How To Build A Stacking Harness

How To Build A Stacking Harness

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http://www.bloomington.in.us/~wh2t/Stack.htm

From Dr.Ace – WH2T How to Build a Home Brew Coax Harness for Co-Phasing And/Or Stacking Two 50 Ohm Antennas When making a Co-Phasing Stacking Harness try to avoid splicing the bare coax wires together. Always use the appropriate UHF PL-259 Coaxial Connectors, PL-258 barrel connectors and RFU 533 (83-1T) “T” connectors. If properly stacked, You add approximately 3db Gain each time the number of Yagi antennas is doubled.

A note about the phasing lines below L = Left and R = Right Both phasing lines MUST be of equal length. UHF “T” Coax Connector RFU 533 (83-1T) | | | | Phasing Line L = | Phasing Line R = Any Odd Multiple | Any Odd Multiple Of Quarter Wave Lengths | Of Quarter Wave Lengths Of any 50 Ohm Coax | Of any 50 Ohm Coax With a PL-259 connector | With a PL-259 connector Screwed onto the “T” Connector | Screwed onto the “T” Connector | | | | | | | | | V V V Antenna #1 ____________________

___________________ Antenna #2 T I ß UHF Coaxial barrel connector (PL-258)

-I- ß Upside Down T Connector RFU 533 (83-1T) | | | | |

| | | | |

ß Two equal lengths of any 75 Ohm Coax Each an electrical ¼ Wave Length Long Each has a PL-259 connector on

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How To Build A Stacking Harness

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BOTH | |

| | T

ends = Matching Q Section.

ß UHF “T” Coax Connector RFU 533 (83-1T)

I ß UHF Coaxial barrel connector (PL-258) Then use any needed length of any 50 Ohm coax with a PL-259 connector on each end from the bottom UHF Coaxial barrel connector (PL-258) above to reach your Ham Shack.

Here is how to figure out an electrical 1/4 wave length of coax: * In Feet: 246 x (Velocity Factor) / Frequency (MHz) = Length in Feet * In Inches: 2952 x (Velocity Factor) / Frequency (MHz) = Length in Inches

Here is the Formula to Properly Determine the Optimal Broadside Stacking Distance for Two Yagi Antennas: Stacking Distance in Wavelengths = 52 / 3db Beamwidth in Degrees. OR If you don't want to do the math, OR you don't know the antenna's 3db Beamwidth in Degrees. Here's a (not as good) less scientific method. Recommended Broadside Stacking Distances for 2 Meter Band Yagis 82” or 2.08 meters Minimum --- 132” or 3.37 meters Maximum. I Recommend stacking 1.25 wavelengths apart i.e. 8 Feet 5.4 Inches or 101.4 Inches, or 2.6 meters apart at 144.15 Mhz. OR 8 feet, or 96 Inches, or 2.46 meters apart at 146 Mhz.

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How To Build A Stacking Harness

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http://www.bloomington.in.us/~wh2t/Stack.htm

information: VELOCITY FACTOR (VF) OF COMMON COAXIAL CABLES CABLE RG-8 LMR-400 RG-8X RG-11 RG-58 LMR-195 RG-59 RG-62 RG-174 RG-213 RG-214 RG-217 RG-218 RG-316 RG-400 LMR-500 LMR-600 1/2 HARD 7/8 HARD LDF all ver

VF .66 .85 .84 .75 .66 .83 .82 .84 .66 .66 .66 .66 .66 .79 .695 .85 .86 .81 .81 .88

Phasing Line Information, Stacked Antennas Antenna

Coax Type

Cut Length

Freq

6M5

LMR-400

105" x 2

50mHz

6M7

LMR-400

205" x 2

50mHz

6M2WLC

LMR-400

402" x 2

50.1mHz

6M2.5WLC LMR-400

402" x 2

50.1mHz

6M7JHV

LMR-400 305" x 2 (with M2 PD)

50mHz

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2M4

LMR-400

72" x 2

144mHz

2M7

LMR-400

106" x 2

144mHz

2M9SSB

LMR-400

144" x 2

144mHz

2M9FM

LMR-400

142" x 2

144mHz

2M12

LMR-400

178" x 2

144mHz

2M5WL

LMR-400

284" x 2 (H or V)

144mHz

2M18XXX

LMR-400

285" x 2

144mHz

2M8WL

LMR-400

385" x 2

144mHz

2MCP14

LMR-400

175" x 2

144mHz

2MCP22

LMR-400

214" x 2

144mHz

2MXP20

LMR-400

248" x 2

144mHz

2MXP28

LMR-400

360" x 2

144mHz

222-7EZ

LMR-400

48" x 2

222mHz

222-10EZ

LMR-400

115" x 2

222mHz

222-7WL

LMR-400

255" x 2 (H & V)

222mHz

222-5WL

LMR-400

210" x 2

222mHz

420-50-5HD LMR-400

34" x 2

432mHz

440-50-11

LMR-400

35" x 2

432 mHz

440-18

LMR-400

84" x 2 (H & V)

432 mHz

118" x 2

432 mHz

168" x 2 (H & V)

432 mHz

226" x (H & V)

432 mHz

LMR-400

163" x 2

432 mHz

436CP42UG LMR-400

176" x 2

432 mHz

440-21ATV LMR-400 432-9WL

LMR-400

432-13WLA LMR-400 436CP30

902-18EZ

LMR-400

32" x 2

902mHz

902-14WL

LMR-400

102" x 2

902mHz

23CM22EZ LMR-400

36" x 2

1296mHz

23CM35EZ LMR-400

80" x 2 (H & V)

1296mHz

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http://www.bloomington.in.us/~wh2t/Stack.htm

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24/02/07 4:09 PM