Topband: Best wire antenna for roof top location
Dear all, In preparation of this coming WW big contest, I plan to install wire antenna on a roof top of a 33rd storey building (about 110metres above the ground) for operating on the 160M, 80M and 40M band. The building roof top rectangular size about 45 metres long (from NWtoN-326.8 degress to SEtoS-146.8degrees) and 33 metres wide (fromNEtoE-56.8 degrees to SWtoW-236.8 degrees) located in centre of Jakarta city. The roof top have plenty of cellulair microwave operator antennas (operating in 5GHz and above ALSO one TV operator with around 400MHz working freq.) and there are also two SelfSupportingTower-15metres high, on each end of the long side of the building. There is also one-SST belong to theTV operator which is about 50 metres high, located on the SE end of the roof top. Good grounding terminal is available as it's used for grounding all the communication antennas/equipments. I have my own room in the centre of the roof top where we put all our indoor microwave devices and routers/switch. Prefereable wire antenna is lazy 'laying'H or quad, dipole, slope.. I appreciate verymuch any suggestion, input from all, regarding the best wire antenna for this site to be used in the 160M, 80M and 40M band. Thankyou very much indeed in advance. Regards, Nuradi, YB0UNC / KU2B Cellulair +62811138378 _ Topband Reflector Archives - http://www.contesting.com/_topband
Re: Topband: [Bulk] Best wire antenna for roof top location
Have you surveyed the site for HF RFI? One mountain top property I was considering had awesome 360d unlimited visibility but had so much power supply hash, PIM, intermod, etc. from comm installations that any amateur operation would be near impossible. My spectrum analyzer showed huge amounts of general hash RF that could not be high pass band filtered out. Grant KZ1W On 8/7/2015 16:52 PM, Nuradi wrote: Dear all, In preparation of this coming WW big contest, I plan to install wire antenna on a roof top of a 33rd storey building (about 110metres above the ground) for operating on the 160M, 80M and 40M band. The building roof top rectangular size about 45 metres long (from NWtoN-326.8 degress to SEtoS-146.8degrees) and 33 metres wide (fromNEtoE-56.8 degrees to SWtoW-236.8 degrees) located in centre of Jakarta city. The roof top have plenty of cellulair microwave operator antennas (operating in 5GHz and above ALSO one TV operator with around 400MHz working freq.) and there are also two SelfSupportingTower-15metres high, on each end of the long side of the building. There is also one-SST belong to theTV operator which is about 50 metres high, located on the SE end of the roof top. Good grounding terminal is available as it's used for grounding all the communication antennas/equipments. I have my own room in the centre of the roof top where we put all our indoor microwave devices and routers/switch. Prefereable wire antenna is lazy 'laying'H or quad, dipole, slope.. I appreciate verymuch any suggestion, input from all, regarding the best wire antenna for this site to be used in the 160M, 80M and 40M band. Thankyou very much indeed in advance. Regards, Nuradi, YB0UNC / KU2B Cellulair +62811138378 _ Topband Reflector Archives - http://www.contesting.com/_topband _ Topband Reflector Archives - http://www.contesting.com/_topband
Re: Topband: [Bulk] Best wire antenna for roof top location
For 160 DX, a vertically-polarized antenna (fed against a proper ground) is best. http://www.w0btu.com/160_meters.html 73, Mike www.w0btu.com On 8/7/2015 16:52 PM, Nuradi wrote: I plan to install wire antenna on a roof top of a 33rd story building (about 110 metres above the ground) for operating on the 160M, 80M and 40M band. ... Preferable wire antenna is lazy 'laying'H or quad, dipole, slope.. _ Topband Reflector Archives - http://www.contesting.com/_topband
Re: Topband: [Bulk] Best wire antenna for roof top location
