Re: Topband: 160M Rhombics
On 07/26/2013 04:23 PM, ZR wrote: For the guy who has the land and wants to own 20-10M in one or two directions for his daily chats, a rhombic will cost a lot less than a rotating tower with stacked yagis for each band. Also consider what seems like a very narrow beamwidth at the antenna can cover a lot of the planet by the time it reaches its antipode. With 2 rhombics and some relays to switch termination points a mighty potent signal can cover a lot in 4 directions. You can do the same thing even cheaper, and probably with slightly higher gain, with two lazy H antennas for 20-10m :) I have one lazy H pointed east west, and am itching to build one that points north south, once the leaves fall off the trees... -- All rights reversed. _ Topband Reflector
Re: Topband: 160M Rhombics
W0BTU: For whatever reason, there's what seems to be a lot of hype about W6AM's rhombics. Such as: The W6AM station was legendary around the world. Don could beat you in a pileup for some obscure African station no matter what band, and even if you were on the east coast. And him in Southern California. Don was #1 on ARRL's DXCC Honor Roll, and you didn't argue. No matter where you were, no matter what you were running, Don had beaten you in a pileup. More than once. Beat anyone on the east coast to Europe from California every time? I'm sorry, but a rhombic is just not that good, even if you DO have one pointed at every direction of the compass as W6AM did. Absolutely a lot hype, as you stated. The real King of the Hill in those days was Frank Lucas W3CRA: Gus Browning, W4BPD wrote (from Ahoy Aldabra! article in February 1964 CQ Magazine): After staying up for the long path opening to the U. S. which was 4:00 AM local time, I intended sleeping on a small bunk at the rear of the boat. After lying down for a while and wondering about the 5-9 plus 20 db signal that signs W3CRA when all the others on the band are S7, I came to the conclusion that Frank must have the world's best QTH. When the band is dead he's always S7 and when the W-boys are S7 Frank is always over S9. This just isn't once in a while, it's an every day occurrence. Frank did this with a single 3 element homebrew Yagi but his secret was location, location, location; as this webpage explains. http://users.vnet.net/btippett/w3cra.htm W6AM at the top of the Honor Roll? More hype. Charlie Mellen W1FH in Boston ran a simple 3 element Yagi and had 311/337 (current/cumulative including deleted) when W6AM was at 307/332 in November 1964. Here's the *complete* DXCC Honor Roll listing: http://users.vnet.net/btippett/dxcc_honor_roll.htm W6AM may have closed the gap for current entitiess in later years but W1FH was one of very few to work W6ODD/CR8 from Damao/Diu in 1948, which W6AM missed. W1FH was the first post-war DXCC holder and W3CRA was the first pre-war DXCC holder. Frank apparently quit submitting cards for the post-war award but he was very much King of the Hill signal-wise as W4BPD verified above. http://oldqslcards.com/W1FH.pdf http://hamgallery.com/qsl/deleted/Damao_Diu/w6odd.htm Just to keep this from being totally off-topic, note the many Topband DXers at the bottom of the DXCC page above. 73, Bill W4ZV _ Topband Reflector
Re: Topband: 160M Rhombics
On 7/27/2013 3:23 AM, Bill Tippett wrote: W0BTU: For whatever reason, there's what seems to be a lot of hype about W6AM's rhombics. Such as: The W6AM station was legendary around the world. Don could beat you in a pileup for some obscure African station no matter what band, and even if you were on the east coast. And him in Southern California. Don was #1 on ARRL's DXCC Honor Roll, and you didn't argue. No matter where you were, no matter what you were running, Don had beaten you in a pileup. More than once. Beat anyone on the east coast to Europe from California every time? I'm sorry, but a rhombic is just not that good, even if you DO have one pointed at every direction of the compass as W6AM did. Absolutely a lot hype, as you stated. The real King of the Hill in those days was Frank Lucas W3CRA: A old friend of mine told me that he use to regularly beat W6AM in pileups with a long boom 20M monobander at 70ft from a small city lot in Los Angeles. I think he was running a tetrode with handles, but from what I hear about W6AM that wasn't necessarily an unfair advantage :-) With regard to the impact of favorable terrain, N6NB tells some good stories about running QRP class in DX contests from his mountaintop QTH in Tehachapi, Ca and all the accusations of cheating that would come his way as result. 73, Mike W4EF/6 (whose amp is so small it doesn't have handles, let alone the tubes in it)... _ Topband Reflector
