Delano presentation for the SFDXA - QSL.netDelano Transmitting Station Compound and Antenna Field...

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Voice Of America Delano, Calif.

Transcript of Delano presentation for the SFDXA - QSL.netDelano Transmitting Station Compound and Antenna Field...

Page 1: Delano presentation for the SFDXA - QSL.netDelano Transmitting Station Compound and Antenna Field December 1998 Total of 6 reversible Rhombics Low band dipole curtains High band dipole

Voice Of America

Delano, Calif.

Page 2: Delano presentation for the SFDXA - QSL.netDelano Transmitting Station Compound and Antenna Field December 1998 Total of 6 reversible Rhombics Low band dipole curtains High band dipole

VOA in Delano, CA

Between Visalia and Bakersfield, this 801 acre location houses

one of the last powerful HF international

broadcast stations.

Page 3: Delano presentation for the SFDXA - QSL.netDelano Transmitting Station Compound and Antenna Field December 1998 Total of 6 reversible Rhombics Low band dipole curtains High band dipole

View from Melcher Road

Dipole array towers Rhombic towers

Page 4: Delano presentation for the SFDXA - QSL.netDelano Transmitting Station Compound and Antenna Field December 1998 Total of 6 reversible Rhombics Low band dipole curtains High band dipole

Rhombic Antenna Towers

Page 5: Delano presentation for the SFDXA - QSL.netDelano Transmitting Station Compound and Antenna Field December 1998 Total of 6 reversible Rhombics Low band dipole curtains High band dipole

Dipole Array Towers

These are 406 ft ‘skyhooks’

Page 6: Delano presentation for the SFDXA - QSL.netDelano Transmitting Station Compound and Antenna Field December 1998 Total of 6 reversible Rhombics Low band dipole curtains High band dipole

Delano Transmitting StationCompound and Antenna FieldDecember 1998

Total of 6 reversible Rhombics

Low band dipole curtains

High band dipole curtains

VOA Delano, Calif.

Page 7: Delano presentation for the SFDXA - QSL.netDelano Transmitting Station Compound and Antenna Field December 1998 Total of 6 reversible Rhombics Low band dipole curtains High band dipole

Dipole Array Tower(Side View)

The precision design and workmanship were extraordinary.

Page 8: Delano presentation for the SFDXA - QSL.netDelano Transmitting Station Compound and Antenna Field December 1998 Total of 6 reversible Rhombics Low band dipole curtains High band dipole

Immense Footings

Can you imagine the forces exerted on each tower leg?’

Mark Carson painted the towers

Page 9: Delano presentation for the SFDXA - QSL.netDelano Transmitting Station Compound and Antenna Field December 1998 Total of 6 reversible Rhombics Low band dipole curtains High band dipole

Up close and ‘personal’

Notice the perfect, alternatingwhite and red painting detail

Page 10: Delano presentation for the SFDXA - QSL.netDelano Transmitting Station Compound and Antenna Field December 1998 Total of 6 reversible Rhombics Low band dipole curtains High band dipole

Part of the dipole arraysstrung between the towers

Multiple transmission linesallowed for azimuthal and elevation angle slewing.

Page 11: Delano presentation for the SFDXA - QSL.netDelano Transmitting Station Compound and Antenna Field December 1998 Total of 6 reversible Rhombics Low band dipole curtains High band dipole

Maintenance at 200’

Page 12: Delano presentation for the SFDXA - QSL.netDelano Transmitting Station Compound and Antenna Field December 1998 Total of 6 reversible Rhombics Low band dipole curtains High band dipole

Balanced, open-wire feedlines connectedthe antennas to the switch-bay on the right.

Each of the lines could handle 250 kW.

Page 13: Delano presentation for the SFDXA - QSL.netDelano Transmitting Station Compound and Antenna Field December 1998 Total of 6 reversible Rhombics Low band dipole curtains High band dipole

Precise tensioning resulted in this wire layout

This was built in the early 1940’sand is still functional

Page 14: Delano presentation for the SFDXA - QSL.netDelano Transmitting Station Compound and Antenna Field December 1998 Total of 6 reversible Rhombics Low band dipole curtains High band dipole

Tensioning weights

Each of the 13 plates probably weighs well over 100 lbs

Look how flat the terrain is!

Page 15: Delano presentation for the SFDXA - QSL.netDelano Transmitting Station Compound and Antenna Field December 1998 Total of 6 reversible Rhombics Low band dipole curtains High band dipole

HF Exciters

The 1 Megawatt transmitter had already been disassembled

Page 16: Delano presentation for the SFDXA - QSL.netDelano Transmitting Station Compound and Antenna Field December 1998 Total of 6 reversible Rhombics Low band dipole curtains High band dipole

Delano Transmitter/Operating Schedule

Page 17: Delano presentation for the SFDXA - QSL.netDelano Transmitting Station Compound and Antenna Field December 1998 Total of 6 reversible Rhombics Low band dipole curtains High band dipole

Several of the higher power amplifier tubes

Where does the power come from?

Page 18: Delano presentation for the SFDXA - QSL.netDelano Transmitting Station Compound and Antenna Field December 1998 Total of 6 reversible Rhombics Low band dipole curtains High band dipole

Forward and Reflected Power Meters

2 kW is considered a reasonable reflected power

Page 19: Delano presentation for the SFDXA - QSL.netDelano Transmitting Station Compound and Antenna Field December 1998 Total of 6 reversible Rhombics Low band dipole curtains High band dipole

Perfect for your new High Power 6m linear amplifier? They have probably all been thrown out by this time. They must have had 40 of these there.

JenningsVacuum

Variables25 – 650 pF

55 kV

Page 20: Delano presentation for the SFDXA - QSL.netDelano Transmitting Station Compound and Antenna Field December 1998 Total of 6 reversible Rhombics Low band dipole curtains High band dipole

Early View of VOA Control Room

Page 21: Delano presentation for the SFDXA - QSL.netDelano Transmitting Station Compound and Antenna Field December 1998 Total of 6 reversible Rhombics Low band dipole curtains High band dipole

2012 view of the control room after dismantling

Much of the Electronics

were in these cabinets

An IBM “386-x” controlled all antennas and transmitters

Page 22: Delano presentation for the SFDXA - QSL.netDelano Transmitting Station Compound and Antenna Field December 1998 Total of 6 reversible Rhombics Low band dipole curtains High band dipole

VOASatellite

InterconnectSystem

Delano connected by satellite the US, Indian and Pacific Ocean Regions

Page 23: Delano presentation for the SFDXA - QSL.netDelano Transmitting Station Compound and Antenna Field December 1998 Total of 6 reversible Rhombics Low band dipole curtains High band dipole

Satellite Interconnections

Washington, DC provided the programming for overseas broadcasts

Page 24: Delano presentation for the SFDXA - QSL.netDelano Transmitting Station Compound and Antenna Field December 1998 Total of 6 reversible Rhombics Low band dipole curtains High band dipole

LargestSatellite System at

VOA

That’s It Folks!

Questions?