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RoomCap Antenna
Can anyone tell me about this RoomCap Antenna?
The best I can find on the antenna is a picture of what looks like a piece of PVC with a capacity hat on it. I keep getting advertisements on the email reflectors and when I check the website, it asks for me to email for more information. I have done so several times and never received a response. What can you all tell me about this antenna? Thanks, Buck -- 73 for now Buck N4PGW |
RoomCap Antenna
Buck wrote:
Can anyone tell me about this RoomCap Antenna? The best I can find on the antenna is a picture of what looks like a piece of PVC with a capacity hat on it. I keep getting advertisements on the email reflectors and when I check the website, it asks for me to email for more information. I have done so several times and never received a response. What can you all tell me about this antenna? Thanks, Buck http://home.datacomm.ch/hb9abx/ant--abx-e.htm larry kd5foy |
RoomCap Antenna
On Mon, 01 May 2006 00:07:08 GMT, larry d clark
wrote: Buck wrote: Can anyone tell me about this RoomCap Antenna? The best I can find on the antenna is a picture of what looks like a piece of PVC with a capacity hat on it. I keep getting advertisements on the email reflectors and when I check the website, it asks for me to email for more information. I have done so several times and never received a response. What can you all tell me about this antenna? Thanks, Buck http://home.datacomm.ch/hb9abx/ant--abx-e.htm larry kd5fo Thanks, larry, but I have been there. There is not information directly related to the antenna other than the hype about the antenna from the maker. I wanted to know more details about whether or not it is good and just how it is made up. -- 73 for now Buck N4PGW |
RoomCap Antenna
try this one 73 ve7ado
http://www.eh-antenna.com/library/EH...A_FOR_HAMS.pdf "Buck" wrote in message ... Can anyone tell me about this RoomCap Antenna? The best I can find on the antenna is a picture of what looks like a piece of PVC with a capacity hat on it. I keep getting advertisements on the email reflectors and when I check the website, it asks for me to email for more information. I have done so several times and never received a response. What can you all tell me about this antenna? Thanks, Buck -- 73 for now Buck N4PGW |
RoomCap Antenna
On Wed, 03 May 2006 03:49:40 GMT, "Don" wrote:
try this one 73 ve7ado http://www.eh-antenna.com/library/EH...A_FOR_HAMS.pdf "Buck" wrote in message .. . Can anyone tell me about this RoomCap Antenna? Thanks, Don. -- 73 for now Buck N4PGW |
Quote:
The RoomCap Antenna is NOT an EH-Antenna. You should know that, if you have read the homepage of the antenna. If you really want to know how it works, and you want be be the owner of such antenna, you may obtain the construction guide. You find all this information on: http://home.tiscali.ch/hb9abx/ant--abx-e.htm Please take the time to read all, then you get the right information with best 73 Felix HB9ABX (the developer of the RoomCap Antenna) BTW: I sent you a normal email after your first request. |
RoomCap Antenna
Hi "Buck" The RoomCap Antenna is NOT an EH-Antenna. You should know that, if you have read the homepage of the antenna. If you really want to know how it works, and you want be be the owner of such antenna, you may obtain the construction guide. You find all this information on: http://home.tiscali.ch/hb9abx/ant--abx-e.htm Please take the time to read all, then you get the right information with best 73 Felix HB9ABX (the developer of the RoomCap Antenna) BTW: I sent you a normal email after your first request. Someone else sent a link to an EH antenna as the answer. I guess they were wrong. Right now I cannot link to your site. For some reason, I am unable to send email to your address, I think it has something to do with spam filters. I get this periodically as someone on bellsouth sends a message to a spam trap and the entire ISP is blocked. Likewise, I have not received an email from you, probably because the address in this is fake due to the magnitude of spam generated. Someone else did forward an email from you that you send out showing that what you are doing is selling the information. No one in his right mind would order an item in which they must agree to abide by the terms and conditions that they can't read before buying the product. Nothing personal, but your website is anything but professional looking. I do recall the following: you rant and rave about what others have said that disagree with you or your findings about your antenna. Most, if not all these arguments, I can only find on your own site, so your defense against these allegations and the attitude you portray only distract focus from one's interest, your antenna, and instead lays it onto your frustration and other's arguments. Additionally, you could just as easily have posted the required information about the costs and the obligatory terms and conditions of purchase of your CD-ROM. I must say, that based on the information on your site, there is a lot of controversy over what your antenna actually is, or how it performs. I notice that you don't actually sell the antenna, only the design information on a CD-ROM. Of course, that could reinforce the idea that you could be treading on the EH antenna design patents as someone else suggested (that your antenna is actually an EH design.) Personally, I think you could greatly benefit by removing all the controversy, give a little more detail about your antenna and specifically, adding the details of your private email that has to be requested to learn more about the antenna. How much are the parts required to make the antenna? After you so carefully protected me from receiving the minimum information on obtaining more information about the antenna, how do I know you aren't hiding something else such as a part you manufacture that I have to buy from you before being able to successfully build that antenna. In all reality, you have frightened me from buying the information from you about this antenna. I would like to hear from someone who has actually gotten your disc and possibly built the antenna so I can