[Elecraft] K3 Ant 1 and Ant 2 Isolation?
During FD we were discussing portable antenna options for next year. We were considering a 33' fiberglass pole with a veritical and a G5RV on the same pole. A 31' piece on wire running vertically down the pole and also a G5RV supported by that same pole. Then just connect them to the K3 Ant 1 and 2 jacks and away we go, however should we expect to flood the Ant jack which is not in use with RF due to the antennas being so close? Any thoughts? Rich __ Elecraft mailing list Home: http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/mmfaq.htm Post: mailto:Elecraft@mailman.qth.net This list hosted by: http://www.qsl.net Please help support this email list: http://www.qsl.net/donate.html Message delivered to arch...@mail-archive.com
Re: [Elecraft] K3 Ant 1 and Ant 2 Isolation?
Rich, It all depends on how you have configured the AUX ANT input for the subRX. If you have configured the Sub AUX ANT to use the non-transmit ANT1/2 jacks, then you may have a problem with overload and COR activation on the non-transmit antenna. In that case, the use of some external protection device may be prudent. If you do not have the subRX, it should be no problem or if you have that subRX AUX ANT connected to the BNC jack, there should not be a problem as long as the BNC jack is left open or grounded. The selection between ANT1 and ANT2 uses a relay, so except for the situation posed in paragraph 1, there should not be a problem. 73, Don W3FPR On 7/9/2014 9:32 AM, Rich wrote: During FD we were discussing portable antenna options for next year. We were considering a 33' fiberglass pole with a veritical and a G5RV on the same pole. A 31' piece on wire running vertically down the pole and also a G5RV supported by that same pole. Then just connect them to the K3 Ant 1 and 2 jacks and away we go, however should we expect to flood the Ant jack which is not in use with RF due to the antennas being so close? __ Elecraft mailing list Home: http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/mmfaq.htm Post: mailto:Elecraft@mailman.qth.net This list hosted by: http://www.qsl.net Please help support this email list: http://www.qsl.net/donate.html Message delivered to arch...@mail-archive.com
Re: [Elecraft] K3 Ant 1 and Ant 2 Isolation?
Probably not a good idea. The interaction between the vertical and the feed to the G5RV will be severe. You will have large quantities of RF forced onto the G5RV feeder. I ran a quick EZNEC model of 2 verticals 2.4 apart. It indicates that at 100w you would induce 45w onto the feeder. Even QRP levels would not appear to be safe. I'd think you are pretty assured of blowing something up. It would be an interesting experiment though, if you wanted to try it and report back on what burned up . . . 73 de dave ab9ca/4 On 7/9/14 8:32 AM, Rich wrote: During FD we were discussing portable antenna options for next year. We were considering a 33' fiberglass pole with a veritical and a G5RV on the same pole. A 31' piece on wire running vertically down the pole and also a G5RV supported by that same pole. Then just connect them to the K3 Ant 1 and 2 jacks and away we go, however should we expect to flood the Ant jack which is not in use with RF due to the antennas being so close? Any thoughts? Rich __ Elecraft mailing list Home: http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/mmfaq.htm Post: mailto:Elecraft@mailman.qth.net This list hosted by: http://www.qsl.net Please help support this email list: http://www.qsl.net/donate.html Message delivered to ho13d...@gmail.com __ Elecraft mailing list Home: http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/mmfaq.htm Post: mailto:Elecraft@mailman.qth.net This list hosted by: http://www.qsl.net Please help support this email list: http://www.qsl.net/donate.html Message delivered to arch...@mail-archive.com
Re: [Elecraft] K3 Ant 1 and Ant 2 Isolation?
Most interactions between feeders and antennas and other antennas and other antennas' feeders can be managed with physical layout design and effective attention to common mode current blocking. To be aware of these interactions, one must cultivate vision of these circumstances as a soup of *all* conductors. Just presume every conductor induces every other conductor, far and away a more accurate assumption than just considering antenna wires and assuming feedlines are invisible. Once comfortable with that inconvenient truth about ham sites, one sees that some combinations of wire and ferrite just aren't worth the trouble. Too much to figure out, too much to clean up, particularly for field day with its time constraints. Issues between wires are modulated by the wire/rope/support opportunities at a given site. In my case this last FD, optimally located trees in a far corner of the property where an RV could be parked, allowed an interesting specially designed sloped antenna I would never have tried in more crowded circumstances for considerable cause (long story). This particular long sloper turned out to be a killer on 40m CW (1119 Q's at 100w). It was removed from interaction only by the 75 yards back to the nearest station in our 3A entry. With the all-conductors-in-play principle firmly in mind for a carefully planned layout of antennas and conductors, no station ever heard the other. With a trio of K3's in operation, even with frequent SSB and CW on the same band, we heard no crud, no crosstalk, no intermod, no transmitted phase noise, which is a much harder to satisfy requirement than not burning out front ends. Some considerable portion of the credit for this result goes to the K3's front-end immunity and clean transmitted signal. BOTH the K3 immunity/clean TX signal AND the interaction-scrubbed antenna layout design were required to achieve this result. The question as to whether paying attention to such niceties is a handicap to a high score will be answered firmly enough by looking for N4C in the 3A listing in November's FD score reporting -- PVRC NC at Grey Goose Farm. And yes, the owner did name the farm after the vodka. You should see his man cave :) Making interaction go away with a simple one-size-fits-all rule just does not happen in less than very large spaces. But understanding the electronic physics of interactions and seeing all the conductors in the solution, one can dance with the physics and the physical layout possibilities to create some imaginative and excellent site-specific solutions in the field. EZNEC and an *all-conductor* model preliminary design is a very good start. 