Re: [digitalradio] Re: How Can We Push HF Emcomm Messages to the Field?
Hi Rick, The numbers for the models seem very optimistic. Normal gain for J-pole (theoretical) can not be more than a dipole, since the antennas is an end fed dipole with the Q section for matching. This means at most 2.14 dBi, but maybe you are experiencing some ground gain which you can get on vertical too from my limited understanding? Yes, ground gain is mostly responsible for the higher gain figures. The J-pole in free space has a modeled gain of 2.34 dBi at 10.2 degrees, very close to the isotropic dipole value of 2.2 dBi, or 2.14 dBi. However, over real ground, 10 feet up, the gain increases to 5.17 dBi at 6.2 degrees. Flipping it horizontally, the gain increases to 7.81 dBi at 9.7 degrees, but for a better comparison, the gain horizontally is 6 dBi at 6 degrees and 10 feet. Mounted on a car at 5 feet, the takeoff angle increases to 19.1 degrees and the gain at 6 degrees is only 1.2 dBi horizontally. Rotated back to vertical at 5 feet, the gain is 4 dBi at 8 degrees, or 3 dBi at 6 degrees. In comparison, the square quad loop has 9.21 dBi of gain at 14 degrees, or 5.3 dBi at 6 degrees. So, in an apples-to-apples comparison, the single quad loop still excels the J-pole by 3 dB, which appears to be what we are finding, instead of the 6 dB difference previously noted, which did not normalize everything to a 6 degree takeoff angle. When the CSVHFS does annual parking lot type tests each year and they seem to come up with higher numbers than the theoretical. That may be why KU4AB's halo antenna exceeds the theoretical maximum by quite a bit. And the take off angle is very important as you note. There are companies that make claims of very high gain numbers but they are not toward the horizon, HI. I have a KU4AB square loop - in fact I started on 2m with a stacked pair. Comparing it to a dipole on my beacon, I find that the pattern has serious nulls, especially in the back (-6 dB!), and is just not omnidirectional. I tracked NK4Q across the center of South Carolina comparing the KU4AB loop to a single stretched quad loop (facing me) and there were many times that he could not even copy me on the KU4AB loop when copy was perfect on the stretched quad loop. A true halo works much better. The nice thing about quads is that they are easier to match than yagis often requiring only a direct connection to the driven element since the other elements reduce the impedance closer to 50 ohms and away from the 100+ ohms of a single loop. Although a bit bulky, with a three dimensional form factor, it is less likely you will poke out your eye. For portable use, my OptimizedQuad (two stretched rectangles in a diamond configuration) in a driven element/reflector arrangement, is probably a good compromise. It is only 20 x 20 x 13, so will fit in a trunk and does not have to be reassembled in the field - only put it up on a portable mast as high as is practical. If that gain (8.2 dBi at 6 degrees over real ground) is not enough for the distance or terrain, I also have a 4-element quad design with 14 dBi of gain (over read ground) at 6 degrees at 10 feet which can be unplugged and also fit in a trunk. The big 3 x 5/8 collinears may be able to reach just over 8 dBi, but it just is not enough for the longer reach. It is of course way better than a half wave J-pole. When you need over 12 dBi or more on one end, (vertical or horizontal), it is pretty hard to do better than a rotatable yagi. An important question to ask: If you need to operate on battery power, will you be able to rotate the base station antenna? Most would at least need AC generator power although an inverter used for short periods, might be possible. Good point! The 4-element quad beam with its 5 foot boom fills that bill nicely and is easy to set up! The beamwidth is a wide 60 degrees, so it can be just pointed by hand in the general direction of the EOC and does not need a rotator. In a true field situation, the antenna will probably never be out of reach, so it can be turned by the arnstrong method. Four of the recent Cebik triple dipole arrays look like one of the ways to get the most gain for a stationary antenna. I have asked some antenna companies if they are considering making such an antenna, but no response. Are you talking about his horizontal polling array paper? That was written because I asked him if he could find out what spacing I needed between 3-element quad antennas placed around a circle, but he did the article using moxon rectangles. In our area, we have some hams with rotating twist type Cushcraft 10 element V and H switchable beams, smaller beams, and some with double 13 element vertically stacked. Interestingly, these are hams who are also more into public service and don't normally get involved in weak signal work. It is a tough call to decide which way to polarize since hardly anyone is going to have H with any mobile setup and you need to have mobile
