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#11
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Wellbrook ALA1530+ Vs. ALA100?
Seeing-I-dawg wrote: Here's another idea: Custom made, 5ft square, rotatable loop using Wellbrook ALA-100 amp "...so far it looks to be a fine replacement for my 700 ft. NW Beverage antenna..." http://sdr-1000.blogspot.com/2006/07...0-antenna.html __________________________________________________ ____________ "Seeing-I-dawg" wrote in message ... Do you currently use a longwire or dipole or have the real estate for one? Have you been considering the ALA1530+ instead? I exchanged emails with Wellbrook about using the ALA100 with my current 70M fullwave Horizontal loop. About Horizontal loops http://www.cebik.com/wire/hl.html http://www.cebik.com/fdim/atl1.html http://www.cebik.com/wire/horloop.html About ALA100 http://www.wellbrook.uk.com/ALA100b.html The ALA100 will allow me to use a coax feeder instead of the noise prone 450ohm ladder-line and dispense with the antenna tuner/matchbox. Per Wellbrook, "You may also find that a smaller vertical loop with ALA100 will give better directivity for MW plus very high gain at HF. The ALA100 will out perform the ALA1530+ , because the loop area is much larger." So if you are considering a ALA1530+ and are currently occupying real estate with a long-wire or dipole, you may consider joining the ends with the ALA100 for a loop in either the horizontal or vertical plane. Here's to the '06/'07 DXing season! Post your logs and good luck. Once you have about 50ft on the ALA100, it really cranks. I have mine in a multi-turn loop as well. With 50ft, myAR7030+ needs to switch in the attenuator on local BCB. |
#12
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Wellbrook ALA1530+ Vs. ALA100?
You pretty much nailed it. No antenna is ideal. The fun is finding one,
two, three... that work respectably with your gear, your particular RF environment, and your listening goals. That could be anything from a beverage to a rubber duck :-) IM - yech! Outboard filter(s) to knock down the offending station(s) perhaps? Regarding longwires; Why? It will have peaks and valleys in reception across the RF spectrum. Join the ends to make a horizontal loop and that will disappear - linear response. I respect Guy Atkins remarks regarding his dissappointment with the Wellbrook 1530. I have never owned a loop of that size and type and have always been apprehensive about trying it. Noise isn't a huge problem here. If I can replace my 450 ohm ladder-line feed to my horizontal loop with coax (using the ALA100 amp) I may be able to eliminate most of the remaining noise and pick up a db or two (except I can no longer transmit into it). I no longer am a DYI with electronics. I just don't have the time or patience to gather the parts, solder the board and cross my fingers. If someone sells an assembled Dallas amplifier I may bite. I am really getting excited about the software defined radio Guy Atkins uses. After listening to his sound bites on his SDR-1000 blog I have to lock up the credit cards. I would really enjoy attending one of his DXpeditions. EOM wrote in message ups.com... On Oct 4, 6:36 pm, "Seeing-I-dawg" wrote: Terry, Please read the last paragraph of this 1991 paper:http://www.kongsfjord.no/dl/Antennas...ensitivity.pdf Yep, the directivity of a loop is what the "magic" is all about. Dallas' active dipole exhibited better, as in a better null, directivity from 100KHz (loran) to CB. A good buddy ratchet mouth about 3 miles from me makes a great far field test signal. The Feb 1955 "Wireless Engineer" paper by J.S.Belrose gives some very usefull info on loop. I am not saying loops have no place. Jeff, the guy I traded the wellbrook to, loves it. In his RF hell it works better then anyother antenna he has tried. Once I get the shack rebuilt I intend to take my latest version of Dallas' active dipole there to see if the tighter null will help. I plan on building the WL1030 that RHF mentioned. Martinn Hagg's design look workable. I have major doubts about wide band OpAmps in a harsh RF task, but I am willing to give it a try. I suspect that Dallas' Ultra Linear Amplifier will work as well as the Wellbrook loop maker. And it would be a lot less expensive. The Kiwa amp version 2, should also work. It will need a ?1:! broadband transformer but it is a pretty good amp. The Belrose paper explained why the 2 different heads I have for my McKay-Dymek DA5 behave so differently under temperature extremes. The unit that performs the best under wide, 100F to -20F temperature swings has a slot lengthwise to the hollow center. I have been in a heated conversation with some SWL aquantances here in the central KY area about how long a "long wire" should be. And at what length does it start degrading radio performance. Most SWL or hams, or even professional RF engineers, either don' know, or refuse to think about, the effects too much signal can cause. Front ends and first mixers behave very badly with 1dB to many. I envy DXace becuase he clearly has a superior RF location with a low enough background RF to degrade his R8B. Sadly around here, anything over 100' is more likely to cause problems then help you dig out the really weak DX. Jeff, he lives in a downtown Lexington condo, has had nasty experiences with out of band overload causing all sorts of receiver misbehavoir. And he has an AOR7030, not the plus version. Terry |
#13
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Wellbrook ALA1530+ Vs. ALA100?
