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Base station construction, antenna/mounting questions (WITH VIDEO!)

I think that 1dB price is a very inexpensive one, and worth the cost. I also think that depending on the length of that 2 meter coax run, you could probably do a little 'economizing' there too. That 'little' is relative, and if it's much like my relatives, you may not want to do much of it, sort of.
That 'relative' thingy is the whole name of the game with this sort of thing, and changes with the frequency/band of use. Being realistic about what you will be 'saving' is the biggy.
- 'Doc

ALL puns are definitely intended, even the ones I didn't see. If that 'relative's name was 'H.Hefner', I would definitely want more of his friends around! Considering my relatives... who cares?
 
Well, my setup changed a little bit.

I ended up picking up a Radioshack HTX-242 off a fellow ham, W8RFK, off of craigslist. He saw that I was a beginning operator, and was VERY nice about it. He threw in a 5-element 2m beam antenna, and an NMO-magnet mount antenna too!

So, 2m is my priority now, rather than 10/11m.

antennasetup.jpg

antenna001.jpg


Had to put two more holes in the antenna so I could flip it for vertical polarity...when I got it, it was set up for horizontal polarity.

However, let me know how this looks. Due to the rather light wind load this setup will generate, I'm just going to use a TV-antenna rotator setup. However, I WILL use a thrust bearing towards the top to prevent putting a lot of stress on the rotator.

Still planning to use LMR-400 for the VHF antenna. However, I'm thinking about using LMR-240 for the HF band run. LMR-240 is only 1.3 dB/100ft on 30mhz, as opposed to RG8X which is 2.0 dB/100ft. Their prices are rather close anyways.

-Richard-
 
You might want to rethink the polarity thing, as most 2m activity that will use a yagi will be horizontal. Put it right and ad a J-Pole and you will have both local and distance covered.
 
If you leave the 2 meter antenna vertical make up a mount to put the entire antenna out in front of the mast. That mast is currently in the same plane as your elements and will ruin the antenna pattern.

When you start adding more mast and you will it can be guyed to the four corners of the roof. That will make the installation very strong. I'd suggest losing that slip together 16 guage mast and using chain link fence top rail instead.

The guy wires WILL most definately effect your wire antenna and must be insulated every so many feet. I forget the length for 80 - 10 meters. Ecectric fence or ceramic insulators can be used. The mast in the tripod will now develop a lot of vertical thrust. You might try using some sort of gizmo placed on the peak of the roof for that load to get it off the tripod. Bring the mast all the way down through the tripod. Just use he tripod clamps to keep the mast from twisting.

The wire antenna should have it's feedpoint as high as you can afford. The ends can be slightly lower. I see trees. Use the trees Luke.

Ever try a Jack Nicholson impression? Just asking.
 
packrat said:
You might want to rethink the polarity thing, as most 2m activity that will use a yagi will be horizontal. Put it right and ad a J-Pole and you will have both local and distance covered.
Click to expand...

I do not have SSB, AM, or CW capabilities.

Everybody around here uses verticals.

So rather than cutting the signal strength in half, I'd rather just run what everybody else is running.

I live in the middle of nowhere, I don't think a J-pole would get me out that far on 10w.

I'm more interested in hitting repeaters in Grand Rapids, Holland, or South Bend more than anything else. Maybe Chicago on a good day.

Although the signal-plane problem that HiDef brought up, might make me run horizontal just for that reason...

HiDef said:
If you leave the 2 meter antenna vertical make up a mount to put the entire antenna out in front of the mast. That mast is currently in the same plane as your elements and will ruin the antenna pattern.

When you start adding more mast and you will it can be guyed to the four corners of the roof. That will make the installation very strong. I'd suggest losing that slip together 16 guage mast and using chain link fence top rail instead.

The guy wires WILL most definately effect your wire antenna and must be insulated every so many feet. I forget the length for 80 - 10 meters. Ecectric fence or ceramic insulators can be used. The mast in the tripod will now develop a lot of vertical thrust. You might try using some sort of gizmo placed on the peak of the roof for that load to get it off the tripod. Bring the mast all the way down through the tripod. Just use he tripod clamps to keep the mast from twisting.

The wire antenna should have it's feedpoint as high as you can afford. The ends can be slightly lower. I see trees. Use the trees Luke.

Ever try a Jack Nicholson impression? Just asking.
Click to expand...

Damn, that was on the edge of my mind. I'm still new to antenna theory, but yeah, I was thinking of that. I may just end up running it horizontal. That 5-element beam is all aluminum. It's quite a bit of weight. I don't think I'd trust sticking the entire thing off one side of the mast.

Yeah, I was considering using a cut down piece of EMT conduit as a mast. I don't really trust the fence-post pipe, it's not always welded completely.

Each piece of guy-wire is 25 ft long. 27 ft is regarded as a "non-resonant length". We'll see how badly it affects my SWR. If it does, I'll go ahead and add some insulators to help "break it up" a bit. The tripod is lag-bolted through the roof with 3/8 lag bolts, into 2x4s. I don't think it's going anywhere. :blushing:

The guy-wire is 3/16", which is rated for 3700 lbs. Each eyelet-bolt is going into a roof stud. So yeah, I think I'm covered.

For the dipole, you're suggesting the feedpoint "be in the trees".

So are you saying I should run an inverted vee?
Or run the signal wire straight across, then slope the ground wire down?

DIAGRAMS PLEASE!

