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Canasoppa
08-19-2005, 08:12 AM
Hello..

Exaple picture found from A.Net (http://www.airliners.net/open.file/903572/M)

Anyone can tell me what is the purpose for the wire between rudder and that thing behind cockpit? You can find similar wires from many planes.. http://forums.ubi.com/groupee_common/emoticons/icon_confused.gif

Or is it just a decoration?


Edit: Or is it for radio? (antenna)

EiZ0N
08-19-2005, 08:19 AM
Always assumed it was the radio

Tex-Hill-AVG
08-19-2005, 08:25 AM
Radio antenna to be more exact.

bogusheadbox
08-19-2005, 09:04 AM
Originally posted by Tex-Hill-AVG:
Radio antenna to be more exact.

Correct.

Also used as a cloathes line while on the deck

stansdds
08-19-2005, 11:51 AM
Before the days of VHF and UHF, radios required long antennas in order to have good broadcasting and reception at great distances, so the actual antenna is a wire stretched usually from the tail to the cockpit, sometimes to a point ahead of the cockpit. VHF and UHF just don't need big antennas. Kind of like AM radio vs. FM radio. AM required an external antenna for good reception and the signal is easily blocked by concrete and steel, that's why the signal fades when you pass beneath a bridge. FM requires virtually no antenna and the signal is much harder to block.

jarink
08-19-2005, 01:30 PM
Many heavy US bombers even had trailing-wire antennas for better long-range reception. VHF/UHF may require smaller antennas, but HF is less dependent on line-of-sight and has a huge range advantage. Many HF signals can be bounced off the atmosphere, futher increasing range. That's how ham operators can talk to people halfway around the world. The US Army still used
HF for some comms until the mid-80s (replacing it mainly with satellite links).

Here's the antenna reel in a B-17G just aft of the ball turet:
http://www.flightjournal.com/FJ/images/plane_profiles/b17g/37.jpg

Tex-Hill-AVG
08-19-2005, 04:40 PM
The US Army still used
HF for some comms until the mid-80s (replacing it mainly with satellite links).


More like early 90's. My unit used PRC-77's until '93. The weaknesses of these types of radios include security of the broadcast and the ability of the enemy to triangulate your position.

Today's systems (you can't call them radio's since they don't use radio frequencies anymore), are a lot more secure in these areas.

In real life, the ability to triangulate the position of a radio transmission is the reason why units practiced radio silence. Hollywood makes you think that radio silence was observed to keep the enemy from listening to your broadcasts.

Waldo.Pepper
08-19-2005, 08:53 PM
Hollywood makes you think that radio silence was observed to keep the enemy from listening to your broadcasts.

Largely I agree. But listening into the enemy radio broadcasts was an excellent way of gathering intelligence.

During the North African campaing a signifigant portion of Rommel's success can be attributed to lax radoi security by the British/Commonwealth forces.

Also during the night bomber campaign Bomber Command would often spoof the Luftwaffe night fighters and redirected them away from the bomber stream.

Radio security is always a good idea IMHO.

jarink
08-20-2005, 12:39 AM
I used to do radio intercept for about 8 1/2 of my 11 years in the Army.

VHF/UHF is much easier to DF than HF. Tighter waves, usually higher power, too.

The PRC-77 is VHF. The HF stuff I recall was mainly for Brigade and higher comms, since range was important. Generally speaking, military VHF runs from around 25-120 MHz. HF is 5-25, UHF is 120 to 300-ish. Newer radios like SINCGARS still transmit RF, but the use frequency hopping (several times a second) and spread spectrum transmitters to make intercept much more difficult. Other comms like MSE uses even higher frequencies, very similar to a cell phone system.

I can definitely say from real-world experiaence that listening to enemy comms is an excellent source of info. However, DF (Direction Finding - triangulation) and some good traffic analysis can produce some excellent targets for artillery and air. That's mainly what we did in Iraq in '91 since we had only 2 Arab linguists per 6-man team (and they were Kuwaiti nationals given a quick 2 week Basic Training). All the rest of us were Russian linguists... http://forums.ubi.com/images/smilies/blink.gif

Here's a pic of the good 'ol Turkey 32, like what I served on:
http://wwwbobbythomas.homestead.com/files/trq32.jpg
It was a very good system for using mainly off-the shelf parts. The best things about it were 1) fully enclosed cab 2) 120AC power 3) air pump for the antenna mast was also good for blowing up footballs and volleyballs 4) Could pick up TV, radio stations and some cordless phones (20-500 MHz reception). During Desert Shield, we could even eavesdrop on satellite phone conversations. Several people got in trouble for COMSEC (communications security) violations while we were doing that. http://forums.ubi.com/groupee_common/emoticons/icon_eek.gif