UK Vintage Radio Repair and Restoration Powered By Google Custom Search Vintage Radio and TV Service Data

Go Back   UK Vintage Radio Repair and Restoration Discussion Forum > Specific Vintage Equipment > Vintage Amateur and Military Radio

Notices

Vintage Amateur and Military Radio Amateur/military receivers and transmitters, morse, and any other related vintage comms equipment.

Closed Thread
 
Thread Tools
Old 29th Mar 2015, 9:14 pm   #21
majoconz
Heptode
 
majoconz's Avatar
 
Join Date: Jan 2008
Location: Ashhurst, Manawatu, New Zealand
Posts: 570
Default Re: Aircraft Main Antenna - Quick Question

Quote:
The tighter the antenna wire the less it would flap but the thicker it would need to be. While in straight and level flight the wire is hit 'head-on' however any turns or dives would subject the wire to sideways forces.
Regardless of any of the antics of a reasonably large non-aerobatic aircraft, forward airspeed must always be maintained. Any turning forces on the antenna would by mimimal compared to the force exerted by just flying straight and level. Co-ordinated turns (banking - aileron and rudder movement together to keep your C of G straight down through your seat!) should negate any side thrust on the antenna.

The antenna is kept tight by the in-line tensioner - a spring under compression - between the insulator and the tail mounting. You can see one in the Dayton-Grainger advert with a 30lb spring.
__________________
Cheers - Martin ZL2MC
majoconz is offline  
Old 30th Mar 2015, 9:48 am   #22
GMB
Dekatron
 
GMB's Avatar
 
Join Date: Aug 2003
Location: near Reading (and sometimes Torquay)
Posts: 3,086
Default Re: Aircraft Main Antenna - Quick Question

I think the main issue with wires like this is oscillation and resonance (not RF but mechanical!).

The wire needs to be the right stiffness and in the right tension to not vibrate itself to failure. The problem with a cylinder in a flowing fluid is that vortex shedding constantly "plucks" the wire to keep it vibrating.
GMB is offline  
Old 30th Mar 2015, 8:10 pm   #23
Ed_Dinning
Dekatron
 
Join Date: Jan 2004
Location: Newcastle upon Tyne, Tyne & Wear, UK.
Posts: 8,173
Default Re: Aircraft Main Antenna - Quick Question

Hi James, have you had a look at the stuff that Birkett's of Lincoln have?
Worth a mail to him in case he has an actual antenna; better still to have a visit and see the stuff in the flesh.

Ed
Ed_Dinning is offline  
Old 4th Apr 2015, 7:07 pm   #24
jamesinnewcastl
Heptode
 
jamesinnewcastl's Avatar
 
Join Date: Jul 2009
Location: Newcastle upon Tyne, Tyne & Wear, UK.
Posts: 722
Default Re: Aircraft Main Antenna - Quick Question

Hi Ed

I came across his shop quite accidentally once when visiting Lincoln some years ago - it was shut but that seems to be not unusual! Lots of desirable goodies!

Does he 'do' email?

James
jamesinnewcastl is offline  
Old 4th Apr 2015, 7:49 pm   #25
Ed_Dinning
Dekatron
 
Join Date: Jan 2004
Location: Newcastle upon Tyne, Tyne & Wear, UK.
Posts: 8,173
Default Re: Aircraft Main Antenna - Quick Question

Hi James, I think he has an E-address and will normally respond within a day or so, but nothing to beat a visit and browse.

Ed
Ed_Dinning is offline  
Old 4th Apr 2015, 8:41 pm   #26
Radio Wrangler
Moderator
 
Radio Wrangler's Avatar
 
Join Date: Mar 2012
Location: Fife, Scotland, UK.
Posts: 22,801
Default Re: Aircraft Main Antenna - Quick Question

John is probably best phoned.

David
__________________
Can't afford the volcanic island yet, but the plans for my monorail and the goons' uniforms are done
Radio Wrangler is offline  
Closed Thread

Thread Tools



All times are GMT +1. The time now is 8:57 am.


All information and advice on this forum is subject to the WARNING AND DISCLAIMER located at https://www.vintage-radio.net/rules.html.
Failure to heed this warning may result in death or serious injury to yourself and/or others.


Powered by vBulletin®
Copyright ©2000 - 2024, vBulletin Solutions, Inc.
Copyright ©2002 - 2023, Paul Stenning.