely when I reverse the phase on the NCC-1 (or -2). The charts of phased arrays in the ARRL Antenna Book and ON4UN's Low Band antennas book are useful in positioning of the various arrays for placing the null in a desired direction. 73/Jon Jon P. Zaimes, AA1K Tower climber for hire Felton, Delaware http://www.aa1k.us/ Reviews of AA1K tower work on eham website: http://www.eham.net/reviews/detail/12922 Hug your favorite tower every day, and always stay connected to it. On Saturday, December 16, 2023 at 10:05:41 PM EST, Kenny Silverman wrote: Rick, my application is for an in-band RX antenna, but on a higher band. I just thought the guys here might know more about the NCC-2, MFJ or QRM eliminator than most others. One thought was to create a 2 ele phased vertical array for the RX antenna with a known pattern and put the null towards the TX array, along with physical separation to allow in-band receiving. But I was thinking an adjustable phasing system may produce a better null. But I wouldn’t want the adjustable unit to create a clover leaf pattern for example. One null might take out the interference but another null towards the desired receiving direction might be created and is not desired. I hope I’m explaining this well. Regards , Kenny K2KW > On Dec 16, 2023, at 9:47 PM, Rick Kunath wrote: > > What's your application Kenny and what would you be feeding the antenna > output of the phaser into? > > Rick Kunath, K9AO > _ Searchable Archives: http://www.contesting.com/_topband - Topband Reflector _ Searchable Archives: http://www.contesting.com/_topband - Topband Reflector
Re: Topband: NCC-2 antenna pattern?
I did exactly the same thing as what Tree describes. It worked pretty well using just a Kenwood TS-570 as the 2nd receiver. Getting a really deep null on the loop requires attention to various details: 1. RF leakage into the feedline 2. Nearby metallic objects messing up the pattern of the loop 3. The loop must be fairly small for a good null 4. The so-called "N6RK loop" with varactor tuning cannot be used as is. Instead, fixed capacitors must be used to tune it. It was somewhat debatable as to how much the SO2R operation improved my contest score. Rick N6RK On 12/17/2023 11:12 AM, Tree wrote: I have been successful with in-band receiving on 160 with a loop antenna about 800 feet away from the TX vertical with the null parked on the TX antenna. On 20 meters, I have done it with about 500 feet separation. It's obviously a lot easier with low power (like used in the NAQP). The Tree N6TR _ Searchable Archives: http://www.contesting.com/_topband - Topband Reflector
Re: Topband: NCC-2 antenna pattern?
Let's agree to disagree. It is not. I can send you a long list of station around me, down here is Broward County , Fort Lauderdale FL, just mentioning a few friends Peter N8PR. Ron W4BP. Scott W4SO. We were around 120 to 150 worked countries on 160m back on 2004. The RX antennas was mainlining EWE.s EWE';s in phase, When I upgrade my tower form 80FT to 120FT, all my RX antennas stopping working. I took a hit and figure it out, I needed to detune the tower. At the same time I built a Vertical Waller Flag. In the first year I reach 200 and in few more years 250. All my local friends, here in the same location did not hear the weak signals like my station and they did not move up on the 160m DXCC, not even close to 170 countries on 160m. The average here is 150 countries worked on 150m for a good station. I am not the only one 160m DXer in Florida, most of them are still below 200 countries in 160 after 30 or 40 years in the band. All of us are in the same location. You can go to ARRL list and find 100's of station in Florida but only 3 above 300's on 160m. N4WW Austin is in the band for 50 years. Doug NX4D and I less than 15 years, All is Florida On 160m the MUF is always good, the signal always arrive, the issue is signal to noise ratio. A good RX antenna have a directivity of 