Presentation on theme: "Why Do They Call It Wireless"— Presentation transcript:
1 Why Do They Call It Wireless Why Do They Call It Wireless? Behind the Radios in Multi-Radio Contest StationsBy Contest Station Builders WorldwideCollected and Edited by Pete Smith, N4ZR
2 The approachIdentify the challenges in the design and construction of complex contest stations (other than antennas).Collect and present solutions from station builders worldwide.Thanks, VE1JF
3 CaveatsSuccessful contest stations come in all varieties, from fully-engineered to “growed like topsy.”There is no single “right way”Presentation based on input from station builders – not comprehensive
4 Neatness is optionalThis is a view of the back side of a very successful, high-tech contest station. I’m not saying whose, but the fact is, I received any number of pictures showing equally messy “back views,” including several I couldn’t distinguish from this one. Whoever you are, you ARE not alone.
5 Challenge – Basic design decisions “Architecture” choicesDegree of automation.Location of physical antenna switching/phasing.Layout of operating position and cable runs
6 Solutions Full automatic/remote RF switching Hybrid approach Manual 2X6 6X2 switchingOther manual approachesMechanical switch w/interlockPatch panelCables on the floor
7 Footnote – What is 2X6 6X2 switching? “Industry standard” automation – highest isolation, either rig connects to all antennas, fail-safeSix-Pack switching uses just the left side – lower isolation but study suggests it is not the limiting factor in the real world.Courtesy Top Ten Devices
8 Full automation/remote RF switching SO2R switching and antenna selection done remotely, but controlled from the operating position. Maximum computer integration. Cable for data, not RF.Backup manual systems or spares are essential.
9 For Example …. K4JAUtter simplicity – belies what is under the covers.
10 Equally simple from the back View is in wiring closet that extends across back of all op positions. Amps and SO2R switching are in closet. Cables include amp control, one band data line to SO2R panel, rotator control cable, AC power. Antenna switching still to come.K4JA
11 But lots of hardware required to support the up-front simplicity Bandpass filters, 2 6-way relay boxes, 6 A/B selectors(no antennas connected to A/B boxes yet)K4JA
13 Remote antenna selection More remote relay boxes, switched from operating position, or…Stackmatches or equivalent, similarly controlledKC1XX
14 Hybrid approach Most stations have been evolving for years. Can’t always do everything at once.
15 For example …. W9REAs everyone knows, Mike’s been at the complex station game a long time.A/B switching is automated now, but selection of antennas remains manual, and all the switches are at the operating position.
16 Homebrew 6X2 relay boxUnder the operating tableW9RE
18 Manual 2X6 6X2 switching … KQ2M Operationally equivalent to the full-auto arrangement, but all manual.Risk of error, fatigue is the big drawback. No interlock in A/B selection.KQ2M
19 A Scottish solution GM4AFF Stewart has kindly marked the switches – the interlock is mechanical, so that only 1 from radio 1 and 1 from radio 2 can be selected at one time. Relay box wiring prevents both being on the same band.GM4AFF
20 Ultimate simplicity? W5KFT Cables from amps go to patch panel (only one connected here). One jack per band, no relays (but 6 coax cables to the operating position). Virtually foolproof as long as you remember which amp cable is which.W5KFT
21 And simpler yetTom’s message to me was titled “World Class automation”K1KI
22 Challenge – Cable entry How to get feedlines and control cables into the shack areaNow down to nuts and bolts
39 Bundle by band, type (RF, control, etc.) K9NS/K9HMB
40 Use a cable trayFabricated from 2X4s and plywood, with hinged tops and slots for cables to get in and out.WX0B
41 Other options (no pictures) Contractors’ snap-open wire hangers“Panduit” extruded plastic cable trays and associated fixtures – separate cables by functionBicycle hangers, vinyl dipped huge screw hooks, etc.
42 Challenge – Access to cabling Free-standing operating table with access from rearCable closetConsole on wheels
43 Access from rearThis one a little skinnier than most – 24-30” generally recommendedGM4AFF
44 Cable closetRigs to left, coax entry from right – 34” wideK4JA
46 Console on wheelsEverything rolls out away from the wallVK5GN
47 Cable marking techniques Labelmakers – Dymo, P-Touch, Casio, etc. with clear heat-shrink or tapeColored tape – use resistor color codeMS Word/Magic TapePaint pen w/ silver inkIt’s important to label cables fully – what is it, what does it connect to
48 Cable bundling techniques Color-coded Velcro tiesTie-wraps – reusable or disposableTHHN wire twistedSpiral wrap tubing (Alpha or Panduit)Split-loom tubing (SPC or Panduit)
49 Other cabling hintsUse pigtails with terminal strips to ease the task of changing radio-specific connectorsOf course, that way you have to label both the terminal strip and the cables.HC8N
50 And more…Use unique connectors to reduce risk of mistakes when recablingUse multiple conductor cables where possibleCareful attention to grounding can reduce inter-station interferenceW3PP found that multiple ground leads to a single ground bus around the outside of his shack helped reduce interstation interference dramatically
51 Documentation Station notebook is essential Document everything in one placeSchematicsCable lengthsMeasured resistances, SWRs, etc.Critical computer infoEverything you might need at 4 AM
52 Special solutions for special problems Phasing multiple antennas on separate towers on 10m – OK2RZManaging multiple receiving antennas on 160 – W8JI
53 OK2RZ8 antennas/45 elements on 5 towers, including 3-high stack – 10m onlyAbility to drive either 2 or 4 simultaneouslyPhasing line length determined experimentally
54 OK2RZ 10m antennas Former military communications facility Hilltop at 1000’ ASL
55 OK2RZ antenna phasing Surplus mechanical switch Only part of the phasing lines – impedance matching a real challenge
56 W8JI Primarily a 160m station Three operating positions Many receiving antennas/arraysChallenge – how to make antennas available to all operating positions simultaneouslyUse of BCD for control wiring sharply reduces the number of conductors to remote array hubs – up to 2000’ away3 conductors, up to 8 selections, decoded by relay/diode matrixes
57 Receiving multicoupler 6 antenna inputs at top – preamps using CATV transistorsAny output to any receiver simultaneously – BCD data at right from operating positions
58 SO2R Audio/CW Controller Options Commercial unitsTop Ten DevicesArray SolutionsHomebrew approachesImportant to simple, reliable wiring at the operating position