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 <[email protected]> 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:[email protected]] On Behalf Of Grant > Saviers > Sent: Friday, July 26, 2013 11:03 AM > To: ZR > Cc: [email protected]; [email protected] > 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" <[email protected]> >> To: <[email protected]> >> 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
