Re: Topband: How Increase 160m power on FL2100z
I owned a FT2100Z for several years and the power on 160m was the same as other bands. I don't expect any design flaw. The original tubes are not available anymore, the 572's tubes manufactures nowadays are different and optimized for audio applications and does not perform at the same level as the originals 572's. You may just need more drive or change the input circuit for 160m. Regards N4IS _ Topband Reflector Archives - http://www.contesting.com/_topband
Re: Topband: Crossed Field Antenna
This antenna was evaluated before and published in QEX May June 2005 Just google Broadcast CFA antenna 73's N4IS -Original Message- From: Topband [mailto:topband-boun...@contesting.com] On Behalf Of Guy Olinger K2AV Sent: Thursday, April 10, 2014 2:43 AM To: Bill Aycock Cc: Michael St. Angelo; TopBand List Subject: Re: Topband: Crossed Field Antenna Let's see, what was that term, undead? 73, Guy. On Wed, Apr 9, 2014 at 11:31 PM, Bill Aycock billayc...@mediacombb.netwrote: WOW!! I thought that had been shot with a silver bullet, at a crossroad, and had a stake driven through its heart over ten years ago! The Flat-Earthers are still among us. Bill--W4BSG -Original Message- From: Michael St. Angelo Sent: Wednesday, April 09, 2014 8:28 PM To: topband@contesting.com Subject: Topband: Crossed Field Antenna It's been quiet on this group. The April 9th issue of Radio World Magazine has an article about the Crossed field Antenna. An company, Crossed Field Antennas LTD, Has filed a comment with the FCC espousing its advantages: http://apps.fcc.gov/ecfs/comment/view?id=6017582994 This should rustle you from you winter doldrums.. 73, Mike N2MS _ 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 Reflector Archives - http://www.contesting.com/_topband
Re: Topband: Shunt feeding the Skyneedle - new developments
I'm sure it will play well in terms of keeping your transmitter happy but the relatively large bandwidth you are measuring is indicative of substantial loss in the system somewhere. This would be a large bandwidth even if you did not have the bandwidth narrowing effects of a shunt feed. Hi guys, the 3 wires is actually a transmission line and the antenna is well known as Folded Unipole with 200 ohms impedance. My antenna is a Folded Unipole as well and has the same broadband SWR measurement's. The loss is the same for any tuning circuit it has nothing to do with the bandwidth. The ground plane does, and in this case it is the same, right? 73's JC N4IS _ Topband Reflector Archives - http://www.contesting.com/_topband
Re: Topband: Shared Apex Loop Array
Hi Jim The antenna geometry indicates that it should perform similar to a Waller Flag *under the same conditions*. The perform under same conditions is expected, however the WF RDF is between 11.5db to 12 db. How that compares with a 8.5db RDF antenna? I would say two antennas with the same RDF should perform similar. The WF is a different antenna, it's a rotatable pair of loaded loops. Each loop is open and loaded with a resistor. Regards JC N4IS _ Topband Reflector Archives - http://www.contesting.com/_topband
Re: Topband: circular polarization on 160m
Tom ' The way I see it is if the rate is not 0.546 uS or so, you do not have circular polarization.You have a slowly rotating wave, and the sense of the RX antenna would be meaningless unless you could time-sync rotation at that slow fading rate. Someone correct me if I am wrong. 100% correct My system has two WF's, same gain, one vertical and another horizontal, feeding two preamps into IC7800 two receivers. When there is fading on the signal E-W, the time of the rotation from H to V could be long as 5 minutes, most of the time between 1 to 2 minutes. Using M=S on the IC7800 I can keep the two receivers at same frequency, and I can hear one receiver on each ear. I used to QSO Raoul ZS1REC during summer time and sometimes we start the QSO using V pol and finished on H pol.. About the signal noise gain using H and V with two identical receivers, I can say there is no gain at all, when the signal is weak, I switch the other antenna off and hear with only one channel. The advantage to have both is just to avoid listening in the wrong antenna listening on both antennas at the same time. It is not diversity eider because my antennas are only 60 ft. apart . Besides E-W when the signal is coming from less 45 degree and it is fading, I never see rotation, the vertical signal can have a deep QSB and the horizontal signal constant with no QSB. That