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

[office888]

YouTube - HAM + CB Roof Antenna Tripod Install

Does everything look okay so far? Yes, I know I went nuts with the roofing sealant on the bolts...

3ft antenna tripod, lag bolted (3/8"x2") into 2x4s on the other side of the roof to help distribute the load, so it's not just threads in 1/2" piece of wood + a shingle holding the antenna in place.

4ft masts, currently two. Haven't decided if I want to do maybe three or four, and guywire it.

Planned:
Sirio 827 10/11m vertical on top of the mast, for working local CB / 10m.

10-80m dipole, ran from about 20 ft off the ground off masts attached to the fenceline, straight to the middle of the mast (Perfect distance). Perfect East/West signal.

2m J-Pole (MAYBE!)

Any questions? Comments?

Mind you though, I'm a poor college student. Here's some pics of my base right now.

The Heathkit DX40 still needs a bit of work to be in perfect working order. It's only outputting about 5w..I need to replace the 6146 final tube. Already replaced a few of the capacitors. Looking to get a Yaesu FT101 as my "official" HF rig. Currently, do NOT own a base/mobile 2M radio. All I have is my Yaesu FT270r handheld.

-Richard-

 

[kd-5-bgt]

Getting a nice collection started up....

I am seeing signs of that dreaded ham condition known as "packrat itus"
There is no known cure,but the symptoms can be controled by getting more gear

 

[Nightshade]

I have only one comment to make that I'm sure will help you long term.

Whenever you use a roof tripod overkill on the size of tripod is good since the larger tripod spreads the twisting/side loads that tripod will push against out over a larger foot print on the roof. Makes the whole antenna assembly much stronger.

As to how you've installed the one you have all I can say is.......Well Done!
(just don't go to high mast only. If you get much past 10 ft you'll need to look at guying the mast.)

 

[Robb]

Even though you live in a high wind area, I would still put the antenna feedpoint @ 36 ft above the ground. Minimum of 30 ft. Might as well do it right and not need to look back. Of course, guy wires will be necessary! In fact, install them at two different height levels and be sure they are all anchored to something that is sturdy. One must also consider that if it should come down for whatever reason, that it doesn't hit power wires. Hard to do - I know - but it must always be considered when putting any antenna up. Have a friend or three help you install the antenna, it is safer that way and makes the job much easier to do.

Be sure you ground your system too.
Can't get around that one - either.

The antenna choice is a fine one - it pays to have the best antenna you can afford. Have you also considered the Sirio Vector 4000? Pretty popular for the right reason - they work exceptionally well and are relatively inexpensive.
Welcome to the forum!

 

[office888]

As to how you've installed the one you have all I can say is.......Well Done!
(just don't go to high mast only. If you get much past 10 ft you'll need to look at guying the mast.)

Thanks! I'm coming from an automotive background, and I've learned from that, that it's better to overengineer a solution to guarantee durability, rather than halfass it and have stuff break.

If I exceed 2 masts (12ft), I will DEFINITELY guywire it. The only thing I was worrying about with that, is what media should I use? I was hearing that the traditional steel cable interferes with HF operation.

Even though you live in a high wind area, I would still put the antenna feedpoint @ 36 ft above the ground. Minimum of 30 ft. Might as well do it right and not need to look back. Of course, guy wires will be necessary! In fact, install them at two different height levels and be sure they are all anchored to something that is sturdy. One must also consider that if it should come down for whatever reason, that it doesn't hit power wires. Hard to do - I know - but it must always be considered when putting any antenna up. Have a friend or three help you install the antenna, it is safer that way and makes the job much easier to do.

Be sure you ground your system too.
Can't get around that one - either.

The antenna choice is a fine one - it pays to have the best antenna you can afford. Have you also considered the Sirio Vector 4000? Pretty popular for the right reason - they work exceptionally well and are relatively inexpensive.
Welcome to the forum!

Mounted on the second mast, the feedpoint will be pretty close to the suggested ~36ft. That peak of the roof is decently tall. I still might go with the two extra masts, giving it an extra ~8-10ft boost, so I have a little more room on the mast to mount my 2m J-Pole.

Should I try to mount the feedpoint on the 10-80m dipole higher too? I've got more than enough room, so that if both ends were level, the antenna would BARELY drape to a "vee".

Ground, I was going to run some thick ground wire, copper preferably, from one of the legs, off the side of the house, into a stake in the ground. I'm also going to attach a PL259 Lightning Arrestor to the feed on the antenna, and run the wire for that to the ground wire as well.

Antenna wise, 827 vs Vector 4000, is it really that much of a performance difference? Is it worth the extra ~$40? Is it a durable antenna? I'm mainly looking to work local on 10/11m, so Benton Harbor-or-Kalamazoo (Both are about 30 miles). I wouldn't mind working a bit of skip too.

Thank you very much for your comments so far...

-Richard-

 

[Nightshade]

Thanks! I'm coming from an automotive background, and I've learned from that, that it's better to overengineer a solution to guarantee durability, rather than halfass it and have stuff break.

