Re: Topband: Waller Flag Question
And if you look at US Patent 2,247,743, it appears that Harold Beverage conceived of a horizontal Flag around 1941. best wishes, Nick At 21:52 06-09-15, you wrote: Bruce wrote on Sept 6. Snip < Check it out http://www.qsl.net/k4fk/presentations/WF-receiver-antennas-SFDXAs.pdf > Bruce, ref to the link above there is a gap in the "History of the Flag Antenna" The earliest fef. to the Terminate loop I have found is in Keenâs Wireless Direction Finding 1927 Ed. Page 75. Keen describes a two turn resistance terminated loop used by Societe Francaicse Radio-Electrique. It resembles the K9AY and uses a similar operation to create a cardiode. 73 Andrew Ikin G8LUG _ Topband Reflector Archives - http://www.contesting.com/_topband _ Topband Reflector Archives - http://www.contesting.com/_topband
Re: Topband: Waller Flag Question
On Sun,9/6/2015 4:31 PM, Tom W8JI wrote: Thanks for the insights. I have no doubt the theory is correct. My sense, though, is that in the denser suburbs, we live in a "fog" of local radio noise, generated by the scores of digital and other devices that surround us. The sad thing is that many of us have a score of noise sources in our own homes, and more in the homes that surround us. I have at least that many products that came with SMPS wall warts or equivalent, and many of the products themselves are potential noise sources. I've replaced all of the SMPS blocks that came in my door with vintage linear supplies (and some are vintage linear supplies float-charging sealed lead acid batteries. Both the supplies and batteries are chosen so that the battery doesn't get overcharged. And I have a "poor man's UPS" in the form of this setup. I've also choked cables coming from noisy gear to kill common mode current on those cables that could otherwise radiate. 73, Jim K9YC _ Topband Reflector Archives - http://www.contesting.com/_topband
Re: Topband: Waller Flag Question
Thanks for the insights. I have no doubt the theory is correct. My sense, though, is that in the denser suburbs, we live in a "fog" of local radio noise, generated by the scores of digital and other devices that surround us. A similar observation was made 20 years ago by Brian Beezley, K6STI, in a QST article titled "A Receiving Antenna that Rejects Local Noise" (September, 1995, page 33): I've been looking around for something that might work better than my present antenna, and I see good reports about the Waller flag from people who are actually using it. So I'll give it a try and see how well the theory matches up with actual practice. That's what ham radio is all about -- no? You said earlier: The on-line materials about Waller Flags says that a modest size WF would need about 40 dB of gain to boost the signal to a usable level. One of the postings says that cascading two preamps of 20 dB each seems to add extra noise, and they talk about developmental work being done on a single preamp of 40 dB. I'm not sure where "need about 40 dB of gain to boost the signal to a usable level" comes from. 40dB is an unworkable amount of gain, unless the basic receiver is deaf. Here is an example: An Elecraft K3 has about -138 dB noise floor with preamp on. 40 dB more gain, or -178 dBm noise floor, would require a preamp noise figure of -18dB at 250 Hz BW and -24 dB NF at 1 kHz BW by my calculations. That's 100 times less noise than no noise. :) Maybe the reason people can't get two preamps cascaded to work isn't because it is two separate amplifiers, but they are trying to do something unnecessary and impossible? It seems to me 20-25dB would be more than enough for most receivers. 73 Tom _ Topband Reflector Archives - http://www.contesting.com/_topband
Re: Topband: Waller Flag Question
Bruce wrote on Sept 6. Snip < Check it out http://www.qsl.net/k4fk/presentations/WF-receiver-antennas-SFDXAs.pdf > Bruce, ref to the link above there is a gap in the "History of the Flag Antenna" The earliest fef. to the Terminate loop I have found is in Keen’s Wireless Direction Finding 1927 Ed. Page 75. Keen describes a two turn resistance terminated loop used by Societe Francaicse Radio-Electrique. It resembles the K9AY and uses a similar operation to create a cardiode. 73 Andrew Ikin G8LUG _ Topband Reflector Archives - http://www.contesting.com/_topband
Re: Topband: Waller Flag Question