just happened last Saturday with the FT5ZM, the horizontal signal was solid all the time with no variation on the intensity, however the vertical signal had deep and fast QSB. My take on that is the propagation mode or multi-path, signals can arrive from a refraction out of a duct and or from the same direction but from a different region on the ionosphere. There is no real correlation between the two polarizations signals, in practice they don't mix. It is very different from HF or VHF where the wave is always coming from the same media. Another point is that refraction increase with the decrease square of the in frequency, on 160m the refraction is stronger than 80 or up, as a result it is not necessary to transmit a horizontal signal to answer a horizontal polarized income signal. When the TX signal reach the first refraction point the wave split in two one vertical and another horizontal. What means is the efficiency to couple the TX signal with the atmosphere this is more important than the polarization itself, but 160m only, moving up in frequency the results are completely different, and 30 MHz to 50 MHz it is even special because it is transition from HF to VHF propagation mode. The experiments on 28 MHz does not apply to 1.8 MHz. Between 1 and 2 MHz , everything is different from HF or VHF Regards JC N4IS _ Topband Reflector Archives - http://www.contesting.com/_topband
Re: Topband: circular polarization on 160m
James You brought a good article about HF propagation, however the behavor on 160m is different from HF. If you check on the KL7A arcticle figure 1 what is happening between 1 and 2 MHz you can see that the green and red does not behaivor the same way as above 2 MHz. This subject is more complex because there us no shirt answer, actualy between 1 and 2 MHz. the ionosphere does not support linear polariration wave. The wave are actualy eliptical and not circular for most directions. You can check the long answer on the must read book from NM7M . R Brown 'The Big Gun's Guied to Low Band Propagation . Magneto-iomic Theory pag 47 to 56 ; and Power coupling pag 57. Thanks to Karl. K9LA, the book is available on his also must read site on the 160m link http://k9la.us/html/160m.html Regards JC N4IS _ Topband Reflector Archives - http://www.contesting.com/_topband
Re: Topband: circular polarization on 160m
Hi Carl and top-band lovers I would like to mention Chapter 7.6 as well, polarization matching, and also 7.7 Fading. I started developing my HWF early 2009 and I think there is no more to squeeze from it. Here some update in respect of polarization on 160m. It is a game!, vertical and horizontal field changes all the time, an elliptic can describe better the waves on 160m. My last HWF tuning gave me another 6-8 db improvement on the signal noise ratio. The HWF is really an all directions noise cancelling antenna ( Va-Vb=0), the goal is maximum attenuation on the vertical field an good directivity on the horizontal field. The takeoff angle is always the same and does not change with the height above ground ,it always very close to 40 degree. It is alike high horizontal dipole that takeoff change with the height from ground. The HWF has a deep null from high angle signals at any height above ground. The game is maximum attention on the vertical signal because most of the manmade noise, power line noise, city noise propagate with vertical polarization due the proximity with the ground for 160m waves. For 160m the HWF needs to be over 100 ft. to perform well on the horizontal signals, 50 ft. is ok for 80m and up. The HWF works 160m to 30m with excellent performance depending on the area of the loops. The HWF gain is around -43 db, and the vertical attenuation can be adjusted to deep another -50db, the total attenuation front and back is -90 db , It has a front null and a back null for vertical signals. This is a weak, weak, weak signal system implementation, very complex by nature by receiving near the receiver noise floor most of the time. Depending on the direction of the wave the H/V ratio can be -20 db or more both ways, most of the time the vertical component is 10 to 20 db stronger than the horizontal component. When you combine the 4 variables, vertical gain, horizontal gain, vertical noise QRM and the signal H/V ratio you have your final signal to noise ratio, however on top of that you need to add the propagation noise as well. Another dependence is the solar cycle. We are at the peak of the solar cycle and the propagation this year has been very