know how it performs from someone else's point of view. If it performs as well as you claim it does, or if it is similar to the performance of an EH per size,(for example, hypothetically speaking, a 3 foot antenna performs as well as a 1/2 wave vertical 20 meter antenna), and if the cost and skill level required for building the antenna is suitable to me, I might be interested in purchasing the plans for your antenna. However, your website leaves me with the impression that you are afraid of being criticized, almost to the point of paranoia, and from a business standpoint, I may be the only person who does this, but I actually READ contracts before I sign them. If I can't read it, it won't get signed. This is nothing personal as neither of us knows each other. I am not accusing you of anything, good nor bad. I am just stating things as I see them. From what I see on your website only makes me want to know more from what others who have interacted with your antenna have to say before I proceed further in entering a contract with you. Thanks for trying to send me the email. I do get frustrated at this mess with spam filters blocking all my ham buddies and passing spam all day long. 73 for now, Buck N4PGW -- 73 for now Buck N4PGW |
Quote:
EH-Antenna an RoomCap antenna: These are two different types of antennas, as the basic principle of the EH-Antenna is the use of a phase shift network that shall produce a 90 degree phase shift between the current and voltage to the antenna. This phase shift does not exist in the RoomCap antenna. But there are further main constructional differences, which can be seen in detail in the construction guide. The RoomCap antenna is working basically with the electric field which is produced into the open space between the radiator and the counter plane. To achive this, a so called VARYLINK is used to feed the antenna with an SWR of 1:1 on each band. The VARYLINK does not exist in the EH-Antenna. Regarding my personal email: - First email: hb9abx at tiscali.ch - Second email: hb9abx-1 at hispeed.ch Note: The first construction guides have been mailed 2 weeks ago and arrived a few says ago. Now many HAMs are working on their construction. Let's see their results. Best 73s Felix HB9ABX |
RoomCap Antenna
RoomCap Antenna web site proclaims:
"A new, revolutionary design allows the construction of small HF antennas, which provide the same efficiency as large antennas." Throw in the perpetuum mobile and the picture is complete. Imagine, for over 100 years we were stuck on stupid and using them unsightly, large antennas. Viva Zapata, Viva la revolucion! With all them revolutionary antennas arriving on radio landscape I am ashamed of using them biiiig ugly antennas, when I could have used all those miracle whip designs and doubled my contest scores. Time to make room for the new wizards of antenna magique and humbly tear down unsightly monsters and put up 174 cm miracle whips. BTW I have discovered way of shrinking RoomCap Antenna (it's called BUmTenna) on the same principle down to 1/10 size and blew the receiver front ends in the whole Warsaw Pact. I had to put attenuators in the feedline in order to protect NATO receivers. I have a CD with detailed information, Brooklyn bridge drawings are also included as well as swamp land in Sahara. Standby for the patent fights between Freaktenna, EHtenna, Univ of RItenna, RoomCrapTenna, ???tenna Happy Mother's Day to all mothers who did not abort us! Yuri da BUm |
RoomCap Antenna
Buck wrote:
. . . If it performs as well as you claim it does, or if it is similar to the performance of an EH per size,(for example, hypothetically speaking, a 3 foot antenna performs as well as a 1/2 wave vertical 20 meter antenna), and if the cost and skill level required for building the antenna is suitable to me, I might be interested in purchasing the plans for your antenna. . . . You must mean, "If it performs as well as the EH antenna claims to perform." If it can do that, it's miraculous indeed. It's no trick to make an antenna perform as well as an EH -- a 3 foot high (fat) vertical performs as well as a 3 foot high EH. Roy Lewallen, W7EL |
RoomCap Antenna
On Sun, 14 May 2006 14:43:53 -0700, Roy Lewallen
wrote: Buck wrote: . . . If it performs as well as you claim it does, or if it is similar to the performance of an EH per size,(for example, hypothetically speaking, a 3 foot antenna performs as well as a 1/2 wave vertical 20 meter antenna), and if the cost and skill level required for building the antenna is suitable to me, I might be interested in purchasing the plans for your antenna. . . . You must mean, "If it performs as well as the EH antenna claims to perform." If it can do that, it's miraculous indeed. It's no trick to make an antenna perform as well as an EH -- a 3 foot high (fat) vertical performs as well as a 3 foot high EH. Roy Lewallen, W7EL You got it right. I take it you aren't a fan of the EH design? ;) I would love to see the EH and the RoomCap in an antenna shootout against the screwdriver and texas bugcatcher. -- 73 for now Buck N4PGW |
Quote:
QRV with RoomCap antenna on 80m On May 15th, 2006 I was QRV on 80 m during 1 1/2 hour. Tcvr: TS-50 (100 W PEP), QRG = 3.770 - 3.787 Mhz Antenna: RoomCap with 1.66m radiator length installed on my car. SWR = 1.0 QTH: Peripheral part of city of Basel. Conditions: The band was weak with a lot of QRN. Here follows the contacts and the received signal reports: 20:10 DJ6YF, 59+10, Hans, Bielefeld 20:10 DL3EAI, 59, Reino, Mittetal (nr border to PA) 20:14 DJ6LGB, 58, Peter, Lüneburg 20:17 G4KHM, 57, John, nr. Brighton 20:23 DL1JGG, 58, Renald,Plauen 20:30 DC4HW, 59 Walter, Lauenburg nr Lueneburg 20:33 DG6DAG, 59+10, Otto, Nord-Hessen nr Kassel 20:40 YO4RDW, 57, Romeo, Odfbesei, Rumaenien 20:50 F4AWH, 59, Jean-Luc, nr Besancon 20:55 2E0BOT, 59, John, Stratford UK 21:10 DF9YK, 59, Wolfgang, Mainz 21:11 SP8TDV, 57, Adam, Lublin, Poland 21:13 HB9AQA, 59+10 - +20, Ferdi, nr Lenzburg 21:22 9A4M, 59, Mate, Sisah, Croatia 21:28 G1RVP, 57, Pete, Dereham 21:30 DJ6MM, 59+10, Paul, Eifel 21:38 DK5WN, 59, Thomas nr Erfurt 21:39 SP1DTE 58, Luk Koloberg, Poland 21:40 HB9XJ, 59+10, Hans, Zuerich 21:43 QRT With best 73s Felix HB9ABX |