Careful Mike! Jakarta is close to the equator, and power coupling is likely to be better from a horizontally polarised antenna, especially in an E-W direction. Ref The Big Gun's Guide to Low-Band Propagation by Bob Brown, NM7M (SK) On 2015-08-08 12:40 p.m., Mike Waters wrote: For 160 DX, a vertically-polarized antenna (fed against a proper ground) is best. http://www.w0btu.com/160_meters.html 73, Mike www.w0btu.com On 8/7/2015 16:52 PM, Nuradi wrote: I plan to install wire antenna on a roof top of a 33rd story building (about 110 metres above the ground) for operating on the 160M, 80M and 40M band. ... Preferable wire antenna is lazy 'laying'H or quad, dipole, slope.. _ Topband Reflector Archives - http://www.contesting.com/_topband _ Topband Reflector Archives - http://www.contesting.com/_topband
Re: Topband: [Bulk] Best wire antenna for roof top location
Really?! I think I just learned something important. Thanks, Greg! 73, Mike www.w0btu.com On Fri, Aug 7, 2015 at 8:24 PM, Greg - ZL3IX zl...@inet.net.nz wrote: Careful Mike! Jakarta is close to the equator, and power coupling is likely to be better from a horizontally polarised antenna, especially in an E-W direction. Ref The Big Gun's Guide to Low-Band Propagation by Bob Brown, NM7M (SK) On 2015-08-08 12:40 p.m., Mike Waters wrote: For 160 DX, a vertically-polarized antenna (fed against a proper ground) is best. http://www.w0btu.com/160_meters.html 73, Mike www.w0btu.com On 8/7/2015 16:52 PM, Nuradi wrote: I plan to install wire antenna on a roof top of a 33rd story building (about 110 metres above the ground) for operating on the 160M, 80M and 40M band. ... Preferable wire antenna is lazy 'laying'H or quad, dipole, slope.. _ 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: [Bulk] Best wire antenna for roof top location
And Bob Brown used a monograph by J.A. Ratcliffe--The Magneto-Ionic Theory and its Application to the Ionosphere which says the same thing. It has to do with the angle between the E vector and the Earth's Geomagnetic Field, which is horizontal at the geomagnetic equator. Bob borrowed my copy of the book when he was writing the Big Gun's Guide. Garry, NI6T On 8/7/2015 6:24 PM, Greg - ZL3IX wrote: Careful Mike! Jakarta is close to the equator, and power coupling is likely to be better from a horizontally polarised antenna, especially in an E-W direction. Ref The Big Gun's Guide to Low-Band Propagation by Bob Brown, NM7M (SK) On 2015-08-08 12:40 p.m., Mike Waters wrote: For 160 DX, a vertically-polarized antenna (fed against a proper ground) is best. http://www.w0btu.com/160_meters.html 73, Mike www.w0btu.com On 8/7/2015 16:52 PM, Nuradi wrote: I plan to install wire antenna on a roof top of a 33rd story building (about 110 metres above the ground) for operating on the 160M, 80M and 40M band. ... Preferable wire antenna is lazy 'laying'H or quad, dipole, slope.. _ 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: [Bulk] Best wire antenna for roof top location
And remember -- the roof of this building is 110m, so a horizontal antenna is high enough to have pretty good low angle radiation! See http://k9yc.com/VertOrHorizontal-Slides.pdf and double the heights for the graphs of 80M performance. When you're thinking height, consider the building a tower -- it's mostly the far field reflection that determines the vertical pattern. As to ground for a vertical antenna -- let's not confuse the word ground with counterpoise or radial system. An end-fed current-fed vertical needs a counterpoise or radials, NOT a connection to earth. I strongly concur with the advice to spend some serious time LISTENING on that roof before doing anything else. It's pretty common for the stuff described on that roof to be MONDO NOISY, and it's unlikely that you can do much about most of it unless the guys who maintain it are HF hams. 73, Jim K9YC On Fri,8/7/2015 8:02 PM, Garry Shapiro wrote: And Bob Brown used a monograph by J.A. Ratcliffe--The Magneto-Ionic Theory and its Application to the Ionosphere which says the same thing. It has to do with the angle between the E vector and the Earth's Geomagnetic Field, which is horizontal at the geomagnetic equator. Bob borrowed my copy of the book when he was writing the Big Gun's Guide. Garry, NI6T On 8/7/2015 6:24 PM, Greg - ZL3IX wrote: Careful Mike! Jakarta is close to the equator, and power coupling is likely to be better from a horizontally polarised antenna, especially in an E-W direction. Ref The Big Gun's Guide to Low-Band Propagation by Bob Brown, NM7M (SK) _ Topband Reflector Archives - http://www.contesting.com/_topband
