Home |
Search |
Today's Posts |
#11
![]() |
|||
|
|||
![]() I want to raise the centre of my 91 ft folded dipole to at least 35 feet. I live on the west coast of Florida with all the attendant possibilities of hurricanes. I cannot afford a retractable tower and do not have room for proper guy wires. I want to be able to put a pulley at the top so I am able to lower the antenna in the event of high winds. I have a cement block house with a roof peak of about 16 feet, I would prefer not to have to pour a base for the "mast". I would appreciate any advice on supporting the "mast" to the house wall and what material to use for the "mast" so that it might not be permanently bent by 125 mph winds. Any constructive help gratefully welcomed Hey, I take it you guys don't have military surplus outlets? Surely !! What about pump up field masts and the like.......... Otherwise square steel tube reducing in diameter size until you achieve the required total height. Using a piece of heavy steel plate, 900mmx900mm, obtain a 150mm length of box section just wider than your bottom box section piece and weld that section to the plate [ your bottom section sits in this ] Drill a hole straight through this to accommodate a bolt through both box sections [ stops the section being lifted out ] Weld a plate that will accommodate a galvanized hand winch [ the type used on boat trailers ] to the largest bottom section, weld an eye to the top smallest box section [ the winching cable attaches to this ] Leaving at least 600mm in each extended section, fabricate a collar that will lock each section in place as it is risen upwards [ to stop it falling ] Or weld two nuts on each top section side, drilling the centres away for a bolt/set screw to fix through, which will then stop the box sections from sliding back down. Choose a cable of suffcient winching breaking strain. Crank away until the desired height is obtained, locking each section in place. Reverse the procedure for dropping down. Attach any guy wires to additional eyes on various sections, which should be welded on at each section top. Choose a secure and fixed location for the floor plate. If you don't utilise or need a floor plate, fabricate fixings that will be able for the bottom section to be fixed to the wall [ stand off's ] Sounds a big job but it's easy done and not megga bucks either. Not knowing what a 125MPH hurricane is like in the UK, do's it make yer jowls chatter in the wind? LOL Hey Bobs yer uncle, job done. Cheers Dave -- Amateur Radio Call Sign M1BTI, Located in Manchester England. Locator square IO83TK Chairman Of Trafford Radio Club. Club Call Signs G0TRG & M1BBP Located at Umist, University Of Manchester Institute For Science And Technology Share What You Know, Learn What You Don't. |
#12
![]() |
|||
|
|||
![]() |
#13
![]() |
|||
|
|||
![]()
Bob Miller wrote:
There's a nice A-frame wood mast in the ARRL Handbook that's about 40 feet high, and can be made from just a few pieces of lumber. If you can find nice, clear 2x3's 20+ feet long. Maybe back in the 50's when those first appeared in the Handbook, but not any more... |
Reply |
|
Thread Tools | Search this Thread |
Display Modes | |
|
|
![]() |
||||
Thread | Forum | |||
Antenna Suggestions and Lightning Protection | Shortwave | |||
Wideband VHF Yagi - Do I have to use a folded dipole configuration? | Antenna | |||
Confirm the resonant frequency of this folded dipole | Antenna | |||
suggestions for a limited space HF antenna.. vertical or dipole | Antenna | |||
Tuning a folded Dipole? | Antenna |