Re: [digitalradio] Re: Odd noise in receiver
Thanks, Gary! I'm trying to be open-minded about this. Today the noise seems to be gone completely. It disappeared yesterday evening and haven't heard it since. If it reappears on Monday, I'll have a better clue that it's something that belongs to the local cable company. I used to work in cable TV years ago, and I seem to recall a test device that sent this type of signal over the cable to test the in-line amplifiers, but my memory is not something to be relied on too heavily hi hi! Thanks and have a great weekend! 73 Dave KB3MOW grwescom wrote: This kind of noise has been showing up quite a lot lately. I've chased down a couple TVI complaints with similar characteristics. The problem has consistently been battery chargers, especially the kind to used to charge the batteries for portable tools. They tend to cycle charging power on and off. Now some of the wall wart chargers for small electronic stuff is starting to create the same kind of noise. This may not be your problem but I would recommend against ignoring the possibility that it might be. Gary - N0GW --- In digitalradio@yahoogroups.com mailto:digitalradio%40yahoogroups.com, Dave 'Doc' Corio [EMAIL PROTECTED] wrote: Wonder if anyone has encountered this type of noise. It's a raspy, pulsating sound. It lasts 10 seconds, is silent for 5, then starts again The pulses are about 5 per second. It's showing up on a lot of bands. Right now I have it at about 21.048, but have heard it on several ham frequencies. We haven't added any new electronics in the house at all. We are in a rural setting, with the nearest neighbor several hundred feet away. We do have cable TV and cable internet, and I wonder if this might be a test birdie I've heard mentioned in the past. It seems to run 24/7, and just started up within the last few days. Any ideas? Thanks in advance 73 Dave KB3MOW
[digitalradio] You Have Mail Re: How Can We Push HF Emcomm Messages to the Field?
Here are some possibilities: 1. Teams have their radios on all the time, or perhaps only on the top of the hour for 10 minutes to check in - so their welfare and status is known and for delivering any important messages. 2. Teams connect to an email server via the radio at least once an hour. This can be to a VHF RMS Packet station, an HF RMS Packet station, or RFSM8000. (My local MARS group has been experimenting with RFSM8000) It is not cheap, but if prepared with a deep cycle battery, appropriate charger, and a few solar panels (100 watts each), an email station can be available at scheduled times. Perhaps all day during daylight hours, and 15 minutes out of each hour during night-time hours? Perhaps even 24/7 if equipped for it. 3. D-Star radios - they have the ability for 'call-sign squelch'. A member will only hear messages explicitly sent to his call-sign. Thus he would not have to listen regularly in an hourly net for information specific for him. This can also be accomplished on FM radios using different squelch codes - though not as well. If VHF simplex can provide for the coverage area - that's fine. If you need a central voice repeater, digipeater, or email server - figure out how to have it available without electricity from the electric company. If HF is needed, again plan for that. Equipment costs more and antennas are larger. What equipment is needed - how many participants. What antennas can be easily errected in the field, and stored compactly in a vehicle? Electiricy requirements? Maybe people's vehicles will be the generators needed? Then you need some regular practice to see that it all works, equipment is operational, and people retain familiarity with equipment and procedures. Whatever approach you want to take, just think about it, plan for it, and practice it. There are many approaches, probably more ideas exist in your organization than I have thought of here. Howard --- In digitalradio@yahoogroups.com, expeditionradio [EMAIL PROTECTED] wrote: The core question still remains: How can we initiate (push) a message to the mobile or portable operator in the field, when the field operator has no expectation that a message will be sent? Or, even more simply, how can we timely notify the field operator You Have Mail via HF? During the Katrina disaster the traditional HF voice nets failed to adequately provide this type of notification service. It's been 3 years since Katrina. What has we done to improve our ability to notify field ops via HF? How can we work together to forge unified or standard methods to make this happen... in a way that will function across the various ham Emcomm platforms and nets? Bonnie VR2/KQ6XA .