different . Long pass is peaking at the SS or SR and the signals from North are showing a strong horizontal component. or it could be just coincidence, just time will tell. Nowadays I can copy better weak signals with my HWV than my VWF in all directions. I just observed that recently with 8Q7BM, NH0Z,V63DX,4J6RO, 4K6FO and 4L5O, signals from NNW and NNE better on HWF. It is the first time I can hear better signals coming North with the HWF. It is all about signal noise ratio. For long path the new adjust also helped a lot. I detuned the TX tower to minimum noise on the HWF, making the diagram symmetrical on the polar plot. It looks like a butterfly for local vertical signals. Peter HS0ZKX is coming strong from SSW every 28 days. Just after the solstice last month the long path propagation was just fantastic. WV8. H40,RA0. JA. BA. BG and DU7 copy with Q5 from SSW from Dec 25th to Jan 1st , but few QSO's. only JA and DU7 on the log. FT5ZM only on the HWF as well. I agree with Carl. There hasn't been much work in polarization field on 160m, however It is a fascinate subject. Come on in folks! Regards JCarlos N4IS -Original Message- From: Topband [mailto:topband-boun...@contesting.com] On Behalf Of Carl Luetzelschwab Sent: Monday, February 03, 2014 12:17 PM To: topband@contesting.com Subject: Topband: circular polarization on 160m I hope everyone has had a chance to work FT5ZM on topband. With respect to circular polarization on our HF bands (3.5 - 28 MHz) and on 6m, theory says both the ordinary and extraordinary waves propagate thru the ionosphere with pretty much equal ionospheric absorption. Thus circularly polarized antennas can provide an advantage. Some of the real-world examples I'm aware of have been documented by G2HCG on 10m (in the old Communications Quarterly), by the original K6CT on 20m (in the RSGB Bulletin) and by WA3WDR on 75m (a web paper). I'm sure there are others out there, too. On 160m, theory says the extraordinary wave incurs much more ionospheric absorption (more heavily attenuated) due to 1.8 MHz being so close to the electron-gyro frequency. Thus in theory only the ordinary wave is useful on 160m, which says circular polarization wouldn't do any good. Now things happen on 160m in the real-world that we simply don't understand. For example, an ordinary wave can excite an extraordinary wave under certain ionospheric conditions (if you'd like to read more, curl up in a warm place on a cold night with Chapter 3 in Ionospheric Radio by Kenneth Davies). Could this be happening? I don't think we can rule it out. In my opinion based on all the reports on this reflector over the years, it seems to me that having selectable elevation angles is more important than polarization. But I also admit that there hasn't
Re: Topband: Single antenna port xcvr but want to employ separate receive antenna
Hi James There are several solutions for a separated receive port. However let me comment on some details, 1- Small Delta loop. To be a receiver antenna the antenna gain need to be less than 20 db, why ? simple. Connect a power meter and a 50 ohms load on the Small Delta loop and measure how much power is captured from the TX antenna, I know several guy the burn the RX port on ICOM and YAESU radios using transmit antennas as receiver and injecting 100W into the RX port when transmitting with a legal limit amplifier. Port isolation and RF protection must be the first concern for any solution. If the antenna used for RX is resonant on the same TX band , you can really burn you RX front end. 2- Switch speed. The receive port need to switch fast than TX port. 20ms is not enough, most small frame relays switch around 20ms , To play safe it is necessary 10 ms. Another thing to consider. 3- The RX antenna only will add some SN if it adds some directivity, otherwise the attenuator at -20db will do the same job. 4- Isolation, on low bands if you have s9+10db noise and only 50 db isolation between the RX and TX port, the signal from the TX antenna will be add to you RX signal degrading the signal to noise and reducing side and back nulls form the RX antenna. I can list another several reason to the subject but the T/R switch is a very important part of the receiver system if you want to have some improvement on the signal noise. I sent one RTR-1 to T6LG to use with a good Preamp from KD9SV and a Delta Flag antenna using twisted pair. Without the RTR-1 the system would not perform well as it did. Just my two cents. Regards JC N4IS -Original Message- From: Topband [mailto:topband-boun...