Re: Topband: alternative feedpoint capacitor
You probably have a current fed vertical so you don't have to worry very much about the voltage on the cap. Any air variable with around 1/4 inch spacing will be fine. It should not be hard to find something with the value you need--the tune cap in any ham RF amp will probably be okay as an example of what to look for. Put it in a wx shielded enclosure. Another thing to look for that is ridiculous overkill but cheap are fixed vacuum caps--most hams have no idea what to do with them so they are inexpensive on eBay and you can put a short bread slicer paralleled with one to vary it. look for 200 pF--they will handle all the current you want to put out for ham power levels. Doorknobs are effective but expensive. Old micas can be leaky. I'd just use an air variable and be done. 73 Rob K5UJ _ Topband Reflector Archives - http://www.contesting.com/_topband
Topband: Top Band Antenna
Gentlemen, I have the following which I would like to turn into a topband antenna if possible. My mast is approximately 40 feet high and there is rotor cage with a 10 foot stub mast, on the stubmast I have an 8 el.log periodic and above that a rotary dipole for 30/40m. I attached a drop wire at approx. 38 feet high, I grounded this wire and tried to grid dip the wire plus mast, all as per ON4UN's book USING THE BEAM TOWER AS A LOW BAND VERTICAL the results were zilch, nadda nothing at all, no dip anywhere on any band. I used the MFJ 259B with the GDO accessory. 1. Am I doing this all wrong..highly possible.!! 2. Is the mast not high enough to be used for top band.? I am totally out of my depth here.so any guidance would be much appreciated. Many thanks, Rodger/GM3JOB _ Topband Reflector Archives - http://www.contesting.com/_topband
Re: Topband: Top Band Antenna
Hi Rodger, You will have better success if you add a top loading wire to your mast, which makes it into an inverted-L. Suggest you start with an 80 foot wire in a straight line if possible but otherwise route it any shape necessary . You can increase or decrease the length of the top loading wire to improve the match. As an alternative to shunt feeding your mast, you could simply install an 130 foot inverted-L parallel to your mast and direct feed it from the bottom. You could add a loading coil to the wire if 80 feet is too long. 73 Frank W3LPL - Original Message - From: rodger bryce gm3...@hotmail.com To: topband@contesting.com Sent: Friday, August 7, 2015 2:54:40 PM Subject: Topband: Top Band Antenna Gentlemen, I have the following which I would like to turn into a topband antenna if possible. My mast is approximately 40 feet high and there is rotor cage with a 10 foot stub mast, on the stubmast I have an 8 el.log periodic and above that a rotary dipole for 30/40m. I attached a drop wire at approx. 38 feet high, I grounded this wire and tried to grid dip the wire plus mast, all as per ON4UN's book USING THE BEAM TOWER AS A LOW BAND VERTICAL the results were zilch, nadda nothing at all, no dip anywhere on any band. I used the MFJ 259B with the GDO accessory. 1. Am I doing this all wrong..highly possible.!! 2. Is the mast not high enough to be used for top band.? I am totally out of my depth here.so any guidance would be much appreciated. Many thanks, Rodger/GM3JOB _ Topband Reflector Archives - http://www.contesting.com/_topband _ Topband Reflector Archives - http://www.contesting.com/_topband
Re: Topband: Which is best for copying the weakest DX - DSP or the ear-brain combo?