Re: [digitalradio] Re: Odd noise in receiver
Hi, Dave and Gary: The absolute worst offender I've found at my QTH is the charger for my Motorola cell phone. 73, Mike N5UKZ Dave 'Doc' Corio wrote: Thanks, Gary! I'm trying to be open-minded about this. Today the noise seems to be gone completely. It disappeared yesterday evening and haven't heard it since. If it reappears on Monday, I'll have a better clue that it's something that belongs to the local cable company. I used to work in cable TV years ago, and I seem to recall a test device that sent this type of signal over the cable to test the in-line amplifiers, but my memory is not something to be relied on too heavily hi hi! Thanks and have a great weekend! 73 Dave KB3MOW grwescom wrote: This kind of noise has been showing up quite a lot lately. I've chased down a couple TVI complaints with similar characteristics. The problem has consistently been battery chargers, especially the kind to used to charge the batteries for portable tools. They tend to cycle charging power on and off. Now some of the wall wart chargers for small electronic stuff is starting to create the same kind of noise. This may not be your problem but I would recommend against ignoring the possibility that it might be. .
Re: [digitalradio] Re: Odd noise in receiver
I've never noticed anything from the charger for my Motorola, and sometimes I charge it right at the radio desk! Unfortunately, I haven't charged it for a few days, so I know it isn't that. Haven't charged anything or plugged anything new or different in. Noise disappeared last night and still isn't back, so maybe it moved on? Wishful thinking? Tnx es 73 Dave KB3MOW Mike Blazek wrote: Hi, Dave and Gary: The absolute worst offender I've found at my QTH is the charger for my Motorola cell phone. 73, Mike N5UKZ Dave 'Doc' Corio wrote: Thanks, Gary! I'm trying to be open-minded about this. Today the noise seems to be gone completely. It disappeared yesterday evening and haven't heard it since. If it reappears on Monday, I'll have a better clue that it's something that belongs to the local cable company. I used to work in cable TV years ago, and I seem to recall a test device that sent this type of signal over the cable to test the in-line amplifiers, but my memory is not something to be relied on too heavily hi hi! Thanks and have a great weekend! 73 Dave KB3MOW grwescom wrote: This kind of noise has been showing up quite a lot lately. I've chased down a couple TVI complaints with similar characteristics. The problem has consistently been battery chargers, especially the kind to used to charge the batteries for portable tools. They tend to cycle charging power on and off. Now some of the wall wart chargers for small electronic stuff is starting to create the same kind of noise. This may not be your problem but I would recommend against ignoring the possibility that it might be. .
[digitalradio] KIJT WSPR BEACON - 503KHZ (CARRIER) NOW TILL LATE
KIJT WSPR BEACON - 503KHZ (CARRIER) NOW (1800 HRS GMT 29/11) TILL LATE Running K1JT WSPR beacon Carrier frequency 503 KHz Dial set 501.5 Khz usb , audio tone 1500 Hz Running approx 100 watts to 35 ft top loaded vertical , (If the pa trips beacon will continue at -14 db level) Reports welcome Tnx - Graham G0NBD / IO83LK
[digitalradio] CSS Announces Upgrade Offer for Users of Old MS-DOS and Windows 3.1 Radio Software
CSS Announces Upgrade Offer for Users of Old MS-DOS and Windows 3.1 Radio Software Users of HostMaster, KaWin, KaGOLD, PkGOLD and PC PakRatt Can Upgrade to the Radio Operations Center Digital Desktop and Save 20 Percent FOR IMMEDIATE RELEASE: November 26, 2008 — Creative Services Software, Inc. (CSS) today announced a special upgrade offer for licensed users of HostMaster, KaWin, KaGOLD, PkGOLD and PC PakRatt software. With a valid serial number for any of these older MS-DOS and Windows 3.1-based products, users can upgrade to CSS’ Radio Operations Center (ROC) Digital Desktop™ for $79.95, a 20 percent savings off the regular retail price of $99.95. The special upgrade offer will expire on January 31, 2009. Radio operators can also take advantage of a free, 30-day trial of