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#11
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RHF wrote:
What Diriection would you 'Point' the Bottom-End of a Sloper Antenna for the best DXing from : Europe ? Middle-East ? Africa ? and India ? ? N ? E ? W ? S ? and WHY ? in search of the one-best answer . . . ~ RHF . . Have you generated a Great Circle map centered on your location? That would be step one. |
#12
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On Sep 1, 3:49*pm, dave wrote:
bpnjensen wrote: On Sep 1, 3:44 am, *wrote: I already have two SWL Antennas up here in Twain Harte, CA -but- neither seems bring in Europe; the Middle-East; Africa and India. That's why they call it DX, I guess! *Our California location simply is not at anybody's target area, and only occasionally off the backside of the beam. *If we were in someone's sights, or if we had that extra bit of ocean between us and them, we'd probably hear them better. Also, most of the European stations either totally ignore NA or else use relays to get their point across, resulting in service only from other locations. *The ones that still use their native soils for transmitting to us - Czechia, Romania, Albania - all manage fairly well some of the time. India is especially absent from California airwaves. *Don't know why, exactly. Bruce Jensen Antipodal? Maybe - but I get other such stations fairly regularly - RN/VOA Madagascar, BBC Seychelles, Sri Lanka...? |
#13
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On Sep 1, 3:49*pm, dave wrote:
bpnjensen wrote: On Sep 1, 5:43 am, *wrote: RHF wrote: On Aug 31, 10:00 am, * *wrote: On Aug 31, 7:11 am, * *wrote: RHF wrote: What is the Best Direction to 'Point' a Sloper Antenna for DX ? Given an area where you could locate a Sloper Antenna with a Tall Mounting Pole "Top-End-Feed-Point' and the ability to move the Bottom-Far-End around the full circle of 360 Degrees. Where would you place 'Point' the Bottom-Far-End for the best DXing ? [ N ? E ? W ? S ? ]& * * *WHY ? Top-fed slopers in an open space are essentially omnidirectional. *Most of the radiation happens at the feed point. The slantwire and the support structure form a low Q mass that also radiates, equally well in all directions. - Dale P. has always recommended using his PAR end-fed as a sloper with - the feedpoint near the bottom and thus giving a nice short run to - ground. *Good omni results and a high radiation angle. *I think this - would work for me if I did not have such a battery of RFI generators - around my home. - - Bruce BpnJ, Now that is very Smart of Dale Par [W4OP] http://www.eham.net/reviews/detail/3707 {Now... Why Didn't I Think of That !?!} Plus -if- you run the Coax Cable directly underneath the Antenna Wire; it would act as a Counterpoise and a more uniform ground field. - simplify - simplify - simplify - Sort of the same approach that Wellbrook in the UK recommends for a Far-End feed-point for a better Inverted "L" Antenna. http://www.wellbrook.uk.com/longwire.html But that would eliminate the Tall rotational Center-Point for directional testing : Which is OK since I am only looking for the best single Direction be it N? E? W? S? I guess that the SWL Sloper Antenna Designs by both Alpha Delta and Eavesdropper were built around using the Side of a House* as the High-Mounting-Point. * Taking what the Customer already has and building on that; to make the installation as simple and easy as possible. {A No Brainer} While most Amateur {Ham} Sloper Antennas generally have a Bottom Feed-Point except for those attached to an existing Tower/Mast. BpnJ - tyvm for the tip ~ RHF * *. * *. I have an Alpha Delta DX-B half sloper. It feeds at the top. *That's why it works so good. The current max is 40 feet in the air.- Hide quoted text - - Show quoted text - How do you suspend the top? 50' telescoping mast and lots of Dacron I like it! :-) |
#14
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On Aug 31, 7:11*am, dave wrote:
RHF wrote: What is the Best Direction to 'Point' a Sloper Antenna for DX ? Given an area where you could locate a Sloper Antenna with a Tall Mounting Pole "Top-End-Feed-Point' and the ability to move the Bottom-Far-End around the full circle of 360 Degrees. Where would you place 'Point' the Bottom-Far-End for the best DXing ? [ N ? E ? W ? S ? ]& *WHY ? - Top-fed slopers in an open space are essentially - omnidirectional. OK but most are 'in' close-in space with all sorts of things around them. -*Most of the radiation happens at the feed point. Yes there is more power radiating around the feed-point. -but- I a talking about a SWL Receiving Antenna. - The slantwire and the support structure form a - low Q mass that also radiates, equally well in - all directions. Not 'If' the Support Structure is a Grounded Metal Tower/Mast. Many of the Commercial Slopers use an attached Counterpoise Insulated Wire to hang-down to the ground along the Side of a Building to act as the Grounded Tower/Mast {Reflector} to give the Sloper some directivity and to better 'Match' the Antenna to the Feed-in-Line. http://www.universal-radio.com/catalog/sw_ant/0013.jpg http://www.alphadeltacom.com/images/dxswl.gif http://t2k.wdfiles.com/local--files/...sloper-002.jpg "A Sloper which is at an angle they will be more directional the direction that they are sloped." http://www.angelfire.com/mb/amandx/dipole.html Full 1/2 Wave Sloper Antenna : The radiation pattern will be almost omnidirectional ... with a slight advantage toward the "sloping" direction. http://www.hamradiosecrets.com/ham-r...f-antenna.html Half 1/4 Wave Sloper Antenna : Omni-Directional pattern, but with some "warping" in the direction of the wire slope. http://mysite.ncnetwork.net/resvzazs/80endfed.htm 1/4 Wave Sloper : It does appear to offer gain in the direction of the sloping element. http://home.centurytel.net/WD0M/antennas1.html Some of this may be the fact that these Slopers are Mounted to Metal Towers/Masts and the Grounded Tower/Mast may be acting like a back Reflector and causing some of the Radiated Directivity from the Tower to the Sloping Wire and out away from them. |