73, Guy K2AV On Wed, Jul 9, 2014 at 10:15 AM, dave ho13d...@gmail.com wrote: Probably not a good idea. The interaction between the vertical and the feed to the G5RV will be severe. You will have large quantities of RF forced onto the G5RV feeder. I ran a quick EZNEC model of 2 verticals 2.4 apart. It indicates that at 100w you would induce 45w onto the feeder. Even QRP levels would not appear to be safe. I'd think you are pretty assured of blowing something up. It would be an interesting experiment though, if you wanted to try it and report back on what burned up . . . 73 de dave ab9ca/4 On 7/9/14 8:32 AM, Rich wrote: During FD we were discussing portable antenna options for next year. We were considering a 33' fiberglass pole with a veritical and a G5RV on the same pole. A 31' piece on wire running vertically down the pole and also a G5RV supported by that same pole. Then just connect them to the K3 Ant 1 and 2 jacks and away we go, however should we expect to flood the Ant jack which is not in use with RF due to the antennas being so close? Any thoughts? Rich __ Elecraft mailing list Home: http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/mmfaq.htm Post: mailto:Elecraft@mailman.qth.net This list hosted by: http://www.qsl.net Please help support this email list: http://www.qsl.net/donate.html Message delivered to ho13d...@gmail.com __ Elecraft mailing list Home: http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/mmfaq.htm Post: mailto:Elecraft@mailman.qth.net This list hosted by: http://www.qsl.net Please help support this email list: http://www.qsl.net/donate.html Message delivered to k2av@gmail.com __ Elecraft mailing list Home: http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/mmfaq.htm Post: mailto:Elecraft@mailman.qth.net This list hosted by: http://www.qsl.net Please help support this email list: http://www.qsl.net/donate.html Message delivered to arch...@mail-archive.com
Re: [Elecraft] K3 Ant 1 and Ant 2 Isolation?
Hi to Rich and the group During field day I ran my KX3 with the tuner from the KXPA100 at 5 watts. I had my 44 ft doublet fed with 22 ft of window line on my 24 ft painters pole in the center with a 10 ft PVC support on each end of the doublet. I had a 33 ft MFJ fiberglass mast with 29 ft of wire fastened to it as a vertical about 2 ft away from the support for the doublet. The doublet through a W2DU balun was on antenna 1 and the vertical fed against the frame of my fiberglass camper was on antenna 2. Both antennas were pre tuned by the tuner on each band before field day started. I could chose either antenna instantly. Most of the field day the doublet was about the same as the vertical and I used it. I found the vertical to be the better antenna in the late evening and night on 40 meters so I used that. There was one weak point to my station and that was me as an operator but the KX3 and the 2 antennas worked great. I made 118 CW 5 watt battery search and pounce contacts and could have made many m ore if I was just a better operator. I hope my experience can be of some help. I have pictures on qrz.com not of field day but of the different parts of my station I put together for field day. 73 Ken W0CZw0cz at i29 dot net Sent from my iPad On Jul 9, 2014, at 8:32 AM, Rich rwnewbo...@comcast.net wrote: During FD we were discussing portable antenna options for next year. We were considering a 33' fiberglass pole with a veritical and a G5RV on the same pole. A 31' piece on wire running vertically down the pole and also a G5RV supported by that same pole. Then just connect them to the K3 Ant 1 and 2 jacks and away we go, however should we expect to flood the Ant jack which is not in use with RF due to the antennas being so close? Any thoughts? Rich __ Elecraft mailing list Home: http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/mmfaq.htm Post: mailto:Elecraft@mailman.qth.net This list hosted by: http://www.qsl.net Please help support this email list: http://www.qsl.net/donate.html Message delivered to w...@i29.net __ Elecraft mailing list Home: http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/mmfaq.htm Post: mailto:Elecraft@mailman.qth.net This list hosted by: http://www.qsl.net Please help support this email list: http://www.qsl.net/donate.html Message delivered to arch...@mail-archive.com
Re: [Elecraft] K3 ANT 1-2 isolation
