Nostalgia & History > What's this 1940s radio antenna for? (no rail)

The two towers on either side of
the control tower -- the antenna is
strung between them, along with
the vertical antennas on each tower?

https://flickr.com/photos/skyhawkpc/8191321715/in/album-72157632008286563/

What sort of radio looks likely
for each antenna? The puzzle
is, I don't think towers like this
were usual at airports.



Edited 1 time(s). Last edit at 06/02/23 11:49 by timz.

From appearances, the wire between the towers is likely a variation of a shortwave (perhaps several MHz) dipole antenna for long distance communication via ionospheric hops.

Oliver Barrett

ShoreLineRoute Wrote:
-------------------------------------------------------
> From appearances, the wire between the towers is
> likely a variation of a shortwave (perhaps several
> MHz) dipole antenna for long distance
> communication via ionospheric hops.
>
> Oliver Barrett

Lost me there. I know nothing about the subject. However here is an example of directional transmission by an AM radio station.:

BambergersWOR1922 - Directional antenna - Wikipedia

Also notice the antenna on the plane. I think it's call an RDF antenna - Radio  Direction Finder. I am guessing that WWII new technology superseded what we are seeing here.

"Aimed at" means the antenna is perpendicular to
the line to what it's aimed at?

So more of a puzzle what it was doing at an airport.

timz Wrote:
-------------------------------------------------------
> "Aimed at" means the antenna is perpendicular to
> the line to what it's aimed at?
>
> So more of a puzzle what it was doing at an
> airport.

In the 1930s that would have been like a highway in the skies.

1930s radio ranges didn't use horizontal
wires as antennas, did they?

Wow-some fabulous milatary photos at that Flicker site.

Looks like a regular old Non Directional Radio Beacon to me. Radio beacons are what you're tracking when you're using your Automatic Direction Finder (ADF). This was "high tech" for the 1930's.

Some old tim-ey Aviation RF overviews here:

https://www.ed-thelen.org/TJohnson-LFRDF.html

> Looks like a regular old Non Directional Radio
> Beacon to me.

NDBs didn't need two towers, did they/

Wouldn't having two towers make it
non-non directional?

To me it looks like verticals on the towers are the right length for airband VHF (~120 MHz). The wire antennas in between are likely HF (high frequency) dipoles for longer distance commucation (beyond line of sight.) If you look closely, the insulators are in different positions, suggesting the antennas are tuned to different bands.

Paul Wilson
Arlington, VA

I can't say with certainty but to me it looks like "state of the art" air-ground radio communicatations facility, state of the art for the time period of the airliner. Things have changed over the years but it could well be the communications antenna for transmissions in use at the time.

As an example, I remember growing up in Cincinnati and hearing the police radio on 1705 Khz. Yes,  just above the AM broadcast band!  If I recall correctly that was one-way, transmitter to car, no two-way.

I'll leave anything more difinitive that my guess to someone who can be more conclusive.

DaleR

I finally got some free time to carefully examine the photograph. There is a wealth of interesting items to look at and enjoy perhaps 90 years in the future.

In carefully looking at the photograph, and "prepped" with the discussion above,two things that jump out at me is the paint on the airplane says Air Transfer Service and the caption says it's for SkyTrain service. Hmmmmmm....

Add to that, the comments above discussing air ground communications.

It got me to thinking about an article in Classic Trains, I believe, published 4 or 5 years ago of a post-depression era railroad and airplane cross country passenger service.

The passengers would be flown during the daylight hours to an airport near a train station on both carrier's routes and the passengers transferred to their assigned sleeping car accommodations. The passengers got a good night's rest while getting 500 miles closer to their destination versus spending a night in a hotel. Perhaps a full dining car dinner and breakfast were part of the package as well.

I think the article stated the price was exorbently high and the service only lasted a short time before a lack of customers caused them to shut down. The photo could easily be remnants of that service. Late 1930s perhaps?

Prior to that article in Classic Trains, I never knew such a service existed. It was faster than an airplane alone by 12 hours as they did not fly at night at the time and faster than a train alone by at least 48 hours.

Posted from Android

The DC-3 entered service in 1935-1936

Posted from Android

BRAtkinson Wrote:
-------------------------------------------------------
> I finally got some free time to carefully examine
> the photograph. There is a wealth of interesting
> items to look at and enjoy perhaps 90 years in the
> future.
>
> In carefully looking at the photograph, and
> "prepped" with the discussion above,two things
> that jump out at me is the paint on the airplane
> says Air Transfer Service and the caption says
> it's for SkyTrain service. Hmmmmmm....

In this case, the plane in question belongs to the Naval Air Transport Service. NATS was created right after Pearl Harbor was attacked.

The Douglas C-47 military version of the DC-3 was designated by the US Military as Skytrain. The name also included the DC- 3 naval version R4D variants.