Re: Topband: 160M Rhombics
When I was first discovering DXing, I very clearly remember a wise and seasoned DXer in the Chicago area telling me: Any amplifier that you can pick up, is not worth picking up. 73, Mike Cizek W3MC -Original Message- From: Topband [mailto:topband-boun...@contesting.com] On Behalf Of Michael Tope 73, Mike W4EF/6 (whose amp is so small it doesn't have handles, let alone the tubes in it)... _ Topband Reflector _ Topband Reflector
Re: Topband: 160M Rhombics
On Sat, Jul 27, 2013 at 7:20 PM, Bob Kupps n...@yahoo.com wrote: With a web site like yours I wouldn't be accusing others of over hyping. ?? _ Topband Reflector
Re: Topband: 160M Rhombics
When I was floating around in the Med for the USN in the early 60's, the bases I visited were all using rhombics pointed at DC mounted on 80-120' wooden poles. These consistently outperformed a 20M 6 el Telrex at similar heights at the ham station into the same area. The arguments were going on strong even way back then and hams often had times they could use the rhombics and run tests with buddies at the ham station a mile or so away. The sites I regularly stopped at were Rota, Rhodes, just S of Athens, and Libya. For the guy who has the land and wants to own 20-10M in one or two directions for his daily chats, a rhombic will cost a lot less than a rotating tower with stacked yagis for each band. Also consider what seems like a very narrow beamwidth at the antenna can cover a lot of the planet by the time it reaches its antipode. With 2 rhombics and some relays to switch termination points a mighty potent signal can cover a lot in 4 directions. This is no more space than a decent Beverage farm. A rhombic isnt very practical on the lower bands for most hams as that link shows but for 20-10 it can be very effective. Carl KM1H If we want an antenna just for looks, might as well make it all out of a non-conductor such as plastic rope. :-) Seriously, Tom is right. Take time to study his rhombic page. However, as one wise man once told me, Time spent doing something you enjoy is not wasted time. Putting up a rhombic might also be a good learning experience. But you better make sure that you aim it right where you need it. 73, Mike www.w0btu.com On Fri, Jul 26, 2013 at 12:33 PM, Jeff Blaine j...@ac0c.com wrote: Why? The same reason guys put up quads. They LOOK very cool! Imagine standing on one end of the rhombic and saying well, you can't see the end of the antenna without the binoculars - but it's out that-way somewhere. _ Topband Reflector - No virus found in this message. Checked by AVG - www.avg.com Version: 10.0.1432 / Virus Database: 3209/6022 - Release Date: 07/26/13 _ Topband Reflector
Re: Topband: 160M Rhombics
Anybody on this list have a Rhombic for 160M? W1AW used to use one for bulletins and code practice on 160M but I think it came down years ago (1989?) They come in here literally against the pin which makes me wonder about the power used. Even the New England QRO++ Dxers and contesters arent that strong unless real close. I seem to recall pics in CQ of a big California desert DX'er who had what was essentially a radial array of rhombics for maybe 160M or 80M. Tim N3QE That was likely Don Wallace, W6AM overlooking the Pacific from a bluff in Rancho Pales Verdes. Google his antenna farm and then do a Google Earth of the place today! Carl KM1H -Original Message- From: Topband [mailto:topband-boun...@contesting.com] On Behalf Of Grant Saviers Sent: Friday, July 26, 2013 11:03 AM To: ZR Cc: g...@ka1j.com; topband@contesting.com Subject: Re: Topband: Topband Inv-L Joy Posted on towertalk yesterday was the link to the free download of the 1952 text Radio Antenna Engineering http://www.lulu.com/us/en/shop/edmund-laport/radio-antenna-engineering/ebook/product-17560294.html Some fascinating stuff since much of the focus is high power broadcasting LF/HF and point to point reliable RF links with high gain HF wire antennas. (many pictures of amazing arrays). A quick peruse found in a later chapter how to build high power non-inductive terminations for rhombics etc. Make an open wire feeder of the needed Z from iron or stainless wire and as long as the db's you wish to absorb and with wire heavy enough to handle the current. Clever stuff, invented when HF was a primary long distance communications technology. The formulas are there for resistivity and ferromagnetic losses. Of course some of the content is now pretty irrelevant since we have cheap great coax, ferrite, and NEC software and a billion times the worlds 1952 total computing power on every desktop. Grant KZ1W On 7/25/2013 8:17 AM, ZR wrote: On a side note WD-1A conductors are a copper/cadmium alloy; whatever that means in RF resistance. Fine for a Beverage but what is the loss? Carl KM1H - Original Message - From: Gary Smith g...