RHF wrote:
However - The Practical {Use} Equation {Societal Factoring} may make the 'near invisibility' of the Small {Short-and-Thin} Vertical Whip Antenna the only realistic choice for an Antenna by a Shortwave Listener (SWL) "When NO Antenna Is Allowed." what antenna ? i don't see an antenna : i ain't got no stinking antenna ~ RHF My 6 DA100E whips and 2 ALA1530s are disguised as bird feeders and bird houses, not because of any restriction but because it makes it neighbor-friendly. loop in foreground and whip in background http://home.att.net/~rhhardin/antenna.jpg Both are supported by 8' ground rods tapped in a few feet; the ALA1530 is on a galvinized pipe slipped over the ground rod, with a floor flange screwed on the bottom so it doesn't sink into the ground, making it rotatable by hand. The coax comes off the outside of the pipe and makes a few turns looped around the pipe for slack, this loop being covered by a stove burner reflector against lawnmower attacks. The bird feeder is supported by the antenna rather than vice versa, incidentally. -- Ron Hardin On the internet, nobody knows you're a jerk. |
#14
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Wellbrook ALA1530+ Vs. ALA100?
Seeing-I-dawg wrote: You pretty much nailed it. No antenna is ideal. The fun is finding one, two, three... that work respectably with your gear, your particular RF environment, and your listening goals. That could be anything from a beverage to a rubber duck :-) IM - yech! Outboard filter(s) to knock down the offending station(s) perhaps? Regarding longwires; Why? It will have peaks and valleys in reception across the RF spectrum. Join the ends to make a horizontal loop and that will disappear - linear response. I respect Guy Atkins remarks regarding his dissappointment with the Wellbrook 1530. I have never owned a loop of that size and type and have always been apprehensive about trying it. Noise isn't a huge problem here. If I can replace my 450 ohm ladder-line feed to my horizontal loop with coax (using the ALA100 amp) I may be able to eliminate most of the remaining noise and pick up a db or two (except I can no longer transmit into it). I no longer am a DYI with electronics. I just don't have the time or patience to gather the parts, solder the board and cross my fingers. If someone sells an assembled Dallas amplifier I may bite. I am really getting excited about the software defined radio Guy Atkins uses. After listening to his sound bites on his SDR-1000 blog I have to lock up the credit cards. I would really enjoy attending one of his DXpeditions. EOM Guy Atkins is very lucky to live in what must be one of the quitest RF environments around. My home RF level isn't as bad as I had thought, I know see what real bad RFI is, but at that there is very little I can hear on a AOR7030+, R8B, or a R2000. The first 2 recivers do a much beter job in very crowded band conditions with very strong signlas next to weak ones that I am intereted in. On a "remote" mountain top in eastern KY I enjoyed pushing the AOR to the limits. That quite location showed the difference between a great receiver and a much more modest (R2000) receiver. Perversly better locations deserve better recveivers. Since the local noise floor sets the limit to our reception it makes sense but it does feel odd. I have been busy trying to eliminate, or at least reduce, any unwanted RF noise. Sadly while I have had great success at eliminating the RF noise emitted by/within our home. We got rid of our desk top PCs, tossed the TV and similar steps have reduced my noise floor as much as I can. Too bad I can;t convine my nieghbors to limit thier RFI. I had hoped the Wellbrook ALA 1530 would reduce noise from nearby homes, but either the whole lopp concept is flawed, which I believe, or my in location all the noise is "far field" and a loop won't help. Terry |
#15
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Wellbrook ALA1530+ Vs. ALA100?
wrote I had hoped the Wellbrook ALA 1530 would reduce noise from nearby homes, but either the whole lopp concept is flawed, which I believe, or my in location all the noise is "far field" and a loop won't help. Curious that Wellbrook states that the 1530 will operate best when it is about 30ft away from your home and for best MW reception mounted near the ground. It alegedly performs better on SW when mounted up high at the cost of MW reception. Where's that credit card!? LOL |
#16
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Wellbrook ALA1530+ Vs. ALA100?