Interesting. I looked at it from the other direction. With the K3 ANT1 connected to a dummy load and ANT2 connected also to a dummy load via my WM-2 QRP wattmeter. With 100W out at ANT1, out of ANT2 I measured 30mW at 50MHz down to 1mW at 7.1MHz. A range of -30dB to -50dB. 50MHz is not in the WM-2 spec, however, 25mW was measured at 28.2MHz which gives -36dB. There are obviously potential measurement errors there so no one needs to take it as absolute. Perhaps someone with access to precision equipment could also do the test. Regards, Mike VP8NO On 28/04/2012 12:27, Mark - G4AXX wrote: The isolation between ANT 1 and ANT 2 varies from -76dB at 1.8MHz to -46dB at 50MHz. This is measured with a signal generator, using the K3 S-meter, with ANT 2, AUX RF and RX ANT IN terminated in 50 Ohms. http://elecraft.365791.n2.nabble.com/file/n7509068/ANT1-2_leakage.jpg The isolation between AUX RF and ANT 1/2 is95dB (1-30MHz), rising to -70dB (52MHz). This was measured with an N2PK VNA. I have tried to dress the unscreened wires from ANT 1 2 to the ATU in a way to minimise coupling, but the coupling is dominated by the capacitance of relays K18 K19. Using ANT1/2 for Diversity reception means the receivers are never truly independent. There is likely to be more coupling inside the K3 than can usually be achieved by physical separation of the antennas. Operating Diversity reception with the SUB RX fed from the AUX RF BNC input is the way to go. 73 Mark G4AXX __ Elecraft mailing list Home: http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/mmfaq.htm Post: mailto:Elecraft@mailman.qth.net This list hosted by: http://www.qsl.net Please help support this email list: http://www.qsl.net/donate.html
[Elecraft] K3 ANT 1-2 isolation
Oops, I should have written that I saw 100mW at 50MHz, not 30 which was the loss in dB. Regards, Mike VP8NO __ Elecraft mailing list Home: http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/mmfaq.htm Post: mailto:Elecraft@mailman.qth.net This list hosted by: http://www.qsl.net Please help support this email list: http://www.qsl.net/donate.html
Re: [Elecraft] K3 ANT 1-2 isolation
You are getting some really worse numbers than I did. You may have ant2 only terminated on one end of its cable connections, which would be really worse on 6 meters than 160. There is one of those bitty jacks that needs a cable attached to it and then terminated. It's the other antenna connection that allows you to listen on whichever of ANT1/2 the TX is NOT using. Out on Core Banks, NC, we were using doublets at right angles on the same pole to ANT1 and ANT2, receiving with diversity. There was 30 dB separation with the two antennas hanging on the same pole. How much better does it have to be inside the K3? You need to terminate the internal K3 connection of ANT2 when you make the measurement. Also the shields of both cable connections at both ends need to be grounded as well as terminated. 73, Guy. On Sun, Apr 29, 2012 at 9:28 AM, Mike Harris mike.har...@cwimail.fk wrote: Interesting. I looked at it from the other direction. With the K3 ANT1 connected to a dummy load and ANT2 connected also to a dummy load via my WM-2 QRP wattmeter. With 100W out at ANT1, out of ANT2 I measured 30mW at 50MHz down to 1mW at 7.1MHz. A range of -30dB to -50dB. 50MHz is not in the WM-2 spec, however, 25mW was measured at 28.2MHz which gives -36dB. There are obviously potential measurement errors there so no one needs to take it as absolute. Perhaps someone with access to precision equipment could also do the test. Regards, Mike VP8NO On 28/04/2012 12:27, Mark - G4AXX wrote: The isolation between ANT 1 and ANT 2 varies from -76dB at 1.8MHz to -46dB at 50MHz. This is measured with a signal generator, using the K3 S-meter, with ANT 2, AUX RF and RX ANT IN terminated in 50 Ohms. http://elecraft.365791.n2.nabble.com/file/n7509068/ANT1-2_leakage.jpg The isolation between AUX RF and ANT 1/2 is95dB (1-30MHz), rising to -70dB (52MHz). This was measured with an N2PK VNA. I have tried to dress the unscreened wires from ANT 1 2 to the ATU in a way to minimise coupling, but the coupling is dominated by the capacitance of relays K18 K19. Using ANT1/2 for Diversity reception means the receivers are never truly independent. There is likely to be more coupling inside the K3 than can usually be achieved by physical separation of the antennas. Operating Diversity reception with the SUB RX fed from the AUX RF BNC input is the way to go. 73 Mark G4AXX __ Elecraft mailing list Home: http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/mmfaq.htm Post: mailto:Elecraft@mailman.qth.net This list hosted by: http://www.qsl.net Please help support this email list: http://www.qsl.net/donate.html __ Elecraft mailing list Home: http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/mmfaq.htm Post: mailto:Elecraft@mailman.qth.net This list hosted by: http://www.qsl.net Please help support this email list: http://www.qsl.net/donate.html
Re: [Elecraft] K3 ANT 1-2 isolation
I thought it was clear that all I was looking at was a transmit parameter, that is, what came out of ANT2 when ANT1 was was carrying a signal. This gives an idea of the coupling across the C/O relay K18 which selects ANT1 or 2. In this context both ports were terminated. I fail to see why I should also have to terminate J43 on the KAT3, it would in effect doubly terminate the port with one termination before the wattmeter and one after. Not a satisfactory situation for the measurement. Naturally, if the Sub RX is connected to J43 that job would be being done by the input of the RX and readings might be different. I have my Sub RX either listening to the same antenna as the Main RX or to the Aux antenna port. Nothing connected to J43. The idea was to see what happens with one of a set of standard set-ups, not one where the configuration has been rigged to try and maximise a reading. If there is a real need to absolutely minimise what came out of, or into, the unused antenna port then by all means terminate J43. It's yours to do with what you like. Regards, Mike VP8NO On 29/04/2012 17:06, Guy Olinger K2AV wrote: You are getting some really worse numbers than I did. You may have ant2 only terminated on one end of its cable connections, which would be really worse on 6 meters than 160. There is one of those bitty jacks that needs a cable attached to it and then terminated. It's the other antenna connection that allows you to listen on whichever of ANT1/2 the TX is NOT using. Out on Core Banks, NC, we were using doublets at right angles on the same pole to ANT1 and ANT2, receiving with diversity. There was 30 dB separation with the two antennas hanging on the same pole. How much better does it have to be inside the K3? You need to terminate the internal K3 connection of ANT2 when you make the measurement. Also the shields of both cable connections at both ends need to be grounded as well as terminated. 