@ka1j.com To: topband@contesting.com Sent: Thursday, July 25, 2013 1:22 AM Subject: Re: Topband: Topband Inv-L Joy Had a more difficult time getting the antenna up there this time. The first spud snapped away from the fishing line in the dense thicket I was unable to find where it landed. Had to make another the mosquitos were so thick they posted a LUAU sign on my forehead. Till I get something better I retrieved my WD-1A military field phone wire that was left out in the marsh as my old beverage wire. and after a comedy of errors I finally got the antenna up. I was earlier getting a SWR of 1.1 on 160 before and now am getting 1.1 on 1.74365 MHZ 1.74365mhz R=51 X= 6,7,8 swr 1.1 At the desired frequency to match the antenna I've aimed for 1.8MHZ here's the information I was able to get at my desired frequency: 1.8025 mhZ Coax loss 6.3db C=4193 XC=21 L=1.970 X1=21 r=41 x=21 swr 1.6 So this is what the antenna is giving me at this moment. I need to get back down and add the broken wire to the radial bed and I should also trim some length to bring my values to 1.1 at 1.025MHz. Given the info above from the MFJ 259B any idea how much I might nibble off and more, is there anything in this info that tells me I should look to do anything differently? Hopefully the coax loss will be mitigated by a friend bringing me 350' of hardline. Can't wait! Thanks, Gary KA1J _ Topband Reflector - No virus found in this message. Checked by AVG - www.avg.com Version: 10.0.1432 / Virus Database: 3209/6019 - Release Date: 07/25/13 _ Topband Reflector _ Topband Reflector _ Topband Reflector - No virus found in this message. Checked by AVG - www.avg.com Version: 10.0.1432 / Virus Database: 3209/6022 - Release Date: 07/26/13 _ Topband Reflector
Re: Topband: 160M Rhombics
I dont see anything from then that disagrees with what I said today Mike, QRO in those days was a smaller ratio from what is daily these days. There are even a couble of super QRO SWBC stations owned by hams that pop up for a once a year show Tubes such as the 3CX15000B7, 3CW2A7, and various tetrode versions, are all over the place for not much money. All you need is someplace to bring in a big 3 phase AC line if you want to max them out. Carl KM1H - Original Message - From: Mike Waters mikew...@gmail.com To: ZR z...@jeremy.mv.com; topband topband@contesting.com Sent: Friday, July 26, 2013 4:42 PM Subject: Re: Topband: 160M Rhombics Carl, I based what I said partly on your statements at http://forums.qrz.com/showthread.php?297870-How-to-design-rhombic-antenna . Looking back at that page, I see that perhaps I misunderstood your statements there. Look at the photos of his shack. If he wasn't running a lot of power, you would never know that from the size of the antenna switches, feedline, standoff insulators, etc. 73, Mike www.w0btu.com On Fri, Jul 26, 2013 at 3:28 PM, ZR z...@jeremy.mv.com wrote: That excuse doesnt cut it Mike and from what I was told by those who were there his power would be considered pretty normal these days. You can only get so much out of a pair of 450TL's, 4-1000A's, etc. Some on here that you seem to look up to run more than that. OTOH you completely discounted Dons LOCATION, LOCATION, LOCATION. Carl KM1H There were a lot of tall tales told about W6AM's rhombics. Don't base a desire to have a rhombic on those fables. And that's where the term California Kilowatt came from. I'm told his rhombics were loud mostly for that reason. I forget what tubes were in his amp, but they sure weren't 6V6s. ;-) 73, Mike www.w0btu.com On Fri, Jul 26, 2013 at 12:36 PM, HAROLD SMITH JR w0ri...@sbcglobal.net wrote: Years ago, W6AM had a Rhombic Farm near San Francisco. _ Topband Reflector - No virus found in this message. Checked by AVG - www.avg.com Version: 10.0.1432 / Virus Database: 3209/6022 - Release Date: 07/26/13 _ Topband Reflector
Re: Topband: 160M Rhombics
