|
|
|
21
|
eHam Forums / Antennas and Towers and more / RE: Defeat wind noise from bracketed tower?
|
on: May 17, 2013, 06:17:06 AM
|
|
A simple way to decrease the wind induced harmonics transmitted down the tower legs is to install small diameter aircraft type cable with small turnbuckle in middle between two opposing legs in a crisscross fashion as you go up,just a slight amount of tension is needed and only a few between house level and about 10 ft. above roof level is needed.This will not completely eliminate the vibration hum but will reduce it considerably.I never tried the rubber spacers but it sounds like a good idea.
|
|
|
|
|
24
|
eHam Forums / Antennas and Towers and more / RE: Anyone had antenna pole break?
|
on: May 17, 2013, 03:04:11 AM
|
|
Re:WH7DX
The mast for my homebrew hex beam is very similar to yours.Two 10 ft. sections of Home Depot electrical conduit 1 3/4 in.od inserted 14 in.into the 2 in. od.pipe with the gap filled with spiral wound medium speaker wire for a tight fit and no slop then through bolted.This is mounted to a 8 ft. 6x6 post cemented 2 ft. into the ground with foam board insulation to prevent frost heave.Mast swivel is 1 ft. down from top of post,just a 7 in.long 2 in.dia.black pipe as a through bolt with flange and 2 U bolts to clamp to mast.Base of mast is 2 ft. up from ground and slips over a 6 in.high pipe mounted vertical on an angle bracket.The mast rotates freely by the armstrong method and locked into position by a C clamp.
Top 20 meter element is about 24 ft. high.Tilting method was originally a 5 gal. cement filled plastic bucket with small block/tackle for a counter weight at mast base,but now have a permanent tag line attached half way up the mast at the pipe joint that I can run a 45 ft. long small block/tackle from to a tree.This has survived its second winter with Gale force winds and outer edge of Sandy with only slight sway.I believe as others have said that the 20 ft.mast of this type is the limit before bending moments are compromised during tilting.
|
|
|
|
|
26
|
eHam Forums / SWL (Shortwave Listening) / RE: Elecraft.LW,MW BCB SW radio?
|
on: May 16, 2013, 10:47:24 AM
|
|
Re:K0OD
Your post has merit.I was just going by the topic heading and looking at my 30 yr.old SONY ICF-7600D BCB/FM/LW/MW/SW synthesized receiver and small size which is still working as new.No knob tuning is no problem,it has a fine tune knob and works very well as a receiver for fun qrp ops with my homebrew 3 watt xtmr.. Yes it is probably time for something new on the market with the latest and greatest technology.
|
|
|
|
|
27
|
eHam Forums / SWL (Shortwave Listening) / RE: Elecraft.LW,MW BCB SW radio?
|
on: May 16, 2013, 03:55:09 AM
|
|
No,I was under the impression that the KX3 was a transceiver designed mostly for the use on the amateur frequencies but I may be wrong.If you want a GENERAL communications receiver about the size of the KX3 just buy a Sony 7600 series.
|
|
|
|
|
Loading...
|