73, Guy. On Sun, Apr 29, 2012 at 9:28 AM, Mike Harrismike.har...@cwimail.fk wrote: Interesting. I looked at it from the other direction. With the K3 ANT1 connected to a dummy load and ANT2 connected also to a dummy load via my WM-2 QRP wattmeter. With 100W out at ANT1, out of ANT2 I measured 30mW at 50MHz down to 1mW at 7.1MHz. A range of -30dB to -50dB. 50MHz is not in the WM-2 spec, however, 25mW was measured at 28.2MHz which gives -36dB. There are obviously potential measurement errors there so no one needs to take it as absolute. Perhaps someone with access to precision equipment could also do the test. Regards, Mike VP8NO On 28/04/2012 12:27, Mark - G4AXX wrote: The isolation between ANT 1 and ANT 2 varies from -76dB at 1.8MHz to -46dB at 50MHz. This is measured with a signal generator, using the K3 S-meter, with ANT 2, AUX RF and RX ANT IN terminated in 50 Ohms. http://elecraft.365791.n2.nabble.com/file/n7509068/ANT1-2_leakage.jpg The isolation between AUX RF and ANT 1/2 is95dB (1-30MHz), rising to -70dB (52MHz). This was measured with an N2PK VNA. I have tried to dress the unscreened wires from ANT 1 2 to the ATU in a way to minimise coupling, but the coupling is dominated by the capacitance of relays K18 K19. Using ANT1/2 for Diversity reception means the receivers are never truly independent. There is likely to be more coupling inside the K3 than can usually be achieved by physical separation of the antennas. Operating Diversity reception with the SUB RX fed from the AUX RF BNC input is the way to go. 73 Mark G4AXX __ Elecraft mailing list Home: http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/mmfaq.htm Post: mailto:Elecraft@mailman.qth.net This list hosted by: http://www.qsl.net Please help support this email list: http://www.qsl.net/donate.html __ Elecraft mailing list Home: http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/mmfaq.htm Post: mailto:Elecraft@mailman.qth.net This list hosted by: http://www.qsl.net Please help support this email list: http://www.qsl.net/donate.html
Re: [Elecraft] K3 ANT 1-2 isolation
In your context the ANT1 circuit was normally terminated, one port in the transmitter, the other in an antenna. That's normal, a load on both ends. ANT2 was NOT normally terminated unless you want to treat the reactive 10 k+ Z termination of the tiny capacitance across the relay as normal. If antenna two was actually being used for something while TX on ANT2, there would be something on J43 when not in transmit. If you have a sub RX on the non-TX line, then the crossover means something, as in do I need to close the COR relay. But that now is the same as your ANT1 termination, TX on one end, ANTenna on the other, except RX on one end and antenna on the other. I could say that your method was the one rigged (as in not normal), and was devised to come up with the worst possible reading. I actually USE ANT 2 during TX on ANT 1. That's when you want to know the separation. I don't get readings as bad as yours. 73, Guy. On Sun, Apr 29, 2012 at 5:51 PM, Mike Harris mike.har...@cwimail.fk wrote: I thought it was clear that all I was looking at was a transmit parameter, that is, what came out of ANT2 when ANT1 was was carrying a signal. This gives an idea of the coupling across the C/O relay K18 which selects ANT1 or 2. In this context both ports were terminated. I fail to see why I should also have to terminate J43 on the KAT3, it would in effect doubly terminate the port with one termination before the wattmeter and one after. Not a satisfactory situation for the measurement. Naturally, if the Sub RX is connected to J43 that job would be being done by the input of the RX and readings might be different. I have my Sub RX either listening to the same antenna as the Main RX or to the Aux antenna port. Nothing connected to J43. The idea was to see what happens with one of a set of standard set-ups, not one where the configuration has been rigged to try and maximise a reading. If there is a real need to absolutely minimise what came out of, or into, the unused antenna port then by all means terminate J43. It's yours to do with what you like. Regards, Mike VP8NO On 29/04/2012 17:06, Guy Olinger K2AV wrote: You are getting some really worse numbers than I did. You may have ant2 only terminated on one end of its cable connections, which would be really worse on 6 meters than 160. There is one of those bitty jacks that needs a cable attached to it and then terminated. It's the other antenna connection that allows you to listen on whichever of ANT1/2 the TX is NOT using. Out on Core Banks, NC, we were using doublets at right angles on the same pole to ANT1 and ANT2, receiving with diversity. There was 30 dB separation with the two antennas hanging on the same pole. How much better does it have to be inside the K3? You need to terminate the internal K3 connection of ANT2 when you make the measurement. Also the shields of both cable connections at both ends need to be grounded as well as terminated. 73, Guy. On Sun, Apr 29, 2012 at 9:28 AM, Mike Harrismike.har...