Those Alpha 77's, DX or SX went thru the Nye tuners shown and they were maxed out at around 4KW. The rack stuff was old school with glass tubes and mercury vapor rectifiers and took a lot of room for modest power. Don still enjoyed AM which is what most of that stuff was. The tubes you can see are pretty small and maybe the 2 x 4-1000A amps were gone when those pix were taken. Before that the racks held PP 450TL's with little to no shielding and pre WW2 the bottles such as the 851/852 barely made it to 20M. I dont believe Ive heard or saw pictures of him using tubes such as the 750TL and 1000 to 2000T. So yeah, 3-5KW CW and AM was the norm there and a 77SX will barely do 3KW on SSB with the stock SX transformer and I dont see any external iron in those pix. Remember that a 5KW carrier on AM fully modulated is 20KW PEP and with the voltages on those open wire lines those tuner caps needed lots of spacing. Carl KM1H - Original Message - From: Mike Waters To: Carl Cc: topband Sent: Friday, July 26, 2013 5:38 PM Subject: Re: Topband: 160M Rhombics Could be. Here's some photos of Don's station, FWIW: http://www.qsl.net/ne6i/w6am/shack.html . Alpha amplifiers, and huge tall racks that look like they might require one of those Alphas to drive them. But who can say for sure? :-) For whatever reason, there's what seems to be a lot of hype about W6AM's rhombics. Such as: The W6AM station was legendary around the world. Don could beat you in a pileup for some obscure African station no matter what band, and even if you were on the east coast. And him in Southern California. Don was #1 on ARRL's DXCC Honor Roll, and you didn't argue. No matter where you were, no matter what you were running, Don had beaten you in a pileup. More than once. Beat anyone on the east coast to Europe from California every time? I'm sorry, but a rhombic is just not that good, even if you DO have one pointed at every direction of the compass as W6AM did. More info and photos: http://www.qsl.net/ne6i/w6am/recollections.html http://www.qsl.net/ne6i/w6am/others.html 73, Mike www.w0btu.com On Fri, Jul 26, 2013 at 3:58 PM, Carl k...@jeremy.mv.com wrote: I dont see anything from then that disagrees with what I said today Mike, QRO in those days was a smaller ratio from what is daily these days. No virus found in this message. Checked by AVG - www.avg.com Version: 10.0.1432 / Virus Database: 3209/6022 - Release Date: 07/26/13 _ Topband Reflector
Re: Topband: 160M Rhombics
Hi all It has been interesting to read the comments about rhombic antennas. We used a rhombic beam antenna at ZL6QH. It had 100 metre legs (to make a total wire length of 400 metres) located at a height of approximately 20 meters AGL. The beam was made reversible by using a relay and open wire line to switch the terminating resistor to either end of the antenna. As antenna modelling predicts, this rhombic antenna was a cloud warmer for 160M, although it was sometimes useful as an alternative receiving antenna on this band. Its performance was generally not as good as vertical antenna on 80M but it did perform well in the designed direction on the higher bands. However, the narrow nature of the forward lobe meant that it was only useful for reaching a relatively small geographic area at the remote end of the path. The loss of up to 3 dB in the termination resistor was also a negative factor. We found that unterminated long wire antennas in the form of vee beams (with 300 metre legs) were more effective than the rhombic due to them having broader lobes in the azimuth plane. The lack of termination resistors also meant that stations could also be worked simultaneously in both the front and back directions. The combination of these factors meant that vee beams more useful for working stations over a wider geographic area in contest scenarios. Vee beams were also easier to construct as they only required 3 supporting masts. However, like the rhombic, they were cloud warmers on 160M and were really only competitive on the 40M and higher bands. Although we erected a number of vee beams and found them to be useful, they were still not effective as yagi beam antennas erected at a similar height. Our long boom mono-band yagi antennas for 20M, 15M and 10M all performed better than the long wire antennas in contests. Antenna modelling shows that these yagi antennas had broader patterns than vee beams in both the azimuth and elevation planes, and without sacrificing much in the way of overall gain. The broader range of take-off angles and directions meant that more stations could work us on the yagi antennas. The downside of the yagi antennas was the difficulty of keeping them intact and up in the air during the gale force winds that regularly swept the ZL6QH coastal site. In order to address these issues, the yagi antennas were fixed (not rotatable) and they used a ruggedised design consisting of aluminium elements mounted on a rope supporting structure. See http://www.zl6qh.com/cvradiofest.pdf for more information about the antennas and the ZL6QH story. 73 Brian VK3MI ZL1AZE _ Topband Reflector
