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WX3B es Force 12 refector (thought this reply might be of common interest and spark some additional solutions) de VE1JF WX3B--a familiar call! TNX 4 bands in WPX SSB (VC1R--op K6IF@VE1JF--top claimed SOABHP in VE or US) Yes, we have a 3stack of C51XRN/C31XR-H/C51XRN per the article, my website and the force12inc site (under "customer stacks"--need to update this to reflect single-band feed and latest excellent results) Yes, we operate full tilt on (any) two different bands 10-40 on the same boom or stacks at will. That's the good news. Is it perfect? Not always--some degree of interference noticeable with some frequency combinations. It was awful for YCCC when they first came up for WWSSB2001, but K1IR and W1WEF kindly gave me lots of good advice over the coming months and the situation was vastly improved by the 2002/3 season. Another set of changes coming this summer; also I'll pass along thoughts about what I might have done differently if I had started fresh. The good news is the YCCC has stuck by me and a team led by NB1B is coming up for WWCW for YCCC's fourth presence here. As you will see in WWCW2002 results, NB1B and K3NA with 16 hours relief operating by VE1JF did well in M/2. Which combinations cause interference seem to vary in ways we have never pinned down--lots of variables at play--the obvious one of the same booms must play a role but not as obvious and consistent as I might have thought. I'll give you three scenarios: what we do, with asterisked items added at YCCC recommendation after Oct 2001; what we plan to do differently this summer building season; other ideas WHAT WE PRESENTLY DO o DuneStar 600 multiband filters on each radio o Single-band feed* (used to use triband feed on 10-15-20 and an Array Systems switch to divert the bottom triband section to a second radio) o One set of regular coax stubs* (K2TR design) for 20-15-10, at the doghouse (see NCJ) THIS SUMMER'S ADDITIONS o double set of hardline coax stubs spaced 1/4 wl on at least 10-15-20, maybe 40, between the StackMatches and the tower-end WX0B UNUNS for the hardline feeds; could move this set 200' to the SPOE if proves necessary but a heck of a lot easier to fit in physically at the tower where the stubs can be laid out in the woods instead of further complicating a busy SPOE area WHAT I MIGHT HAVE DONE DIFFERENTLY IF STARTING FRESH o the relatively new WA3NQN multiband selectible filters from Array Systems-- I hear they offer around 35db more rejection than the DuneStar 600s--but I don't think this upgrade will be necessary here--we'll see. Sometimes ops (including me) report literally no trace of interference. Sometimes they report "could hear some in there but swamped by ambient roar of the contest". Occasionally they report "interference on this combination (particularly where the exact harmonic is involved) was annoying but we could continue operating." We've got it down to the point that I hope the added hardline stubs will take any real remaining problem down to trace levels. Never yet operated M/M here but the principle would be the same. Would need to go to a next level of switching beyond the present Array Systems 6X2. VE1JF was designed to be truly competitive up to the M/2 level, but with guest-brought equipt we could play at M/M and maybe surprise some people. 73, Jim, VE1JF and until 1 June 2003 VC1R jwfisher@alumni.princeton.edu http://www.ve1jf.com see article on p.32 of most recent NCJ Message text written by James Nitzberg >Hi Jim; I read with great interest the article on your station in NCJ this month. I also looked briefly at your Web site. I see that you do Multi-Two contesting from your station - and I know you have 3 Force 12 antennas that cover 10 - 40 meters, right? Since each band on your Force 12 is fed with a separate feed line, does this mean you can run a "stack" on 10, and a "stack" on 15 at the same time, with two radios CQing? I'm curious how badly the inter-station interference is, especially on bands like 40 & 15 at the same time, or 10 & 20. Is it really possible to be using 3 or 4 bands on one boom - stacked - at the same time? Have you every tried a Multi-Multi entry with your system? Thanks for your thoughts. If it's really possible to run multiple bands on the same antenna (at high power!) simultaneously - I'd like to try it. 73, Jim Nitzberg WX3B< -------------------------------------------- Force12Talk mailing list provided as a service by Force 12 Antennas, Inc. Force12 Web Site: http://www.force12inc.com To Submit Message to the List: Force12Talk@qth.com To unsubscribe and view the Message Archive: see http://qth.com/force12/list For problems with the list: contact n4zr@qth.com |
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