10 to 12 db RDF, a TX vertical 5 to 6 db RDF, the difference is 5 to 6 db. I measured signal to noise for decades, for each 1 db improvement in RDF, you gain 2 db on signal to noise ratio, so a good vertical RX antenna can hear 10 db better than a TX antenna, the HWF because the polarization filter can hear 20 db better them my TX antenna. Signal to noise ratio in your station! That is the secret, You can work the weak signal your neighbor can not if your care about keep the patter clean on your RX antenna, not the RDF in the paper, the one in your back yard. YES, l you can reduce the noise on your own RX antenna, RDF is the key, but if you allow the TX antenna interact with your RX antenna, you are deteriorating the patter and never experience the RDF improvement , because the actual RDF is reduced. You end up hearing the reflected signal from your TX antenna into your RX antenna and no gain in signal to noise can be achieved. This is not because your location, it is because the way you assembly your station. If you want to try it, check my presentation on World Wide Radio Operators Foundation https://wwrof.org/webinar-archive/n4is-waller-flag-construction/ https://wwrof.org/webinar-archive/high-performance-rx-antennas-for-a-small-l ot/ High Performance RX Antennas for a Small Lot. It not just a concept it is a proved concept with practical results! Don't tell my neighbors that they are in a fantastic 160m location, Florida used to be a black hole for low bands, and still is a black hole for most of us, if you don't detune your TX antenna, and all others cables 30 FT or longer. 73's JC N4IS -Original Message- From: Topband On Behalf Of Jim Clymer Sent: Tuesday, December 19, 2023 7:58 AM To: n...@comcast.net Cc: Jim Brown ; topband Subject: Re: Topband: NCC-2 antenna pattern? Come on, JC... Even I know, YOU know what K9YC is talking about! After living in IN for 15 years, CA for 34 years, and VA for 10 years, with essentially the same station setup, over the long term, for success on TB, QTH is paramount. (detuned TX antennas notwithstanding) BTW: I like your initials! 73, Jim - WS6X On Mon, Dec 18, 2023, 9:26 PM wrote: > So you cannot detune a TX antenna in IL, just in Florida? > > JC > Archives: http://www.contesting.com/_topband - Topband Reflector > > > _ > Searchable Archives: http://www.contesting.com/_topband - Topband > Reflector > _ Searchable Archives: http://www.contesting.com/_topband - Topband Reflector _ Searchable Archives: http://www.contesting.com/_topband - Topband Reflector
Re: Topband: NCC-2 antenna pattern?
Come on, JC... Even I know, YOU know what K9YC is talking about! After living in IN for 15 years, CA for 34 years, and VA for 10 years, with essentially the same station setup, over the long term, for success on TB, QTH is paramount. (detuned TX antennas notwithstanding) BTW: I like your initials! 73, Jim - WS6X On Mon, Dec 18, 2023, 9:26 PM wrote: > So you cannot detune a TX antenna in IL, just in Florida? > > JC > Archives: http://www.contesting.com/_topband - Topband Reflector > > > _ > Searchable Archives: http://www.contesting.com/_topband - Topband > Reflector > _ Searchable Archives: http://www.contesting.com/_topband - Topband Reflector
Re: Topband: NCC-2 antenna pattern?
So you cannot detune a TX antenna in IL, just in Florida? JC Archives: http://www.contesting.com/_topband - Topband Reflector _ Searchable Archives: http://www.contesting.com/_topband - Topband Reflector
Re: Topband: NCC-2 antenna pattern?
On 12/18/2023 5:35 AM, n...@comcast.net wrote: Hi Rob, my city lot backyard is 50x100 and I worked (CW only) 305 confirmed on 160m from 2006 to 2019 You're in Florida. Rob is in IL. Very different. Most of your path to country-rich EU and SA is over water, and not via the AU oval. Even more different here in W6. 73, Jim K9YC _ Searchable Archives: http://www.contesting.com/_topband - Topband Reflector
Re: Topband: NCC-2 antenna pattern?