Re: Topband: 160M Rhombics
It still boils down to location and propagation. Nobody is King all the time and some hams have real jobs that keep them away during some important openings. Charlie had a very modest and average location and was near the top of DXCC even before he put up a yagi. Maybe one of those places rumored to exist where the magic lines of force happens. Dean, as N6BV/1, also modeled my QTH for the original TA program that was part of the K6STI AO/YO package. You might want to check it out. I make no particular claims but contest results during the stations active days as well as the ease I worked DX on any band support Deans analysis. He started the program to see why I consistently beat him during the many times our paths crossed. He was on another hilltop about 15 miles away and we were LOS. I felt it was my homebrew stacked monobanders versus his 4 high stack of TH-7's but he showed it was the location. Contesting became boring and the stacks were scaled down to single antennas and I get on when I feel like it and no longer driven. BTW, I worked W3CRA Thursday on 40M AM, it is now the Collins Radio Association often on daily with W3ST operating. Carl KM1H - Original Message - From: Bill Tippett btipp...@alum.mit.edu To: topband@contesting.com Sent: Saturday, July 27, 2013 6:23 AM Subject: Re: Topband: 160M Rhombics W0BTU: For whatever reason, there's what seems to be a lot of hype about W6AM's rhombics. Such as: The W6AM station was legendary around the world. Don could beat you in a pileup for some obscure African station no matter what band, and even if you were on the east coast. And him in Southern California. Don was #1 on ARRL's DXCC Honor Roll, and you didn't argue. No matter where you were, no matter what you were running, Don had beaten you in a pileup. More than once. Beat anyone on the east coast to Europe from California every time? I'm sorry, but a rhombic is just not that good, even if you DO have one pointed at every direction of the compass as W6AM did. Absolutely a lot hype, as you stated. The real King of the Hill in those days was Frank Lucas W3CRA: Gus Browning, W4BPD wrote (from Ahoy Aldabra! article in February 1964 CQ Magazine): After staying up for the long path opening to the U. S. which was 4:00 AM local time, I intended sleeping on a small bunk at the rear of the boat. After lying down for a while and wondering about the 5-9 plus 20 db signal that signs W3CRA when all the others on the band are S7, I came to the conclusion that Frank must have the world's best QTH. When the band is dead he's always S7 and when the W-boys are S7 Frank is always over S9. This just isn't once in a while, it's an every day occurrence. Frank did this with a single 3 element homebrew Yagi but his secret was location, location, location; as this webpage explains. http://users.vnet.net/btippett/w3cra.htm W6AM at the top of the Honor Roll? More hype. Charlie Mellen W1FH in Boston ran a simple 3 element Yagi and had 311/337 (current/cumulative including deleted) when W6AM was at 307/332 in November 1964. Here's the *complete* DXCC Honor Roll listing: http://users.vnet.net/btippett/dxcc_honor_roll.htm W6AM may have closed the gap for current entitiess in later years but W1FH was one of very few to work W6ODD/CR8 from Damao/Diu in 1948, which W6AM missed. W1FH was the first post-war DXCC holder and W3CRA was the first pre-war DXCC holder. Frank apparently quit submitting cards for the post-war award but he was very much King of the Hill signal-wise as W4BPD verified above. http://oldqslcards.com/W1FH.pdf http://hamgallery.com/qsl/deleted/Damao_Diu/w6odd.htm Just to keep this from being totally off-topic, note the many Topband DXers at the bottom of the DXCC page above. 73, Bill W4ZV _ Topband Reflector - No virus found in this message. Checked by AVG - www.avg.com Version: 10.0.1432 / Virus Database: 3209/6024 - Release Date: 07/26/13 _ Topband Reflector
Re: Topband: 160M Rhombics
Anybody on this list have a Rhombic for 160M? W1AW used to use one for bulletins and code practice on 160M but I think it came down years ago (1989?) I seem to recall pics in CQ of a big California desert DX'er who had what was essentially a radial array of rhombics for maybe 160M or 80M. I can't imagine why anyone would have one today. Here is an analaysis of Rhomics. http://www.w8ji.com/rhombic_antennas.htm 73 Tom _ Topband Reflector
Re: Topband: 160M Rhombics
