Re: Topband: standoff for inv L
I'd likely continue to use the fiberglass but I might fit a hardwood dowel inside its length to stiffen it. PVC can work that way too but you MUST have something to make it rigid. I had a side arm made from wood stuffed grey PVC pipe that was out in the weather for over 20 years with no negative effects. Does it break where the clamps attach it? I always insert a plug of a non-crushable material where any holes are drilled for bolts or where clamps bear against fiberglass tube, otherwise that can be a sure failure point. 73 Phil, KB0NES On Saturday, December 26, 2020, 05:25:58 PM CST, WW3S wrote: I lost my fiberglass pole that I use for a standoff for my inv L off my 50' tower.second or third time in 12 years or so, victim of the recent ice/snow storm we just had.I've been using fiberglass to isolate it from the tower.but the wire for the antenna goes thru an insulator attached to a rope thru a pulley off the fiberglass arm.should I continue to go with fiberglass, or would metal be ok, since I have the rope and other insulator there _ Searchable Archives: http://www.contesting.com/_topband - Topband Reflector _ Searchable Archives: http://www.contesting.com/_topband - Topband Reflector
Topband: standoff for inv L
At my remote site I have an inverted L that is supported by a 40ft square aluminium lattice “frangible" tower. Yes I have it guyed. There is a 14ft fibreglass pole fixed to the top of the tower. There is short piece of aluminium tubing in the top of the pole and the bend in the L wire is essentially at 56ft. The pole is from a wind surf board that was destroyed in a very big wave. which took four feet of the pole as well. The wind surf pole is nicely tapered and in one piece. The bottom is about 2 inch diameter tapering to 1 inch at the top.I am not the surfer - I have a friend who is into this kind of thing.! It is very stiff and supports the L wire very nicely. The wire I use is a very small but very strong flex weave type of wire that came from a decommissioned TCI portable Log Periodic. There is significant "pull" from the horizontal wire and I have a back stay from the top of the pole to an outrigger arm at the 30ft level. The back stay keeps the pole nicely straight and I adjust the tension at the far end to minimize the deflection. I don’t know if all Wind Surf poles are like this one but its worth checking out. I have been using it on top of my 40ft tower for 5-6 years and it has survived hellish storms with 120kmph winds and ice and snow etc. 73 Frank VO1HP _ Searchable Archives: http://www.contesting.com/_topband - Topband Reflector
Re: Topband: standoff for inv L
FWIW Probably 15-20 years ago I was thinking of building an LPD HF antenna, I purchased two 20 foot lengths of 2" x 1/8" wall square fiberglass tubing for the boom. The antenna never happened and the tubing has been laying on the ground in the Arizona sun since then. It looks essentially as it did years ago. It's "Extren" (series 525 if memory serves) by Strongwell. Amazing stuff. https://www.strongwell.com/products/structural-shapes-and-plate/ Wes N7WS On 12/27/2020 9:08 AM, Grant Saviers wrote: I've been using 8' 1.5" dia painted fiberglass top and bottom of my 85ft T as standoffs from a fir tree. An 18" long bracket is lagged to the tree both places to make it stable and lower the FG stress. OK after 6 years, occasional ice and snow. PVC gets very flabby at 80F and higher and isn't anywhere near as strong. Grant KZ1W On 12/27/2020 07:20, Mike Smith VE9AA wrote: VE9AA: I don't have a tower supported Inverted L, but I have a slightly different way of supporting the center of a 20m 4-square array of inverted L's and wanted something non conductive so I use 1.5" grey electrical PVC conduit and it's stood up many years in a harsh environment with wild temperature swings and all winter can throw at it, but the UV up here is on the lower end of the scale. Because PVC can get floppy in the heat or with lots of ice buildup, support it from above (from the far end, back to the tower, some distance above the PVC arm) with rope. (think triangulation) If you are located where UV may be an issue, tape it like Jim has said. === WW3S: I lost my fiberglass pole that I use for a standoff for my inv L off my 50' tower.second or third time in 12 years or so, victim of the recent ice/snow storm we just had.I've been using fiberglass to isolate it from the tower.but the wire for the antenna goes thru an insulator attached to a rope thru a pulley off the fiberglass arm.should I continue to go with fiberglass, or would metal be ok, since I have the rope and other insulator there _ Mike VE9AA Mike, Coreen & Corey Keswick Ridge, NB _ Searchable Archives: http://www.contesting.com/_topband - Topband Reflector _ Searchable Archives: http://www.contesting.com/_topband - Topband Reflector _ Searchable Archives: http://www.contesting.com/_topband - Topband Reflector