Maybe his secret is a preamp cooled with liquid helium! ;-) Seriously, there are preamps operating at 70 degrees F (for example) that have less than a 1 dB NF at VHF. They are usually mounted at the feedpoint of a high gain array, because of feedline loss. Today, I have the type of terrible cold (hay fever?) that seriously interferes with one's thinking but I still have an open mind about this subject. Waller Flags fascinate me. I'm in learning mode and watching this thread closely. >From everything I have read in the past about the WF, it'll equal a one-wavelength Beverage in only 30' of space. And it's tough to rotate any Beverage for 160. How a WF would compare with my Beverages in this quiet rural location, I can't say. 73, Mike On Sun, Sep 6, 2015 at 1:53 PM, Tom W8JI wrote: > ... a modest size WF would need about 40 dB of gain >> > > ... would require a 1 dB noise figure front end. That's about 35 deg K > noise temperature. > > 40 dB gain in front of a receiver is pure fantasy,... > _ Topband Reflector Archives - http://www.contesting.com/_topband
Re: Topband: Waller Flag Question
Tom -- Thanks for the insights. I have no doubt the theory is correct. My sense, though, is that in the denser suburbs, we live in a "fog" of local radio noise, generated by the scores of digital and other devices that surround us. A similar observation was made 20 years ago by Brian Beezley, K6STI, in a QST article titled "A Receiving Antenna that Rejects Local Noise" (September, 1995, page 33): "During times of no detectable power line noise, we often noticed a curious effect: The loop still enhanced signal-to-noise ratio by one or two S units, making copy of moderately weak signals more pleasant. . . . We believe that the unidentified noise is local and propagates by the ground wave. We speculate that it may be the sum of hundreds of weak man-made noise sources in the densely populated suburb" (36). This problem has only gotten worse in the years since. Many 60-meter stations that I used to listen to are now on the lower edge of audibility, even on the best days. (Yes, I know my ears are older than they used to be!) At an earlier QTH, I built the antenna described by Beezley and it made a huge difference; stations that were barely hets with other antennas suddenly had fair audio. At my current QTH, the layout isn't quite right for that antenna, so I've been looking for something else that will cut through the "fog." My east-facing pennant does a pretty good job, but even it brings a lot of noise to the antenna port of the receiver. And, of course, it's a fixed-direction antenna. I've been looking around for something that might work better than my present antenna, and I see good reports about the Waller flag from people who are actually using it. So I'll give it a try and see how well the theory matches up with actual practice. That's what ham radio is all about -- no? Art > From: w...@w8ji.com > To: topband@contesting.com > Date: Sun, 6 Sep 2015 14:53:55 -0400 > Subject: Re: Topband: Waller Flag Question > > > The on-line materials about Waller Flags says that a modest size WF would > > need about 40 dB of gain to boost the signal to a usable level. One of > > the postings says that cascading two preamps of 20 dB each seems to add > > extra noise, and they talk about developmental work being done on a single > > preamp of 40 dB. > > > > Is there now such a 40 dB preamp? Is it made commercially? > > Alternatively, are there plans on-line somewhere? Has someone actually > > used it in a high-RF urban/suburban area, with multiple 50 kW AM BC > > stations? With what results? > > > > At some point we have to be realistic. > > A typical receiver is somewhere in the -130 dBm sensitivity range, depending > on bandwidth and other things. > > At -140 dBm and 250 Hz noise bandwidth, the system would require a 1 dB > noise figure front end. That's about 35 deg K noise temperature. > > If you need a 40 dB amplifier (or even close to 20dB) into a normal good > receiver, you will never get the noise temperature of things in front cool > enough to let external noise set noise floor. The issue isn't connecting two > amplifiers in cascade, the issue is the limit of noise temperature. > > The only place negative gain antennas that require more than ~ 20 dB gain > with a normal receiver at a quiet location will work into the external > ambient noise floor generated outside the antenna is in a location blanketed > with strong local noise. Besides that, if the gain is so far negative the > coaxial cable will easily become more of an antenna than the thing we call > an antenna. > > 40 dB gain in front of a receiver is pure fantasy, unless the receiver is > dead as a door nail. > > 73 Tom > > _ > Topband Reflector Archives - http://www.contesting.com/_topband _ Topband Reflector Archives - http://www.contesting.com/_topband