Tom, Why? The same reason guys put up quads. They LOOK very cool! Imagine standing on one end of the rhombic and saying well, you can't see the end of the antenna without the binoculars - but it's out that-way somewhere. 73/jeff/ac0c www.ac0c.com alpha-charlie-zero-charlie -Original Message- From: Tom W8JI Sent: Friday, July 26, 2013 12:27 PM To: Shoppa, Tim Cc: topband@contesting.com Subject: Re: Topband: 160M Rhombics Anybody on this list have a Rhombic for 160M? W1AW used to use one for bulletins and code practice on 160M but I think it came down years ago (1989?) I seem to recall pics in CQ of a big California desert DX'er who had what was essentially a radial array of rhombics for maybe 160M or 80M. I can't imagine why anyone would have one today. Here is an analaysis of Rhomics. http://www.w8ji.com/rhombic_antennas.htm 73 Tom _ Topband Reflector _ Topband Reflector
Re: Topband: 160M Rhombics
Anybody on this list have a Rhombic for 160M? W1AW used to use one for bulletins and code practice on 160M but I think it came down years ago (1989?) I seem to recall pics in CQ of a big California desert DX'er who had what was essentially a radial array of rhombics for maybe 160M or 80M. I can't imagine why anyone would have one today. Here is an analaysis of Rhomics. http://www.w8ji.com/rhombic_antennas.htm 73 Tom Years ago, W6AM had a Rhombic Farm near San Francisco. Ian, VK3MO had stacked Rhombics. I don't believe that either used them on 160. Ian as always was a Bomb on 20 meters long path. 73 Price W0RI _ Topband Reflector
Re: Topband: 160M Rhombics
If we want an antenna just for looks, might as well make it all out of a non-conductor such as plastic rope. :-) Seriously, Tom is right. Take time to study his rhombic page. However, as one wise man once told me, Time spent doing something you enjoy is not wasted time. Putting up a rhombic might also be a good learning experience. But you better make sure that you aim it right where you need it. 73, Mike www.w0btu.com On Fri, Jul 26, 2013 at 12:33 PM, Jeff Blaine j...@ac0c.com wrote: Why? The same reason guys put up quads. They LOOK very cool! Imagine standing on one end of the rhombic and saying well, you can't see the end of the antenna without the binoculars - but it's out that-way somewhere. _ Topband Reflector
Re: Topband: 160M Rhombics
There were a lot of tall tales told about W6AM's rhombics. Don't base a desire to have a rhombic on those fables. And that's where the term California Kilowatt came from. I'm told his rhombics were loud mostly for that reason. I forget what tubes were in his amp, but they sure weren't 6V6s. ;-) 73, Mike www.w0btu.com On Fri, Jul 26, 2013 at 12:36 PM, HAROLD SMITH JR w0ri...@sbcglobal.netwrote: Years ago, W6AM had a Rhombic Farm near San Francisco. _ Topband Reflector
Re: Topband: 160M Rhombics
Rhombics definitely look cool, but modern antennas definitely outperform them My favorites: - four stacked rhombics, (two wide, two high) over a salt marsh in ZC4 this array was replaced by a curtain array, steerable in azimuth and elevation - a rosette of sloping rhombics occupying one square mile. Sloping rhombics broaden the elevation pattern, much like stacked Yagis. - many pairs of very wide spaced rhombics used for diversity reception at VOA Greenville Site C As for 160 meters, I'll keep my 4-square transmitting array, Beverages and phased arrays of short receiving verticals! 73 Frank W3LPL - Original Message - From: Jeff Blaine j...@ac0c.com To: Tom W8JI w...@w8ji.com, Tim Shoppa tsho...@wmata.com Cc: topband@contesting.com Sent: Friday, July 26, 2013 6:33:49 PM Subject: Re: Topband: 160M Rhombics Tom, Why? The same reason guys put up quads. They LOOK very cool! Imagine standing on one end of the rhombic and saying well, you can't see the end of the antenna without the binoculars - but it's out that-way somewhere. 73/jeff/ac0c www.ac0c.com alpha-charlie-zero-charlie -Original Message- From: Tom W8JI Sent: Friday, July 26, 2013 12:27 PM To: Shoppa, Tim Cc: topband@contesting.com Subject: Re: Topband: 160M Rhombics Anybody on this list have a Rhombic for 160M? W1AW used to use one for bulletins and code practice on 160M but I think it came down years ago (1989?) I seem to recall pics in CQ of a big California desert DX'er who had what was essentially a radial array of rhombics for maybe 160M or 80M. I can't imagine why anyone would have one today. Here is an analaysis of Rhomics. http://www.w8ji.com/rhombic_antennas.htm 73 Tom _ Topband Reflector _ Topband Reflector _ Topband Reflector
Re: Topband: 160M Rhombics
