Wow forgot about him.. Checked out his videos, some good stuff there.
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Imax 2000 only 7' off ground??
- Thread starter CB590
- Start date
w9 , and it all started here WWDX ! Hobie is one smart guy . I have to give him a LL it's been a while since we chatted . You should make contact him via radio , you can I can't ! My problem !
I just might do thatYou should make contact him via radio , you can I can't ! My problem !
BJ radionut
Supporting Member and 6m addict
10 Meter 1/4 Wave Vertical and Counterpoise
« Reply #4 on: February 28, 2002, 11:57:58 AM »
I agree that you are likely to have better results if you can get the
antenna up off the ground. Perhaps you can mount it at the edge
of the roof and run one radial each direction in the rain gutter. (Or
just use the rain gutter for the radials if it is metal.)
However, if ground mounting is your best option, it will work best
if the radials are NOT burried in the dirt. The easiest approach that
I have found it is best to lay the radials on top of the ground(added by me: Or under thin layer of gravel in the driveway...etc) and hold them
down with little wire staples. (A 2" piece of baling wire or rebar tie
wire bent in half works great, or the staples used to hold barbed
wire to a wooden fence post.) You can use fairly thin magnet wire
so the wire is cheap and hard to see. If you mow the grass very
short you can lay down the wires without too much trouble, then
just let the grass grow back over it. Then you can mow the lawn
at the regular height without fear of hitting the wires.
While you are doing it, I'd suggest you put out at least 16 radials.
The exact length doesn't matter (since the ground coupling makes
them non-resonant) but 8 -10' would be a good length. With 16
radials, if you do accidentally mow off one or two of them, it still
should work as well.
Copied from: https://www.eham.net/ehamforum/smf/index.php?topic=15104.0
Same idea for 20m or even 40m vertical...done this for FD operation with as little as 4 radials (more is better but what the hell...do what you can do)!!!!
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BJ radionut
Supporting Member and 6m addict
Likely the roof is grounded someplace...However steel/copper/Alm rain gutters normally are not
Shadetree Mechanic
Delaware Base Station 808
If it is grounded then maybe a gamma match would work?Likely the roof is grounded someplace...However steel/copper/Alm rain gutters normally are not
Done that beforeHowever steel/copper/Alm rain gutters normally are not
New member here, but not new to cb by a long shot. I have HOA issues also, so I have an imax 2000 mounted on a 10 foot pole right now. To keep it from radiating,I put a Daniel Horvat choke at the base, and it doesn’t interfere with anything. I talk DX all over and can talk decent locally. It’s on a tilt over base from DX Engineering. Swr is 1.1-1.2 on all channels, and less than 1% reflect.
I don't have access to my cad here but I'll try to explain .
With RF transparent telescoping tube (fiberglass in this case) what you do is get the largest diameter you can and work your way down .
http://www.mgs4u.com/fiberglass-tube-rod.htm#pricelist
In this case 2 1/2" . Then refer to the "sample kits"
http://www.mgs4u.com/fiberglass-guide.htm
The next size down is 2 1/4" . Cut several rings of the 2 1/4" for bushings and seal support . It works like this . At the top of the 2 1/2" section insert three rings of 2 1/4" leaving enough room between them for a commercial square "O" ring . Do a bit of sluthing on
http://www.mcmaster.com/#o-rings/=13s4y4u
or
http://www.mcmaster.com/#o-rings/=13s4yta
I found the "X" profile to work best with irregular surfaces and the 1/32" inch interference to provide a good seal without a great amount of friction/stiction.
Now you have two internal "O" rings and a bushing at the top of the 2 1/2" base section . Repeat this at the base of the 2" second section making three more rings from the 2 1/4" and gluing them to the 2" section leaving room for the same size "O" ring you used on the top of the 2 1/2" section !
Repeat the process as far as you can and you have a radome that can contain anything you can stuff inside . You can easily get to 40' plus in 6 sections .
Modify a small piston compressor to apply pressure . Turn it around to apply vacuum . Store vacuum as well as pressure in small tanks . This has the added benefit of a vacuum source for de-soldering as well as air pressure for blowing the crud everywhere .