the software, but must complete their purchase by January 31, 2009 to take advantage of the upgrade pricing. “A lot of radio operators still use old software that is no longer in development and no longer supported, which limits their ability to keep up with the latest in amateur radio technology,” said Rick Ruhl, CSS president. “All of these older systems are built on the 16-bit MS-DOS or Windows 3.1 platforms of the 1980s. As older PCs get retired and new radio technology continues to evolve, it becomes less and less feasible to continue to run software that is well more than a decade old.” Because most of the old radio software programs are no longer in development, amateur radio operators cannot take advantage of new features and new capabilities without upgrading to advanced solutions like the Radio Operations Center. Customer service is usually not available at all or available only from other users rather than from software professionals. “If a radio amateur gets a new PC, a new TNC or a new radio, there’s no guarantee their old software will work at all,” Ruhl explained. “And even if they are able to run the software in an emulation window, they’ll run into all kinds of limitations—like the inability to multitask, or to work in full screen, for example. That can take a lot of the enjoyment out of the radio hobby.” CSS cites a number of features and benefits available in the Radio Operations Center Digital Desktop that are not available in older software, including: * The industry's most complete support for digital radio modes in one comprehensive solution. * Advanced radio, TNC and soundcard compatibility, supporting more hardware than any other radio control software solution. * Robust integration with other Windows applications and ham radio tools such as logging programs and call books, supporting both binary and ASCII file transfers as well as Windows cut-and-paste. * The productivity advantage of 32-bit Windows multitasking that frees operators to run other applications, including desktop software such as Microsoft Office, while operating a transceiver at the same time. * Support for more than 70 radios, with an on-going commitment to adding compatibility for the latest radio technology as it develops. * Better performance and reliability, thanks to ROC Digital Desktop’s 32-bit Windows operating system design. The Radio Operations Center is available for a free, 30-day trialon the CSS Website and retails for $99.95. The purchase of ROC Digital Desktop includes one year of e-mail or phone technical support, access to the CSS user forum and free maintenance updates. The $79.95 upgrade offer for licensed users of HostMaster, KaWin, KaGOLD, PkGOLD and PC PakRatt software expires on January 31, 2009, regardless of how long the trial software has been in use. Visit www.cssincorp.com/offers/upgrade-the-old.html for more information, to download the demo version, or to take advantage of the special upgrade offer. CSS products are also available from many ham radio retailers and radio equipment catalogs. About the Radio Operations Center The Radio Operations Center software suite from CSS is the only amateur, MARS and commercial radio software solution that combines the integration, automation and multitasking capabilities of Microsoft® Windows with the flexibility and control to operate on multiple TNCs, soundcard and radio hardware in all the digital modes. The Radio Operations Center allows users to control radios, TNCs, rotors, and to access logging applications, call books and more — all from within a single 32-bit Microsoft Windows application. The software formerly known as PKTerm™ (for Timewave/AEA TNCs) and PacTerm™ (for Kantronics TNCs) are now called ROC Digital Desktop™. Other Radio Operations Center products include EmComm Ops, Marine Radio Opsand Weather Ops. About CSS CSS is a privately held software and technology consulting company specializing in software connectivity for commercial and amateur radio operators; office automation and network management solutions for business; and custom software
Re: [digitalradio] You Have Mail Re: How Can We Push HF Emcomm Messages to the Field?