Seeing-I-dawg wrote:
wrote in message oups.com... Seeing-I-dawg wrote: cut My antenna goal is to have one antenna and to squeeze as much performance out of it on as many frequencies (500KHz-30MHz) as possible. That, my friend, can be most closely accomplished with a large loop. However, I am intriqed by the 15ft vertical that is diagramed at the Kongsfjord noise measurments link. cut An inverted L, 15 feet vertical and 30 feet horizontal, works fine too. You can make it longer and higher, or amplify it if you want more signal. Though more sensitive to horizontal polarization then the vertical, the L still beats the ALA 100 by about 10 dB S/MMN in the near field of power lines, just like the vertical. I used verticals for the previous comparisons because those were what I am using currently (verticals give me better phaser performance in the MW band than L's). |
#17
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Wellbrook ALA1530+ Vs. ALA100?
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#18
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Wellbrook ALA1530+ Vs. ALA100?
wrote in message ups.com... Guy Atkins is very lucky to live in what must be one of the quitest RF environments around. My home RF level isn't as bad as I had thought, I know see what real bad RFI is, but at that there is very little I can hear on a AOR7030+, R8B, or a R2000. Yes, it's very quiet here in the Pacific NW, with the fewest "thunderstorm days" of any place in the continental USA. In mid-winter, with a Western Beverage antenna at dawn, aimed out over the Pacific Ocean, you'd swear your receiver was defective, or the antenna broken. In these conditions, extremely faint tropical band and foreign (TP) mediumwave signals have a fighting chance to be heard (assuming a top-notch, low noise receiver like a AR7030 or my current fave, the SDR-1000. It was under these mid-winter, dawn enhancement conditions that I heard tantalizing faint signals around 3174 kHz (variable) in the late 1990s, which had all the clues of Indonesian "amatir" stations. Think: Indo college kids back home on holiday or weekend breaks, playing non-stop Indo rock music with flea-powered transmitters, no IDs, often distorted audio, no official "RRI" news at the top of the hour, etc. I've heard enough of the real RRI and RPD Indonesian stations to recognize the Indo amatir (pirate) station. Similarly, I've logged very low power Australian x-band stations such as Radio Brisvaani, the Hindi station on 1701 kHz (Brisbane, Queensland). I'd never have a chance to hear this sort of DX, however, at home in the suburban RF jungle near Seattle-Tacoma. These catches were on coastal DXpeditions, under ideal conditions. I do have pretty low noise levels of the RFI, hash-and-buzz sort at home, due to the underground AC mains. The main problem are the dozen or so MW stations registering S-9+40 to S-9+60 dB on the SDR's (calibrated) signal meter. My local 1 kw'er, 1450 KSUH in Puyallup, is a bit over 1 mile from home. When I had a 700 ft. Beverage antenna aimed at my Asian targets, the antenna unfortunately was oriented right at KSUH, too. The signal on 1450 from that antenna registered -13 dBm, which is, I believe, around S-9+65 dB. This is an example of what the trans-Pacific MW stations need to fight through to be heard in a suburban location like this. So far, I'm finding the Wellbrook ALA 100 on a rotator does just fine for snagging the foreign MW DX that makes it through the RF jungle; a Beverage is no advantage. 73, Guy Atkins Puyallup, WA www.sdr-1000.blogspot.com |
#19
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Wellbrook ALA1530+ Vs. ALA100?