Topband: Waller Loop Antenna
Many thanks to everyone who helped in my efforts to get my Waller Loop working correctly. Carlos very kindly sent me an email showing me the effect his tower has on altering the polar plot, his recommendation was detune the tower - this cured his problem - there is a free Polar plotting program available on the net - to answer other questions the transformers were made using the binocular cores as recommended in ON4UN's book, the 9:1 I used 4 and 12 turns, resistors are 560 and 580 ohms and the 1:1 was 4 turns primary and secondary again using a binocular core.Moving onto Eznec - this is very strange as I found a different outcome to my model - I started by downloading the file from Lee's comparison table, this did not have a boom, I added my 26 ft boom and the result was a change for the better in front to back! - I then added my tower into the model and the whole polar diagram fell apart this is different to what Jim found in his Eznec model - so I am not sure, however the final proof to my problem was in my last test. The antenna was mounted above my tower using a fiber glass scaffold pole, I took the complete antenna off the tower and placed it 20 feet up at ground level in one corner of my field - I took no common mode protection because I buried the feed cable 150 feet in to my shack. PERFECT - the antenna worked as it should, good F/B - on 40m beaming into Germany the stations when compared to my 2 phased 4 squares I was seeing I reckon around 20 ish dbs F/B. Its early days and I need to wait for the DX season to start so that I can compare with my beverages, however my immediate feeling is that the loops need to be bigger as there is not enough pick up - I have the low noise pre-amp which helps but at the moment the beverages appear slightly better.Thanks again to everyone who replied. Regards Dave g3rcq _ Topband Reflector Archives - http://www.contesting.com/_topband
Topband: Waller Flag Question
It can be done. JC, N4IS has been doing it and has the DX contacts that most can not hear.. The proof as they say "is in the pudding" He uses balanced twisted pair feed lines with pre-amps, and other noise reduction techniques.. Check it out http://www.qsl.net/k4fk/presentations/WF-receiver-antennas-SFDXAs.pdf 73 Bruce-K1FZ On Sun, 6 Sep 2015 19:53:14 +0100, Andrew Ikin wrote: Art Delibert wrote on Set. 6 snip Art, The Wellbrook FLG100LN Flag Head amplifier may offer a partial solution to the gain and IMD issue with multiple 50kW AM Tx. The amp. has a 23dB gain and a near to zero NF. The current production has an OIP3 of +49dBm and OIP2 of +90dBm. Additional 17dB gain in the shack could be afforded with a Dxeng RPA-1. Unfortunately, the Website details for the FLG100LN have not been updated to reflect the new design. Basically the new FLG100LN is the ALA100LN Loop amplifier with an 800 Ohm input matching/ Isolation transformer. 73 Andrew Ikin G8LUG _ Topband Reflector Archives - http://www.contesting.com/_topband _ Topband Reflector Archives - http://www.contesting.com/_topband
Re: Topband: Waller Flag Question
The on-line materials about Waller Flags says that a modest size WF would need about 40 dB of gain to boost the signal to a usable level. One of the postings says that cascading two preamps of 20 dB each seems to add extra noise, and they talk about developmental work being done on a single preamp of 40 dB. Is there now such a 40 dB preamp? Is it made commercially? Alternatively, are there plans on-line somewhere? Has someone actually used it in a high-RF urban/suburban area, with multiple 50 kW AM BC stations? With what results? At some point we have to be realistic. A typical receiver is somewhere in the -130 dBm sensitivity range, depending on bandwidth and other things. At -140 dBm and 250 Hz noise bandwidth, the system would require a 1 dB noise figure front end. That's about 35 deg K noise temperature. If you need a 40 dB amplifier (or even close to 20dB) into a normal good receiver, you will never get the noise temperature of things in front cool enough to let external noise set noise floor. The issue isn't connecting two amplifiers in cascade, the issue is the limit of noise temperature. The only place negative gain antennas that require more than ~ 20 dB gain with a normal receiver at a quiet location will work into the external ambient noise floor generated outside the antenna is in a location blanketed with strong local noise. Besides that, if the gain is so far negative the coaxial cable will easily become more of an antenna than the thing we call an antenna. 