Howard, Some really good information. Do you use the RFSM8000 server for local e-mail like we used to use for packet, or do you connect into the internet to go outside the ham RF paths? Or maybe both? Do you just use the call sign or some kind of e-mail address? If you buy the server software, can RFSM2400 freeware stations use the system? How does it compare with packet, especially in terms of speed and weak signal capability? 73, Rick, KV9U Howard Z. wrote: Here are some possibilities: 1. Teams have their radios on all the time, or perhaps only on the top of the hour for 10 minutes to check in - so their welfare and status is known and for delivering any important messages. 2. Teams connect to an email server via the radio at least once an hour. This can be to a VHF RMS Packet station, an HF RMS Packet station, or RFSM8000. (My local MARS group has been experimenting with RFSM8000) It is not cheap, but if prepared with a deep cycle battery, appropriate charger, and a few solar panels (100 watts each), an email station can be available at scheduled times. Perhaps all day during daylight hours, and 15 minutes out of each hour during night-time hours? Perhaps even 24/7 if equipped for it. 3. D-Star radios - they have the ability for 'call-sign squelch'. A member will only hear messages explicitly sent to his call-sign. Thus he would not have to listen regularly in an hourly net for information specific for him. This can also be accomplished on FM radios using different squelch codes - though not as well. If VHF simplex can provide for the coverage area - that's fine. If you need a central voice repeater, digipeater, or email server - figure out how to have it available without electricity from the electric company. If HF is needed, again plan for that. Equipment costs more and antennas are larger. What equipment is needed - how many participants. What antennas can be easily errected in the field, and stored compactly in a vehicle? Electiricy requirements? Maybe people's vehicles will be the generators needed? Then you need some regular practice to see that it all works, equipment is operational, and people retain familiarity with equipment and procedures. Whatever approach you want to take, just think about it, plan for it, and practice it. There are many approaches, probably more ideas exist in your organization than I have thought of here. Howard
Re: [digitalradio] KIJT WSPR BEACON - 503KHZ (CARRIER) NOW TILL LATE
Hi Graham Captured you in Norway : 232800 7 -24 1.3-2 0 G0NBD IO83 27 233200 12 -21 1.3-2 0 G0NBD IO83 27 I am using a icom ic-r75 and a 7m long vertical antenna 6m above the ground, feeded with a 9:1 homemade unun. 73 de LA5VNA Steinar Graham wrote: KIJT WSPR BEACON - 503KHZ (CARRIER) NOW (1800 HRS GMT 29/11) TILL LATE Running K1JT WSPR beacon Carrier frequency 503 KHz Dial set 501.5 Khz usb , audio tone 1500 Hz Running approx 100 watts to 35 ft top loaded vertical , (If the pa trips beacon will continue at -14 db level) Reports welcome Tnx - Graham G0NBD / IO83LK No virus found in this incoming message. Checked by AVG - http://www.avg.com Version: 8.0.176 / Virus Database: 270.9.11/1819 - Release Date: 29.11.2008 10:37
[digitalradio] You Have Mail Re: How Can We Push HF Emcomm Messages to the Field?
Hi Howard, Thank you for the interesting reply. It is the first one that I've seen that actually addresses the core issues. Certainly, your item 1 suggestion, have their radios on all the time is a necessary fundamental for push messaging to work, and it is the prerequisite for it to function. This begs the question: How is the notification routed to the specific operator, notifying the operator that an email or SMS cell phone text message is pending? Your item 2 suggestion is good (check your email once per hour), but respectfully, it is still the old check in and pull a message technique of the early 20th century ARRL nets, rather than the quick push messaging that is needed today. Your item 3 suggestion is good (use D-Star calling) for notification from one radio operator to another. But, the weak part of the monitoring a voice net approach is that the members of a voice net or D-Star net may not know when that specific operator has an email or text message pending, so even if they can manually call the operator, how would they know when to call? The obvious limitations of D-Star on VHF/UHF and the