N2GZ identifies fatigue is an important issue. A sort of acoustical psychosis sets in if you listen to a static crashy band with the same narrow filter for hours at a time. One advantage of having multiple filters available (either analog or DSP) is that you can switch between filters to help relieve this psychosis. What's very nice about modern DSP, is you can dial the bandwidth up and down very nicely. Not that this was completely unavailable with passband tuning in older analog rigs, but the best DSP filters default to a very nice shape that can reduce the ringing that also leads to acoustical psychosis. Crystal filters with Gaussian shapes to reduce ringing have been available for decades, but not generally used in ham equipment. The reason? They were not brick wall filters with sharp shape factors - and crystal filter shape factors have been used in ham radio marketing for a long time. The best of the DSP equipment available today has CW filters that are inspired by Gaussian filter shapes. The shape factors are not as impressive but the resulting filter is far more useful for CW guys in crashy low bands. Tim N3QE On Tue, Aug 4, 2015 at 9:26 PM, Greg Zenger n...@gregzenger.com wrote: I suspect a well trained and practiced brain may be able to out perform a DSP assisted average brain... However over the course of a contest (24-48 hours of [near] continuous operating) a DSP assisted average brain may have an advantage due reduced listening fatigue... Of course some DSP can positively contribute to listening fatigue and others negatively... Quality of DSP and operators ability to adjust are key factors here. This is a topic I follow closely, but can't think of any articles or studies off hand that would answer your question... A sold PhD thesis topic this would be. Greg N2GZ On Aug 4, 2015 9:02 PM, Roger D Johnson n...@roadrunner.com wrote: Although I don't consider myself among the highly-skilled and talented, I can't think of an instance where DSP made the difference between making a contact or not. I do have an Autek QF-1A wired into the audio of the main receiver of the K3 as the AudioPeakingFilter on the K3 is too sharp. 73, Roger N1RJ On 8/4/2015 8:25 PM, Art Snapper wrote: Mike, Are you referring to a specific modulation mode? How about adjacent channel interference issues? I like your question. Art ᐧ On Tue, Aug 4, 2015 at 7:39 PM, Mike Watersmikew...@gmail.com wrote: I'd like to know whether it's ever been established that some very talented hams can out-hear the best SDRs and/or DSP available. Can a skilled ear-brain combo (such as some highly-skilled and talented 160 meter contesters) beat state-of-the art digital signal processing when it comes to copying the very weakest of signals buried in the noise? I always thought Linrad was the best DSP software, though I never got it working right here (older sound card issues in Xubuntu). I asked the following question at http://www.eham.net/ehamforum/smf/index.php?topic=104388.msg861047#msg861047 : Are there any people who can hear weak signals with a good analog receiver, who --if they could instantly switch their antenna and headphones from the analog RX over to the best SDR made today-- simply couldn't hear any better with today's best SDRs and/or DSP software? There's been a few opinions, but how about multiple valid tests? 73, Mike www.w0btu.com _ 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 _ Topband Reflector Archives - http://www.contesting.com/_topband
Re: Topband: Which is best for copying the weakest DX - DSP or the ear-brain combo?
And - do not underestimate the ability of your brain to act as a CW filter. When I was doing EME on six meters (using CW) - I found using SSB bandwidths made it easier to copy the weak signal. You can hear a few recordings of EME signals with SSB bandwidths here: http://www.kkn.net/n6tr/sixeme.html 73 Tree N6TR On Fri, Aug 7, 2015 at 5:58 AM, Tom W8JI w...@w8ji.com wrote: I'd like to know whether it's ever been established that some very talented hams can out-hear the best SDRs and/or DSP available. Can a skilled ear-brain combo (such as some highly-skilled and talented 160 meter contesters) beat state-of-the art digital signal processing when it comes to copying the very weakest of signals buried in the noise? Excluding time-synchronized signal processing methods, I've never found any DSP system do better or do more than an analog system in signal readabilitly. They are really just different methods of doing the same thing analog systems can do. I actually find DSP detector systems inhibit my ability to hear or copy noise floor signals in rough noise. I'm not sure why that is, but it is more difficult for me to piece together a signal that is in the noise when it has been detected in a DSP system. I normally set my K3's so DSP filtering is wider than the analog filter at filter switch in, so I can change the DSP bandwidth from wider than any analog filter down to the DSP being narrower, but I still think analog detection is much better for signals below the level of rough noise. 73 Tom _ Topband Reflector Archives - http://www.contesting.com/_topband _ Topband Reflector Archives - http://www.contesting.com/_topband
Re: Topband: Top Band Antenna