@contesting.com] On Behalf Of James Rodenkirch Sent: Monday, January 13, 2014 8:36 AM To: Top Band Contesting Subject: Topband: Single antenna port xcvr but want to employ separate receive antenna Have my vertical working great and have a small Delta-loop low band receive antenna BUT the Ten Tec Jupiter doesn't have a separate receive antenna like a K2, for instance (I borrowed a K2 to try out but the buttons/controls are to small for me to operate as I have a severe case of peripheral neuropathy, courtesy of Agent Orange).So, I am up and running and will be in the CQ 160 contest at the end of January but have no means, currently, of switching rapidly 'tween the top loaded vertical and loop. A T/R switch won't do it for meso looking at a DX Engineering RTR-1A but sure don't like the price!!http://www.dxengineering.com/parts/dxe-rtr-1a Anyone have an RTR-1 or 1A that is excess to their needs and willing to sell OR have another idea of how I can employ a separate receive antenna when I have one antenna port? Thank you, in advance, for any repliesoff line replies work for me. 72/73, Jim Rodenkirch K9JWV _ Topband Reflector Archives - http://www.contesting.com/_topband _ Topband Reflector Archives - http://www.contesting.com/_topband
Re: Topband: Digital mode spurious issues
Tom, Mike is right, the issue with audio overload is complex for most of new radios, most of them have A/D just at the MIC input, if the A/D overloads the RF chain is compromised. These radios have no actual filters, everything is digital, like the IC7600. An analog radio is BW limited by the SSB crystal filter but SDR don't, when the A/D overloads, there are spoors everywhere several KHz far from the carrier; enough to trash the entire band. Using a SDR water fall it is easy to see the signal transitions and associate the trash with the main signal. I've seen several spoors every 10 KHz almost 100KHz up and down 1838. This is a growing problem. 73, JC N4IS -Original Message- From: Topband [mailto:topband-boun...@contesting.com] On Behalf Of Mike Waters Sent: Monday, December 30, 2013 1:31 PM To: Tom W8JI Cc: Topband Subject: Re: Topband: Digital mode spurious issues Tom, I believe the mode that operates at 1873-1838 is JT65, and WSJT is needed to decode it. I never tried it. It was developed by K1JT for weak-signal and EME work. http://www.physics.princeton.edu/pulsar/K1JT/wsjt.html A common scenario with digital modes is that the audio into the mic input is too high, causing unwanted spurs. 73, Mike www.w0btu.com On Mon, Dec 30, 2013 at 11:11 AM, Tom W8JI w...@w8ji.com wrote: ... a digimode station up roughly around 1837 came on with a LSB spurious signal on 1833. His signal was a series of slowly changing stepped tones. I don't know what mode that was. His unwanted sideband suppression was about 40 dB, but that was not nearly enough. He was 15 dB out of noise with his unwanted sideband. Does anyone know of a universal software to decode signals? Since the FCC does not require a CW ID, I think that is the only way to identify stations. ... _ Topband Reflector Archives - http://www.contesting.com/_topband _ Topband Reflector Archives - http://www.contesting.com/_topband
Re: Topband: Beverage antenna terminations
Bruce I lost several resistors on my WF until I started to use NTE 3 W Metal on the vertical Waller Flag and on the Horizontal WF I am using an array of 9 parallel/series. http://www.nteinc.com/resistor_web/pdf/threew.pdf Since that I never replaced it a single time in the last 4 years. The resistor has very low inductance but it is hard to find it, average price is near U$1. http://www.sourceresearch.com/store1/quickstore.cfm?ProductID=48700do=detai l Regards JCarlos N4IS -Original Message- From: Topband [mailto:topband-boun...@contesting.com] On Behalf Of Bruce Sent: Tuesday, September 24, 2013 10:46 PM To: Tom W8JI; topband@contesting.com Subject: Re: Topband: Beverage antenna terminations They were supposed to be non-inductive carbon, but need to find something better like carbon film. - Original Message - From: Tom W8JI w...@w8ji.com To: Bruce k...@myfairpoint.net; topband@contesting.com Sent: Tuesday, September 24, 2013 2:55 PM Subject: Re: Topband: Beverage antenna terminations What kind of resistors are you using? They shouldn't do that if you use the right type. - Original Message - From: Bruce k...@myfairpoint.net To: topband@contesting.com Sent: Tuesday, September 24, 2013 8:50 PM Subject: Topband: Beverage antenna terminations After recent night time thunder storm activity, two Beverage antennas lost some directivity. Termination resistors looked normal, but an ohmmeter checked reviled they had each gone hundreds of ohms higher. Replaced resistors and back to normal. 73 Bruce-K1FZ www.qsl.net/k1fz/bogantennanotes/index.html _ Topband Reflector - No virus found in this message. Checked by AVG - www.avg.com Version: 2014.0.4117 / Virus Database: 3604/6694 - Release Date: 09/24/13 _ Topband Reflector _ Topband Reflector _ Topband Reflector