@cwimail.fk wrote: Interesting. I looked at it from the other direction. With the K3 ANT1 connected to a dummy load and ANT2 connected also to a dummy load via my WM-2 QRP wattmeter. With 100W out at ANT1, out of ANT2 I measured 30mW at 50MHz down to 1mW at 7.1MHz. A range of -30dB to -50dB. 50MHz is not in the WM-2 spec, however, 25mW was measured at 28.2MHz which gives -36dB. There are obviously potential measurement errors there so no one needs to take it as absolute. Perhaps someone with access to precision equipment could also do the test. Regards, Mike VP8NO On 28/04/2012 12:27, Mark - G4AXX wrote: The isolation between ANT 1 and ANT 2 varies from -76dB at 1.8MHz to -46dB at 50MHz. This is measured with a signal generator, using the K3 S-meter, with ANT 2, AUX RF and RX ANT IN terminated in 50 Ohms. http://elecraft.365791.n2.nabble.com/file/n7509068/ANT1-2_leakage.jpg The isolation between AUX RF and ANT 1/2 is95dB (1-30MHz), rising to -70dB (52MHz). This was measured with an N2PK VNA. I have tried to dress the unscreened wires from ANT 1 2 to the ATU in a way to minimise coupling, but the coupling is dominated by the capacitance of relays K18 K19. Using ANT1/2 for Diversity reception means the receivers are never truly independent. There is likely to be more coupling inside the K3 than can usually be achieved by physical separation of the antennas. Operating Diversity reception with the SUB RX fed from the AUX RF BNC input is the way to go. 73 Mark G4AXX __ Elecraft mailing list Home: http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/mmfaq.htm Post: mailto:Elecraft@mailman.qth.net This list hosted by: http://www.qsl.net Please help support this email list:
Re: [Elecraft] K3 ANT 1-2 isolation
So what you are essentially saying is the K3 has a design fault because in a perfectly normal factory configuration it is leaving a port unterminated. Maybe it is the electronic equivalent of a Persian rug. I'm not rigging anything, it's how it is right out of the box. I think the real objection here is simply that a low number is reported which is contrary to the perceived wish for the K3 to be somehow perfect. Regards, Mike VP8NO On 29/04/2012 21:47, Guy Olinger K2AV wrote: In your context the ANT1 circuit was normally terminated, one port in the transmitter, the other in an antenna. That's normal, a load on both ends. ANT2 was NOT normally terminated unless you want to treat the reactive 10 k+ Z termination of the tiny capacitance across the relay as normal. If antenna two was actually being used for something while TX on ANT2, there would be something on J43 when not in transmit. If you have a sub RX on the non-TX line, then the crossover means something, as in do I need to close the COR relay. But that now is the same as your ANT1 termination, TX on one end, ANTenna on the other, except RX on one end and antenna on the other. I could say that your method was the one rigged (as in not normal), and was devised to come up with the worst possible reading. I actually USE ANT 2 during TX on ANT 1. That's when you want to know the separation. I don't get readings as bad as yours. 73, Guy. On Sun, Apr 29, 2012 at 5:51 PM, Mike Harrismike.har...@cwimail.fk wrote: I thought it was clear that all I was looking at was a transmit parameter, that is, what came out of ANT2 when ANT1 was was carrying a signal. This gives an idea of the coupling across the C/O relay K18 which selects ANT1 or 2. In this context both ports were terminated. I fail to see why I should also have to terminate J43 on the KAT3, it would in effect doubly terminate the port with one termination before the wattmeter and one after. Not a satisfactory situation for the measurement. Naturally, if the Sub RX is connected to J43 that job would be being done by the input of the RX and readings might be different. I have my Sub RX either listening to the same antenna as the Main RX or to the Aux antenna port. Nothing connected to J43. The idea was to see what happens with one of a set of standard set-ups, not one where the configuration has been rigged to try and maximise a reading. If there is a real need to absolutely minimise what came out of, or into, the unused antenna port then by all means terminate J43. It's yours to do with what you like. Regards, Mike VP8NO On 29/04/2012 17:06, Guy Olinger K2AV wrote: You are getting some really worse numbers than I did. You may have ant2 only terminated on one end of its cable connections, which would be really worse on 6 meters than 160. There is one of those bitty jacks that needs a cable attached to it and then terminated. It's the other antenna connection that allows you to listen on whichever of ANT1/2 the TX is NOT using. Out on Core Banks, NC, we were using doublets at right angles on the same pole to ANT1 and ANT2, receiving with diversity. There was 30 dB separation with the two antennas hanging on the same pole. How much better does it have to be inside the K3? You need to terminate the internal K3 connection of ANT2 when you make the measurement. Also the shields of both cable connections at both ends need to be grounded as well as terminated. 73, Guy. On Sun, Apr 29, 2012 at 9:28 AM, Mike Harrismike.har...@cwimail.fk wrote: Interesting. I looked at it from the other direction. With the K3 ANT1 connected to a dummy load and ANT2 connected also to a dummy load via my WM-2 QRP wattmeter. With 100W out at ANT1, out of ANT2 I measured 30mW at 50MHz down to 1mW at 7.1MHz. A range of -30dB to -50dB. 50MHz is not in the WM-2 spec, however, 25mW was measured at 28.2MHz which gives -36dB. There are obviously potential measurement errors there so no one needs to take it as absolute. Perhaps someone with access to precision equipment could also do the test. Regards, Mike VP8NO On 28/04/2012 12:27, Mark - G4AXX wrote: The isolation between ANT 1 and ANT 2 varies from -76dB at 1.8MHz to -46dB at 50MHz. This is measured with a signal generator, using the K3 S-meter, with ANT 2, AUX RF and RX ANT IN terminated in 50 Ohms. http://elecraft.365791.n2.nabble.com/file/n7509068/ANT1-2_leakage.jpg The isolation between AUX RF and ANT 1/2 is95dB (1-30MHz), rising to -70dB (52MHz). This was measured with an N2PK VNA. I have tried to dress the unscreened wires from ANT 12 to the ATU in a way to minimise coupling, but the coupling is dominated by the capacitance of relays K18K19. Using ANT1/2 for Diversity reception means the receivers are never truly independent. There is likely to be more coupling inside the K3 than can usually be achieved by physical separation of the