You probably know this Rodger, but just in case... Radials are ESSENTIAL. As many as you can as long as you can make them (up to 1/4 wave) in as many directions as i s possible. I staple mine down with lawn staples (I find them at home improvement stores) and after a year or so they tend to migrate underground. Till then, you may have to set your lawn mower to leave a bit higher grass and perhaps mow carefully where they are vulnerable due to one's lawn not being perfectly flat . When I moved QTH after 4 years a while back and decided to remove the radials, I had to rip them up to get them out, so they were essentially invisible by then. Having a radial connection plate, either commercial or home brew (I use the one from DX E ngineering) makes things easier and neater. I have a wire T with a 40 ft vertical section and a 90 ft horizontal section and about 35 radials, some as long as 50/60/ft and some as short as 20/30 ft (some even go down my basement access hatch and run in the rafters through my basement, be creative)! I mo deled this in a simple antenna program (that I didn't kn ow much about using, it came with an ARRL Antenna Book) and it spit out values for a matching network that got me into the ballpark. The idea for the L is another good one and only requires the ability to have space and an anchor point in one direction. Try to keep the loading wire as parallel to the ground as you can, but don't worry if you can't do that perfectly. Again, antenna modeling software will save you much time matching the antenna. On my T, one leg e nds up at 50 ft and the other at about 20 feet (due to the supports available ), I would say don't obs ess about it, just do what you can. I live on a small lot and that's what I can do in my context and this works positively, err OK, especially for DX. To put it in context, it is MUCH better than a Butternut vertic al over the same radial field, so the loading wires can buy you a lot . Think about a RX antenna too. I have a K9AY that is not as optimal as I would like, but it still often makes the difference between copy/no copy for DX (often on bands other than 160, BTW, I have used it up to 15 meters at times!) . Again, be creative and search the internet for ideas. I have not set any new world DX records with this set up, but I did finish my DXCC, so it at least gets you into the game. Best, Kevin K3OX - Original Message - From: donov...@starpower.net To: topband@contesting.com Cc: rodger bryce gm3...@hotmail.com Sent: Friday, August 7, 2015 12:16:17 PM Subject: Re: Topband: Top Band Antenna Hi Rodger, You will have better success if you add a top loading wire to your mast, which makes it into an inverted-L. Suggest you start with an 80 foot wire in a straight line if possible but otherwise route it any shape necessary . You can increase or decrease the length of the top loading wire to improve the match. As an alternative to shunt feeding your mast, you could simply install an 130 foot inverted-L parallel to your mast and direct feed it from the bottom. You could add a loading coil to the wire if 80 feet is too long. 73 Frank W3LPL - Original Message - From: rodger bryce gm3...@hotmail.com To: topband@contesting.com Sent: Friday, August 7, 2015 2:54:40 PM Subject: Topband: Top Band Antenna Gentlemen, I have the following which I would like to turn into a topband antenna if possible. My mast is approximately 40 feet high and there is rotor cage with a 10 foot stub mast, on the stubmast I have an 8 el.log periodic and above that a rotary dipole for 30/40m. I attached a drop wire at approx. 38 feet high, I grounded this wire and tried to grid dip the wire plus mast, all as per ON4UN's book USING THE BEAM TOWER AS A LOW BAND VERTICAL the results were zilch, nadda nothing at all, no dip anywhere on any band. I used the MFJ 259B with the GDO accessory. 1. Am I doing this all wrong..highly possible.!! 2. Is the mast not high enough to be used for top band.? I am totally out of my depth here.so any guidance would be much appreciated. Many thanks, Rodger/GM3JOB _ 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: Top Band Antenna
Rodger It seems a bit short electrically but with all that top loading you should be able to radiate with a good ground radial system. Just measure the impedance of the slant wire and design a match for that value, I presume the mast is grounded at the base well. If you want to make things easier you may wish to try a three of four wire cage around the mast and connect it to the rotor cage and feed the cage at the found level. Don't look for dips just look for a good match. Herb Schoenbohm, KV4FZ On 8/7/2015 10:54 AM, rodger bryce wrote: Gentlemen, I have the following which I would like to turn into a topband antenna if possible. My mast is approximately 40 feet high and there is rotor cage with a 10 foot stub mast, on the stubmast I have an 8 el.log periodic and above that a rotary dipole for 30/40m. I attached a drop wire at approx. 38 feet high, I grounded this wire and tried to grid dip the wire plus mast, all as per ON4UN's book USING THE BEAM TOWER AS A LOW BAND VERTICAL the results were zilch, nadda nothing at all, no dip anywhere on any band. I used the MFJ 259B with the GDO accessory. 1. Am I doing this all wrong..highly possible.!! 2. Is the mast not high enough to be used for top band.? I am totally out of my depth here.so any guidance would be much appreciated. Many thanks, Rodger/GM3JOB _ Topband Reflector Archives - http://www.contesting.com/_topband _ Topband Reflector Archives - http://www.contesting.com/_topband
Re: Topband: Which is best for copying the weakest DX - DSP or theear-brain combo?
Correction to my previous posting (see below). Not a few tenths of a Hz wide, instead it should say a few Hz wide, say 20-50Hz.. 73 Peter SM2CEW At 19:04 2015-08-07 , Peter Sundberg wrote: Granted, tuning in a very weak steady carrier in a narrow DSP filter (a few tenths of Hz wide) can give you the impression that DSP is magic stuff. 73 Peter SM2CEW _ Topband Reflector Archives - http://www.contesting.com/_topband
Re: Topband: Which is best for copying the weakest DX - DSP or theear-brain combo?