"Since I am on a 50 x 100 foot lot, it is impossible for me to separate my rx antennas from my tx antenna. " Hi Rob, my city lot backyard is 50x100 and I worked (CW only) 305 confirmed on 160m from 2006 to 2019, it is not easy but doable to detune your TX antenna. I use a wire skirt around my tower, making it a UNIPOLE, the skirt and the grounded tower works like a 1/4 wave stub, with a high impedance at the base. That way the TX antenna does not interact with the RX antenna. Distance is another like what you want, but 1 wave distance is not far enough ,and It is 525FT for 160m, Detune is not the impedance on the fed line, it is the impedance from the antenna to the ground. If you TX antenna is isolated from the ground a relay can isolate the antenna from the ground. Any cable longer than 30FT should be take care as well., including rotor cables. Doug NX4D lives in 1/5 acre and he worked #315 from 2003 to 2019,. So don't give up. topband is a fantastic band when you can hear the weak signals. 73's JC N4IS -Original Message- From: Topband On Behalf Of Rob Atkinson Sent: Monday, December 18, 2023 6:14 AM To: topband@contesting.com Subject: Re: Topband: NCC-2 antenna pattern? Since I am on a 50 x 100 foot lot, it is impossible for me to separate my rx antennas from my tx antenna. Of course on transmit, preamps and the NCC1 are deactivated, but even so, the NCC1 had internal relay chatter (there are around nine PC board mounted relays inside). Small RF chokes in series with the DC power line to the box eliminated the chatter. I may have added bypass caps inside it but I can't remember if I did that or not. But if so, that wasn't enough. The chokes did the trick. Merry Christmas Rob K5UJ _ Searchable Archives: http://www.contesting.com/_topband - Topband Reflector _ Searchable Archives: http://www.contesting.com/_topband - Topband Reflector
Re: Topband: NCC-2 antenna pattern?
Since I am on a 50 x 100 foot lot, it is impossible for me to separate my rx antennas from my tx antenna. Of course on transmit, preamps and the NCC1 are deactivated, but even so, the NCC1 had internal relay chatter (there are around nine PC board mounted relays inside). Small RF chokes in series with the DC power line to the box eliminated the chatter. I may have added bypass caps inside it but I can't remember if I did that or not. But if so, that wasn't enough. The chokes did the trick. Merry Christmas Rob K5UJ _ Searchable Archives: http://www.contesting.com/_topband - Topband Reflector
Re: Topband: NCC-2 antenna pattern?
OK Kenny. I understand now. Not all of the TX will be under control of the transceiver at the operating position that is using the in-band antenna, so you need RF protection while also receiving in-band. I think your phased vertical idea could work. But, a pair of flag antennas would also work well. And they're ground independent too. You would want endfire arrays here. As was mentioned, about 100-foot separation is a good starting point, and that's inline of course. In the case of either the 2 vertical array or the 2 flag array you could use coax sections cut to the appropriate length considering the velocity factor of the coax to get the pattern that you want. One other thing about the flag option is that the antennas can be either unterminated, and the pair will give you a really deep null at low elevations, or you can add VACTROL termination and adjust it on the fly. In your case with the TX going on I think I'd install the VACTROLs, tweak the terminating resistance to the best values, and then measure it and replace the VACTROLs with a several watt non-inductive combination of fixed resistors that give you that same value. No TX worries then. Terminated, the flags will give you a deeper back null than the verticals will. The flags don't need to be huge. You didn't specify the bands of interest but a 10-foot by 25-foot flag with the bottom wire 3-feet off of the ground works well from mediumwave to over 40 meters, maybe higher. I have a pair of these in an inline configuration and unterminted I can sweep a null from horizon to horizon. Terminated I can deepen the null and swing the max null angle some against the horizon. I have my flags setup so they're moveable. I used 4 5-gallon plastic buckets and put a 3 foot PVC pipe with a cap centered, bolted the cap to the center of the bucket bottom, and then filled the buckets with concrete. I can move them and they stay put even in high winds. I have a 10-foot piece of PVC in a PVC coupling on top of the bucket cemented pipe section and on each end that supports the antenna loop. The flags are fed in the lower corner via twisted-pair transmission line and that is back to the shack where any transformation or preamping is done. And then on to the SDR. The termination is at the opposite corner. I modeled and tested corner feed vs center side feed and termination and I did not notice any difference in performance. You could do something similar with a KAZ or Superloop and that would be longer but need only one support at the center. Just a few more thoughts for you to consider... Rick Kunath, K9AO _ Searchable Archives: http://www.contesting.com/_topband - Topband Reflector
Re: Topband: NCC-2 antenna pattern?