RoomCap Antenna
Felix wrote:
Roy Lewallen Wrote: Buck wrote: . . . If it performs as well as you claim it does, or if it is similar to the performance of an EH per size,(for example, hypothetically speaking, a 3 foot antenna performs as well as a 1/2 wave vertical 20 meter antenna), and if the cost and skill level required for building the antenna is suitable to me, I might be interested in purchasing the plans for your antenna. . . . You must mean, "If it performs as well as the EH antenna claims to perform." If it can do that, it's miraculous indeed. It's no trick to make an antenna perform as well as an EH -- a 3 foot high (fat) vertical performs as well as a 3 foot high EH. Roy Lewallen, W7EL HERE A FEW RESULTS: QRV with RoomCap antenna on 80m On May 15th, 2006 I was QRV on 80 m during 1 1/2 hour. Tcvr: TS-50 (100 W PEP), QRG = 3.770 - 3.787 Mhz Antenna: RoomCap with 1.66m radiator length installed on my car. SWR = 1.0 QTH: Peripheral part of city of Basel. Conditions: The band was weak with a lot of QRN. Here follows the contacts and the received signal reports: 20:10 DJ6YF, 59+10, Hans, Bielefeld 20:10 DL3EAI, 59, Reino, Mittetal (nr border to PA) 20:14 DJ6LGB, 58, Peter, Lüneburg 20:17 G4KHM, 57, John, nr. Brighton 20:23 DL1JGG, 58, Renald,Plauen 20:30 DC4HW, 59 Walter, Lauenburg nr Lueneburg 20:33 DG6DAG, 59+10, Otto, Nord-Hessen nr Kassel 20:40 YO4RDW, 57, Romeo, Odfbesei, Rumaenien 20:50 F4AWH, 59, Jean-Luc, nr Besancon 20:55 2E0BOT, 59, John, Stratford UK 21:10 DF9YK, 59, Wolfgang, Mainz 21:11 SP8TDV, 57, Adam, Lublin, Poland 21:13 HB9AQA, 59+10 - +20, Ferdi, nr Lenzburg 21:22 9A4M, 59, Mate, Sisah, Croatia 21:28 G1RVP, 57, Pete, Dereham 21:30 DJ6MM, 59+10, Paul, Eifel 21:38 DK5WN, 59, Thomas nr Erfurt 21:39 SP1DTE 58, Luk Koloberg, Poland 21:40 HB9XJ, 59+10, Hans, Zuerich 21:43 QRT With best 73s Felix HB9ABX Small mobile antennas (in terms of wavelength) aren't generally very efficient. The above test only shows you can make contacts. It doesn't address efficiency or field strength in relation to a similar, but larger antenna. Have you put the plans online for this thing, or are you just using them to augment your net worth? 73, Tom Donaly, KA6RUH |
Anecdotal Antenna Metric, was RoomCap Antenna
Ah, the "it works because I made contacts with the following DX"
antenna argument. This may be an extremely compelling way of measuring performance of an antenna system if done correctly. It's certainly the most compelling kind of marketing argument snagging prospective "magic antenna" buyers, especially those who don't have another antenna up for comparison. But is there a way to make such an anecdotal claim and have it mean something? I'm thinking something along the lines of probability of making contact with a station with identical equipment, averaged over a very very long time. If you know the statistical ionospheric loss for the path, the power levels involved, and antenna gain (or LOSS) you can calculate such a thing. I've heard an argument recently that a particular antenna system must not be too inefficient because it was able to produce contacts with stations in Australia and New Zealand. The data below are in the same category. How do you know that the RoomCap antenna contacts were not made because the stations on the OTHER END have much MUCH better antennas? The dynamic range of signals present on the amateur bands is enormous. You could have an antenna with a gain of -35dBi and still make regular contacts. That doesn't mean it's good. How about if we stick to dB gain relative to some simple reference antenna or the isotropic for antenna reporting? Don't get me wrong, you can have tons of fun with a bad antenna. I'm sure that all the great DX I can work with my 100 feet of magnet wire at 30 feet is largely due to the stations on the other end, and if you're doing the best you can given the limitations of the situation, then you're holding up your end of the DX bargain. I worked 9M2CNC the other day on 17m with my antenna system! Does that mean I get to sell it for $190 to suckers? Or does it just mean that the propagation was good, the station on the other end was good, and I'm managing to not turn all of my 100W into local heating? 73, Dan N3OX HERE A FEW RESULTS: QRV with RoomCap antenna on 80m On May 15th, 2006 I was QRV on 80 m during 1 1/2 hour. Tcvr: TS-50 (100 W PEP), QRG = 3.770 - 3.787 Mhz Antenna: RoomCap with 1.66m radiator length installed on my car. SWR = 1.0 QTH: Peripheral part of city of Basel. Conditions: The band was weak with a lot of QRN. Here follows the contacts and the received signal reports: 20:10 DJ6YF, 59+10, Hans, Bielefeld 20:10 DL3EAI, 59, Reino, Mittetal (nr border to PA) 20:14 DJ6LGB, 58, Peter, Lüneburg 20:17 G4KHM, 57, John, nr. Brighton 20:23 DL1JGG, 58, Renald,Plauen 20:30 DC4HW, 59 Walter, Lauenburg nr Lueneburg 20:33 DG6DAG, 59+10, Otto, Nord-Hessen nr Kassel 20:40 YO4RDW, 57, Romeo, Odfbesei, Rumaenien 20:50 F4AWH, 59, Jean-Luc, nr Besancon 20:55 2E0BOT, 59, John, Stratford UK 21:10 DF9YK, 59, Wolfgang, Mainz 21:11 SP8TDV, 57, Adam, Lublin, Poland 21:13 HB9AQA, 59+10 - +20, Ferdi, nr Lenzburg 21:22 9A4M, 59, Mate, Sisah, Croatia 21:28 G1RVP, 57, Pete, Dereham 21:30 DJ6MM, 59+10, Paul, Eifel 21:38 DK5WN, 59, Thomas nr Erfurt 21:39 SP1DTE 58, Luk Koloberg, Poland 21:40 HB9XJ, 59+10, Hans, Zuerich 21:43 QRT With best 73s Felix HB9ABX Small mobile antennas (in terms of wavelength) aren't generally very efficient. The above test only shows you can make contacts. It doesn't address efficiency or field strength in relation to a similar, but larger antenna. Have you put the plans online for this thing, or are you just using them to augment your net worth? 73, Tom Donaly, KA6RUH |
RoomCap Antenna
Felix HB9ABX Small mobile antennas (in terms of wavelength) aren't generally very efficient. The above test only shows you can make contacts. It doesn't address efficiency or field strength in relation to a similar, but larger antenna. Have you put the plans online for this thing, or are you just using them to augment your net worth? 73, Tom Donaly, KA6RUH He is definitely holding them hostage to his profit. You will note that he has not responded to the fact that he requires the buyer to abide by his agreement BEFORE he will show them the agreement. -- 73 for now Buck N4PGW |