It is interesting to note that Tom and others share exactly the same experience as I have. There is a certain 'flavour' to DSP audio that is not making it easier to copy weak signals in the noise. I find that using an (old) analog system actually makes it much easier to copy signals hidden deep down in the noise. I have long experience from listening to extremely weak signals in the noise (CW EME on VHF/UHF and some while Topband DX'ing) and I am still waiting for a DSP radio that outperforms my old analog radios and my homebrew LM13600 audiofilter. The filter was published in QST in October 1983. For EME, my TS2000X with it's filter combinations is just not as comfortable to listen to as the old FT736R and my vintage LM13600 audiofilter. I plain words, I copy much better on the old system. And DSP in the low end Yaesu radios (FT817/897) is not performing anywhere near the old analog systems. The same goes for the SDR's that I use. Granted, tuning in a very weak steady carrier in a narrow DSP filter (a few tenths of Hz wide) can give you the impression that DSP is magic stuff. But as soon as the carrier is chopped up into CW there is a 'mushiness to the DSP processed white noise that affects copyability. For me, this can often be verified when doing an A/B check on a very weak beacon that sends a long carrier between it's CW ID's. In my view, even static crashes when listening to weak signals on Topband are easier to deal with when using analog filters. But the whole audio chain is important. The choice of headphones is certainly a key to success when it comes to copying weak CW in the noise. Each one of course has his/her own preference when choosing headphones. My best ever are a pair of very old Radio Shack Nova 10. They are badly beaten and patched up with tape and glue, but I still use them every day and they are the best headphones for copying weak CW that I've ever tried. And beleive me, I have tried many headphones. Some good tests for copying weak signals in the noise can be found at http://sm2cew.com/wavefiles.html There might be one or two broken links on that page after a transfer to a new server but try the plaintext59_17.wav it is a real challenge. There is a genuine 59 character CW message in the noise and it is possible to copy and decode it 100% by ear when using a good filter. Good luck! 73 Peter SM2CEW At 12:58 2015-08-07 , Tom W8JI wrote: I'd like to know whether it's ever been established that some very talented hams can out-hear the best SDRs and/or DSP available. Can a skilled ear-brain combo (such as some highly-skilled and talented 160 meter contesters) beat state-of-the art digital signal processing when it comes to copying the very weakest of signals buried in the noise? Excluding time-synchronized signal processing methods, I've never found any DSP system do better or do more than an analog system in signal readabilitly. They are really just different methods of doing the same thing analog systems can do. I actually find DSP detector systems inhibit my ability to hear or copy noise floor signals in rough noise. I'm not sure why that is, but it is more difficult for me to piece together a signal that is in the noise when it has been detected in a DSP system. I normally set my K3's so DSP filtering is wider than the analog filter at filter switch in, so I can change the DSP bandwidth from wider than any analog filter down to the DSP being narrower, but I still think analog detection is much better for signals below the level of rough noise. 73 Tom _ Topband Reflector Archives - http://www.contesting.com/_topband _ Topband Reflector Archives - http://www.contesting.com/_topband
Re: Topband: Which is best for copying the weakest DX - DSP or the ear-brain combo?
I'd like to know whether it's ever been established that some very talented hams can out-hear the best SDRs and/or DSP available. Can a skilled ear-brain combo (such as some highly-skilled and talented 160 meter contesters) beat state-of-the art digital signal processing when it comes to copying the very weakest of signals buried in the noise? Excluding time-synchronized signal processing methods, I've never found any DSP system do better or do more than an analog system in signal readabilitly. They are really just different methods of doing the same thing analog systems can do. I actually find DSP detector systems inhibit my ability to hear or copy noise floor signals in rough noise. I'm not sure why that is, but it is more difficult for me to piece together a signal that is in the noise when it has been detected in a DSP system. I normally set my K3's so DSP filtering is wider than the analog filter at filter switch in, so I can change the DSP bandwidth from wider than any analog filter down to the DSP being narrower, but I still think analog detection is much better for signals below the level of rough noise. 73 Tom _ Topband Reflector Archives - http://www.contesting.com/_topband