need for repeaters is a weak point, especially given the hurricane scenario, as Katrina taught us. D-Star would be good as a VHF/UHF component of a larger strategy that includes HF. In response to your comment that the ALE High Frequency Network may have some ideas on how to do Push Messaging, the answer is yes, Push Messaging is being developed now for HFN. But HFN does not want to re-invent the wheel if necessary. Also, HFN wants to understand what has been tried before (if anything) and get any suggestions on how it can be done, or various ways to do it. So far there hasn't been any realistic answers that address the core Push Message question, other than yours, Howard. Bonnie VR2/KQ6XA --- In digitalradio@yahoogroups.com, Howard Z. [EMAIL PROTECTED] wrote: Here are some possibilities: 1. Teams have their radios on all the time, or perhaps only on the top of the hour for 10 minutes to check in 2. Teams connect to an email server via the radio at least once an hour. 3. D-Star radios - they have the ability for 'call-sign squelch'. A member will only hear messages explicitly sent to his call-sign. There are many approaches, probably more ideas exist in your organization than I have thought of here. Howard --- In digitalradio@yahoogroups.com, expeditionradio expeditionradio@ wrote: The core question still remains: How can we initiate (push) a message to the mobile or portable operator in the field, when the field operator has no expectation that a message will be sent? Or, even more simply, how can we timely notify the field operator You Have Mail via HF? During the Katrina disaster the traditional HF voice nets failed to adequately provide this type of notification service. It's been 3 years since Katrina. What has we done to improve our ability to notify field ops via HF? How can we work together to forge unified or standard methods to make this happen... in a way that will function across the various ham Emcomm platforms and nets? Bonnie VR2/KQ6XA
[digitalradio] Re: KIJT WSPR BEACON - 503KHZ (CARRIER) NOW TILL LATE
Thank you Steinar, Its been a intresting night , had a reply from Jay W1VD reporting a decode at -29 db ! a lot of reports coming in via the wspr reporting site as well not bad for 100 watts to a 35 ft vertical with a top loading coil wound on a coa-cola bottel , like the advert says , things go beter with coke hihi --- In digitalradio@yahoogroups.com, Steinar Aanesland [EMAIL PROTECTED] wrote: Hi Graham Captured you in Norway : 232800 7 -24 1.3-2 0 G0NBD IO83 27 233200 12 -21 1.3-2 0 G0NBD IO83 27 I am using a icom ic-r75 and a 7m long vertical antenna 6m above the ground, feeded with a 9:1 homemade unun. 73 de LA5VNA Steinar Graham wrote: KIJT WSPR BEACON - 503KHZ (CARRIER) NOW (1800 HRS GMT 29/11) TILL LATE Running K1JT WSPR beacon Carrier frequency 503 KHz Dial set 501.5 Khz usb , audio tone 1500 Hz Running approx 100 watts to 35 ft top loaded vertical , (If the pa trips beacon will continue at -14 db level) Reports welcome Tnx - Graham G0NBD / IO83LK -- -- No virus found in this incoming message. Checked by AVG - http://www.avg.com Version: 8.0.176 / Virus Database: 270.9.11/1819 - Release Date: 29.11.2008 10:37
Re: [digitalradio] KIJT WSPR BEACON - 503KHZ (CARRIER) NOW TILL LATE
Will give a listen for any trans-Atlantic propagation. On Sat, Nov 29, 2008 at 1:29 PM, Graham [EMAIL PROTECTED] wrote: KIJT WSPR BEACON - 503KHZ (CARRIER) NOW (1800 HRS GMT 29/11) TILL LATE Running K1JT WSPR beacon Carrier frequency 503 KHz Dial set 501.5 Khz usb , audio tone 1500 Hz Running approx 100 watts to 35 ft top loaded vertical , (If the pa trips beacon will continue at -14 db level) Reports welcome Tnx - Graham G0NBD / IO83LK -- Andy K3UK
[digitalradio] 600M Trans-Atlantic reception
G0NBD reports that he has been received in North American 23:52G0NBD [EMAIL PROTECTED]!!!DONE IT !!! First wspr over the pond on 500 !!! report from : Jay W1VD WD2XNS WE2XGR/2 -- Andy K3UK
[digitalradio] HAL ST-8000A to Teletype ASR33
I have a HAL ST-8000A and recently purchased a Teletype ASR33 and want to use these for receiving RTTY. I am looking for anyone who may have, or know where I can find, information on how to properly hookup the HAL to the Teletype. Any information or direction would be greatly appreciated. Regards, Steve R. [EMAIL PROTECTED]
Re: [digitalradio] Re: How Can We Push HF Emcomm Messages to the Field?