HI Tree, Thanks for your input. I'm leaning towards a 2 element phased vertical array with a quasi-cardioid pattern for my application. it will avoid any phasing box overload issues. 73, Kenny K2KW On Sun, Dec 17, 2023 at 2:12 PM Tree wrote: > I think the concern about overload is another reason to not consider it. > That box is not designed to handle a strong signal like another transmitter. > > One other solution is to try and come up with a coax length that presents > an out of phase signal at the right amplitude to cancel it out on the 2nd > receiver. I know W8JI has done this on 160. > > I have been successful with in-band receiving on 160 with a loop antenna > about 800 feet away from the TX vertical with the null parked on the TX > antenna. On 20 meters, I have done it with about 500 feet separation. > It's obviously a lot easier with low power (like used in the NAQP). The > K5KA muiti-ops used an all band vertical for RX for the in band radios. > > Tree N6TR > > Tree N6TR > > On Sun, Dec 17, 2023 at 10:41 AM Kenny Silverman > wrote: > >> Thanks for all the comments, but knowing what the resulting antenna >> pattern seems elusive. >> >> I need in-band RX antenna for a mult station. Typically antenna >> separation, front-to-back and polarization are the main tools for that. >> When I run out of room >> >> I was wondering if phasing from an NCC-2 box is another tool to consider. >> But I don’t want to consider it without knowing what the resulting pattern >> would be. >> >> Many thanks, Kenny K2KW >> >> >> Regards , Kenny >> >> > On Dec 17, 2023, at 1:05 PM, Rick Kunath wrote: >> > >> > I'm not sure we still understand the intended application of the >> original poster, I know I don't. >> > >> > I've done lots of work with loops and loop arrays phased either >> passively (active or entirely passive external phaser boxes) or actively >> phased via an SDR but none of that would eliminate the need for RX >> protection on the receive antenna and any electronics associated with it. >> So if the OP is trying to get away from any protection from the TX energy, >> I think this is false hope. A loop mounted preamp makes that more >> complicated. And The NCC2 does have options for protection boards for TX >> internally. There are several types available and also internal preamps. >> But it cannot set a specific amplitude and phase angle on the phasing. I >> don't have one and haven't ever had the pleasure of using one, but those >> that do tell me they enjoy them and they work well especially for live >> listening. I do like the idea of having the electronics at the shack end of >> things and as little as possible at the antenna when possible, though >> depending on the specifics you will have VACTROL devices or other >> termination devices at at the antenna with at least some antenna types. >> > >> > Preset patterns and unattended work are another case entirely and this >> is best done with specific phase coherent dual-channel SDRs and a specific >> SDR application. >> > >> > I think doing what the OP might want as I might understand it is >> possible, but I'd like to hear more from him about his hopes for the >> project. >> > >> > Rick Kunath, K9AO >> > >> >> _ >> Searchable Archives: http://www.contesting.com/_topband - Topband >> Reflector >> > _ Searchable Archives: http://www.contesting.com/_topband - Topband Reflector
Re: Topband: NCC-2 antenna pattern?
I think the concern about overload is another reason to not consider it. That box is not designed to handle a strong signal like another transmitter. One other solution is to try and come up with a coax length that presents an out of phase signal at the right amplitude to cancel it out on the 2nd receiver. I know W8JI has done this on 160. I have been successful with in-band receiving on 160 with a loop antenna about 800 feet away from the TX vertical with the null parked on the TX antenna. On 20 meters, I have done it with about 500 feet separation. It's obviously a lot easier with low power (like used in the NAQP). The K5KA muiti-ops used an all band vertical for RX for the in band radios. Tree N6TR Tree N6TR On Sun, Dec 17, 2023 at 10:41 AM Kenny Silverman wrote: > Thanks for all the comments, but knowing what the resulting antenna > pattern seems elusive. > > I need in-band RX antenna for a mult station. Typically antenna > separation, front-to-back and polarization are the main tools for that. > When I run out of room > > I was wondering if phasing from an NCC-2 box is another tool to consider. > But I don’t want to consider it without knowing what the resulting pattern > would be. > > Many thanks, Kenny K2KW > > > Regards , Kenny > > > On Dec 17, 2023, at 1:05 PM, Rick Kunath wrote: > > > > I'm not sure we still understand the intended application of the > original poster, I know I don't. > > > > I've done lots of work with loops and loop arrays phased either > passively (active or entirely passive external phaser boxes) or actively > phased via an SDR but none of that would eliminate the need for RX > protection on the receive antenna and any electronics associated with it. > So if the OP is trying to get away from any protection from the TX energy, > I think this is false hope. A loop mounted preamp makes that more > complicated. And The NCC2 does have options for protection boards for TX > internally. There are several types available and also internal preamps. > But it cannot set a specific amplitude and phase angle on the phasing. I > don't have one and haven't ever had the pleasure of using one, but those > that do tell me they enjoy them and they work well especially for live > listening. I do like the idea of having the electronics at the shack end of > things and as little as possible at the antenna when possible, though > depending on the specifics you will have VACTROL devices or other > termination devices at at the antenna with at least some antenna types. > > > > Preset patterns and unattended work are another case entirely and this > is best done with specific phase coherent dual-channel SDRs and a specific > SDR application. > > > > I think doing what the OP might want as I might understand it is > possible, but I'd like to hear more from him about his hopes for the > project. > > > > Rick Kunath, K9AO > > > > _ > Searchable Archives: http://www.contesting.com/_topband - Topband > Reflector > _ Searchable Archives: http://www.contesting.com/_topband - Topband Reflector
Re: Topband: NCC-2 antenna pattern?