Quote:
Dear friends, I am very well aware of what you mean. Read my part "Evaluation of HF Antennas" on my homepage and then, the many comparisons of the RoomCap with many other, well known antennes, which were made side on side, also found on my page. I think, the real comparitive results is the only one that counts for an antenna. With best 73s Felix HB9ABX |
RoomCap Antenna
I think, the real comparitive results is the only one that counts
for an antenna. With best 73s Felix HB9ABX That is only the indication that antenna works. The REAL comparative results are the measurements done on the test range and compared to antenna that you claim to be as good or better. Another indication of performance would be to model the antenna in question vs. "standard" like full size vertical. Another meaningful test would be to compare RoomCap antenna to another efficient mobile antenna like TexasBugcatcher or Screwdriver, on the same car, taking field strength measurements. If it is so good as you claim, normally one would apply for patent and make millions by selling it. Claiming miracles and asking for money to find out what it is, is fishing for fools. Hams are (or were) known to be honest, gentlemen and willing to share their ideas with others for advancement of our art. Looks like lately we have influx of "magicians" claiming to outperform real antennas with some miniatures. So far no winners! Good Luck. Yuri, K3BU, ex OK3BU |
RoomCap Antenna
On Tue, 16 May 2006 11:24:00 +0000, Felix
wrote: Here follows the contacts and the received signal reports: 20:10 DJ6YF, 59+10, Hans, Bielefeld 20:10 DL3EAI, 59, Reino, Mittetal (nr border to PA) 20:14 DJ6LGB, 58, Peter, Lüneburg 20:17 G4KHM, 57, John, nr. Brighton 20:23 DL1JGG, 58, Renald,Plauen 20:30 DC4HW, 59 Walter, Lauenburg nr Lueneburg 20:33 DG6DAG, 59+10, Otto, Nord-Hessen nr Kassel 20:40 YO4RDW, 57, Romeo, Odfbesei, Rumaenien 20:50 F4AWH, 59, Jean-Luc, nr Besancon 20:55 2E0BOT, 59, John, Stratford UK 21:10 DF9YK, 59, Wolfgang, Mainz 21:11 SP8TDV, 57, Adam, Lublin, Poland 21:13 HB9AQA, 59+10 - +20, Ferdi, nr Lenzburg 21:22 9A4M, 59, Mate, Sisah, Croatia 21:28 G1RVP, 57, Pete, Dereham 21:30 DJ6MM, 59+10, Paul, Eifel 21:38 DK5WN, 59, Thomas nr Erfurt 21:39 SP1DTE 58, Luk Koloberg, Poland 21:40 HB9XJ, 59+10, Hans, Zuerich 21:43 QRT With best 73s Felix HB9ABX Felix, first of all, there needs to be a comparison with other antennas over a number of different days with different conditions. Secondly, I can't believe 59 reports from DX stations (I know, this puts you into a handicap situation.) The problem is that many DX stations will report 59 and ask you to repeat your call or name a hundred times. The test really needs to be handled in an antenna shootout of sorts. I have a 20 meter hamstick on my car and I often get 59 reports from dx as well as CONUS stations. When band conditions are well, I can get a 59 signal from a qrp rig. The real test of the antenna will be with comparing the reception and reports with the weakest stations. It takes a tremendous power change to change a strong signal's report. Additionally, you claim to be the creator of this antenna. This is also a problem since you are trying to profit from it's plans. You don't have calibrated or calculated gain/loss, bandwidth or radiation patterns. What's to say your antenna is any better than the grasswire antenna if you haven't compared them? -- 73 for now Buck N4PGW |
RoomCap Antenna
On Wed, 17 May 2006 12:36:28 -0400, "Yuri Blanarovich"
wrote: Hams are (or were) known to be honest, gentlemen and willing to share their ideas with others for advancement of our art. Looks like lately we have influx of "magicians" claiming to outperform real antennas with some miniatures. So far no winners! Good Luck. Do you remember the antenna that came out in the middle to late 70's? It was a dipole antenna with a specially designed cobra-head that tuned it to any HF frequency. The SWR was virtually flat across all bands from 160 meters to 10 meters regardless of the length of wire. No tuner needed! Several companies bought one and tried to disassemble them. The result was always a mess of broken parts. x-rays were fooled by the number of parts, but someone was successful in taking one apart and yet leaving the actual connected parts of the antenna together. It turns out the antenna was nothing but a 50 ohm resister surrounded by many useless, broken parts frozen in the epoxy used to seal and hide the true design of the antenna. I wonder if that genius is still alive and well? -- 73 for now Buck N4PGW |
RoomCap Antenna
"Buck" wrote in message ... On Wed, 17 May 2006 12:36:28 -0400, "Yuri Blanarovich" wrote: Hams are (or were) known to be honest, gentlemen and willing to share their ideas with others for advancement of our art. Looks like lately we have influx of "magicians" claiming to outperform real antennas with some miniatures. So far no winners! Good Luck. Do you remember the antenna that came out in the middle to late 70's? It was a dipole antenna with a specially designed cobra-head that tuned it to any HF frequency. The SWR was virtually flat across all bands from 160 meters to 10 meters regardless of the length of wire. No tuner needed! Several companies bought one and tried to disassemble them. The result was always a mess of broken parts. x-rays were fooled by the number of parts, but someone was successful in taking one apart and yet leaving the actual connected parts of the antenna together. It turns out the antenna was nothing but a 50 ohm resister surrounded by many useless, broken parts frozen in the epoxy used to seal and hide the true design of the antenna. I wonder if that genius is still alive and well? 73 for now Buck N4PGW Yea, it was and believe still is MAXCOM magik flat antenna :-) You can fool some people..... Yuri |
RoomCap Antenna
On Wed, 17 May 2006 23:48:26 -0400, "Yuri Blanarovich"
