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CoffmanStarter
19th Feb 2012, 09:48
Hi all ...

Just interested to know why some variants of the RAF Meteor and Vampire, sported what appear to be upper wing aerials configured with two perpendicular blade type antennas on both port and starboard wings (4 in total).

Here is a picture of a Meteor F8 showing the starboard configuration (2 yellow antennas visible).

http://i1004.photobucket.com/albums/af162/CoffmanStarter/2060163.jpg

On the face of it ... the length of each blade would suggest VHF operation and whilst the upper wing location would produce a good "ground plane", I would have thought at altitude airframe shielding would have hindered optimal propagation for Air/Ground purposes ... if the aerials were connected with Air/Ground Comms that is (following the logic of using Upper and Lower UHF aerials on some later aircraft).

Just curious ...

Kind regards ...

Coff.

spekesoftly
19th Feb 2012, 10:10
I believe they are aerials for Eureka / Rebecca (early homing and DME equipment).

BEagle
19th Feb 2012, 10:33
Correct - Rebecca antennae.

A rather primitive DME-only system that worked at around 220Mhz, although you turned 2 large bakelite knobs to set the correct channel - e.g. C 4 for Cranwell. At closer ranges (about 20nm) it could also provide L/R indications to enable DME let-downs to be flown. Many of us who trained in the 1970s used it in the Jet Provost and Hunter, although Valley Hunters had TACAN. A CRT display version was also fitted in the Varsity. Locations of ground Eureka stations was show on the en-route chart by a a white E on a small black circle.

Wittering had an NDB/DME let-down, but since the Rebecca interfered with the ADF in the Hunter, you were supposed to fly the NDB part first, then bravely switch to Rebecca when steady inbound, if I recall the quick brief I was given. I don't think anybody tried it though!

Fareastdriver
19th Feb 2012, 11:40
On the Vampire they were of an aerodynamic shape but mounted back to front; ie. the sharp end leading. Should you encounter the slightest chance of icing conditions the control stick would start shuddering. Looking along the top of the wing the ariels would just be a blur transmitting the vibration to the ailerons.

CoffmanStarter
19th Feb 2012, 12:33
Thanks Gents ...

Armed with your kind gen and my friend Dr Google ... I have turned up some interesting references on the interweb for Eureka & Rebecca ... so I thought I'd share. See pics on the following URL's ... just love the Rebecca MKIV installation in the Varsity ... real steam driven technology !

Duxford Radio Society: Rebecca & Eureka History (http://www.duxfordradiosociety.org/equiphist/reb-eureka/reb-eureka-hist.html)

Historic Eureka/Rebecca Equipment (http://www.qsl.net/pe1ngz/airforce/airforce-raf/raf-eureka-rebecca.html)

Kind regards ...

Coff.

Pontius Navigator
19th Feb 2012, 14:15
Only one of the pair is the aerial. The other is the director that gathers the signal and helps the polar diagram for a crude direction capability or reflector. The aerial itself is a quarter-wave unipole, ie half a dipole.

Pontius Navigator
19th Feb 2012, 15:30
In about 1971 at Akrotiri we met a young TA officer (I think he was TA) from the Independent Parachute Company, Parachute Regiment. Their role was to jump in advance and mark the main force DZ. His particular role was to jump with a portable Eureka beacon so that the C130s could home in on the DZ.

The 70 Sqn C130 was fitted with a Rebecca so that it could use the Eureka.

IIRC he said his kit weighed 90lbs including the batteries and he thought it was the bees knees. We then showed him the Sarbe which weighed rather less :). The difference of course is that the sabre would guide the aircraft directly to the DZ whereas the Rebecca directional assistance was much cruder.

oxenos
19th Feb 2012, 15:40
One type of a/c ( JP ? ) had the aerials mounted below the fuselage. After an incident in which someone forgot his undercarriage and manage to climb away after hearing the scraping of the aerials on the runway, Wg.Cdr. Spry in Air Clues made some pointed remarks about DISTANCE MEASURING EQUIPMENT.

ACW418
19th Feb 2012, 16:20
In 1964 at Linton a RN Midshipman was night solo and his U/C had self retracted on approach (a common problem due to a mod to the U/C button detent springs which was rubbish) and rounded out but felt he was dropping too low so applied power and managed to overshoot. He bent the DME aerials but no other damage.
I can't remember what happened to him but I know of one instructor who was blamed for his U/C retracting until they discovered the detent spring mod was no good.
We in the RAF doing Advanced Flying Training on the Vampire thought it all very amusing since we had flown the JP with the old detent springs which worked even if the up button nearly broke your finger when you tried to retract the U/C.

ACW