This is interesting! You did all this, Frank? It would be fascinating to hear details of how all this worked, especially the curtain array. 73, Mike www.w0btu.com On Fri, Jul 26, 2013 at 1:40 PM, donov...@starpower.net wrote: - four stacked rhombics, (two wide, two high) over a salt marsh in ZC4 this array was replaced by a curtain array, steerable in azimuth and elevation - a rosette of sloping rhombics occupying one square mile. Sloping rhombics broaden the elevation pattern, much like stacked Yagis. - many pairs of very wide spaced rhombics used for diversity reception at VOA Greenville Site C As for 160 meters, I'll keep my 4-square transmitting array, Beverages and phased arrays of short receiving verticals! _ Topband Reflector
Re: Topband: 160M Rhombics
I did not say it was *only* for looks. It also happens to look amazing. If you are at the ham club and you said hea I just hung up a 160m rhombic - the next comment guys would say is wow, I would love to see that. Big stuff always has a certain sizzle to an observer - no matter what the actual performance results are. 73/jeff/ac0c www.ac0c.com alpha-charlie-zero-charlie -Original Message- From: Mike Waters Sent: Friday, July 26, 2013 12:41 PM To: topband Subject: Re: Topband: 160M Rhombics If we want an antenna just for looks, might as well make it all out of a non-conductor such as plastic rope. :-) Seriously, Tom is right. Take time to study his rhombic page. However, as one wise man once told me, Time spent doing something you enjoy is not wasted time. Putting up a rhombic might also be a good learning experience. But you better make sure that you aim it right where you need it. 73, Mike www.w0btu.com On Fri, Jul 26, 2013 at 12:33 PM, Jeff Blaine j...@ac0c.com wrote: Why? The same reason guys put up quads. They LOOK very cool! Imagine standing on one end of the rhombic and saying well, you can't see the end of the antenna without the binoculars - but it's out that-way somewhere. _ Topband Reflector _ Topband Reflector
Re: Topband: 160M Rhombics
And that's where the term California Kilowatt came from. I'm told his rhombics were loud mostly for that reason. I forget what tubes were in his amp, but they sure weren't 6V6s. ;-) When I was bumming around in the 60's, I visited some west coast stations with large wire antennas with exceptional signals. I remember listening to them on 160, when the power limit was 25 watts INPUT power and the W6's and W8's had to work opposite ends of the band. One was using marine communications shore transmitters that filled an entire wall. :-) _ Topband Reflector
Re: Topband: 160M Rhombics
Carl, I based what I said partly on your statements at http://forums.qrz.com/showthread.php?297870-How-to-design-rhombic-antenna . Looking back at that page, I see that perhaps I misunderstood your statements there. Look at the photos of his shack. If he wasn't running a lot of power, you would never know that from the size of the antenna switches, feedline, standoff insulators, etc. 73, Mike www.w0btu.com On Fri, Jul 26, 2013 at 3:28 PM, ZR z...@jeremy.mv.com wrote: That excuse doesnt cut it Mike and from what I was told by those who were there his power would be considered pretty normal these days. You can only get so much out of a pair of 450TL's, 4-1000A's, etc. Some on here that you seem to look up to run more than that. OTOH you completely discounted Dons LOCATION, LOCATION, LOCATION. Carl KM1H There were a lot of tall tales told about W6AM's rhombics. Don't base a desire to have a rhombic on those fables. And that's where the term California Kilowatt came from. I'm told his rhombics were loud mostly for that reason. I forget what tubes were in his amp, but they sure weren't 6V6s. ;-) 73, Mike www.w0btu.com On Fri, Jul 26, 2013 at 12:36 PM, HAROLD SMITH JR w0ri...@sbcglobal.net wrote: Years ago, W6AM had a Rhombic Farm near San Francisco. _ Topband Reflector
Re: Topband: 160M Rhombics
Could be. Here's some photos of Don's station, FWIW: http://www.qsl.net/ne6i/w6am/shack.html . Alpha amplifiers, and huge tall racks that look like they might require one of those Alphas to drive them. But who can say for sure? :-) For whatever reason, there's what seems to be a lot of hype about W6AM's rhombics. Such as: The W6AM station was legendary around the world. Don could beat you in a pileup for some obscure African station no matter what band, and even if you were on the east coast. And him in Southern California. Don was #1 on ARRL's DXCC Honor Roll, and you didn't argue. No matter where you were, no matter what you were running, Don had beaten you in a pileup. More than once. Beat anyone on the east coast to Europe from California every time? I'm sorry, but a rhombic is just not that good, even if you DO have one pointed at every direction of the compass as W6AM did. More info and photos: http://www.qsl.net/ne6i/w6am/recollections.html http://www.qsl.net/ne6i/w6am/others.html 73, Mike www.w0btu.com On Fri, Jul 26, 2013 at 3:58 PM, Carl k...@jeremy.mv.com wrote: I dont see anything from then that disagrees with what I said today Mike, QRO in those days was a smaller ratio from what is daily these days. _ Topband Reflector
