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Bright Star: 1929

Bright Star: 1929

Washington, D.C., circa 1929. "No caption [radio set]." Experts please opine! Harris & Ewing Collection glass negative. View full size.


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The electronics are completely portable but the overhead structure is permanent. Steel supports penetrate floor and overhead platform. Unlikely to be radiotelescope or radar, particularly since it is indoors.

The factory-style construction (heavy wood floors were standard back then) says production facility. The bomb says aircraft hangar.

The overhead structure appears to be a platform for extensive outrigging and repair of aircraft.

The sheet-metal enclosure may be a recent construction. Note the tin-snips and sheet metal in the lower right. Its shape matters, because it had to curve past the supporting structure rather than attaching to it.

It resembles the profile of the aircraft above, if stood vertically.

The seismograph-looking spool is an old-time tuner.

That may be a small magneto or alternator on the bench, just to the right of the operator.

The whole setup operates on vehicular power sources to replicate the conditions being investigated.

This is probably a test rig for developing solutions to engine interference with radio communications.

It may have been chosen because the overhead structure simulates wings.

The big battery array is probably charging capacitors inside the chamber, where they spark like spark plugs.

Just another step up the ladder of technology

No expert, here, but it looks like a super-heterodyne receiver. Before shortwave, most radio only covered 2 or 300 miles, you needed a really powerful receiver beyond that range.

Experimental battery charging?

This photo possibly has no connection to the airplane photo.

The upper tray of cells consists of 6 banks of 24 cells. The nearest cell in each tray is obscured by the vertical board. The lower tray of cells appears to be identical. The two sets of 6 knife switches appear to be in the disconnected position (both batteries disconnected from any load).

At about 2.2 volts/cell, each bank would produce about 48-53 volts, depending on state of charge. That happens to be the voltage historically used at central telephone exchanges.

Possibly this is a telephone company experiment that is investigating solar cell charging of batteries. Various types of solar cells may be mounted on the top of the wooden structure, facing the sun.

Various loading devices to discharge the batteries, such as resistors (lower left), rheostat (large wirewound resistor with sliding contact), radio or intercomm devices in wooden boxes, and what appears to be a dial tone generator (the motor-like device), would all serve to discharge one battery while the other was being charged.

The photovoltaic effect was known at the time of this picture, and experiments with cadmium-selenium photocells were being conducted. Telephone companies would have had a real interest in this method of charging, for remote sites not served by electric lines.

This writer was a telephone company technician 1968-84.


I believe that this may have been a government sponsored experiment. Radio was still quite new and government and military were trying to see what they could do with the relatively new technology.

[Radio, which got its start with wireless telegraphy, has been around since the 1890s. -Dave]

Radar? ILS? Meteo?

The airplane in the other picture looks like a Ryan. I have no idea if the military used it at any time. It looks mostly unremarkable except for the device it has hanging under it. Looks like a bomb but I'm guessing is a speed meter of some kind. You can see the reel of cable right down the seat. And there's an instrument panel a little too complicated for that plane.

The equipment could be some kind of transmitter. The huge array seems to be of capacitors. The kind of stuff you'd be needing at that time to work a high frequency transmitter. Radar was a known concept at that time and many prototypes existed. None of real practical use. It wasn't until WWII that that first high frequency valve tubes were manufactured in ranges usable for practical detection.

This could be an early prototype of radar or a transmitter of a landing assistance system or part of a meteorological system.

I'd say it's a military installation based on the bomb that can be seen in the back.

Possibly related

Next-door neighbor to this image in the Harris & Ewing archive.

Not Radar

Others have spectulated that this is a radar setup. But if the photo date is correct its very unlikely that this setup has anything to do with radar. Radar (Radio Detection and Ranging) wasn't developed until the late 1930s. My father was a Chief Signalman in the Navy at the time and was one of the first to be trained in use and repair, in England. The gizmo wasn't yet in the US, and if it was it would have been secret, one supposes.

Early radio telescope?

Looks like some sort of receiving apparatus, but no obvious loudspeakers or headsets are in evidence. It may be an early radio telescope. It seems to me that Jansky and others were investigating signals of this sort about this time. One of the closed boxes could easily be some sort of pen recorder.

iPod nano?

The prototype of the iPod nano was not as small or elegant as Steve had hoped for.

Curious about stuff on the table

That stuff beyond the operator is intriguing. A large variable resistor or coil, some motor-like things, a large vertical frame, and those three wooden boxes.

It is most likely an audio setup as others have surmised. The big wooden box looks like a power amplifier with many power output tubes visible inside.

Public Address?

The floor is obviously an interior floor and the raw brick walls make it seem like a utility room. I don't understand what the sheet metal island with the angle framing is but I can't help but think that this might be the PA system at the top of the Capitol for Hoover's inauguration? Must search more.


The odd wall and roof angles appear to be some form of receiving antenna. Sitting in the background, to ensure proper calibration, is the tuning bomb.


Where are the speakers or ear phones? Am not sure this is a radio. Could be an early form of radar or even some type of device for transmitting or strengthening radio signals.

More batteries

The Bright Star "Radio Battery" is likely a C supply, for the tube grids' biasing; very low current, so a long life expected with dry cells.

On the other hand, the huge array of cells remarked upon by khparker looks like rechargeable (probably lead-acid) cells and would provide ~300 Volts per tray, if all banks were switched in series.

Then there's the rig on the floor, beside the 6 Volt A battery; looks like a "dummy load" bank using light bulbs, for tuning up the transmitter.


I'm not sure its a radio. There really aren't any tuning circuits in the picture.

It may simply be an audio amplifier (PA System) for a stadium.

If I were to guess

A large, sloped surface, apparently on a rooftop or at the least an upper floor of a building, with radio equipment hooked up to it, makes me guess that this is possibly some sort of radar array, or something very similar.


Don't know nothin' 'bout no radios.... but sure would like to have that nice cabinet he's twiddling dials on. Looks like nice dense old growth oak.


The Philco battery next to the guy's left shoe is presumbly for the filaments. It's a 6-volt battery (3 x lead-acid cells.)

The large battery on the table to the left is for the plate voltage. Lots of glass-jar cells in series. Looks like 144 cells on each shelf, but with the individual wire bundles coming off each pair of rows, and the knife-switch array at the front, it probably could have delivered quite an assortment of voltages with different selected serial/parallel arrangements.

Philadelphia Storage Battery Company

Finally a Philco battery makes its Shorpy debut. It's right next to the guy's left shoe.

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