#15
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"Just Plain Burr" wrote in message
... Lighting did get me from my Wi-Fi. It jumped around on my desk so fast and was over before I could move. All radios were OK. Lightening not lighting I presume. From your Wi-Fi? In what sense from your Wi-Fi? -- Brian Gregory. (In the UK) To email me remove the letter vee. |
#16
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wrote in message
... Palomar's currently sold 9:1 transformer is good only for a longwire, but not for T2FD. How can that be? -- Brian Gregory. (In the UK) To email me remove the letter vee. |
#17
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On Sep 2, 5:21*pm, "Brian Gregory [UK]" wrote:
wrote in message ... Palomar's currently sold 9:1 transformer is good only for a longwire, but not for T2FD. How can that be? -- Brian Gregory. (In the UK) To email me remove the letter vee. Because the presently made MLB-1 by Palomar Engineersis a UNUN for a longwire. The older transformer which I used (may have the original instruction paper somewhere) was a true BALUN. To build a T2FD we must use a balun, since it is a broadband dipole. |
#18
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On Sep 2, 10:41*pm, wrote:
On Sep 2, 5:21*pm, "Brian Gregory [UK]" wrote: wrote in message .... - - - Palomar's currently sold 9:1 transformer - - - is good only for a longwire, but not for T2FD. - - How can that be? -- Brian Gregory. (In the UK) To email me remove the letter vee. - *Because the presently made MLB-1 by Palomar Engineersis a UNUN for a - longwire. The older transformer which I used (may have the original - instruction paper somewhere) was a true BALUN. To build a T2FD we must - use a balun, since it is a broadband dipole. Buy the PAR Balun which has a Floating Ground Termainal which makes it an BAL-UN or you can connect the Floating Ground to the Coax Ground and have a UN-UN. http://www.monitoringtimes.com/html/...-SWL%20Antenna Opps to Buy the PAR Balun you have to buy the PAR EF-SWL Antenna which includes the http://www.grove-ent.com/ANT8.html http://www.parelectronics.com/pdf/EF-SWL.pdf http://www.universal-radio.com/catalog/sw_ant/2205.html Balun and 45 Feet of HQ* Antenna Wire. "Flex Weave" covered by a protective black polyethylene jacket. * 45 Feet of AWG #14 Black Polyethylene Coated "Flex-Weave" Antenna Wire which is made up of 168 Strands of #36 Gauge Woven Copper Wires. {This is Great Stuff} http://www.radiobanter.com/showthread.php?t=124225 Yes with the PAR EF SWL Antenna you can Rig-It Your Way ! - iane ~ RHF |
#19
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wrote in message
... Because the presently made MLB-1 by Palomar Engineersis a UNUN for a longwire. The older transformer which I used (may have the original instruction paper somewhere) was a true BALUN. To build a T2FD we must use a balun, since it is a broadband dipole. A long wire balun should not assume you want a common ground connection on the input and output. But I've look at the picture and description of the MLB-1 on the web and I agree it's far from clear what connections are provided. However if I bought it and found it did have the grounds joined I'd return it as unacceptable because when using a long wire you want to use a separate good quality earth which is not joined to your receiver's earth which may have RF noise on it. -- Brian Gregory. (In the UK) To email me remove the letter vee. |
#20
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Brian Gregory [UK] wrote:
wrote in message ... Because the presently made MLB-1 by Palomar Engineersis a UNUN for a longwire. The older transformer which I used (may have the original instruction paper somewhere) was a true BALUN. To build a T2FD we must use a balun, since it is a broadband dipole. A long wire balun should not assume you want a common ground connection on the input and output. But I've look at the picture and description of the MLB-1 on the web and I agree it's far from clear what connections are provided. However if I bought it and found it did have the grounds joined I'd return it as unacceptable because when using a long wire you want to use a separate good quality earth which is not joined to your receiver's earth which may have RF noise on it. I disagree. Use on an UnUn (autotransformer) puts all points of the system at ground, provided you ground per electrical code. "Noise" from the radio chassis (?) flows to ground through the IEC cable. Static charges from the antenna system flow to ground at the transmission line point of entry. |
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