Re: Topband: 160M Rhombics
W0AIH has a Rhombic, and it is pretty amazing. Mostly used on 20. Its quieter than the stack, and its louder. Steerable, but NOT rotateable :-) Installing one is NOT a simple task. Took Paul a few tries to figure out how to hang it. Its up about 100 feet, and requires a significant amount of real estate. I could not imaging what it would take to make one for 160, buts its a safe bet that a 4-square will be a lot easier to install/require less real estate. Paul has a 4-square for 160 among other antennas for Topband. Tom - VE3CX On Fri, Jul 26, 2013 at 11:07 AM, Shoppa, Tim tsho...@wmata.com wrote: Anybody on this list have a Rhombic for 160M? W1AW used to use one for bulletins and code practice on 160M but I think it came down years ago (1989?) I seem to recall pics in CQ of a big California desert DX'er who had what was essentially a radial array of rhombics for maybe 160M or 80M. Tim N3QE -Original Message- From: Topband [mailto:topband-boun...@contesting.com] On Behalf Of Grant Saviers Sent: Friday, July 26, 2013 11:03 AM To: ZR Cc: g...@ka1j.com; topband@contesting.com Subject: Re: Topband: Topband Inv-L Joy Posted on towertalk yesterday was the link to the free download of the 1952 text Radio Antenna Engineering http://www.lulu.com/us/en/shop/edmund-laport/radio-antenna-engineering/ebook/product-17560294.html Some fascinating stuff since much of the focus is high power broadcasting LF/HF and point to point reliable RF links with high gain HF wire antennas. (many pictures of amazing arrays). A quick peruse found in a later chapter how to build high power non-inductive terminations for rhombics etc. Make an open wire feeder of the needed Z from iron or stainless wire and as long as the db's you wish to absorb and with wire heavy enough to handle the current. Clever stuff, invented when HF was a primary long distance communications technology. The formulas are there for resistivity and ferromagnetic losses. Of course some of the content is now pretty irrelevant since we have cheap great coax, ferrite, and NEC software and a billion times the worlds 1952 total computing power on every desktop. Grant KZ1W On 7/25/2013 8:17 AM, ZR wrote: On a side note WD-1A conductors are a copper/cadmium alloy; whatever that means in RF resistance. Fine for a Beverage but what is the loss? Carl KM1H - Original Message - From: Gary Smith g...@ka1j.com To: topband@contesting.com Sent: Thursday, July 25, 2013 1:22 AM Subject: Re: Topband: Topband Inv-L Joy Had a more difficult time getting the antenna up there this time. The first spud snapped away from the fishing line in the dense thicket I was unable to find where it landed. Had to make another the mosquitos were so thick they posted a LUAU sign on my forehead. Till I get something better I retrieved my WD-1A military field phone wire that was left out in the marsh as my old beverage wire. and after a comedy of errors I finally got the antenna up. I was earlier getting a SWR of 1.1 on 160 before and now am getting 1.1 on 1.74365 MHZ 1.74365mhz R=51 X= 6,7,8 swr 1.1 At the desired frequency to match the antenna I've aimed for 1.8MHZ here's the information I was able to get at my desired frequency: 1.8025 mhZ Coax loss 6.3db C=4193 XC=21 L=1.970 X1=21 r=41 x=21 swr 1.6 So this is what the antenna is giving me at this moment. I need to get back down and add the broken wire to the radial bed and I should also trim some length to bring my values to 1.1 at 1.025MHz. Given the info above from the MFJ 259B any idea how much I might nibble off and more, is there anything in this info that tells me I should look to do anything differently? Hopefully the coax loss will be mitigated by a friend bringing me 350' of hardline. Can't wait! Thanks, Gary KA1J _ Topband Reflector - No virus found in this message. Checked by AVG - www.avg.com Version: 10.0.1432 / Virus Database: 3209/6019 - Release Date: 07/25/13 _ Topband Reflector _ Topband Reflector _ Topband Reflector _ Topband Reflector
