I am interested in antennas for the hf-range lying on the ground, digged into the ground or placed a very short distance above the ground. ANY information is welcome: Manuals, plans and descriptions and experiences...

If you are interested in this topic, you might like to also do some digging about the use of trees as antennas. It is a long while since I have read anything on this but I am sure a search of the internet will throw up something.

Anyone heard of the 'Snake' antenna, 34mtrs of co-ax with suitable plug on one end then at the far end the inner core & screen are s/c together but one mtr back slice 1cm of the outer sheath & braid completely out. Then just snake along the available ground.
The story has it that this was used in the desert as it couldn't be seen from the air & it was very difficult to get a d/f fix on it. Havn't got round to trying it out but it could be a 'wind-up' I suppose.

Hi,
unfortunately you [I]not [/I]specified the operating frequency of the snake antenna you discribed.
For understanding the principle of operation this knowledge is mandatory. Was it really used in the HF range ? :unsure:
If it was enployed for HF what was the intention? Long range contacts or local communication ?

Greetings,

Edwin14

As a ham I can share a few bits of knowledge on these types of antennas. A BEVERAGE antenna is a kind of longwire (typically 2-wavelengths or greater) that is mounted 10 to 15 feet above ground and terminated with a 500-ohm resistance. A DDRR (Directional Discontinuity Ring Radiator) antenna is a open-ended mounted flatly or parallel to the ground about 1 to 2 feet for the HF range. In some parts of the country where the grond conductivity is good enough, it is possible to use rods driven into the ground and use the underlying water table as a means of propagation .

I progam HF antennas in QBASIC and have the DDRR if you would like it. I can email it if you wish.

Kevin (N9XV)

well as far as i know there is one specific type of antenna the britts use with clansman kit called a ground spike antenna. a 6 - 8 inch spike goes into the ground (works best when wet) and then there is a modual box thinngy which the lead from the radio links into and you can screw in anything up to 3m of screw together antenna into the top. obveously the less you insert the more covert the antena becomes but ramming a metal rod into the ground and then putting the ground spike in contact with it increases the flow through the ground.

Antennas on the (or close to the) ground would depend on the type of antenna you are planning to build, the easiest type of Ae to do this with is a dipole. when lowered, the nearer to the ground it becomes the shorter the range. it is called NVIS (near vertical induced skywave) and is commonly used in the british army.
also if you are using a brityish hf military manpack, then 8 metres of copperwire or braid will work almost everytime and at any frequency when layed on the ground.

The frequency range concerning tactical antennas placed on the ground surface or a short distance below the surface is the classic HF rage (2-30MHz or 1.6-30MHz). The gain was about -20dB.

Of course there are VLF-applications (thinkable) that (may) use this structures with a bigger radiation efficiency than in the HF-range but the intention of subsurface antennas was camouflage and hardening. The VLF-sites are commonly well known, so camouflage is not the intention there, perhaps relyability (weather: ice, storm, etc.) and less service effort are the reason for subsurface antennas there.

The forces of the former german democratic republic had such antennas in the HF-range and there are still such antenna sites in the RUS (former USSR). Some of these antennas seemed like shortened fishbone antennas. I saw a picture of one site taken from a airplane when all wires were torn out of the soil. There were noticeable trenches left where the wire has been torn out...

Antennas swimming on the waters surface (for transmission in the HF-range) or just some meters below (for receiving only) were tested by the german forces in WWII. The topic is about the same.

Is there anyone out there who can supply some literature, even russian or chinese or whatever else? :rolleyes:

73

while in military signal with PRC-77 and VRC-46 I taught field expendent antennas we often use a long wire with resister at end worked well and another was just to point a long wire (at least 5 x wave lenght) in the direction you want to talk it seems to have gain and I heard from special ops guys that they had used much the same but had buried it?? never had energy to try that
useing a 77 once I could only talk about 6 miles and was trying to show if you broke you ant you could use most anything when in need we hooked up one end of a barb wire fence that broken up but about 100 yards was still on wood posts we were able to talk to base about 11 miles away it worked better if the radio was grounded not sure of theory of all this but it worked