Judy and I did further testing of 1/4 wave and 5/8 wave antennas for 2 meters on her vehicle using the ICOM IC-7000 at 50 watts out. The base station continued to be the 30 foot high homebrew J-pole and now has 100 watts out from the ICOM 746 Pro. The mobile antennas were only mag mounts, but then again, that is what most of us use. The furthest point out was 40 miles and we could still communicate on 2 meter SSB, but signals were quite weak. When she was mobile, there were locations that were so weak as to be unreadable at times. Some of those areas are difficult to even work the local FM repeater which is about 200 feet higher than our home QTH antenna and about 6 miles closer than our QTH! There were slight differences between the 5/8 wave and 1/4 wave. Sometimes the quarter wave would out perform the 5/8, but in general, the 5/8 did slightly better, especially farther out. Because of the convenience of the quarter wave (entering the garage), it is hard to beat, but I would like to try a half wave Larsen some time. If I had been using even my modest 4 element Arrow beam, signals would have been quite good at all times, based upon the nearly unity gain verticals. I still need to come up with even rudimentary horizontal dipoles at each end and see how well they compare. Now on the KU4AB squalo antennas, this is one of the only halo types that does not seem to have water ingress detuning issues. Even the M Squared products got low ratings on eham because of this problem. The KU4AB design is the one that got the good numbers on the Central States VHF Society test. They did not mention that there were any anomalies in the omnidirectional pattern, but your experience sounds unacceptable! According to the M Squared advertising on the 144HO loop, they claim as you do that only horizontal type antennas can give you the ground reflection gain. Their numbers and shape of the antenna look very much like the KU4AB. I wonder why so many are going with the squalo shape over what would seem to be a stronger shape when in a circle? Can you recommend any current manufacturer for circular halos? The other well known manufacturer has been SK for some time and no one was interested in taking over the business. Maybe build my own? A single halo may not be too bad, but I don't know if I can do a good job with phasing lines. And those gamma matches are a challenge. What are stretched quad loops? Can't seem to find anything on them. Or is that the optimized quad, but not intended for mobile operation, more for portable? The Cebik antenna was in March 2008 QST entitled, A New Spin on the Big Wheel. While the three dipole design could be homebrewed, a well made more wheel like design would be needed to operate mobile due to his HPOD triangle probably not handling vibration and wind as well. I like the easy matching approach taken. The article has some background information I have not seen elsewhere. He considers the gain to be about 7.2 dBi at 20 feet height, and with very accurate omni characteristics. The second design can be accessed by ARRL members and is a circle of dipoles rather than having them unconnected with any supports to stiffen up the antenna. Harder to build though. 73, Rick, KV9U kh6ty wrote: Hi Rick, The numbers for the models seem very optimistic. Normal gain for J-pole (theoretical) can not be more than a dipole, since the antennas is an end fed dipole with the Q section for matching. This means at most 2.14 dBi, but maybe you are experiencing some ground gain which you can get on vertical too from my limited understanding? Yes, ground gain is mostly responsible for the higher gain figures. The J-pole in free space has a modeled gain of 2.34 dBi at 10.2 degrees, very close to the isotropic dipole value of 2.2 dBi, or 2.14 dBi. However, over real ground, 10 feet up, the gain increases to 5.17 dBi at 6.2 degrees. Flipping it horizontally, the gain increases to 7.81 dBi at 9.7 degrees, but for a better comparison, the gain horizontally is 6 dBi at 6 degrees and 10 feet. Mounted on a car at 5 feet, the takeoff angle increases to 19.1 degrees and the gain at 6 degrees is only 1.2 dBi horizontally. Rotated back to vertical at 5 feet, the gain is 4 dBi at 8 degrees, or 3 dBi at 6 degrees. In comparison, the square quad loop has 9.21 dBi of gain at 14 degrees, or 5.3 dBi at 6 degrees. So, in an apples-to-apples comparison, the single quad loop still excels the J-pole by 3 dB, which appears to be what we are finding, instead of the 6 dB difference previously noted, which did not normalize everything to a 6 degree takeoff angle. When the CSVHFS does annual parking lot type tests each year and they seem to come up with higher numbers than the theoretical. That may be why KU4AB's halo antenna exceeds the theoretical maximum by quite a bit. And the take off angle is very important as you note. There are