Re: [Elecraft] K3 ANT 1-2 isolation
The isolation between ANT 1 and ANT 2 varies from -76dB at 1.8MHz to -46dB at 50MHz. This is measured with a signal generator, using the K3 S-meter, with ANT 2, AUX RF and RX ANT IN terminated in 50 Ohms. http://elecraft.365791.n2.nabble.com/file/n7509068/ANT1-2_leakage.jpg The isolation between AUX RF and ANT 1/2 is 95dB (1-30MHz), rising to -70dB (52MHz). This was measured with an N2PK VNA. I have tried to dress the unscreened wires from ANT 1 2 to the ATU in a way to minimise coupling, but the coupling is dominated by the capacitance of relays K18 K19. Using ANT1/2 for Diversity reception means the receivers are never truly independent. There is likely to be more coupling inside the K3 than can usually be achieved by physical separation of the antennas. Operating Diversity reception with the SUB RX fed from the AUX RF BNC input is the way to go. 73 Mark G4AXX -- View this message in context: http://elecraft.365791.n2.nabble.com/K3-ANT-1-2-isolation-tp7500652p7509068.html Sent from the Elecraft mailing list archive at Nabble.com. __ Elecraft mailing list Home: http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/mmfaq.htm Post: mailto:Elecraft@mailman.qth.net This list hosted by: http://www.qsl.net Please help support this email list: http://www.qsl.net/donate.html
Re: [Elecraft] K3 ANT 1-2 isolation
with isolation numbers like this perhaps there is hope for duplex mode, with transmitting on one band with the subrx enabled and listening on another?? Hopefully! Mark n2qt -Original Message- From: Mark - G4AXX Sent: Saturday, April 28, 2012 11:27 AM To: elecraft@mailman.qth.net Subject: Re: [Elecraft] K3 ANT 1-2 isolation The isolation between ANT 1 and ANT 2 varies from -76dB at 1.8MHz to -46dB at 50MHz. This is measured with a signal generator, using the K3 S-meter, with ANT 2, AUX RF and RX ANT IN terminated in 50 Ohms. http://elecraft.365791.n2.nabble.com/file/n7509068/ANT1-2_leakage.jpg The isolation between AUX RF and ANT 1/2 is 95dB (1-30MHz), rising to -70dB (52MHz). This was measured with an N2PK VNA. I have tried to dress the unscreened wires from ANT 1 2 to the ATU in a way to minimise coupling, but the coupling is dominated by the capacitance of relays K18 K19. Using ANT1/2 for Diversity reception means the receivers are never truly independent. There is likely to be more coupling inside the K3 than can usually be achieved by physical separation of the antennas. Operating Diversity reception with the SUB RX fed from the AUX RF BNC input is the way to go. 73 Mark G4AXX -- View this message in context: http://elecraft.365791.n2.nabble.com/K3-ANT-1-2-isolation-tp7500652p7509068.html Sent from the Elecraft mailing list archive at Nabble.com. __ Elecraft mailing list Home: http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/mmfaq.htm Post: mailto:Elecraft@mailman.qth.net This list hosted by: http://www.qsl.net Please help support this email list: http://www.qsl.net/donate.html __ Elecraft mailing list Home: http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/mmfaq.htm Post: mailto:Elecraft@mailman.qth.net This list hosted by: http://www.qsl.net Please help support this email list: http://www.qsl.net/donate.html
Re: [Elecraft] K3 ANT 1-2 isolation
True that the isolation between ATN1, ANT2 and RX Ant are poor. The solution is to use a preamp in receive antennas so that signals from RX and TX antennas are similar in strength. Ignacy -- View this message in context: http://elecraft.365791.n2.nabble.com/K3-ANT-1-2-isolation-tp7500652p7503048.html Sent from the Elecraft mailing list archive at Nabble.com. __ Elecraft mailing list Home: http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/mmfaq.htm Post: mailto:Elecraft@mailman.qth.net This list hosted by: http://www.qsl.net Please help support this email list: http://www.qsl.net/donate.html
Re: [Elecraft] K3 ANT 1-2 isolation
Poor is a bit harsh, what do you expect from a single small C/O relay. Anything over 30dB isolation is a luxury. Regards, Mike VP8NO On 26/04/2012 11:24, Ignacy wrote: True that the isolation between ATN1, ANT2 and RX Ant are poor. The solution is to use a preamp in receive antennas so that signals from RX and TX antennas are similar in strength. Ignacy __ Elecraft mailing list Home: http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/mmfaq.htm Post: mailto:Elecraft@mailman.qth.net This list hosted by: http://www.qsl.net Please help support this email list: http://www.qsl.net/donate.html
Re: [Elecraft] K3 ANT 1-2 isolation