"Hi, I've got an appointment with Mr. Ullman. My name is Jack Torrance. " :P
 
If the folks you're going to talk to on 2m are all running vertical polarity, you should run your yagi vertical, until such time that you have 2m SSB capabilities. Cross polarization at VHF and higher frequencies can really be a killer.
 
I don't do diagrams.

If you can't put the whole antenna in front of the mast at least stand the 2 meter antenna away from the mast with a perpendicular mount of some kind.
Don't make it horizontal hoping for better results with repeaters.

25 foot length of guy wire will effect your wire antenna on the low bands for sure. IIRC it's supposed to be 17' or less not really sure anymore.

Feedpoint on the roof ends in the trees. Inverted V or whatever you can manage. The next problem is how are you planning on multibanding the dipole?
 
moleculo said:
If the folks you're going to talk to on 2m are all running vertical polarity, you should run your yagi vertical, until such time that you have 2m SSB capabilities. Cross polarization at VHF and higher frequencies can really be a killer.
Click to expand...

So my solutions are to run a non-conductive mast, or to run it off the side of the mast?

Non-conductive masts are expensive as heck, so unless you can make a suggestion for something cheap I can get at least 6 ft of non-conductive mast off of...

Running off the side of the mast, I'll have to homebrew a solution. The antenna currently isn't set up for it, so I'll have to make a mast clamp setup, and an extension out of aluminum stock.

HiDef said:
If you can't put the whole antenna in front of the mast at least stand the 2 meter antenna away from the mast with a perpendicular mount of some kind.
Don't make it horizontal hoping for better results with repeaters.

25 foot length of guy wire will effect your wire antenna on the low bands for sure. IIRC it's supposed to be 17' or less not really sure anymore.

Feedpoint on the roof ends in the trees. Inverted V or whatever you can manage. The next problem is how are you planning on multibanding the dipole?
Click to expand...

That's what I was thinking. I'll probably just fab up a mount, to mount the whole 5-element antenna off the side of the mast. Non-conductive mast was the other option.

I did some research, my length of guy-wire MIGHT generate a little bit of a problem on the low end of 20m, but it's easily solved by placing a few ferrite beads onto the wire.

It's more than 100 ft to the fenceline, so I COULD run it straight out if I wanted to. As mentioned, it would slant downwards slightly. Other option, is to go with your setup, and run the feedpoint as high as I possibly can. What's the ideal angle for an inverted v dipole's wires? About 45 degrees?

I'll be using an antenna tuner to multiband the whole thing. My Heathkit DX40 transmitter actually has one built into it! :laugh:

Thanks everyone for your help by the way!

-Richard-
 
You can buy the Non-Conductive Fiberglass masts on Ebay. Get the military fiberglass masting sections. Just bond them together for the length you need, with guy wire rings installed.
Rich
 
BOOTY MONSTER said:
beware the 827
Click to expand...

Maco V58?

I can get one of those locally for $98. I'll check to see if that's the full price, or if they'll charge me shipping (I don't think they carry them in stock).

n8fgb said:
You can buy the Non-Conductive Fiberglass masts on Ebay. Get the military fiberglass masting sections. Just bond them together for the length you need, with guy wire rings installed.
Rich
Click to expand...

Do those ex-military 4 ft x 1.8" x .105 fiberglass mast tubes do the job okay? I only need about an 8ft section, so two of them put together. I'm still going to use a metal center mast, however for the mast off the rotator, it'd be those fiberglass masts.

-Richard-
 
Unless the layout is changed a fiberglass mast isn't going to help. The feedline for the Sirio antenna will still screw up the 2 meter vertical.
 
Finally got some new additions for my base.

For my antenna, I went with the Maco V5000. Local shop had one in stock for $121. :w00t:

MacoV5000.jpg


YouTube - Maco V-5000 26 33 mhz base antenna

Used RG58A/U for the run, and some awesome-quality PL259 connectors. The outdoor connector has a crapload of electrical tape wrapped around it, to kinda make it an "strain relief" device, and also to prevent water from getting in the connector. Bottom line, I realized I don't care too much about losing ~2.5 db for a run that's purely for 10/11m.

DEFINITELY will be using RG8U for my 10-80m inverted vee dipole run. I might actually go ahead and cash out for a 10-160m dipole to hang, as if I run inverted, I'll have some extra space.

I'm still planning to use LMR400 for my 2m beam. I'm also considering mounting a second 2m/70cm antenna off the brick chimney. Just a little omni-directional antenna, nothing special. Probably a homemade j-pole.

Temporary mount only for the Maco antenna, currently there's only ~8 ft of mast underneath that antenna. Once it's finished, there will be about ~15-18 ft, of mast. It'll be properly guy-wired too.

I must say, I am excited.

I tested the rig out today with my car. My President Dwight D base puts out about 7w. My car rig is a Cobra 29 LTD Classic that puts out 4w through a K30 magnet mount. I had a clear receive from the base 10 miles away, over hills and valleys, but I was starting to get too fuzzy to transmit back.

Can't wait to see how she performs once she's at proper height.

I might go ahead and get a small amplifier for the base as well...nothing too fancy, just something to help me get out a little further!

Addition Number Two:

NJE006.jpg


NJE RVC-36, 0-36vdc 0-15amps industrial power supply. VERY beefy, works perfectly! Zero RF interference. Downside, is that it's fairly noisy. I might make a variable fan-speed control for it. Damn thing sounds like a jet taking off.

-Richard-

Disclaimer : Those power lines are nowhere near as close as they look. Even with the extra mast, they still won't be close.
 

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