Re: Topband: WLW
Here is the K7AGE posts video of WLW's 1932 500,000 Watt AM transmitter http://forums.qrz.com/showthread.php?398944-K7AGE-posts-video-of-WLW-s-1932- 500-000-Watt-AM-transmitter Enjoy it Regards JC N4IS _ Topband Reflector
Re: Topband: Zo of an individual CAT5 twisted pair
Yes, that's a complicated matter. The name and the function can get very confused if you don't know what you are doing. Any transformer can change the voltage from the primary to the secondary and the impedance follow the square of turn ratio. How you connect the transformer is an application. How you build the transformer is an art! For broadband RX antennas you want the transformer to be broadband. For isolation from the primary to the secondary you want low capacitance. An autotransformer could be used as BALUN, balances input and unbalanced output, it could be broadband, but has no isolation. One example, you take a FT140-77 core and build a primary 12 turns in one side and 4 turns on the other side, you have a voltage transformer but it will perform very bad as a BALUN, or a BALBAL or UNUN depending your application. However if you build 3 times 4 turns for the primary and add 4 turns on secondary in between the primary, you can get the same voltage transformer but It will work as a broadband impedance transformer from 1 MHz to 10 MHz with no adding reactance if the load is a pure resistor or low inductance resistor. I did try to explain it with text, I used pictures, I posted diagrams but people come back to me saying the antenna is not working. When I check what the guy did, he was using the wrong transformer. Jim I'm with you again, very few hams really understand it. Regards JCarlos N4IS -Original Message- From: Topband [mailto:topband-boun...@contesting.com] On Behalf Of Shoppa, Tim Sent: Tuesday, August 13, 2013 8:08 AM To: 'j...@audiosystemsgroup.com'; 'topband@contesting.com' Subject: Re: Topband: Zo of an individual CAT5 twisted pair A transformer that is connected such that it is UNbalanced on one side and BALanced on the other, and connected that way on purpose, is not a balun? Tim N3QE - Original Message - From: Jim Brown [mailto:j...@audiosystemsgroup.com] Sent: Tuesday, August 13, 2013 03:16 AM To: topband@contesting.com topband@contesting.com Subject: Re: Topband: Zo of an individual CAT5 twisted pair On 8/12/2013 2:10 PM, JC N4IS wrote: 50/75 BALUN Thanks for the detailed post, Carlos. BUT -- please let's use the right words to describe things so that people understand what you're describing and how it works. I strongly suspect that at least some of those things you are calling a balun are really a simple transformer -- that is, a primary and a secondary with magnetic coupling between them, and probably on a ferrite or powdered iron core. If it's a transformer, let's call it a transformer. Likewise, if we have a common mode choke formed by winding a coil of the transmission line, it is a common mode choke, not a balun. Using the word balun confuses things, because that word is used to describe at least a dozen very different things that I know of. When we use the word balun, it's a magic box that few hams really understand. When we use the right word, most hams have a chance of understanding what it does in a circuit. :) Yes, there are arrays of common mode chokes that can be used to transform impedance, and there are transmission line transformers of various sorts that can do that as well. BTW -- your discussion of phasing between elements of an RX array causes me to add an important post script to my advice that a perfect match is not required. When ANY passive network is used to produce phase shift, the source and termination impedances DO matter. The tricky part, though, is knowing what the input Z of the RX is, and if you're doing something like a phased array using phasing lines that end at the RX input, it might be a good idea to actually measure input Z and the antenna Zs with a VNA. 73, Jim K9YC _ Topband Reflector _ Topband Reflector _ Topband Reflector
Re: Topband: best core material?