Might be considered poor in relation to coaxial switches. Some of these get 70 dB isolation. 73, matt W6NIA On Thu, 26 Apr 2012 15:44:39 -0300, you wrote: Poor is a bit harsh, what do you expect from a single small C/O relay. Anything over 30dB isolation is a luxury. Regards, Mike VP8NO On 26/04/2012 11:24, Ignacy wrote: True that the isolation between ATN1, ANT2 and RX Ant are poor. The solution is to use a preamp in receive antennas so that signals from RX and TX antennas are similar in strength. Ignacy __ Elecraft mailing list Home: http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/mmfaq.htm Post: mailto:Elecraft@mailman.qth.net This list hosted by: http://www.qsl.net Please help support this email list: http://www.qsl.net/donate.html __ Elecraft mailing list Home: http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/mmfaq.htm Post: mailto:Elecraft@mailman.qth.net This list hosted by: http://www.qsl.net Please help support this email list: http://www.qsl.net/donate.html
Re: [Elecraft] K3 ANT 1-2 isolation
I have much greater separations than 30 dB when the jacks are terminated with real lines, so I'll have to assume that readings like 30 dB are listening in an unterminated port with signals on another. You can't measure separation (or RX noise) without line terminations (resistor or real antenna) on ALL ports. 73, Guy. On Thu, Apr 26, 2012 at 3:17 PM, Matt Zilmer mzil...@verizon.net wrote: Might be considered poor in relation to coaxial switches. Some of these get 70 dB isolation. 73, matt W6NIA On Thu, 26 Apr 2012 15:44:39 -0300, you wrote: Poor is a bit harsh, what do you expect from a single small C/O relay. Anything over 30dB isolation is a luxury. Regards, Mike VP8NO On 26/04/2012 11:24, Ignacy wrote: True that the isolation between ATN1, ANT2 and RX Ant are poor. The solution is to use a preamp in receive antennas so that signals from RX and TX antennas are similar in strength. Ignacy __ Elecraft mailing list Home: http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/mmfaq.htm Post: mailto:Elecraft@mailman.qth.net This list hosted by: http://www.qsl.net Please help support this email list: http://www.qsl.net/donate.html __ Elecraft mailing list Home: http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/mmfaq.htm Post: mailto:Elecraft@mailman.qth.net This list hosted by: http://www.qsl.net Please help support this email list: http://www.qsl.net/donate.html __ Elecraft mailing list Home: http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/mmfaq.htm Post: mailto:Elecraft@mailman.qth.net This list hosted by: http://www.qsl.net Please help support this email list: http://www.qsl.net/donate.html
[Elecraft] K3 Ant 1?
Need help with some troubleshooting...here is the background: After being gone for a month I returned to find that my iMac would not boot up, the LP100 display had noticeably dimmed and my Steppir 3 ele beam had super high SWR on 20m only. Although I had disconnected p/s and antennas, we had an unusual amount of t-storm activity while gone. I assumed that static discharges had somehow placed gremlins into my shack. The local Apple guy was able to get the iMac running with no loss of data and Larry kindly helped with getting the latest display chips installed but that left the Steppir...why it worked great on 17-6m and it was a mystery on 20m with infinite swr across the band, even after doing the calibrate procedure. Yesterday I decided to upgrade the software of my Orion II and then later the K3. After the O II upgrade I connected the Steppir and was surprised to see that the swr was normal across the 20m band; I then tried it on the K3, infinite swr...I then tried a dummy load on the k3 and yes, infinite swr but only on 20m. I then moved the dummy load to Ant 2 and all was fine. I then hooked the Steppir to Ant 2 and everything is working great. So, here is the question. If the SO239 was bad at Ant1, why does it work on all bands except 20m? Unfortunately, this was a factory built unit, #250, so my knowledge of the insides is very sketchy. What do I need to look for? Tnx Tom CX7TT aka CW7T in CQ WW cw... __ Elecraft mailing list Home: http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/mmfaq.htm Post: mailto:Elecraft@mailman.qth.net This list hosted by: http://www.qsl.net Please help support this email list: http://www.qsl.net/donate.html
[Elecraft] K3 Ant 1?
Need help with some troubleshooting...here is the background: After being gone for a month I returned to find that my iMac would not boot up, the LP100 display had noticeably dimmed and my Steppir 3 ele beam had super high SWR on 20m only. Although I had disconnected p/s and antennas, we had an unusual amount of t-storm activity while gone. I assumed that static discharges had somehow placed gremlins into my shack. The local Apple guy was able to get the iMac running with no loss of data and Larry kindly helped with getting the latest display chips installed but that left the Steppir...why it worked great on 17-6m and it was a mystery on 20m with infinite swr across the band, even after doing the calibrate procedure. Yesterday I decided to upgrade the software of my Orion II and then later the K3. After the O II upgrade I connected the Steppir and was surprised to see that the swr was normal across the 20m band; I then tried it on the K3, infinite swr...I then tried a dummy load on the k3 and yes, infinite swr but only on 20m. I then moved the dummy load to Ant 2 and all was fine. I then hooked the Steppir to Ant 2 and everything is working great. So, here is the question. If the SO239 was bad at Ant1, why does it work on all bands except 20m? Unfortunately, this was a factory built unit, #250, so my knowledge of the insides is very sketchy. What do I need to look for? Tnx Tom CX7TT aka CW7T in CQ WW cw... __ Elecraft mailing list Home: http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/mmfaq.htm Post: mailto:Elecraft@mailman.qth.net This list hosted by: http://www.qsl.net Please help support this email list: http://www.qsl.net/donate.html
Re: [Elecraft] K3 Ant 1?
