Re: Topband: DX Engineering NCC-1 phase controller
On 12/19/2015 11:46 PM, Rune Øye wrote: a NCC-1 from Dx Engeneering. My plan is to use this with my SAL30 RX array on antenna port A and 73 Rune LA7THA This isn't an answer to your question, but a more straightforward way to accomplish what I think you are trying to do would be to make an array of two loops, where the azimuth of the individual loops can be chosen so that they null out the single point noise source that you are trying to null out with the NCC-1. The azimuth of the array can then be chosen to enhance in the direction of the signal you want to receive. IOW, the orientation of the loops is independent of the orientation of the array. The trouble with the SAL is that the null of the loops is always at a 90 degree angle to the angle of reception. You can't choose the angle. The other trouble with the SAL is that the spacing between the loops is always very small, and you can't choose that either. If you increase the spacing, it isn't a SAL any more, it's just ordinary loops in phase. Rick N6RK _ Topband Reflector Archives - http://www.contesting.com/_topband
Topband: Detuning a nearby Tower
Hello Topbanders I have a two element array 1/8wl away from my 90' Skyneedle tower with Telrex yagi atop. I want to electrically isolate this tower from the array by dropping a shunt wire from near the top of the tower down to the panel where I have an MFJ model 931 artificial ground (input) that then connects to my earth ground. Tuning the 931 to eliminate the RF field strength induced from the array results in an invisible tower to the array...in theory. In the past, I have used a similar method to shunt feed the tower on 160 ala vacuum variable tuning and radials. When I tapped the tower I found a sweet spot at the ~70' level on the skyneedle that provided a fairly good 42 ohm match and, once tuned, it worked pretty well on TX. Here is the concern...I would prefer to use this same tap point for my detuning experiment as it seems to make sense that the same point would induce the max coupling from the array...or at least be a good starting point. ON4UN and others have implied that, when detuning a tower, you should tap it at the TOP of the tower structure and not ¼ of the way down from the top like I's considering. Should I just run the 3' gamma arm off of the very TOP of the tower at the 90' level then down or am I better off tapping the gamma arm at the 67' level as I did when I shunt fed the tower for TX on 160? Comments? Carl _ Topband Reflector Archives - http://www.contesting.com/_topband
Topband: SB-1000
After a pretty thorough check on the ailing 160M section this what I have in mind and would appreciate any further suggestions. All previous owner wiring is ok. One missing connection is 10M mod. 160M Padding cap (170pf, 7500V doorknob) is shot. Band switch appears to be still usable, no damage to contacts etc. Idea now is to replace the cap (with "corona washer") or good mica cap, new style parasitic suppressor, new (al-80a) plate choke and give it a whirl. Regards,jim/k2hn _ Topband Reflector Archives - http://www.contesting.com/_topband
Re: Topband: DX Engineering NCC-1 phase controller
I use the MFJ-1025 (similar to the NCC-1) with my SAL-20. In my case I use my TX antenna as the sense input. My xcvr (FTdx5000) internally feeds the TX antenna to an output connector while in receive. So I just feed that signal to the MFJ-1025. Works great on local powerline buzz as well as switching PS noise that may drift into my receive BW. On 80m my TX antenna is a 4sq and on 160m it's a vertical. Re: SAL pattern. The null is at 180 degrees if you have the delay line and couplers configured right. See the users manual and 4nec2 model. But this is more appropriate fodder for the sharedapexloop yahoo forum. 73, Kris N5KM -- original message -- Date: Sun, 20 Dec 2015 08:09:43 -0800 From: "Richard (Rick) Karlquist" To: Rune ?ye ,"topband@contesting.com" Subject: Re: Topband: DX Engineering NCC-1 phase controller Message-ID: <5676d2c7.3050...@karlquist.com> Content-Type: text/plain; charset=windows-1252; format=flowed On 12/19/2015 11:46 PM, Rune ?ye wrote: > a NCC-1 from Dx Engeneering. My plan is to use this with my SAL30 RX array on antenna port A and > 73 Rune LA7THA This isn't an answer to your question, but a more straightforward way to accomplish what I think you are trying to do would be to make an array of two loops, where the azimuth of the individual loops can be chosen so that they null out the single point noise source that you are trying to null out with the NCC-1. The azimuth of the array can then be chosen to enhance in the direction of the signal you want to receive. IOW, the orientation of the loops is independent of the orientation of the array. The trouble with the SAL is that the null of the loops is always at a 90 degree angle to the angle of reception. You can't choose the angle. The other trouble with the SAL is that the spacing between the loops is always very small, and you can't choose that either. If you increase the spacing, it isn't a SAL any more, it's just ordinary loops in phase. Rick N6RK --- _ Topband Reflector Archives - http://www.contesting.com/_topband
Re: Topband: F-type connectors transmitting question
Gary, Tom, Thanks for the information. I will stick with the compression UHF connectors. Mike N2MS - Original Message - From: Tom W8JI To: Michael St. Angelo Sent: Sun, 20 Dec 2015 00:22:21 - (UTC) Subject: Re: Topband: F-type connectors transmitting question F11 will handle at least 3 kW outside in the air. Don't worry about the braid. The foil plus braid is good enough. You'll never notice any radiation from it. _ Topband Reflector Archives - http://www.contesting.com/_topband
Re: Topband: F-type connectors transmitting question
On Sat, Dec 19, 2015 at 12:08 PM, Michael St. Angelo wrote: > I'd like to try F type connectors. Will the smaller center conductor pin > of the F type connector handle power when transmitting? > I'll just answer this part of your question: YES. It will likely handle whatever the coax is rated for. I have never had a problem running 1500 watts through an F connector. They don't even get warm. A UHF connector will handle at least 10 kW. 73, Mike www.w0btu.com _ Topband Reflector Archives - http://www.contesting.com/_topband