Thanks for all the comments, but knowing what the resulting antenna pattern seems elusive. I need in-band RX antenna for a mult station. Typically antenna separation, front-to-back and polarization are the main tools for that. When I run out of room I was wondering if phasing from an NCC-2 box is another tool to consider. But I don’t want to consider it without knowing what the resulting pattern would be. Many thanks, Kenny K2KW Regards , Kenny > On Dec 17, 2023, at 1:05 PM, Rick Kunath wrote: > > I'm not sure we still understand the intended application of the original > poster, I know I don't. > > I've done lots of work with loops and loop arrays phased either passively > (active or entirely passive external phaser boxes) or actively phased via an > SDR but none of that would eliminate the need for RX protection on the > receive antenna and any electronics associated with it. So if the OP is > trying to get away from any protection from the TX energy, I think this is > false hope. A loop mounted preamp makes that more complicated. And The NCC2 > does have options for protection boards for TX internally. There are several > types available and also internal preamps. But it cannot set a specific > amplitude and phase angle on the phasing. I don't have one and haven't ever > had the pleasure of using one, but those that do tell me they enjoy them and > they work well especially for live listening. I do like the idea of having > the electronics at the shack end of things and as little as possible at the > antenna when possible, though depending on the specifics you will have > VACTROL devices or other termination devices at at the antenna with at least > some antenna types. > > Preset patterns and unattended work are another case entirely and this is > best done with specific phase coherent dual-channel SDRs and a specific SDR > application. > > I think doing what the OP might want as I might understand it is possible, > but I'd like to hear more from him about his hopes for the project. > > Rick Kunath, K9AO > _ Searchable Archives: http://www.contesting.com/_topband - Topband Reflector
Re: Topband: NCC-2 antenna pattern?
I'm not sure we still understand the intended application of the original poster, I know I don't. I've done lots of work with loops and loop arrays phased either passively (active or entirely passive external phaser boxes) or actively phased via an SDR but none of that would eliminate the need for RX protection on the receive antenna and any electronics associated with it. So if the OP is trying to get away from any protection from the TX energy, I think this is false hope. A loop mounted preamp makes that more complicated. And The NCC2 does have options for protection boards for TX internally. There are several types available and also internal preamps. But it cannot set a specific amplitude and phase angle on the phasing. I don't have one and haven't ever had the pleasure of using one, but those that do tell me they enjoy them and they work well especially for live listening. I do like the idea of having the electronics at the shack end of things and as little as possible at the antenna when possible, though depending on the specifics you will have VACTROL devices or other termination devices at at the antenna with at least some antenna types. Preset patterns and unattended work are another case entirely and this is best done with specific phase coherent dual-channel SDRs and a specific SDR application. I think doing what the OP might want as I might understand it is possible, but I'd like to hear more from him about his hopes for the project. Rick Kunath, K9AO _ Searchable Archives: http://www.contesting.com/_topband - Topband Reflector
Re: Topband: NCC-2 antenna pattern?
