Why Do They Call It Wireless? Behind the Radios in Multi Radio Contest Stations

By Contest Station Builders Worldwide Collected and Edited by Pete Smith, N4ZR

The approach  Identify the challenges in the design and construction of complex contest stations (other than antennas).

 Collect and present solutions from station builders worldwide.

Thanks, VE1JF

Caveats  Successful 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

Neatness is optional

Challenge – Basic design decisions  “Architecture” choices  Degree of automation.

 Location of physical antenna switching/phasing.

 Layout of operating position and cable runs

Solutions  Full automatic/remote RF switching  Hybrid approach  Manual 2X6  6X2 switching  Other manual approaches  Mechanical switch w/interlock  Patch panel  Cables on the floor

Footnote – What is 2X6  6X2 switching?

Courtesy Top Ten Devices

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.

For Example …. K4JA

Equally simple from the back K4JA

But lots of hardware required to support the up-front simplicity K4JA

Especially at a multi-multi KC1XX

Remote antenna selection KC1XX

Hybrid approach  Most stations have been evolving for years.

 Can’t always do everything at once.

For example …. W9RE

Homebrew 6X2 relay box W9RE

Manual antenna selection W9RE

Manual 2X6  … KQ2M 6X2 switching KQ2M

A Scottish solution GM4AFF

Ultimate simplicity?

W5KFT

And simpler yet K1KI

Challenge – Cable entry  How to get feedlines and control cables into the shack area

Solution - Through-wall panel K4OJ

On a larger scale ….

KC1XX

The dryer-vent approach K5ZD

Or through the siding K4JA

With the connections made inside… K4JA

Challenge – Lightning protection  Some measures essential  Protect vs disconnect

Solution - disconnect everything K5ZD

Control cables, too K4OJ

Solution – protectors on coax, control lines. Inside, VE1JF

… or at the tower base N3RR

Inside the box N3RR

Grounding at the entry panel N1LO

A closer look N1LO

Cable support and low inductance grounding N1LO

Challenge – cable support, protection and management  Keep them out from underfoot  Protect against accidental damage  Retain flexibility for easy change, maintenance

Suspend from ceiling joists K9NS/K9HMB

Bundle by band, type (RF, control, etc.) K9NS/K9HMB

Use a cable tray WX0B

Other options (no pictures)  Contractors’ snap-open wire hangers  “Panduit” extruded plastic cable trays and associated fixtures – separate cables by function  Bicycle hangers, vinyl dipped huge screw hooks, etc.

Challenge – Access to cabling  Free-standing operating table with access from rear  Cable closet  Console on wheels

Access from rear GM4AFF

Cable closet K4JA

Another more spacious approach K9NS/K9HMB

Console on wheels VK5GN

Cable marking techniques  Labelmakers – Dymo, P-Touch, Casio, etc. with clear heat-shrink or tape  Colored tape – use resistor color code  MS Word/Magic Tape  Paint pen w/ silver ink

Cable bundling techniques  Color-coded Velcro ties  Tie-wraps – reusable or disposable  THHN wire twisted  Spiral wrap tubing (Alpha or Panduit)  Split-loom tubing (SPC or Panduit)

Other cabling hints  Use pigtails with terminal strips to ease the task of changing radio-specific connectors HC8N

And more…  Use unique connectors to reduce risk of mistakes when recabling  Use multiple conductor cables where possible  Careful attention to grounding can reduce inter-station interference

Documentation  Station notebook is essential  Document everything in one place  Schematics  Cable lengths  Measured resistances, SWRs, etc.

 Critical computer info  Everything you might need at 4 AM

Special solutions for special problems  Phasing multiple antennas on separate towers on 10m – OK2RZ  Managing multiple receiving antennas on 160 – W8JI

OK2RZ  8 antennas/45 elements on 5 towers, including 3-high stack – 10m only  Ability to drive either 2 or 4 simultaneously  Phasing line length determined experimentally

OK2RZ 10m antennas

OK2RZ antenna phasing

W8JI  Primarily a 160m station  Three operating positions  Many receiving antennas/arrays  Challenge – how to make antennas available to all operating positions simultaneously

Receiving multicoupler

SO2R Audio/CW Controller Options  Commercial units  Top Ten Devices  Array Solutions  Homebrew approaches

Array Solutions SO2R www.arraysolutions.com

TopTen DX Doubler http://www.qth.com/topten/

Homebrewers K6LL

More examples  N6TR – One of the first http://www.kkn.net/~k5tr/trlog/switch.pdf

 S56A – relayless SO2R controllers http://artinian.bit.si/radio.htm

 KG5U – manual – audio and antennas http://www.hal-pc.org/~kg5u/2radctlr.html

 W2UP – audio only http://w2up.home.mindspring.com/SO2R-audio controller.doc

 K5FD – full auto w/ antenna switching www.qsl.net/k5fd

Thanks to the following contributors : EI8IC, GM4AFF, HA1AG, K0FF, K0HB, K0XG, K1DG, K1GQ, K1IR, K1KI, K3BU, K3NA, K3ND, K3OO, K3WW, K4JA, K4OJ, K4ZA, K5FD, K5TR, K5ZD, K6LA, K6LL, K7NV, K7ZO, K8CC, K8DX, K9GS, K9GY, KC4UZ, KG5U, KI7WX, KI7Y, KL7RA, KQ2M, KS9W, N1KWF, N1LO, N3BB, N3RR, N5NJ, N5OT, N5ZC, N8YYS, OK2RZ, S56A, VE1JF, VE3PN, VE7QO, VK5GN, W1YL, W2UP, W2VJN, W3PP, W4AN, W7TI, W7ZR, W7ZRC, W8JI, W9RE ,WE9V ,WX0B