If I exceed 2 masts (12ft), I will DEFINITELY guywire it. The only thing I was worrying about with that, is what media should I use? I was hearing that the traditional steel cable interferes with HF operation.

At 12 ft you will need guy wires!

As to cable interfering with the signal.... only if they are directly in the signal path. Just don't hook'em to the antenna itself ( :w00t: ) and you'll be ok. Use your geometry to get the angle right,roof to antenna MAST!

 

[office888]

At 12 ft you will need guy wires!

As to cable interfering with the signal.... only if they are directly in the signal path. Just don't hook'em to the antenna itself ( :w00t: ) and you'll be ok. Use your geometry to get the angle right,roof to antenna MAST!

Obviously not to the antenna.

It's just a simple vertical antenna, not expecting a lot of wind load. I worried about the whole "power lines" thing, then I got on the roof and looked...they're waaayyy far away. I guess I'll go ahead and guy wire it then...

Anyone have a diagram / formula for guy-wires?

-Richard-

 

[Marconi]

Obviously not to the antenna.

It's just a simple vertical antenna, not expecting a lot of wind load. I worried about the whole "power lines" thing, then I got on the roof and looked...they're waaayyy far away. I guess I'll go ahead and guy wire it then...

Anyone have a diagram / formula for guy-wires?

-Richard-

888, true the Siro GP does not have a lot of wind load, but you're mistaken that it will not be affected much by the wind and for sure with such an unsure base mount. The base of the mast is not even secured and is just hanging out in space and this is where most of the stress from wind will occur---just as Nighshade suggested. Multiply all this by 5 when adding each of those flimsy stacking type elements.

Anyway, how do you plan to get that big ole' GP up on top of 15' feet of those poles mounted inside that tri-mount?

There are lots of good reasons not to ever mount an antenna attached in-any-way to your home.

 

[Nightshade]

There are lots of good reasons not to ever mount an antenna attached in-any-way to your home.

Not to discount what you say but it's hard for many today to afford a good tower. I know , in my case, it took me 20 years to free up enough money for a good stand alone tower to get my antenna off my roof.

 

[office888]

888, true the Siro GP does not have a lot of wind load, but you're mistaken that it will not be affected much by the wind and for sure with such an unsure base mount. The base is not even secured and is just hanging out in space and this is where most of the stress from wind will occur---just as Nighshade suggested. Multiply all this by 5 when adding each of those flimsy stacking type elements.

Anyway, how do you plan to get that big ole' GP up on top of 15' feet of those poles mounted inside that tri-mount?

There are lots of good reasons not to ever mount an antenna attached in-any-way to your home.

Trust me, it's secure. I made sure of that. I can lean all 150 lbs of me against it, and it flexes (just as it should), but nothing moves. I went overboard with the mounts to the roof.

My neighbor has been running a 3 ft tripod, NOT installed like mine (flimsy mount, screwed to roof only, not to 2x4s), running 2x masts with a huge TV antenna + rotator on top, no guy wires, and for the 10+ years I've lived here, that antenna is still up.

Getting the antenna up onto the mast is going to be the tricky part. I'm going to pre-mount the antenna onto the mast itself, then install the mast into the tripod. I'm sure it'll be a circus act to watch, but I'll have some help, and I'll do it on a day with no wind.

If you want to give me an 80 ft tower, pay for tree trimming, and ladder-line to make up for the distance losses, be my guest...I'm not stopping you. Just PM me for my name and address. :laugh:

Other than that, I'll go with what I can afford. This tripod puts it close to my radio room, so coaxial cable expenditures are minimal. The tripod was cheap, masts are cheap, and even guywires are cheap.

The fun part will be mounting the 2m J-pole, dipole signal end, and guy-wires to the mast...

-Richard-

 

[Robb]

Even though you can lean all of your weight against the bottom portion - one needs to remember that adding length is adding leverage at the highest point of the antenna. Add a large wind, and the the antenna is blown down. I would use 10 ft sections of masting so that it is solid. But I would SURELY use guy wires on what you are setting up. Even that is no insurance against high winds - but is sure helps immensely. Definitely use guy wires. Use the search feature on this site - or Google it for more info on guying - there is plenty info available.

I looked at your video. The peak of your house is ~12 ft off the ground. You will need 20 ft of masting before you put your antenna on it - that will make the feedpoint of the antenna approximately 32 ft. Which is a decent minimal to use (even though 36 ft is preferred). Two 10 ft sections of mast plus guy wires will work out the best - IMO. A Vector 4000 installed at 32 ft/height would make the overall height at/about 60 ft. Set the guy point @ 2/3 the height of the 20 ft mast - about the 13 ft point of a 20 ft section of mast for best results. Using four guy wires @ 90 degrees apart should make it fairly sturdy. The other Sirio you intend to use will make the overall height 52 ft - whch will be fine. But I would DEFINITELY use 20 ft of masting.