If you can get that close I suggest a small explosive charge 73, Pete N4ZR On 12/17/2023 10:31 AM, John Kaufmann via Topband wrote: If you are going to use the NCC-2 to null a nearby in-band transmitter, I think it's very likely that the NCC-2 will get overloaded by the extremely strong RF and not be usable. I've tried this before and found that to be the case. In fact, I designed my own totally passive nuller to get around this problem. It worked and was able to create very deep nulls on an in-band transmitter, but turned out to be very impractical because it required constant adjustment to maintain a null as antennas were changed or rotated. The other thing to consider is that if the interference is coming from the same direction as a signal you want to hear, nulling the interference will also null the signal. Nulling works best when the interference comes from a very different direction than the signal. It also helps greatly if the interference sensing antenna receives the interference much more strongly than the main antenna. This can be done by placing the sensing antenna close to the interference source, if that's possible. 73, John W1FV -Original Message- From: Topband On Behalf Of Kenny Silverman Sent: Saturday, December 16, 2023 10:05 PM To: Rick Kunath Cc: topband Subject: Re: Topband: NCC-2 antenna pattern? Rick, my application is for an in-band RX antenna, but on a higher band. I just thought the guys here might know more about the NCC-2, MFJ or QRM eliminator than most others. One thought was to create a 2 ele phased vertical array for the RX antenna with a known pattern and put the null towards the TX array, along with physical separation to allow in-band receiving. But I was thinking an adjustable phasing system may produce a better null. But I wouldn’t want the adjustable unit to create a clover leaf pattern for example. One null might take out the interference but another null towards the desired receiving direction might be created and is not desired. I hope I’m explaining this well. Regards , Kenny K2KW On Dec 16, 2023, at 9:47 PM, Rick Kunath wrote: What's your application Kenny and what would you be feeding the antenna output of the phaser into? Rick Kunath, K9AO _ Searchable Archives:http://www.contesting.com/_topband - Topband Reflector _ Searchable Archives:http://www.contesting.com/_topband - Topband Reflector _ Searchable Archives: http://www.contesting.com/_topband - Topband Reflector
Re: Topband: NCC-2 antenna pattern?
If you are going to use the NCC-2 to null a nearby in-band transmitter, I think it's very likely that the NCC-2 will get overloaded by the extremely strong RF and not be usable. I've tried this before and found that to be the case. In fact, I designed my own totally passive nuller to get around this problem. It worked and was able to create very deep nulls on an in-band transmitter, but turned out to be very impractical because it required constant adjustment to maintain a null as antennas were changed or rotated. The other thing to consider is that if the interference is coming from the same direction as a signal you want to hear, nulling the interference will also null the signal. Nulling works best when the interference comes from a very different direction than the signal. It also helps greatly if the interference sensing antenna receives the interference much more strongly than the main antenna. This can be done by placing the sensing antenna close to the interference source, if that's possible. 73, John W1FV -Original Message- From: Topband On Behalf Of Kenny Silverman Sent: Saturday, December 16, 2023 10:05 PM To: Rick Kunath Cc: topband Subject: Re: Topband: NCC-2 antenna pattern? Rick, my application is for an in-band RX antenna, but on a higher band. I just thought the guys here might know more about the NCC-2, MFJ or QRM eliminator than most others. One thought was to create a 2 ele phased vertical array for the RX antenna with a known pattern and put the null towards the TX array, along with physical separation to allow in-band receiving. But I was thinking an adjustable phasing system may produce a better null. But I wouldn’t want the adjustable unit to create a clover leaf pattern for example. One null might take out the interference but another null towards the desired receiving direction might be created and is not desired. I hope I’m explaining this well. Regards , Kenny K2KW > On Dec 16, 2023, at 9:47 PM, Rick Kunath wrote: > > What's your application Kenny and what would you be feeding the antenna > output of the phaser into? > > Rick Kunath, K9AO > _ Searchable Archives: http://www.contesting.com/_topband - Topband Reflector _ Searchable Archives: http://www.contesting.com/_topband - Topband Reflector
Re: Topband: NCC-2 antenna pattern?
On 12/16/2023 7:04 PM, Kenny Silverman wrote: Rick, my application is for an in-band RX antenna, but on a higher band. As detailed in the link I posted, the NCC2 is designed for use on the lower bands, 160, 80, maybe 60 and 40. My measurements show this. I've mostly used the VE3DO array on 160, a bit on 80. My Beverages work up to 20M -- when I first moved to W6, I had them a couple of years before I found a place to turn the little 3-el SteppIR between the dense redwoods, and used one extensively to listen to EU on 20. 73, Jim K9YC _ Searchable Archives: http://www.contesting.com/_topband - Topband Reflector
Re: Topband: NCC-2 antenna pattern?
