[600MRG] Free standing verticals
Roger Graves
ve7vv at shaw.ca
Thu Feb 8 01:27:56 EST 2018
Ben,
I am using one of the 4 ft 4X4 fence posts of my back fence, to that I have screwed a 10 ft 2X4. The army surplus 2 inch fiberglass tubing mast is bolted to the 2X4. (That tubing is reinforced with some aluminum tubing as it is not stiff enough w/o guying. A further length of telescoped sections of aluminum tubing is bolted to the fiberglass tubing to give me 40 ft of basically self-supporting mast. #12 wire goes to the the top of that, then 95 ft of #28 wire to a 30 ft mast that is of a similar construction, again bolted to a 4X4 fence post. Not ideal, but it was a “quick and dirty” approach to get something up for 630. It has lasted for several months. I plan to improve it mechanically soon and will try to get the supports up to 50 and 40 ft.
BTW, I just answered your JT9 CQ, but nobody is hearing me tonite.
Roger
> On Feb 7, 2018, at 9:10 PM, Ben Gelb <ben at gelbnet.com> wrote:
>
> Thanks all for the replies.
>
> Yard is 30' wide by perhaps 45' deep behind my rental house in San Francisco. There is one tree of substantial height (the one thats going away) on one corner of the yard (up against mine and my neighbor's house on the east side of me). That currently gives me about 30' of vertical for my inverted L, and then I have a fiberglass fishing pole supporting the end of the top-hat about 30' away from the vertical. (this inverted L is my only transmitting antenna currently, but for MF and HF - I also have a couple of small receiving loops on a rotatable base at ground level)
>
> With the tree gone will need to provide my own structure, and I would prefer to avoid a lot of guying if possible, as there's not a lot of room for it, and it will really consume the entire yard. I was thinking to sink a 4x4 or 6x6 post into the ground (i have a post-hole digger) and then maybe attach some sort of mast to it, hopefully stiff enough to not need any guying (or at least not much). Alternatively, the DX Engineering MBVA-5A looks like it might be a reasonable option, albeit perhaps a bit more expensive than some home-depot option (ostensibly it doesn't require guying).
>
> If I were to kludge up some set of metal pipes and tubes, I wonder how I might mount it to a wooden post - I'm thinking a wooden post might not be a great dielectric (tree sure wasn't) and might lead to some burning. Anybody tackled that problem?
>
> I do have some of the 4' military mast sections (mine are aluminum not fiberglass though) but I think they'll get pretty floppy over 15-20' or so w/o some guying...
>
> Neighbor mentioned being open to draping a wire over his house if it helped.... but I think more useful would be expanding the radial field throughout his backyard... haven't broached that subject. He might be less excited about that.
>
>
>
> On Wed, Feb 7, 2018 at 5:35 AM, Dave Riley <dave.riley3 at verizon.net <mailto:dave.riley3 at verizon.net>> wrote:
> Hello Ben,
>
> Can you give us more info concerning your real estate plot such as square footage, relationship to power lines, existing antennas, size and height of your home, any neighbors who would allow you to span their property, or any obstructions that would be in the way of an antenna and lastly what you have for antennas for ham use at this time?
>
> Are you presently using any sort of loop or probe antenna for receive?
>
> All the answers to your quest so far sound workable so maybe a mix or some kind of a modification could allow you to enjoy the new band.
>
> Thanks from DaveR @ aa1a
>
>
>
> On 2/4/2018 7:11 PM, Ben Gelb wrote:
> My neighbor is taking down my antenna tree ... possibly this week :(.
>
> Its actually the right thing - the tree is very unbalanced and needs to go. But it means my undersized antenna will be even smaller (gone) soon...
>
> Seems like I may need to try to get something in the air that doesn't require a tree or permanent support structure. I can probably fashion some kind of vertical pole out of cheap materials, but imagine it will require a lot of guys to remain vertical - which I'd kind of like to avoid since I don't have a lot of room for guys.
>
> Any suggestions from this group?
>
>
>
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