Re: Topband: JT65 to EU?
I'm similarly half way to DXCC and in Europe. WSJT has been exclusively in the 1838 segment and accounts for at least half of my DXCC total. We cannot use 1800-1810 here. Jim Miller j...@jtmiller.com wrote: I'm about half way to DXCC on 160 and looking for any way to move the needle. Most of my EU 160 has been CW but I've been wondering if any have had luck using WSJT modes either JT65 or JT9. If so is the 1838 segment where this occurs or do EU DX call in the DX window? 73 jim ab3cv _ Topband Reflector Archives - http://www.contesting.com/_topband -- Brian D G3VGZ Yarm England Europe _ Topband Reflector Archives - http://www.contesting.com/_topband
Re: Topband: JT65 to EU?
Hi Brian Thanks for the quick reply! Has it been mostly JT65 or have you seen JT9 in use? Thanks again Jim ab3cv On Tue, Nov 11, 2014 at 5:33 AM, Brian Duffell topb...@planet3.freeuk.co.uk wrote: I'm similarly half way to DXCC and in Europe. WSJT has been exclusively in the 1838 segment and accounts for at least half of my DXCC total. We cannot use 1800-1810 here. Jim Miller j...@jtmiller.com wrote: I'm about half way to DXCC on 160 and looking for any way to move the needle. Most of my EU 160 has been CW but I've been wondering if any have had luck using WSJT modes either JT65 or JT9. If so is the 1838 segment where this occurs or do EU DX call in the DX window? 73 jim ab3cv _ Topband Reflector Archives - http://www.contesting.com/_topband -- Brian D G3VGZ Yarm England Europe _ Topband Reflector Archives - http://www.contesting.com/_topband
Re: Topband: Balun or no balun
I have put up a 160 meter horizontal loop fed with 30 feet of 450 ohm feed line to my tuner. I have a Radioworks 4 to 1 balun. I am considering splicing into the feed line at 10 feet so I can run 20 feet of coax into the shack. Thoughts? I run a qrp plus on 160. Hi Kirk, Are you using the antenna on multiple bands? The best way to feed really depends on how you want to use the antenna. A resonant 160 meter loop around 20-30 feet above the ground has a feedpoint impedance of around 50 ohms on 160, and about 80 ohms on 80 meters. The antenna impedance isn't really high until 40 meters, where it would be resonant far outside the band and have a terrible mismatch to any feedline. 450 ohm line (which are usually around 400 ohms) is a needless mismatch for 160 and 80, but would be better for 40 meters and up. The 4:1 balun is the wrong impedance balun on any band for any feedline. 73 Tom _ Topband Reflector Archives - http://www.contesting.com/_topband
Re: Topband: New RF interference killing RX at my QTH
By looking at the panadapter on my flex 6500, I can see KEES; they're not even THAT strong, (around -40 dbm) but the crud is definitely there, only down about 30 db from the main signal. It takes multiple phone calls, emails, mean facebook posts, and text messages to KEES and the FCC to get anything done about it. Same thing happened couple years ago... When this happened before, do you know what happened to fix it? I've had problems like that several times, sometimes from stations hundreds of miles away. Sometimes it is parasitics in the transmitter, and sometimes it is arcing in the antenna system. Although it could be anything, for my cases the real long distance stuff has always been parasitics in transmitters. Parasitics are frequency selective, perhaps a few hundred kilohertz wide. The close-in stuff from local stations has usually been arcing in antenna systems. Arcing in antennas is generally very wide bandwidth. About half the time a nice call to the correct person at the radio station will get things fixed. The rest of the time it takes FCC involvement, which can be difficult. In the interests of smaller government and lack of skilled field engineers, the FCC has become far understaffed. You have to figure out how to work around the field engineer shortage problem, if you are sure it is the station's problem and the station does not want to fix it. 73 Tom _ Topband Reflector Archives - http://www.contesting.com/_topband
Re: Topband: JT65 to EU?