Tom, So, here is the question. If the SO239 was bad at Ant1, why does it work on all bands except 20m? Unfortunately, this was a factory built unit, #250, so my knowledge of the insides is very sketchy. What do I need to look for? Before doing anything else, connect the dummy load to Ant 1, turn on the ATU and run a couple ATU Tune cycles. The K3 stores antenna and tuner data on a per antenna per band basis and it's possible that the data has gotten scrambled. If nothing else running the ATU Tune cycle might get the tuner off a bad setting 73, ... Joe, W4TV On 11/26/2010 5:23 AM, cx...@4email.net wrote: Need help with some troubleshooting...here is the background: After being gone for a month I returned to find that my iMac would not boot up, the LP100 display had noticeably dimmed and my Steppir 3 ele beam had super high SWR on 20m only. Although I had disconnected p/s and antennas, we had an unusual amount of t-storm activity while gone. I assumed that static discharges had somehow placed gremlins into my shack. The local Apple guy was able to get the iMac running with no loss of data and Larry kindly helped with getting the latest display chips installed but that left the Steppir...why it worked great on 17-6m and it was a mystery on 20m with infinite swr across the band, even after doing the calibrate procedure. Yesterday I decided to upgrade the software of my Orion II and then later the K3. After the O II upgrade I connected the Steppir and was surprised to see that the swr was normal across the 20m band; I then tried it on the K3, infinite swr...I then tried a dummy load on the k3 and yes, infinite swr but only on 20m. I then moved the dummy load to Ant 2 and all was fine. I then hooked the Steppir to Ant 2 and everything is working great. So, here is the question. If the SO239 was bad at Ant1, why does it work on all bands except 20m? Unfortunately, this was a factory built unit, #250, so my knowledge of the insides is very sketchy. What do I need to look for? Tnx Tom CX7TT aka CW7T in CQ WW cw... __ Elecraft mailing list Home: http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/mmfaq.htm Post: mailto:Elecraft@mailman.qth.net This list hosted by: http://www.qsl.net Please help support this email list: http://www.qsl.net/donate.html __ Elecraft mailing list Home: http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/mmfaq.htm Post: mailto:Elecraft@mailman.qth.net This list hosted by: http://www.qsl.net Please help support this email list: http://www.qsl.net/donate.html
Re: [Elecraft] K3 Ant 1?
A relay switches the KAT3 output between Ant 1 and Ant 2 and there's a discharge tube on each Ant circuit. It sounds like the relay or the discharge tube circuit on Ant 1 has been damaged. Suggest you send an e-mail to k3support at elecraft dot com and they'll help you get it put right. 73, Ron AC7AC -Original Message- From: elecraft-boun...@mailman.qth.net [mailto:elecraft-boun...@mailman.qth.net] On Behalf Of cx...@4email.net Sent: Friday, November 26, 2010 2:24 AM To: elecraft@mailman.qth.net Subject: [Elecraft] K3 Ant 1? Need help with some troubleshooting...here is the background: After being gone for a month I returned to find that my iMac would not boot up, the LP100 display had noticeably dimmed and my Steppir 3 ele beam had super high SWR on 20m only. Although I had disconnected p/s and antennas, we had an unusual amount of t-storm activity while gone. I assumed that static discharges had somehow placed gremlins into my shack. The local Apple guy was able to get the iMac running with no loss of data and Larry kindly helped with getting the latest display chips installed but that left the Steppir...why it worked great on 17-6m and it was a mystery on 20m with infinite swr across the band, even after doing the calibrate procedure. Yesterday I decided to upgrade the software of my Orion II and then later the K3. After the O II upgrade I connected the Steppir and was surprised to see that the swr was normal across the 20m band; I then tried it on the K3, infinite swr...I then tried a dummy load on the k3 and yes, infinite swr but only on 20m. I then moved the dummy load to Ant 2 and all was fine. I then hooked the Steppir to Ant 2 and everything is working great. So, here is the question. If the SO239 was bad at Ant1, why does it work on all bands except 20m? Unfortunately, this was a factory built unit, #250, so my knowledge of the insides is very sketchy. What do I need to look for? Tnx Tom CX7TT aka CW7T in CQ WW cw... __ Elecraft mailing list Home: http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/mmfaq.htm Post: mailto:Elecraft@mailman.qth.net This list hosted by: http://www.qsl.net Please help support this email list: http://www.qsl.net/donate.html __ Elecraft mailing list Home: http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/mmfaq.htm Post: mailto:Elecraft@mailman.qth.net This list hosted by: http://www.qsl.net Please help support this email list: http://www.qsl.net/donate.html
