Author Topic: The Joan-Eleanor antenna, Was it directive?  (Read 1915 times)

Offline Greekman

  • Survival Demonstrator
  • *******
  • Posts: 4050
  • Karma: 207
  • New TSP Forum member
The Joan-Eleanor antenna, Was it directive?
« on: August 03, 2015, 03:18:58 AM »
I saw this antenna on a wWII documentary.
The downside transeiver had a T-shaped folding antenna.
Was it directive? Or just a dipole?
Any contemporary equivalents?

references
http://www.militaryradio.com/spyradio/joaneleanor.html
http://militaryradio.com/spyradio/joan_ant_patent.jpg
http://www.freepatentsonline.com/2587146.pdf

Offline Carl

  • Mr HamTastic!
  • Forum Veteran
  • *********
  • Posts: 13105
  • Karma: 715
  • COW?...No ,I haven't seen your cow.
Re: The Joan-Eleanor antenna, Was it directive?
« Reply #1 on: August 03, 2015, 07:02:53 AM »
It was a dipole and with the "mud flat" reflector would have about 3 DB gain toward the sky
for it was a ground unit to talk to aircraft from the ground in the UHF band that the Germans
had little or none  receivers to listen to that frequency.

Compare it to a NVIS dipole with a reflector wire on the ground or the driven element of a yagi
without all of the director elements that produce directionality and gain.

If UP is a direction...I guess you could call it a directional antenna .

Offline Greekman

  • Survival Demonstrator
  • *******
  • Posts: 4050
  • Karma: 207
  • New TSP Forum member
Re: The Joan-Eleanor antenna, Was it directive?
« Reply #2 on: August 03, 2015, 07:14:02 AM »
thanks...I expected more, it being directional to talk to aircraft comign from a particular direction.
But I guess the aircraft were much better suited in receiving and transmitting.

BTW, forgot to include the footage
https://www.youtube.com/watch?feature=player_detailpage&v=WvCUpL7b2o8#t=2647

Offline Carl

  • Mr HamTastic!
  • Forum Veteran
  • *********
  • Posts: 13105
  • Karma: 715
  • COW?...No ,I haven't seen your cow.
Re: The Joan-Eleanor antenna, Was it directive?
« Reply #3 on: August 03, 2015, 07:35:29 AM »
thanks...I expected more, it being directional to talk to aircraft comign from a particular direction.
But I guess the aircraft were much better suited in receiving and transmitting.

BTW, forgot to include the footage
https://www.youtube.com/watch?feature=player_detailpage&v=WvCUpL7b2o8#t=2647

Excellent video ...you should post it in the VIDEOs thread . The Eleanor Joan was directional...but only 3 DB BUT
3 DB is double the non direction signal and these were SPY RADIOs of the day when a field radio needed a
deuce and a half truck and a trailer/generator with a 4 man crew to operate and support the equipment.

Here is another good video of the radio in use.

https://www.youtube.com/watch?v=ycCxRPWPidc