Of my 55 dxccs on topband, 48 are cw, 34 JT65 and only 11 are JT9. There seems little JT9 activity on 160 here. JT9 tends to overlap the JT65 segment as phone is often using the higher end. Quite a few europeans are calling CQ most evenings with few takers. W tends to start coming in around z in the winter months peaking around 0300 after which I'm rarely around, but I was surprised to get W1AW/4 in VA at 2220z cw last month. Jim Miller j...@jtmiller.com wrote: Hi Brian Thanks for the quick reply! Has it been mostly JT65 or have you seen JT9 in use? Thanks again Jim ab3cv On Tue, Nov 11, 2014 at 5:33 AM, Brian Duffell topb...@planet3.freeuk.co.uk wrote: I'm similarly half way to DXCC and in Europe. WSJT has been exclusively in the 1838 segment and accounts for at least half of my DXCC total. We cannot use 1800-1810 here. Jim Miller j...@jtmiller.com wrote: I'm about half way to DXCC on 160 and looking for any way to move the needle. Most of my EU 160 has been CW but I've been wondering if any have had luck using WSJT modes either JT65 or JT9. If so is the 1838 segment where this occurs or do EU DX call in the DX window? 73 jim ab3cv _ Topband Reflector Archives - http://www.contesting.com/_topband -- Brian D G3VGZ Yarm England Europe _ Topband Reflector Archives - http://www.contesting.com/_topband -- Brian D G3VGZ _ Topband Reflector Archives - http://www.contesting.com/_topband
Re: Topband: Balun or no balun
Kirk, I put up a large horizontal loop and can use it just about everywhere but since I have a Yagi for 20-6M, the loop gets used primarily on 160-30M. The loop I put up is about 1100 feet of wire in a square up 65 feet (supported by four 70 foot utility poles I planted in my field) fed with about 220 feet of 450 ohm window line. The 1100 feet amount of wire was chosen more based on what I could fit but I wanted about 2 wavelengths on 160M. It works VERY well for DX on 80-40-30M and depending on wave angles, can work very well for DX on 160M. Stateside signals on 160-30M are very good as well. I worked FT5ZM on Amsterdam on 160M and I had a time window of about 20 minutes in my morning with signals up to 4 S units out of the noise, no headphones needed! There are many mechanical considerations when using a feedpoint that is not supported but floating (I use a pulley system to raise and lower each corner). I bring it back to the shack horizontally supported by PVC topped 10 foot TV mast. Then right where it enters my shack through a board pinched by the sliding window, I use RG-213 for about 5 feet to get through the wood and not to worry about unbalancing the parallel conductors as it is near metals in the window frame, etc. To do this, I use the center conductors of the coax as each leg of the feedline and ground the shields at the tuner but leave the shields open where it meets the 450 ohm feedline. I use simple banana plugs/jacks at that outside junction to quickly disconnect for lightning. I tune it with a Palstar BT-1500A true balanced line tuner. I hope this gives you some food for thought showing how one Ham did it. On 80M results are sometimes better, sometimes worse than my full size 80M vertical, depending on what DX I'm working. It has been said by many once you put up a loop, you never take it down. If you are feeding it with 30 feet of 450 ohm window line that means it will not be up very high so I would expect your DX results would be limited on 160 and 80M. Undoubtedly there will be opinions but I can tell you that this configuration works incredibly well for me. 73, Dan W7RF www.radiodan.com Fort Collins, CO Message: 6 Date: Tue, 11 Nov 2014 04:46:56 GMT From: W3AW via Topbandtopband@contesting.com To:topband@contesting.com topband@contesting.com Subject: Topband: Balun or no balun Message-ID:000f425e.05b960860e39f...@aol.com Content-Type: text/plain; charset=utf-8 I have put up a 160 meter horizontal loop fed with 30 feet of 450 ohm feed line to my tuner. I have a Radioworks 4 to 1 balun. I am considering splicing into the feed line at 10 feet so I can run 20 feet of coax into the shack. Thoughts? I run a qrp plus on 160. Kirk W3AW Illinois -- 73, Dan W7RF www.radiodan.com _ Topband Reflector Archives - http://www.contesting.com/_topband
Re: Topband: Balun or no balun
Tom wrote: A resonant 160 meter loop around 20-30 feet above the ground has a feedpoint impedance of around 50 ohms on 160, and about 80 ohms on 80 meters. The antenna impedance isn't really high until 40 meters, where it would be resonant far outside the band and have a terrible mismatch to any feedline. Expanding a bit on what Tom said, the source resistance at resonance will also depend on the type of ground. With AutoEZ, I first used this dialog to create a 4-sided horizontal loop having a perimeter of P ft at a height of H ft above ground. http://ac6la.com/adhoc/160mLoop1.png I then created a series of test cases with H ranging from 10 to 90 ft (~0.02 to 0.16 λ at 1.8 MHz) in 5 ft steps and with P having an initial value of 560 ft (~1005/Freq). Then the Resonate button was used to automatically adjust the loop perimeter P for resonance at each height. http://ac6la.com/adhoc/160mLoop2.png Repeating that process for three different ground types gives this result for the source resistance. http://ac6la.com/adhoc/160mLoop3.png With the perimeter frozen at 560 ft, on 40m the loop will not be resonant, as Tom said. The source *reactance* will be a few hundred ohms negative. The source *resistance* will look like this. http://ac6la.com/adhoc/160mLoop4.png On the other hand, if you calculate the source resistance for a 40m *resonant* loop (*not* the scenario that the OP described nor which Tom addressed but just to illustrate), where the loop perimeter is ~145 ft and where 90 ft above ground is ~0.65 λ instead of ~0.16 λ, you'll get this. http://ac6la.com/adhoc/160mLoop5.png If you'd like to duplicate these results, or run calculations for a different band, the following model file is suitable for use with the free demo version of AutoEZ (http://ac6la.com/autoez.html). You'll also need EZNEC and Microsoft Excel. http://ac6la.com/adhoc/160mLoop.weq Download that file, use the AutoEZ Open Model File button to open it, tab to the Calculate sheet, select all the P values (cells D11-D27), and click the Resonate button. Or change all the frequencies to your new choice and set all the initial P values to ~1005/Freq (initial value not critical), then click Resonate. Or just set all the frequencies and P values as desired and click Calculate All Rows instead of Resonate. In any case, make sure EZNEC is already open in a separate window beforehand. When the calculations finish tab to the Custom chart sheet. Select R at Src for the chart Y axis and Variable 1 (which is H, height) for the chart X axis. Dan, AC6LA http://ac6la.com _ Topband Reflector Archives - http://www.contesting.com/_topband
Topband: Nintendo 3DS After Market Power Supply 160 meters RFI
This past weekend I encountered interference on 160 meters that I tracked down to a neighbors Nintendo 3DS after market power supply. Full details can be found on a simple website I created to document this case. My website URL is http://sites.google.com/site/3dspowersupplyrfi/ 73, Don Kirk (wd8dsb) _ Topband Reflector Archives - http://www.contesting.com/_topband