Lots of good info on some of these posts already. Although I like a pair of inline flag antennas terminated with VACTROLs separated by 100 feet inline better than the center feed/terminated design I saw earlier. Great F/B and tweakable remotely to make sure that F.B is maxedd at the frequency of interest or what is best across a band for unattended use. There are other variations like the KAZ or the DKAZ or the Superloop. But whatever works is the right antenna for the job. Will you be needing at the loop preamplification? Were you wanting this receive antenna for 160-meters or a higher band? And will you be receiving live or will you be recording either audio or more likely I/Q unattended? Rick Kunath, K9AO _ Searchable Archives: http://www.contesting.com/_topband - Topband Reflector
Re: Topband: NCC-2 antenna pattern?
Rick, my application is for an in-band RX antenna, but on a higher band. I just thought the guys here might know more about the NCC-2, MFJ or QRM eliminator than most others. One thought was to create a 2 ele phased vertical array for the RX antenna with a known pattern and put the null towards the TX array, along with physical separation to allow in-band receiving. But I was thinking an adjustable phasing system may produce a better null. But I wouldn’t want the adjustable unit to create a clover leaf pattern for example. One null might take out the interference but another null towards the desired receiving direction might be created and is not desired. I hope I’m explaining this well. Regards , Kenny K2KW > On Dec 16, 2023, at 9:47 PM, Rick Kunath wrote: > > What's your application Kenny and what would you be feeding the antenna > output of the phaser into? > > Rick Kunath, K9AO > _ Searchable Archives: http://www.contesting.com/_topband - Topband Reflector
Re: Topband: NCC-2 antenna pattern?
On 12/16/2023 5:46 PM, Kenny Silverman wrote: Does the NCC-2 create a predictable antenna pattern? I’m just wondering how to null the noise but not create some weird pattern which may also produce a null in the desired direction. Here's how it can be made to work with suitable antennas. http://k9yc.com/VE3DO.pdf As my measurements of my NCC1, it's well engineered product. After first getting it running with a pair of VE3DO loops spaced 5/8 wave on 160 aimed at EU (and reversible to VK/ZL), I verified with on-air testing that the patterns I modeled in NEC were accurate. For noise rejection, I'd suggest one or more pairs of verticals carefully matched to each other. I'm guessing that 5/8 wave spacing might be a good starting point. And I'd pay attention to W3LPL's excellent talks on how various types of RX antennas and arrays work (or don't) with surrounding objects, including vegetation. 73, Jim K9YC _ Searchable Archives: http://www.contesting.com/_topband - Topband Reflector
Re: Topband: NCC-2 antenna pattern?
What's your application Kenny and what would you be feeding the antenna output of the phaser into? Rick Kunath, K9AO _ Searchable Archives: http://www.contesting.com/_topband - Topband Reflector
Re: Topband: NCC-2 antenna pattern?
I am not sure "predictable" is one of the attributes I would use when using one of these devices. Really - the real benefit of them is to annihilate a local noise source. I remember getting a really deep null (50 db) on a station that was about 1 mile away with a similar device. I did spend some time trying to peak a specific DX station by playing around with the knobs - but never really felt like anything was "predictable". Just my experience. Was using mostly the JPS ANC-4 back in the day or the MFJ-1026 more recently. Perhaps the NCC-2 is a bit more refined and the settings have enough calibration to produce reproducible and desirable patterns. Obviously using two antennas spaced like 1/8 or 1/4 wavelength apart will help. Tree N6TR On Sat, Dec 16, 2023 at 5:46 PM Kenny Silverman wrote: > Does the NCC-2 create a predictable antenna pattern? I’m just wondering > how to null the noise but not create some weird pattern which may also > produce a null in the desired direction. > > Regards , Kenny K2KW > _ > Searchable Archives: http://www.contesting.com/_topband - Topband > Reflector > _ Searchable Archives: http://www.contesting.com/_topband - Topband Reflector
Topband: NCC-2 antenna pattern?
Does the NCC-2 create a predictable antenna pattern? I’m just wondering how to null the noise but not create some weird pattern which may also produce a null in the desired direction. Regards , Kenny K2KW _ Searchable Archives: http://www.contesting.com/_topband - Topband Reflector
