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The National Library of Israel has just released 100 images about Operation Horev.

Two images show a jeep that holds a sort of cable attached to a balloon or something, or maybe it is just a very straight fixed antenna?

What is this long cable and what is its purpose?

enter image description here

Another view of a possibly different car: https://commons.wikimedia.org/wiki/File:The_National_Library_of_Israel,_Nadav_Man_-_Bitmuna_Collection,_Operation_Horev_Golany-002.jpg

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I think the 2nd and the one you've shown are different. This here might be antenna support (the mast is placed behind the photographer on a tank or other vehicle). This is because it possibly was not able to hold it to the ground. The 2nd one can be antenna of a movable radio. But these are only my assumptions. –  Voitcus Sep 9 '13 at 9:23
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you can't even see where the cable in that photo ends. To my eye it seems to never intersect with the vehicle at all, so it's more likely indeed a mast anchor that ends at something driven into the ground behind the jeep. The second is just a whip antenna. –  jwenting Sep 9 '13 at 11:00
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2 Answers

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As jwenting and Voitcus have suggested in the comments, this cable is not attached to the jeep, so the other picture of the jeep you referred to is not relevant.

See below, a magnified and enhanced image of the critical section of this photo, which appears to show clearly that the cable in question runs behind the shoulder of the soldier on the left side of the jeep. Based on the cable's trajectory in the picture, juxtaposed with the position of the jeep, its point of fixture appears of necessity to be in the ground behind the jeep, near its left hand rear side.

The faint line that appears to show that the cable runs in front of the soldier's shoulder is in fact the shadow of the pennant mounted on the front of jeep, cast by the sun shining from the upper right hand side of the picture, as is visible in the original picture: Note shadow of the jeep's rear right corner, and the shadow of the beard of the soldier on the right, veering off to the rear left of the picture, proving that the sun was shining from the upper right, and also creating the shadow of the pennant, which is cast on exactly the same point where in the image, the cable intersects with the soldier's shoulder. (The shadows are quite shallow and the sunlight on the soldiers appears to be quite direct, so the picture was probably taken near noon time.)

shoulder-cable-jeep

In addition, the cable in question, although very long, is apparently quite taut, showing no sagging or bending - indicating that is it is secured somewhere further up towards the upper right, outside the scope of the picture. If it was a long, extended whip antenna,for a radio possibly mounted on the far left rear of the jeep, it would be mounted vertically and be shorter, as in the other picture (that orientation aids propagation of the RF) And, it would usually sag and droop when extended to such a length and angle.

Also, it has neither the correct angle nor the correct structure for a ground mounted antenna, which would be vertical, not angled, and normally thicker. The other candidate would be a wire antenna used for a dipole antenna, but they are generally strung horizontally and held by non conductive vertical supports.

Since that cable is fixed, fairly thick and taut, the most likely candidate is that's it's a guy-wire supporting an antenna or observation tower of some sort. I don't know how thick a cable to hold a balloon needs to be, but I did some research and didn't find anywhere that balloons were used in Operation Horev.

See All about Vertical Antennas, one of numerous sources: Wire and vertical antennas are very popular with amateur radio operators and the HF frequencies used by hams were the most commonly used then for military operations, (as they were in WW2) before modern technology allowed military operations to switch to VHF and UHF, which can do with much more compact, portable and easier to manage hardware. See Radio-Communications Theory:

High-frequency (HF) communication was first made practical in the 1920's when the first actual radio system was installed in Europe. The desire to go to higher frequencies was caused by the need for longer range, higher capacity circuits. Until HF came about, transatlantic communication was by cable or mail. World War II had a profound impact on the use of the radio-frequency spectrum. Military leaders realized higher capacity communications were needed. Naturally, the solution was to go to even higher frequency bands. During the early part of the war, a system called radar was developed. The development of components and equipment to operate at the higher radar frequencies led to the development of higher frequency radio systems.

Here is picture of an HF vertical "antenna farm": Note structure of the antennas and the supporting guy wires.

enter image description here

Contrast with a simple HF dipole - note the horizontal orientation and plastic insulator: enter image description here

Problems with this analysis:


  • Based on the image, the guy wire would have been anchored very close to the shore, in unstable, water-logged gravel and sand: Not a good place for an anchor. This might be a serious problem for my answer, although perhaps there is some boulder or rocky structure along the shoreline, its view obstructed by the jeep, that was suitable for an anchor.

