What is a Harp Antenna?

[PutPut]

My next project is a Berliner Joyce OJ-2 scout, both land and sea versions. Paul Matts drawings show what is called a Harp Antenna strung between the wings two places on one side of the plane. See the picture below. Easy to see why it's called a Harp Antenna, it looks like two sets of harp strings. I cannot find out how this was used as my Google efforts all point to an arrray used in the Artic during the cold war. Does anyone have a reference to this thing? Inquiring minds want to know. :isadizzy:

Best, Paul

View attachment 70544

 

[Ickie]

I use to be a ham operator and i'll take a stab at this,
back in the early radio days the only freq's were real long wave and the antenna's were really long too, "freq divided by 468= length in meters" so my guess is they just folded them into a "harp" to get them under the wings.

 

[PutPut]

Hi, Ickie, Makes sense to me. I really can't find out much about it; Google and Bing keep wanting me to look at Haarp antennas which had nothing to do with Naval Aviation. I am assuming it was used for some kind of plane to base or plane to ship communications.

Thanks, Paul

 

[Ickie]

it works like the twin or duel trucker antenna's, each string is measured like maybe 1/32 of a wave length, it musta been hell matching them strings up to the 1.5 SWR readings, lol

 

[TeaSea]

This would be a "modern" version (TAK-Tenna HF for small areas), but it's essentially a dipole (doublet) 1/2 wave . I think Ickie's correct in that you're just looking at an HF Antenna configured to something less than 1/4 wave. You might not have the most efficient HF antenna, but might get back on the LOS side with the A/C altitude....so maybe not all that important.

The OJ-2 was used by the Navy for testing the concept of Instrument landings, and their first tests involved HF radio systems. You know Ickie, since these are crystal radios, I bet you could physically match the antenna prior to take off. Your freqs were more or less set....don't know though.

 

[Ickie]

i have looked myself on google and nothing references a harp antenna on airplanes.
here is an interesting web page
http://www.qsl.net/aa0ni/antennafaq.html

 

[An-225]

Google and Bing keep wanting me to look at Haarp antennas which had nothing to do with Naval Aviation. I am assuming it was used for some kind of plane to base or plane to ship communications.

HAARP is capable of generating ELF and VLF waves, and its strategic location up there in Alaska suggests it could be used to communicate with submerged SSBNs in the Bering Strait. I don't know how this is done normally, it certainly isn't with the trailing ELF antenna on the E-4B. More interesting, however, is official EU Parliament literature on HAARP...

 

[TuFun]

The only thing I could find, that may explain the unusual array for this type of aircraft...

Lieutenant Frank Akers made a hooded landing in an OJ-2 at College Park, Maryland, in the first demonstration of the blind landing system intended for carrier use and under development by the Washington Institute of Technology. May 1934

In 1931, Lieutenant Frank Akers, was a student of electronics at the Postgraduate School in Annapolis, Maryland. He continued studying at Harvard Graduate School in Cambridge, Massachusetts. It was here that he received his Master of Science Degree in Electronic Communications in 1933.


As Flight Test Officer and Project Officer for Instrument Flying Development at the Naval Air Station in San Diego, California, Lieutenant Akers participated in an unusually hazardous experiment on July 30, 1935. He was told that the nation's first aircraft carrier, the USS Langley, was somewhere at sea approximately 150 miles away. It was his job to locate the carrier and land aboard it using only instruments. The aircraft was fitted with a special hood preventing visual contact with the outside world. He chalked up another Navy "first" when the plane touched down on the carrier deck and caught the Number 4 arresting wire. This was a feat that earned him the distinguished Flying Cross.


Landing a plane on a carrier, blind in 1935... wow!

 

[Ickie]

HAARP is something all together different.

 

[Ickie]

after looking at this, and if the hight of these and the width between them is the same it would be a matched antenna system.