The hybrid . With a non-conductive base and metal follow on sections you can make a tuned vertical at any of the common magic lengths . The same practice applies . Skip one size on the way down for bushing and seal support all the way to 1/4" if you think you can get it to work . I found that 3/4" is the practical lower limit . Some sort of electrical continuity will have to be maintained section to section. A simple replaceable brass or copper , sprung , feeler strip is probably okay for all but kilowatt operation .
As far as tuning a 31' or 43' vertical ? SG-230 , manual , rotary switched loading or tuner of your choice . As far as stuffing the radome goes , you are a resourceful experimenter with some imagination or you wouldn't have read this far .
Hope it helps some one .
With RF transparent telescoping tube (fiberglass in this case) what you do is get the largest diameter you can and work your way down .
http://www.mgs4u.com/fiberglass-tube-rod.htm#pricelist
In this case 2 1/2" . Then refer to the "sample kits"
http://www.mgs4u.com/fiberglass-guide.htm
The next size down is 2 1/4" . Cut several rings of the 2 1/4" for bushings and seal support . It works like this . At the top of the 2 1/2" section insert three rings of 2 1/4" leaving enough room between them for a commercial square "O" ring . Do a bit of sluthing on
http://www.mcmaster.com/#o-rings/=13s4y4u
or
http://www.mcmaster.com/#o-rings/=13s4yta
I found the "X" profile to work best with irregular surfaces and the 1/32" inch interference to provide a good seal without a great amount of friction/stiction.
Now you have two internal "O" rings and a bushing at the top of the 2 1/2" base section . Repeat this at the base of the 2" second section making three more rings from the 2 1/4" and gluing them to the 2" section leaving room for the same size "O" ring you used on the top of the 2 1/2" section !
Repeat the process as far as you can and you have a radome that can contain anything you can stuff inside . You can easily get to 40' plus in 6 sections .
Modify a small piston compressor to apply pressure . Turn it around to apply vacuum . Store vacuum as well as pressure in small tanks . This has the added benefit of a vacuum source for de-soldering as well as air pressure for blowing the crud everywhere .
The hybrid . With a non-conductive base and metal follow on sections you can make a tuned vertical at any of the common magic lengths . The same practice applies . Skip one size on the way down for bushing and seal support all the way to 1/4" if you think you can get it to work . I found that 3/4" is the practical lower limit . Some sort of electrical continuity will have to be maintained section to section. A simple replaceable brass or copper , sprung , feeler strip is probably okay for all but kilowatt operation .
As far as tuning a 31' or 43' vertical ? SG-230 , manual , rotary switched loading or tuner of your choice . As far as stuffing the radome goes , you are a resourceful experimenter with some imagination or you wouldn't have read this far .
Hope it helps some one .
Got some satin Rust-Oleum paint.
Ivory Silk for the bottom to match mobile home..
And a London Gray for the top in the air.. this says also bonds to plastic..
Still flashing off..
Ivory Silk for the bottom to match mobile home..
And a London Gray for the top in the air.. this says also bonds to plastic..
Still flashing off..
The view point.. mast and antenna will be on other side of trailer..
Posts test run.. way tall.. going to need a SO-239 to SO-239 to add a few more feet of the LMR-240.. damn. :/ . If I have to I will put the adapter inside the shack and just slide some more out the wall.. I don't like connectors outside in the weather.
From opposite side of trailer.. blends nice.. damn tree though.. not mine..
May go with antenna base at 18' and tip at 36' (A99).. that should give me wiggle room and if I have to cut branches back I will..
I'm going to cut 2-3' off the bottom mast. Then the top most wall bracket will have have top mast inside the bracket to keep it more secure.. got some self tapping screws to bond the posts together too..
Also trying to maintain 1/2 wave off ground if possible..
From opposite side of trailer.. blends nice.. damn tree though.. not mine..
May go with antenna base at 18' and tip at 36' (A99).. that should give me wiggle room and if I have to cut branches back I will..
I'm going to cut 2-3' off the bottom mast. Then the top most wall bracket will have have top mast inside the bracket to keep it more secure.. got some self tapping screws to bond the posts together too..
Also trying to maintain 1/2 wave off ground if possible..
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Nice work painting it to match the wall. It stinks that we have to get creative but that’s the HOA for you. Too bad you can’t stick it out of the top of that tree, that would help your local range for sure.
Here is my mudduck setup on the ground and standing. I can go up about ten more feet at the most with it laying that direction, I keep it that way to stay out of the way for the kids.
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