  • Now that Pradeep's answer has been posted, perhaps there is another problem: The second picture in that answer shows a very similar looking long, rigid antenna, mounted on the right side, very close to the rear of the jeep, pointed at about a 60 degree angle. The object in our picture might be a similar sort antenna mounted on the rear left side. The trajectory of the cable in question would likely support this. As for antenna design theory, in combat situations, ad-hoc implementations were often used even if they were less than optimal in terms of RF engineering. The important thing was that it got the required job done, and was amenable to mobile combat use.

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Using a long enough metal pole you can drive it through the layer of gravel and into the dense packed sand on the shoreline easily. As this picture seems to show a lake (maybe the dead sea) where there are of course no tides, there's no risk of the place flooding. Anywhere much further inland from the shore would possibly have been too rocky for easy erection of the installation. –  jwenting Sep 12 '13 at 8:50
    
Great analysis! Indeed it can't be an antenna itself, and your guy wire theory is most probably true. But zero chance that the guy wire is attached to the left-back of the jeep, behind the soldier? It seems to be a special jeep, that does not move often: They even wrote city distances on the front of the vehicle. –  nic Sep 12 '13 at 9:59
    
@NicolasRaoul - See edit re second answer, second picture. –  comeAndGo Sep 12 '13 at 15:28
    
jwenting - I thought of that - drilling down. Not sure how all the troops moved during that operation but it sure does look like the Dead Sead, and if so, without tides, perhaps there was some solid ground not far below the surface - I edited in light of your comment. If it the was Mediterranean and they were driving south/southwest the sea would be on their right side, not their left. Note also the bleak looking hills on the far shore - on the Mediterranean coast there are no such hills. If so tides would not be an issue. – Vector 1 hour ago –  comeAndGo Sep 12 '13 at 16:21
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I just went through information regarding war jeeps which will have radio communication equipment. I found some interesting points which might help.

  1. If the jeep is equipped with radio communication then it would look something like this in the picture.Modern jeep with antennas In this image we see a wire holding the antenna which looks something similar to Operation Herov image.
  2. To support 1st photo I have included the 2nd photo from old war which also has that long antenna with communication device. Radios and Telephone on Jeep

I found several photos from Operation Horev where we can see this long antenna but not a clear image as they are small and blurred. But I think I am not wrong with the information which I have given ! (One more thing is, there are some war jeeps having flags tied to this kind of long cable.)

Operation Horev is the documentary of the war which might give some clue to this mystery.

This collection of images from The National Library shows many such vehicles with antenna.

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The first image is modern in every respect, including the antenna design itself, so it's not too relevant. But the second image is great - calls into question my answer - in OP's picture, the object in question could have been an antenna mounted on the rear left fender. –  comeAndGo Sep 12 '13 at 15:10
    
@Vector- I appreciate your answer. It helped me. Yeah you are right about the 1st image. I added it just to show how the antenna is held using the 'guy wire'. The second image shows how long an antenna could be. Also I noticed at the base of the antenna some strong "spring base" has been used. Spring base antenna this will help. –  Pradeep Sep 12 '13 at 19:03
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:A spring mount is used in mobile applications or other situations where an extended antenna might be subject to stress that would snap it: Overhanging branches, overpasses, strong winds, etc. They used to be common on military and emergency vehicles-police cars, etc, when the radios used HF (requires a long antenna like on those jeeps). Today with VHF/UHF you don't need such long antennas (consider your cell phone). So you see don't spring mounts often-usually just for ham or CB, which still use HF. (I am a licensed ham operator, do a lot of HF work, so I know about this stuff. :-) –  comeAndGo Sep 12 '13 at 19:26
    
Your information is really helpful. Technical matter make things more clear. –  Pradeep Sep 12 '13 at 20:38
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mind that the antenna on that jeep is not mounted on the fender or wheel arch, but bolted to the side of the body of the vehicle. The stresses on wheel arch or fender would be too great. Also note it's pointed back to allow it to flow under obstructions without snagging. –  jwenting Sep 13 '13 at 5:24
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