wrote: Yea, it was and believe still is MAXCOM magik flat antenna :-) You can fool some people..... Yuri It looks like he is now selling it as an antenna tuner. Not accounting for his marketing technique, his idea wasn't all bad. I found a 100 ohm, 300 watt resistor when I worked for George at Disc-Cap electronics, a surplus sales company. It was heavy, but I wired it across the two legs of an 80 meter dipole and got less than 1.5:1 anywhere I tuned the transmitter. It was lossy compared to a resonant antenna, but it worked ok. I would love to have one again. In an emergency, you can't get the wrong length of antenna wire, even no wire gave a good match and would probably radiate 100 watts at least as well as some QRP stations ;). Of course one needs to HEAR the station they are talking with sometimes.... I would love to compare the results of using that with the t2fd. -- 73 for now Buck N4PGW |
RoomCap Antenna
Felix wrote:
Roy Lewallen Wrote: Buck wrote: . . . If it performs as well as you claim it does, or if it is similar to the performance of an EH per size,(for example, hypothetically speaking, a 3 foot antenna performs as well as a 1/2 wave vertical 20 meter antenna), and if the cost and skill level required for building the antenna is suitable to me, I might be interested in purchasing the plans for your antenna. . . . You must mean, "If it performs as well as the EH antenna claims to perform." If it can do that, it's miraculous indeed. It's no trick to make an antenna perform as well as an EH -- a 3 foot high (fat) vertical performs as well as a 3 foot high EH. Roy Lewallen, W7EL HERE A FEW RESULTS: QRV with RoomCap antenna on 80m On May 15th, 2006 I was QRV on 80 m during 1 1/2 hour. Tcvr: TS-50 (100 W PEP), QRG = 3.770 - 3.787 Mhz Antenna: RoomCap with 1.66m radiator length installed on my car. SWR = 1.0 QTH: Peripheral part of city of Basel. Conditions: The band was weak with a lot of QRN. Here follows the contacts and the received signal reports: 20:10 DJ6YF, 59+10, Hans, Bielefeld 20:10 DL3EAI, 59, Reino, Mittetal (nr border to PA) 20:14 DJ6LGB, 58, Peter, Lüneburg 20:17 G4KHM, 57, John, nr. Brighton 20:23 DL1JGG, 58, Renald,Plauen 20:30 DC4HW, 59 Walter, Lauenburg nr Lueneburg 20:33 DG6DAG, 59+10, Otto, Nord-Hessen nr Kassel 20:40 YO4RDW, 57, Romeo, Odfbesei, Rumaenien 20:50 F4AWH, 59, Jean-Luc, nr Besancon 20:55 2E0BOT, 59, John, Stratford UK 21:10 DF9YK, 59, Wolfgang, Mainz 21:11 SP8TDV, 57, Adam, Lublin, Poland 21:13 HB9AQA, 59+10 - +20, Ferdi, nr Lenzburg 21:22 9A4M, 59, Mate, Sisah, Croatia 21:28 G1RVP, 57, Pete, Dereham 21:30 DJ6MM, 59+10, Paul, Eifel 21:38 DK5WN, 59, Thomas nr Erfurt 21:39 SP1DTE 58, Luk Koloberg, Poland 21:40 HB9XJ, 59+10, Hans, Zuerich 21:43 QRT With best 73s Felix HB9ABX Well well... Whatever one believes and/or thinks about the EH-Antenna, Ted Hart, the creator and the patent holder, is honest enough to release the full design information to the ham community - to hate or to love. The method of selling sealed envelopes is - at the best regrettable and at worst, something really different. As the EH-Antenna is targeted to the commercial world - this antenna is an obvious way of making money out of the non-commercial hams. I think the judgement are coming down hard on you Felix and I have to agree on this judgement. Again, nothing personal but maybe a very much middle European way of selling. As the Ham world is mainly Anglo-Saxon - it just doesn't work! I suggest you do as the EH-Antenna Inc, release the full info for homebrewers and sell a ready made version to the turn-key amateurs instead! Cheers Dan / M0DFI |
RoomCap Antenna
I think the judgement are coming down hard on you Felix and I have to agree on this judgement. Again, nothing personal but maybe a very much middle European way of selling. As the Ham world is mainly Anglo-Saxon - it just doesn't work! I suggest you do as the EH-Antenna Inc, release the full info for homebrewers and sell a ready made version to the turn-key amateurs instead! One of the advantages of selling the ready made version is to ward off those who don't follow construction details carefully and unfairly generate negative reports about the antenna. From what I gather, it is very inexpensive to build which lends to room for a large enough markup to gain some profit. -- 73 for now Buck N4PGW |
RoomCap Antenna agreement
Felix:
You have an agreement buyers must abide by. Would you please post it here so we can all read it before paying? Buck -- 73 for now Buck N4PGW |
RoomCap Antenna
20:10 DJ6YF, 59+10, Hans, Bielefeld
20:10 DL3EAI, 59, Reino, Mittetal (nr border to PA) 20:14 DJ6LGB, 58, Peter, Lüneburg 20:17 G4KHM, 57, John, nr. Brighton 20:23 DL1JGG, 58, Renald,Plauen 20:30 DC4HW, 59 Walter, Lauenburg nr Lueneburg 20:33 DG6DAG, 59+10, Otto, Nord-Hessen nr Kassel 20:40 YO4RDW, 57, Romeo, Odfbesei, Rumaenien 20:50 F4AWH, 59, Jean-Luc, nr Besancon 20:55 2E0BOT, 59, John, Stratford UK 21:10 DF9YK, 59, Wolfgang, Mainz 21:11 SP8TDV, 57, Adam, Lublin, Poland 21:13 HB9AQA, 59+10 - +20, Ferdi, nr Lenzburg 21:22 9A4M, 59, Mate, Sisah, Croatia 21:28 G1RVP, 57, Pete, Dereham 21:30 DJ6MM, 59+10, Paul, Eifel 21:38 DK5WN, 59, Thomas nr Erfurt 21:39 SP1DTE 58, Luk Koloberg, Poland 21:40 HB9XJ, 59+10, Hans, Zuerich 21:43 QRT =-------------------------------------------------------------------------------------------- The reports are pretty lackluster I'd say... A 1/2 dipole would have trounced that thing... It might be small, but so is the performance judging from your reports. If I was working regional distances like that and got 57-58 reports, I'd be wondering who cut my antenna down.. :/ MK |
RoomCap Antenna
On 29 May 2006 06:21:41 -0700, "George" wrote:
How about a design that is small in size, loads the feedline, lights up the shack, and fries my pacemaker? RF has got to go somewhere! It is a good bet that if the military and commercial users have not or do not accept the super design, then I think I will save my $ for the more accepted, tried and true antenna. New ideas need to be consistant with the accepted laws of physics unless what is being proposed is so radical that it breaks new ground. At that point it is the job of the inventor to lay out the theory and application for peer review. Otherwise, we spend a lot of time shooting the bull. Yes but after we shoot the bull the barbecue is so much fun! :} wrote: 20:10 DJ6YF, 59+10, Hans, Bielefeld 20:10 DL3EAI, 59, Reino, Mittetal (nr border to PA) 20:14 DJ6LGB, 58, Peter, Lüneburg 20:17 G4KHM, 57, John, nr. Brighton 20:23 DL1JGG, 58, Renald,Plauen 20:30 DC4HW, 59 Walter, Lauenburg nr Lueneburg 20:33 DG6DAG, 59+10, Otto, Nord-Hessen nr Kassel 20:40 YO4RDW, 57, Romeo, Odfbesei, Rumaenien 20:50 F4AWH, 59, Jean-Luc, nr Besancon 20:55 2E0BOT, 59, John, Stratford UK 21:10 DF9YK, 59, Wolfgang, Mainz 21:11 SP8TDV, 57, Adam, Lublin, Poland 21:13 HB9AQA, 59+10 - +20, Ferdi, nr Lenzburg 21:22 9A4M, 59, Mate, Sisah, Croatia 21:28 G1RVP, 57, Pete, Dereham 21:30 DJ6MM, 59+10, Paul, Eifel 21:38 DK5WN, 59, Thomas nr Erfurt 21:39 SP1DTE 58, Luk Koloberg, Poland 21:40 HB9XJ, 59+10, Hans, Zuerich 21:43 QRT =-------------------------------------------------------------------------------------------- The reports are pretty lackluster I'd say... A 1/2 dipole would have trounced that thing... It might be small, but so is the performance judging from your reports. If I was working regional distances like that and got 57-58 reports, I'd be wondering who cut my antenna down.. :/ MK I've learned that I don't suffer from insanity, I enjoy it! (The hell with my X-wife!) Remove the x for e-mail reply www.outdoorfrontiers.com www.SecretWeaponLures.com A proud charter member of "PETAF", People for Eating Tasty Animals and Fish!!! |
George wrote:
- New ideas need to be consistant with the accepted laws of physics - unless what is being proposed is so radical that it breaks new ground. - At that point it is the job of the inventor to lay out the theory and - application for peer review. Otherwise, we spend a lot of time shooting - the bull. Theory is as good, as it corresponds with the real world. If your theory does not correspond to the real world results you have to revise it. But maybe it is just your understanding of the full theory. The design is available for anybody who wants to check it. Contact me with best regards Felix HB9ABX |
RoomCap Antenna
The design is available for anybody who wants to check it. Contact me Felix HB9ABX ===================================== How much money do you want up front? |
NEW: RoomCap 160 m Antenna
4th August 2006 I am glad to announce, that the 160 m version is ready, and has been tested successfully. This constitutes a new milestone in antenna technology! The radiator measures only 2% of the wavelength and works equally well as a 36 m longwire. The length of the radiator is 320 cm, and the test antenna was installed on my car. Within a few seconds the SWR is set to 1.0 in the full band from 1.8 to 2.0 MHz, simply by pressing a botton. The last 4 nights I could test and compare this new antenne, and it was a real pleasure. However, one must be aware that the topband 160 m is a night band. Band opening is about at 22h, something for night fans. The comparison was against a 36 m longwire, perfectly matched, 9 m above ground in free environment. Both station were operating with the same power, at the same location (within 300 m). (Thank you Sergio, HB9BXS for your preseverance!) The remote stations gave the following reports, always after a couple of short changeovers between our 2 stations: DJ5MX (Böblingen near Stuttgart) QRB = 170 km - Roomcap is 1 S-point stronger DJ1HS (Lauterhofen nr. Nuernberg) QRB = 360 km - both stations have the same signal strength DJ8YP (Sigmaringen) QRB = 140 km - Roomcap about 3 db weaker DD1IW (nr. Muenchen) QRB = 315 km - both stations are about equal G3IMX (Isle of Wight) QRB = 715 km - Roomcap is 6 to 10 db stronger G0RRM (Lichfield) QRB = 920 km - Roomcap 1/2 S-point weaker G3URM (Staffordshire) QRB = 940 km - Roomcap about 1 S-point stronger + many other stations, confirming the same result. The update for the owners of the construction guide is ready in about 10 days. 73s Felix HB9ABX. |
Confirmation of RoomCap results:
Dear OMs, My published results have been confirmed by several builders of the RoomCap antenna. Here follows the mail I (Felix HB9ABX) received from Belgium: On Sonday, I've done the first test with the roomcap antenna on 14 MC. I've did the test with a - roomcap antenna, 80 cm above the ground. - Microvert 3 m above the ground. The results with the two antenna's: -the roomcap antenna = +1,5 S punt -- +3 S punt better. This result is dependant of different incoming signals. I do have to notice that the roomcap antenna receives more back ground noise. I'll keep you posted on further test-results. Best 73 on6wb albert |
Performance of the ROOMCAP Antenna:
There are many antenna books where you find: You need "much wire in the air" in order to obtain an efficient antenna. Short antennas have an efficiency of 1 to 5 percent ... Now the time has come to revise these statements! The radiator length was 3m and the antenna height was 1.5m above ground, mounted on the car, with 60 W PEP on 160m: Date: Thu, 31 Aug 2006 22:57:42 +0200 From: Heino Held To: hb9abx (at) tiscali.ch Subject: Mobilantenne oder Festantenne Hallo Felix, nach unserem tollen QSO auf 160m waren Peter (DL1BLD) und ich (Heino, DJ5ER) total erstaunt mit welch einer tollen Feldstaerke Du in Bremen angekommen bist. Wie man eine solche Antenne bauen kann moechten wir gerne wissen (auch fuer die anderen KW-Baender). 73 aus Bremen von Peter (DL1BLD) und Heino - DJ5ER Translation: Hello Felix, after our fantastic QSO on 160m we (Peter,DL1BLD) and I (Heino, DJ5ER) we were completely surprised with what a strong field strength you arrived in Bremen. We would like to know how such an antenna can be built (also for the other HF bands). 73 from Bremen .... (QRB = 600 Km) -------------------------------------------------------------------- 5th September 2006: Now I have reduced the length of the radiator to 2m = 1.25% of the wavelength, and I still get the same good reports, as can be seen on the email I received after a few fine contacts last night. Still with 60W PEP, at the border of the city, antenna mounted on the car: Hello Felix. Congratulations for your antenna work. You are the first mobile station on 160 meters for me. Even you are stronger as the Germans on 160 meters. I give you on 1.862 Mhz S 9+15 db in the peak!! The background noise level was S 8 during our QSO Hope to meet you agn for next report and test. Piet Schipper / PA0QRS (near Rotterdam) Schipper mobiele Telecom 2931 LH Krimpen a/d Lek ----------------------------------------------------------------------------------------- Such experiences show, that you can transmit with this small antenna as effective, as with a 60m long wire, up in the air. This is possible with: - Radiating planes and not wires - Differential feeding system - Elaborated grounding system to minimise ground loss - Perfect, low loss matching of antenna radiation resistance With best 73s Felix HB9ABX |