40 dB gain in front of a receiver is pure fantasy, unless the receiver is dead as a door nail. 73 Tom _ Topband Reflector Archives - http://www.contesting.com/_topband
Re: Topband: Waller Flag Question
Art Delibert wrote on Set. 6 snip would need about 40 dB of gain to boost the signal to a usable level. One of the postings says that cascading two preamps of 20 dB each seems to add extra noise, and they talk about developmental work being done on a single preamp of 40 dB. Is there now such a 40 dB preamp? Is it made commercially? Alternatively, are there plans on-line somewhere? Has someone actually used it in a high-RF urban/suburban area, with multiple 50 kW AM BC stations? With what results?> Art, The Wellbrook FLG100LN Flag Head amplifier may offer a partial solution to the gain and IMD issue with multiple 50kW AM Tx. The amp. has a 23dB gain and a near to zero NF. The current production has an OIP3 of +49dBm and OIP2 of +90dBm. Additional 17dB gain in the shack could be afforded with a Dxeng RPA-1. Unfortunately, the Website details for the FLG100LN have not been updated to reflect the new design. Basically the new FLG100LN is the ALA100LN Loop amplifier with an 800 Ohm input matching/ Isolation transformer. 73 Andrew Ikin G8LUG _ Topband Reflector Archives - http://www.contesting.com/_topband
Topband: Waller Flag Question
The on-line materials about Waller Flags says that a modest size WF would need about 40 dB of gain to boost the signal to a usable level. One of the postings says that cascading two preamps of 20 dB each seems to add extra noise, and they talk about developmental work being done on a single preamp of 40 dB. Is there now such a 40 dB preamp? Is it made commercially? Alternatively, are there plans on-line somewhere? Has someone actually used it in a high-RF urban/suburban area, with multiple 50 kW AM BC stations? With what results? Many thanks. Art Delibert KB3FJO _ Topband Reflector Archives - http://www.contesting.com/_topband
Re: Topband: CE1TBN
Congratulations Marco ...good job !!! 73Douglas, CO8DM "No creo que haya alguna emoción más intensa para un inventor que ver alguna de sus creaciones funcionando. Esa emoción hace que uno se olvide de comer, de dormir, de todo." - Nikola Tesla - Original Message - From: "Marco Quijada" To: "Topband" Sent: Sunday, September 06, 2015 11:06 AM Subject: Topband: CE1TBN I am happy I made 20 qso. 4 new one. Thank you CE1TBN Happy Ham El jueves, 3 de septiembre de 2015, Marco Quijada escribió: Good. I ll try to catch you CE1TBN El jueves, 3 de septiembre de 2015, sulaiman Aljedaie 7Z1SJ < s7z...@gmail.com > escribió: hello CE1TBN i will be on All Asia contest this weekend CU 73.s 2015-09-01 16:00 GMT+03:00 Marco Quijada : I will be on 80 meters this weeked. I am lookig for any qso I have a few qso with my call. I can work CW also CE1TBN _ Topband Reflector Archives - http://www.contesting.com/_topband _ Topband Reflector Archives - http://www.contesting.com/_topband _ Topband Reflector Archives - http://www.contesting.com/_topband
Topband: CE1TBN
I am happy I made 20 qso. 4 new one. Thank you CE1TBN Happy Ham El jueves, 3 de septiembre de 2015, Marco Quijada escribió: > Good. I ll try to catch you > > CE1TBN > > El jueves, 3 de septiembre de 2015, sulaiman Aljedaie 7Z1SJ < > s7z...@gmail.com > > escribió: > >> hello CE1TBN >> i will be on All Asia contest this weekend CU >> 73.s >> >> 2015-09-01 16:00 GMT+03:00 Marco Quijada : >> >>> I will be on 80 meters this weeked. I am lookig for any qso I have a few >>> qso with my call. >>> I can work CW also >>> >>> CE1TBN >>> _ >>> Topband Reflector Archives - http://www.contesting.com/_topband >>> >> >> _ Topband Reflector Archives - http://www.contesting.com/_topband