Re: Topband: standoff for inv L
I've been using 8' 1.5" dia painted fiberglass top and bottom of my 85ft T as standoffs from a fir tree. An 18" long bracket is lagged to the tree both places to make it stable and lower the FG stress. OK after 6 years, occasional ice and snow. PVC gets very flabby at 80F and higher and isn't anywhere near as strong. Grant KZ1W On 12/27/2020 07:20, Mike Smith VE9AA wrote: VE9AA: I don't have a tower supported Inverted L, but I have a slightly different way of supporting the center of a 20m 4-square array of inverted L's and wanted something non conductive so I use 1.5" grey electrical PVC conduit and it's stood up many years in a harsh environment with wild temperature swings and all winter can throw at it, but the UV up here is on the lower end of the scale. Because PVC can get floppy in the heat or with lots of ice buildup, support it from above (from the far end, back to the tower, some distance above the PVC arm) with rope. (think triangulation) If you are located where UV may be an issue, tape it like Jim has said. === WW3S: I lost my fiberglass pole that I use for a standoff for my inv L off my 50' tower.second or third time in 12 years or so, victim of the recent ice/snow storm we just had.I've been using fiberglass to isolate it from the tower.but the wire for the antenna goes thru an insulator attached to a rope thru a pulley off the fiberglass arm.should I continue to go with fiberglass, or would metal be ok, since I have the rope and other insulator there _ Mike VE9AA Mike, Coreen & Corey Keswick Ridge, NB _ Searchable Archives: http://www.contesting.com/_topband - Topband Reflector _ Searchable Archives: http://www.contesting.com/_topband - Topband Reflector
Re: Topband: standoff for inv L
VE9AA: I don't have a tower supported Inverted L, but I have a slightly different way of supporting the center of a 20m 4-square array of inverted L's and wanted something non conductive so I use 1.5" grey electrical PVC conduit and it's stood up many years in a harsh environment with wild temperature swings and all winter can throw at it, but the UV up here is on the lower end of the scale. Because PVC can get floppy in the heat or with lots of ice buildup, support it from above (from the far end, back to the tower, some distance above the PVC arm) with rope. (think triangulation) If you are located where UV may be an issue, tape it like Jim has said. === WW3S: I lost my fiberglass pole that I use for a standoff for my inv L off my 50' tower.second or third time in 12 years or so, victim of the recent ice/snow storm we just had.I've been using fiberglass to isolate it from the tower.but the wire for the antenna goes thru an insulator attached to a rope thru a pulley off the fiberglass arm.should I continue to go with fiberglass, or would metal be ok, since I have the rope and other insulator there _ Mike VE9AA Mike, Coreen & Corey Keswick Ridge, NB _ Searchable Archives: http://www.contesting.com/_topband - Topband Reflector
Topband: standoff for inv L
I've used a PVC pipe around 1.5 or 2" o.d. and ~ 3 feet long, for the past 11 years. No problems so far but it is braced with dacron from the insulator end, back up to the mast a few feet above where the PVC is clamped to the mast. Mine is unprotected from sun but the sun exposure is less in the Chicago area. Of course when it eventually fails, it will be in January, hi. If I had it to do over again I would have used the gray PVC that is supposedly UV resilient, and taped over it as K9YC suggested. Mine is hung the same way--wire through dog bone insulator on rope through pulley, pulley attached to PVC. I'll bet that an aluminum pipe would work okay since the wire is well isolated by the insulator, rope, pulley, rope series but use dacron not wire and a decent insulator. 73 Rob K5UJ _ Searchable Archives: http://www.contesting.com/_topband - Topband Reflector
Re: Topband: standoff for inv L
On 12/26/2020 3:25 PM, WW3S wrote: should I continue to go with fiberglass How about PVC conduit, taped to protect it from UV? 73, Jim K9YC _ Searchable Archives: http://www.contesting.com/_topband - Topband Reflector
Topband: standoff for inv L
I lost my fiberglass pole that I use for a standoff for my inv L off my 50' tower.second or third time in 12 years or so, victim of the recent ice/snow storm we just had.I've been using fiberglass to isolate it from the tower.but the wire for the antenna goes thru an insulator attached to a rope thru a pulley off the fiberglass arm.should I continue to go with fiberglass, or would metal be ok, since I have the rope and other insulator there _ Searchable Archives: http://www.contesting.com/_topband - Topband Reflector