Guy is so right about the joys of DXing in a very low noise environment,
such as the Pacific coast Grayland site. I takes a lot of research and running around to find an "ideal" low noise DX site and on our crowded planet they become harder and harder to find. I found such a site in a remote part of our Atlantic coast,Seefontein, miles from the nearest town and miles from the nearest powerline. It's just bliss to have that phenomena that Guy describes: when the noise on the antenna's is so low you start checking to see if in fact they are connected. It is such a joy to hear stations thousand's of miles away waft in over the airwaves as clear as a bell, yet the signal strength is so low it doesn't even move your "S" meter. What a thrill! That's why some of us serious DXer's travel long distances with considerable effort in time and money to enjoy these most favourable DX conditions. Try it = you'll love it.............. -- John Plimmer, Montagu, Western Cape Province, South Africa South 33 d 47 m 32 s, East 20 d 07 m 32 s RX Icom IC-756 PRO III with MW mods Drake SW8 & ERGO software Sony 7600D, GE SRIII, Redsun RP2100 BW XCR 30, Sangean 803A. GE circa 50's radiogram Antenna's RF Systems DX 1 Pro, Datong AD-270 Kiwa MW Loop, POARDT Roelof mini-whip http://www.dxing.info/about/dxers/plimmer.dx "Guy Atkins" wrote in message . .. Yes, it's very quiet here in the Pacific NW, with the fewest "thunderstorm days" of any place in the continental USA. In mid-winter, with a Western Beverage antenna at dawn, aimed out over the Pacific Ocean, you'd swear your receiver was defective, or the antenna broken. In these conditions, extremely faint tropical band and foreign (TP) mediumwave signals have a fighting chance to be heard (assuming a top-notch, low noise receiver like a AR7030 or my current fave, the SDR-1000. It was under these mid-winter, dawn enhancement conditions that I heard tantalizing faint signals around 3174 kHz (variable) in the late 1990s, which had all the clues of Indonesian "amatir" stations. Think: Indo college kids back home on holiday or weekend breaks, playing non-stop Indo rock music with flea-powered transmitters, no IDs, often distorted audio, no official "RRI" news at the top of the hour, etc. I've heard enough of the real RRI and RPD Indonesian stations to recognize the Indo amatir (pirate) station. Similarly, I've logged very low power Australian x-band stations such as Radio Brisvaani, the Hindi station on 1701 kHz (Brisbane, Queensland). I'd never have a chance to hear this sort of DX, however, at home in the suburban RF jungle near Seattle-Tacoma. These catches were on coastal DXpeditions, under ideal conditions. I do have pretty low noise levels of the RFI, hash-and-buzz sort at home, due to the underground AC mains. The main problem are the dozen or so MW stations registering S-9+40 to S-9+60 dB on the SDR's (calibrated) signal meter. My local 1 kw'er, 1450 KSUH in Puyallup, is a bit over 1 mile from home. When I had a 700 ft. Beverage antenna aimed at my Asian targets, the antenna unfortunately was oriented right at KSUH, too. The signal on 1450 from that antenna registered -13 dBm, which is, I believe, around S-9+65 dB. This is an example of what the trans-Pacific MW stations need to fight through to be heard in a suburban location like this. So far, I'm finding the Wellbrook ALA 100 on a rotator does just fine for snagging the foreign MW DX that makes it through the RF jungle; a Beverage is no advantage. 73, Guy Atkins Puyallup, WA www.sdr-1000.blogspot.com |
#20
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Wellbrook ALA1530+ Vs. ALA100?
Ron Hardin wrote: My 6 DA100E whips and 2 ALA1530s are disguised as bird feeders and bird houses, not because of any restriction but because it makes it neighbor-friendly. loop in foreground and whip in background http://home.att.net/~rhhardin/antenna.jpg Both are supported by 8' ground rods tapped in a few feet; the ALA1530 is on a galvinized pipe slipped over the ground rod, with a floor flange screwed on the bottom so it doesn't sink into the ground, making it rotatable by hand. The coax comes off the outside of the pipe and makes a few turns looped around the pipe for slack, this loop being covered by a stove burner reflector against lawnmower attacks. The bird feeder is supported by the antenna rather than vice versa, incidentally. -- Ron Hardin On the internet, nobody knows you're a jerk. Any chance of you posting medium and tight close ups of the DA100Es? A friend in Flagstaff is dealing with (fighting) overly restrictive condo rules and I sent him the photo of the Wellbrook. He may be able to sneak, as in be granted persmission, a vertical active antenna into his backyard. He was allowed to errect a Rat Sahck Diskcone but that makes a very poor HF antenna. Thank you Terry |
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