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#1
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Reading the schematics it is possible that the ANC-4 does not
fully cover the 360 degrees phase shift, just like the MFJ-1025. But it is also possible that you experience more than one noise source on 75 mtrs. A noise canceller (with two inputs/antennas) can cancel only one noise source. I have written about noise cancelling on my site, e.g.: http://www.pa0sim.nl/Phaser%2080%20-%2010%20meters.htm May be it can help. 73 es gl de Jan PA0SIM "Dave Oldridge" schreef in bericht 9... Sun Tzu wrote in news:_rCdndMY26mGEqLYnZ2dnUVZ_oOdnZ2d@hawaiiantel. net: I use an Timewave ANC-4 to reduce noise on the low bands at my location. On 40 & 160 meters I can reduce the noise almost to S1, but on 75 meters I can only reduce it to S4-5. I use a noise sense antenna which is a dipole 4ft on each side about 4 inches off the ground and parallel to the power and telephone lines. Anyone have one of these units and having any ideas I might try to reduce 75 meters to a lower S-meter reading? All my low band antennas are verticals. You might try using a vertical whip for the ANC-4. I use the built-in one on my MFJ-1026. Even so, you may just be experiencing general ionospheric noise at that level if your antenna is fairly good. Is your QTH urban or rural? Here in urban downtown Chilliwack, BC, I get a lot of noise sources and, of course, the 1026 can really only take out the loudest single source. -- Dave Oldridge+ ICQ 1800667 |
#2
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Jan Simons PA0SIM wrote:
Reading the schematics it is possible that the ANC-4 does not fully cover the 360 degrees phase shift, just like the MFJ-1025. But it is also possible that you experience more than one noise source on 75 mtrs. A noise canceller (with two inputs/antennas) can cancel only one noise source. I have written about noise cancelling on my site, e.g.: http://www.pa0sim.nl/Phaser%2080%20-%2010%20meters.htm May be it can help. 73 es gl de Jan PA0SIM Nice website, have you considered modifying the existing units (MFJ & ANC) to do what you have shown? Your idea would make either of these 2 units much better. By the way, I took the sense antenna which is a short dipole and I made one leg vertical and the other horizontal. Now I have almost no noise on 75 meters. I haqve been playing around with this for awhile and it was either all vertical or all horizontal. Now with this configuration the weak signals can be heard. Stan AH6JR "Dave Oldridge" schreef in bericht 9... Sun Tzu wrote in news:_rCdndMY26mGEqLYnZ2dnUVZ_oOdnZ2d@hawaiiantel. net: I use an Timewave ANC-4 to reduce noise on the low bands at my location. On 40 & 160 meters I can reduce the noise almost to S1, but on 75 meters I can only reduce it to S4-5. I use a noise sense antenna which is a dipole 4ft on each side about 4 inches off the ground and parallel to the power and telephone lines. Anyone have one of these units and having any ideas I might try to reduce 75 meters to a lower S-meter reading? All my low band antennas are verticals. You might try using a vertical whip for the ANC-4. I use the built-in one on my MFJ-1026. Even so, you may just be experiencing general ionospheric noise at that level if your antenna is fairly good. Is your QTH urban or rural? Here in urban downtown Chilliwack, BC, I get a lot of noise sources and, of course, the 1026 can really only take out the loudest single source. -- Dave Oldridge+ ICQ 1800667 |
#3
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![]() "Sun Tzu" schreef in bericht ... Jan Simons PA0SIM wrote: Reading the schematics it is possible that the ANC-4 does not fully cover the 360 degrees phase shift, just like the MFJ-1025. But it is also possible that you experience more than one noise source on 75 mtrs. A noise canceller (with two inputs/antennas) can cancel only one noise source. I have written about noise cancelling on my site, e.g.: http://www.pa0sim.nl/Phaser%2080%20-%2010%20meters.htm May be it can help. 73 es gl de Jan PA0SIM Nice website, have you considered modifying the existing units (MFJ & ANC) to do what you have shown? Your idea would make either of these 2 units much better. By the way, I took the sense antenna which is a short dipole and I made one leg vertical and the other horizontal. Now I have almost no noise on 75 meters. I haqve been playing around with this for awhile and it was either all vertical or all horizontal. Now with this configuration the weak signals can be heard. Stan AH6JR Hi Stan, I have considered it, but sometimes it is easier and better to start fresh. First question is always: what phaser/noise canceller do you really want? What do you expect from it? Looking at the design of the MFJ-1025, it would take to much mods to realize my needs. When one of the antennas doesnīt hear the noise source, you donīt need a phaser. But of course that antenna still has to hear your wanted signals. Using a small loop antenna it is sometimes possible to null the noise source. I think playing with a short dipole, as you did, is the same as nulling with small loops. 73 de Jan PA0SIM |