Hi,
many of you have been waiting long time for user evaluations of the RoomCap antenna. Here follows two recent reports: (posted by Felix Meyer HB9ABX) They speak for themself. ------------------------------------------------------------- Betreff: Bravo -Room Cap Antenna Datum: Fri, 20 Oct 2006 18:59:12 -0700 (PDT) Von: Paul Ragany VE3UNF ........ An: hb9abx....... Hi Felix : I have built the 20 meter version and it has reached more than my expectations. The antenna is fantastic - It is unbelieveable- I have been comparing it to my G5RV and it out performs the G5RV . Details: Most tests were conducted between Tampa (Florida), my location, and Toronto (Canada), VE3ZUH, over a distance of 1700 km (1060 miles), using an FT-747 with 75 W output. After two weeks, the results of my testing with VE3ZUH far exceeded my expectations . VE3ZUH consistantly reports 2 s units better on the Roomcap compared to my G5RV. I check in to the Maritime Net everyday on 14300.0 and I consistantly get a strong 5 and 9 report from the net controllers who are scattered all over the U.S. at various times of the day. With the G5RV I get 5 and 8 to 5 and 9 reports. On DX on Oct 19th I talked to OH2BH and OT4A (Belgium) - they report 5 and 9 for my signal and I receive them at 5 and 7 . On Oct 20th talked to Rob -HA503 FIN -special event station in Hungary -he reports a 5 and 9 and I receive him at 5 and 7. The G5RV was hearing 4 and 3to 5. On receive, I average about 2 s units better about 50% of the time. The signals are the same about 25% of the time and the G5RV is about 2 s units better the other 25% of the time. I attribute that to the 180 directionality if the G5RV ( north/south). Thanks for everything and we'll keep in touch, 73 Paul A Ragany VE3UNF PS: The G5RV is 2 x 15,8 m about 9m above ground. The RoomCap has a radiator of 1,5 m length, installed on a wooden stand 1,2 m above ground. --------------------------------------------------------------------- Betreff: hb9abx antenna Datum: Sat, 21 Oct 2006 15:52:40 +0200 Von: jeveraert ON6EJ@....... An: hb9abx@....... Hello Felix, On my way back from work (Italy) to home (Belgium) I had some time to visit you in Basel. I was searching for a good antenna that is small in size. Thanks to the Internet, I came across your website where you published some information about your newly designed RoomCap antenna. I expected to see a mobile antenna that performed well, I have seen other portable and mobile antennae, so I have an idea as to what I might expect. What I have seen was an antenna that, due to it’s design, looked a little bit bulky. This (maybe) disadvantage ‘’look’’ was quickly forgotten when we made the first QSO’s. As simple as it can be, from the car with the TS50, several qso’s were made. No comparison with what I have experienced before during other mobile HF operations. Signal reports obtained were outstanding, even when using a transmit power power of 10 Watts ! My impression of this antenna is very positive. I’ve never seen any antenna performing like the one you have on your car ! (taken into account the size of it) I’m very glad that I’m now able to build my own. Thank you for the good work ! Best Regards Jan, ON6EJ ----------------------------------------------- |
RoomCap Antenna
On Tue, 24 Oct 2006 21:16:21 +0000, Felix
wrote: many of you have been waiting long time for user evaluations of the RoomCap antenna. We already have some old, but superlative evaluations from Wall Street about Enron that are far more useful. |
Quote:
Comparison: RoomCap with EH-Antenna The EH-antenna is offered as a compact, efficient short antenna. The user reports about this antenna are very varying, from enthusiastic to unusable. Therefore, I was interested since long time to perform a comparison test of the RoomCap with this antenna. On Nov 30, 2006 we could do that. Andy, HB9DWF is owner of this antenna, and he was willing to perform a field test. We installed both antennas in a free camp and tested exhaustively on 160m. Comparing antenna: EH Venus from Arno (Italy, WIMO Germany) Length = 2.5m, Diameter = 8cm / 12.5cm, Weight = 4.9 Kg Test antenna : RoomCap 160m, radiator length = 3m, Diameter = 7,5cm with top capacity Both antennas were installed with about 30m separation, at a height of 1.5m above ground, and connected via decoupled coax cable and coax AB switch to the 100 W transceiver. First, the SWR was checked: It was found, that the EH antenna is very narrow, in contrast to the statement of WIMO who says: "due to the design the entire band can be used." The acceptable bandwith of the antenna was found to be just 20 KHz (!) with resonance at 1.860 MHz. In contrast, the RoomCap can be used in the full band from 1.800 to 2.000 with a VSWR 1:1, without using a tuner. This problem complicated the testing somewhat, as we had to ask the remote stations to change the QRG to 1.860 to allow operation of the EH antenna on its best operating frequency. The comparison tests began at 20.00hrs with a duration of one hour and 20 minutes. Until then we had 11 test contacts, and Andy said, that further QSOs do no longer change the result. The result was clear. In each contact the antennas were changed many times, and the remote operators were asked to measure the signal difference. All stations reported that the EH antenna is significantly weaker, and they reported signal differences beween 2 to 4 S points. The averaged signal difference was 3 S points. Some stations were unable to measure the signal difference, as the signal of the EH antenna was not readable. The following stations participated in the comparing test QSOs: F9EZ, I2BBJ, HB9ZY, F/HB9DHO, HB9BBM, HB9AGN, HB9COP, HB9JMD, DL9FCP, DL1EFR, DB3MA. Conclusion: The test showed, that it is possible to make contacts with the EH antenna, however the signal strength in comparison to the RoomCap antenna is about 3 S points weaker. (18 db correspond to a power relation of 1:63). This "good result" is obtained only, if the antenna is operated within 20 KHz of the resonant frequency. If the antenna is used outside this frequency range, an additional signal loss of 1 S point and more is to be expected ... Felix Meyer HB9ABX |