If you plan to use the antenna on 160m you'll need 73 material. 43 works 3.8 up. Regards JC N4IS -Original Message- From: Topband [mailto:topband-boun...@contesting.com] On Behalf Of James Rodenkirch Sent: Monday, August 05, 2013 2:20 PM To: Shoppa, Tim; BY THE LAKE; topband@contesting.com Subject: Re: Topband: best core material? I wasn't going to use a binocular core, Tim - I was going to use the Amidon FT-140-43 OR the FT-140-77 IF it made any noticeable differenceis there some magical reason to use binocular vice standard round? From: tsho...@wmata.com To: rodenkirch_...@msn.com; ma...@isp.ca; topband@contesting.com Subject: RE: Topband: best core material? Date: Mon, 5 Aug 2013 18:12:48 + If receive only, you will do just fine using the 2873000202 binocular 73 material core that Tom mentions. I think this corresponds to Amidon part number BN-202-73. Newark stocks the part under the original Fair-Rite 2873000202 number. Tom shows 2:5 ratio but I've done other ratios just fine. I am very very impressed with the 2873000202 core, in fact I also use it in some DC-DC converters and the core just barely gets warm at the 10 watt level. Whenever I've accidentally transmitted into my receive antenna, the transformer survives just fine, it's the terminating resistor that goes up in smoke. I try not to make a habit of it :-) Tim N3QE -Original Message- From: Topband [mailto:topband-boun...@contesting.com] On Behalf Of James Rodenkirch Sent: Monday, August 05, 2013 2:04 PM To: BY THE LAKE; topband@contesting.com Subject: Re: Topband: best core material? Sorry - didn't make it crystal clear that this is a Delta shaped variant of a EWE antenna My bad for not utilizing all of the necessary verbiage to make that clearyou see it in ON4UN's latest book on page 7-104. From: ma...@isp.ca To: rodenkirch_...@msn.com Subject: Re: Topband: best core material? Date: Mon, 5 Aug 2013 14:00:48 -0400 A full-wave delta loop would have the transformation done with a 1/4 wave line of 75 ohm cable. This must be something other than a full-wave loop? Bill VE3NH - Original Message - From: James Rodenkirch rodenkirch_...@msn.com To: topband@contesting.com Sent: Monday, August 05, 2013 1:33 PM Subject: Topband: best core material? I have a schematic for a delta shaped loop that shows I'll need an 18:1 transformer to transform the 950 ohms of the antenna to 50 ohms (feeding it with 50 ohm coax). One transformer diagram shows an FT-140-43 core being used. BUT, looking over some of Tom's, W8JI, write-ups, I see where he uses 73 material instead. I see where 77 material replaced 73 material so -- is an FT-140-77 the mo betta way to go? Thanks, in advance, for any advice/info. Jim Rodenkirch K9JWV _ Topband Reflector - No virus found in this message. Checked by AVG - www.avg.com Version: 2013.0.3392 / Virus Database: 3209/6552 - Release Date: 08/05/13 - No virus found in this message. Checked by AVG - www.avg.com Version: 2013.0.3392 / Virus Database: 3209/6552 - Release Date: 08/05/13 _ Topband Reflector _ Topband Reflector _ Topband Reflector