#4
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Jan Simons PA0SIM wrote:
"Sun Tzu" schreef in bericht ... Jan Simons PA0SIM wrote: Reading the schematics it is possible that the ANC-4 does not fully cover the 360 degrees phase shift, just like the MFJ-1025. But it is also possible that you experience more than one noise source on 75 mtrs. A noise canceller (with two inputs/antennas) can cancel only one noise source. I have written about noise cancelling on my site, e.g.: http://www.pa0sim.nl/Phaser%2080%20-%2010%20meters.htm May be it can help. 73 es gl de Jan PA0SIM Nice website, have you considered modifying the existing units (MFJ & ANC) to do what you have shown? Your idea would make either of these 2 units much better. By the way, I took the sense antenna which is a short dipole and I made one leg vertical and the other horizontal. Now I have almost no noise on 75 meters. I haqve been playing around with this for awhile and it was either all vertical or all horizontal. Now with this configuration the weak signals can be heard. Stan AH6JR Hi Stan, I have considered it, but sometimes it is easier and better to start fresh. First question is always: what phaser/noise canceller do you really want? What do you expect from it? Looking at the design of the MFJ-1025, it would take to much mods to realize my needs. When one of the antennas doesnīt hear the noise source, you donīt need a phaser. But of course that antenna still has to hear your wanted signals. Using a small loop antenna it is sometimes possible to null the noise source. I think playing with a short dipole, as you did, is the same as nulling with small loops. 73 de Jan PA0SIM I have the ANC-4 which works well. This new sense antenna is really good, as I can hear signals down to S-2 on 75 meters. I guess if I had to do it I would prefer to modify the ANC-4 as its a quality unit, not perfect but it is built well. If you would have any ideas as to modifying the ANC-4 I would'nt mind working with you on this project. But I will leave that one up to you. Hopefully I will be able to hear you in the contest this weekend on 75 meters! Good Luck in the contest my friend! |
#5
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![]() "Sun Tzu" schreef in bericht news:ruCdnermL6SEDd_YnZ2dnUVZ_uydnZ2d@hawaiiantel. net... Jan Simons PA0SIM wrote: "Sun Tzu" schreef in bericht ... Jan Simons PA0SIM wrote: Reading the schematics it is possible that the ANC-4 does not fully cover the 360 degrees phase shift, just like the MFJ-1025. But it is also possible that you experience more than one noise source on 75 mtrs. A noise canceller (with two inputs/antennas) can cancel only one noise source. I have written about noise cancelling on my site, e.g.: http://www.pa0sim.nl/Phaser%2080%20-%2010%20meters.htm May be it can help. 73 es gl de Jan PA0SIM Nice website, have you considered modifying the existing units (MFJ & ANC) to do what you have shown? Your idea would make either of these 2 units much better. By the way, I took the sense antenna which is a short dipole and I made one leg vertical and the other horizontal. Now I have almost no noise on 75 meters. I haqve been playing around with this for awhile and it was either all vertical or all horizontal. Now with this configuration the weak signals can be heard. Stan AH6JR Hi Stan, I have considered it, but sometimes it is easier and better to start fresh. First question is always: what phaser/noise canceller do you really want? What do you expect from it? Looking at the design of the MFJ-1025, it would take to much mods to realize my needs. When one of the antennas doesnt hear the noise source, you dont need a phaser. But of course that antenna still has to hear your wanted signals. Using a small loop antenna it is sometimes possible to null the noise source. I think playing with a short dipole, as you did, is the same as nulling with small loops. 73 de Jan PA0SIM I have the ANC-4 which works well. This new sense antenna is really good, as I can hear signals down to S-2 on 75 meters. I guess if I had to do it I would prefer to modify the ANC-4 as its a quality unit, not perfect but it is built well. If you would have any ideas as to modifying the ANC-4 I would'nt mind working with you on this project. But I will leave that one up to you. Hopefully I will be able to hear you in the contest this weekend on 75 meters! Good Luck in the contest my friend! Sri, I prefer my Digital Signal Processing route with the two Elecraft K2 receivers. DSP makes an ideal phaser. So no need here for a "better" analog one. And DSP gives me a lot more tricks to reduce interference and noise. 73 es gl de Jan PA0SIM |