RoomCap Antenna
Felix wrote:
Comparison: RoomCap with EH-Antenna The EH-antenna is offered as a compact, efficient short antenna. The user reports about this antenna are very varying, from enthusiastic to unusable. Therefore, I was interested since long time to perform a comparison test of the RoomCap with this antenna. Now, an additional comparison was made, now between RoomCap and Magloop antenna. Since long time it was my desire to compare the RoomCap antenna with a good magnetic Loop antenna. On November 30th 2006 this test took place. The test was assisted by Edy, HB9EBG. Comparing antenna = Magnetic Loop, 85cm diameter, 35 mm diameter of tube, copper tube, silvered, with Annecke butterfly capacitor with remote tuning, in vertical position. Test antenna = RoomCap for 20m, 5cm diameter, length of radiator = 150cm, without top capacity. Both antennas were placed at the same height (150 cm above ground) in a free field, using the same 100 W transceiver, and adjusted to VSWR 1:1. In total, 13 comparing QSOs were conducted in the time between 13.30h to 16.00h. In each QSO the antenna was quickly changed many times and the remote station was asked to indicate the average signal strength difference between the two antennas. In all contacts the RoomCap was reported clearly as the stronger antenna, where the smallest reported difference was 1 S point and the largest difference was 5 S points. Here follows the list of the reporting stations with the indicated difference in S points. YO5PDW + 1 LY3ZM + 3 RU6AH + 1 UA3AIU + 1,5 YO3AJN + 2 EA8BRW + 2 LY2SP + 4 UR0EA + 2 YO4AAC + 1 UT8NF + 1 YO6KSU + 2 UR5HDE + 5 SV0XBA + 2 This corresponds to an average difference of 2.11 S points. An S point is defined as 6 db, resulting in about 12 db advantage. (It is clear, that the receivers many times do not follow exactly this definition, but in the average this may be close enough.) In other words: The RoomCap radiates about 15 times stronger than the Magloop. (15 times the power). Felix HB9ABX |
RoomCap Antenna
Felix, I'm surprised over this test... What you are implying but not writing is that your RoomCap doesn't work as well as an EH on 160m... I don't think that was what you intended... Hehe Go home and do some basic math will you... The 160m EH need to be mounted 1/4 of a wavelength up while your RoomCap seems to be a vertical, able or even meant to be used from groundlevel... If, as you claim, the EH is only 2 S units down? Wow! That's good - even absolutely bloody excellent! Well done EH! Unless the compared antenna is crap of course! And as I have not seen any building description on the RoomCap yet, who can tell... If that EH where to be mounted at it's design height, you would have won at least 3 to 6dB signal strength, equal to 1 to 2 S units. Also, the bandwidth of the EH suffers when mounted wrong ( to low ). Why can't these testers RTFM before setting out to prove function or no-function of whatever gadgets they want to test?! It's clearly stated about the mounting height! However!!!!! I'm very concerned over your statement about only one (1) S unit down if you rx/tx outside the EH design frequency ( bandwidth ). My EH's ( proper STAR's ) are shortcircuits when outside the bandwidth! This is why they suppress TVI/RFI and harmonics in general as well as preventing the coax to radiate ( one of the reasons anyway ). If described in S units, the STAR is down 7 to 9 S units ( well outside the 3dB bandwidth )if operated outside the bandwidth. It just goes quiet and the bandnoise just vanishes - exactly like the shorted coax it just became... You just told me the 160m EH you tested radiates from the coax?! As you only had 1 S unit down outside the bandwidth. Bad bad bad! Was that an EH at all?! Or just a short fat dipole? And guess what... All the EH documentation are available on the net for hams to try... without charges and fees... //Dan, M0DFI |
RoomCap Antenna
Felix wrote:
... Felix: Personally, I have a use for a small antenna. One which I can chuck into my trunk and take along on quickly planned days away in the wild. I have used the EH and got it up to good heights using a cord and slingshot. It is not an efficient antenna in accepted terms. The good match it provides over a good bandwidth and small size makes it perfect for some of my adventures though. Hoisted high in a tree at the 11,500 ft elevation makes it look good to me; good to at the 9,500 ft elevation while I fly fish mosquito lakes and have a bit of chat. Efficiency is in the eye of the beholder. Put paying for a CD to show me how to build another of these "dummy load antennas" just doesn't float in my book ... Regards, JS |
RoomCap Antenna
Felix wrote:
... Dummy load antennas are all over, this is one link I stumbled upon today, good pics. http://guests.antennex.com/rooms/hws/ws0900/dda_rf.htm Regards, JS |
RoomCap Antenna
John Smith wrote:
... That didn't work, so here is yet another example: http://home.comcast.net/~ac9ts/pdf/M...rt_english.pdf JS |
RoomCap Antenna
John Smith mentioned the Microvert antenna, which I know very well. I made an extensive comparison of the RoomCap (hb9abx) against Microvert, and was using the best Microvert available (MV-500) for 40m. Test at same location, both antennas at same height in A-B configaration. Test was performed by many rapid changes between the two antennas, and the remote station was observing the signal strength. Result was, that the RoomCap was 2 s-points stronger in average, in receiption as well as in transmission. Rember that 2 s-points correspond to 12 dB. A very clear result. 73s Felix HB9ABX |
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