#6
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Jan Simons PA0SIM wrote:
"Sun Tzu" schreef in bericht news:ruCdnermL6SEDd_YnZ2dnUVZ_uydnZ2d@hawaiiantel. net... Jan Simons PA0SIM wrote: "Sun Tzu" schreef in bericht ... Jan Simons PA0SIM wrote: Reading the schematics it is possible that the ANC-4 does not fully cover the 360 degrees phase shift, just like the MFJ-1025. But it is also possible that you experience more than one noise source on 75 mtrs. A noise canceller (with two inputs/antennas) can cancel only one noise source. I have written about noise cancelling on my site, e.g.: http://www.pa0sim.nl/Phaser%2080%20-%2010%20meters.htm May be it can help. 73 es gl de Jan PA0SIM Nice website, have you considered modifying the existing units (MFJ & ANC) to do what you have shown? Your idea would make either of these 2 units much better. By the way, I took the sense antenna which is a short dipole and I made one leg vertical and the other horizontal. Now I have almost no noise on 75 meters. I haqve been playing around with this for awhile and it was either all vertical or all horizontal. Now with this configuration the weak signals can be heard. Stan AH6JR Hi Stan, I have considered it, but sometimes it is easier and better to start fresh. First question is always: what phaser/noise canceller do you really want? What do you expect from it? Looking at the design of the MFJ-1025, it would take to much mods to realize my needs. When one of the antennas doesnt hear the noise source, you dont need a phaser. But of course that antenna still has to hear your wanted signals. Using a small loop antenna it is sometimes possible to null the noise source. I think playing with a short dipole, as you did, is the same as nulling with small loops. 73 de Jan PA0SIM I have the ANC-4 which works well. This new sense antenna is really good, as I can hear signals down to S-2 on 75 meters. I guess if I had to do it I would prefer to modify the ANC-4 as its a quality unit, not perfect but it is built well. If you would have any ideas as to modifying the ANC-4 I would'nt mind working with you on this project. But I will leave that one up to you. Hopefully I will be able to hear you in the contest this weekend on 75 meters! Good Luck in the contest my friend! Sri, I prefer my Digital Signal Processing route with the two Elecraft K2 receivers. DSP makes an ideal phaser. So no need here for a "better" analog one. And DSP gives me a lot more tricks to reduce interference and noise. 73 es gl de Jan PA0SIM May I ask what the tricks are? |
#7
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.........
If you would have any ideas as to modifying the ANC-4 I would'nt mind working with you on this project. But I will leave that one up to you. ......... Sri, I prefer my Digital Signal Processing route with the two Elecraft K2 receivers. DSP makes an ideal phaser. So no need here for a "better" analog one. And DSP gives me a lot more tricks to reduce interference and noise. 73 es gl de Jan PA0SIM May I ask what the tricks are? Of course: 1) With only one receiver and one antenna: - Noise Reduction and Noise Blanker tricks as you see now implemented in the new DSP transceivers like the Orion and the SDR1000 (all the DSP must be in the AGC loop!). - In DSP it is possible to make very small bandwidth CW filters. - For better CW readability one can use binaural or panoramic reception. - DSP makes multi notch filtering possible (SSB) - In DSP it is possible to realize almost every AGC you can think of. (a better AGC can improve weak signal reception) 2) with two (or more) antennas and two phase coherent receivers - In DSP it is possible to realize the ideal phaser. - An alternative is "effective directivity" by frequency component selection see: http://home.plex.nl/~jmsi/Effective%...20by%20DSP.htm (the audio samples show what is possible with it) - True Diversity Reception, because both receivers can be made identical. - Enhanced Stereo Reception can improve readability for CW/SSB signals. 3) and the tricks I dont know yet. I am not a DSP guru. For example: (Blind) Source Seperation? see: http://en.wikipedia.org/wiki/Source_separation Rather complex stuff HI. Donīt forget that not all DSP in the new tranceivers is well implemented. Important is to recognize that DSP has a bright future for us. 73 de Jan PA0SIM |
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