I use an IMAX 2000 antenna. We don't see large winds in CA often - but when we do - I'm GLAD I have it guyed. The IMAX will bend to a 90 degree angle and not break - as it is made of fibergalss with a copper core. I'm fairly pleased with this $100 antenna. I'll probably be more fond of it when I put the ground plane kit on it with a coax choke!

 

[office888]

Even though you can lean all of your weight against the bottom portion - one needs to remember that adding length is adding leverage at the highest point of the antenna. Add a large wind, and the the antenna is blown down. I would use 10 ft sections of masting so that it is solid. But I would SURELY use guy wires on what you are setting up. Even that is no insurance against high winds - but is sure helps immensely. Definitely use guy wires. Use the search feature on this site - or Google it for more info on guying - there is plenty info available.

I looked at your video. The peak of your house is ~12 ft off the ground. You will need 20 ft of masting before you put your antenna on it - that will make the feedpoint of the antenna approximately 32 ft. Which is a decent minimal to use (even though 36 ft is preferred). Two 10 ft sections of mast plus guy wires will work out the best - IMO. A Vector 4000 installed at 32 ft/height would make the overall height at/about 60 ft. Set the guy point @ 2/3 the height of the 20 ft mast - about the 13 ft point of a 20 ft section of mast for best results. Using four guy wires @ 90 degrees apart should make it fairly sturdy. The other Sirio you intend to use will make the overall height 52 ft - whch will be fine. But I would DEFINITELY use 20 ft of masting.

I use an IMAX 2000 antenna. We don't see large winds in CA often - but when we do - I'm GLAD I have it guyed. The IMAX will bend to a 90 degree angle and not break - as it is made of fibergalss with a copper core. I'm fairly pleased with this $100 antenna. I'll probably be more fond of it when I put the ground plane kit on it with a coax choke!

Crunched some numbers.

House is on a slightly raised foundation due to the basement.
10ft from ground to gutters
5ft from gutters to peak
9ft Tripod (8ft of masts + slightly raised off the peak)
8ft more of mast
=
32ft

Or I could ditch the 4x4ft masts, and use 2x10ft masts, and have 36ft total. More than likely, that's what I'll do. I don't want a jenga tower of masts. :tongue:

I'd go higher, but the slope on the front of the house is steeper than the rear. I've only got about 14 ft of space to work with for guy wires.

I contacted the local hardware store, they've got guy-wire, eyelet kits, and turnbuckles.

I'll post pictures as I go. I'm going to go ahead and order a spool of RG8X coax, and the antenna this week.

Can never have enough spare coax...

-Richard-

 

[Robb]

Crunched some numbers.

House is on a slightly raised foundation due to the basement.
10ft from ground to gutters
5ft from gutters to peak
9ft Tripod (8ft of masts + slightly raised off the peak)
8ft more of mast
=
32ft

Or I could ditch the 4x4ft masts, and use 2x10ft masts, and have 36ft total. More than likely, that's what I'll do. I don't want a jenga tower of masts. :tongue:

I'd go higher, but the slope on the front of the house is steeper than the rear. I've only got about 14 ft of space to work with for guy wires.

I contacted the local hardware store, they've got guy-wire, eyelet kits, and turnbuckles.

I'll post pictures as I go. I'm going to go ahead and order a spool of RG8X coax, and the antenna this week.

Can never have enough spare coax...

-Richard-

Yeah, ditching the 4x4's and going to 2/10 ft masts would be best.
You won't have too look back after it is all installed. I use the same thing on almost the same arrangement and do fairly well with it.

Consider you coax choice carefully! Use only as much as it takes to make the trip from the base of the antenna to your radio with a six feet extra - in case you need to make a coax choke. I used 55 ft of Belden 9913Flex - which has very little line loss - but cost a pretty penny. But well worth it. I would rather have 60 ft of really decent coax - like the Belden 9913Flex - than a 500 ft spool of cheap coax. You will hear a difference with better coax and get more power to the antenna. Now is the time to consider that move - too...

 

[Nightshade]

I'm going to go ahead and order a spool of RG8X coax, and the antenna this week.

Can never have enough spare coax...

-Richard-

One point hardly ever mentioned is the PROPER weatherproofing of the outside coax.

http://www.eham.net/articles/17553

 

[office888]

Yeah, ditching the 4x4's and going to 2/10 ft masts would be best.
You won't have too look back after it is all installed. I use the same thing on almost the same arrangement and do fairly well with it.

Consider you coax choice carefully! Use only as much as it takes to make the trip from the base of the antenna to your radio with a six feet extra - in case you need to make a coax choke. I used 55 ft of Belden 9913Flex - which has very little line loss - but cost a pretty penny. But well worth it. I would rather have 60 ft of really decent coax - like the Belden 9913Flex - than a 500 ft spool of cheap coax. You will hear a difference with better coax and get more power to the antenna. Now is the time to consider that move - too...

RG8X, ~27 mhz = ~1.9 dB loss / 100 ft
9913, ~25 mhz = ~0.9 dB loss / 100 ft

~1 dB is a small price to pay in the long run. It's a 250ft spool, and I'm going to be using it for other purposes, such as wiring the HF stuff up, which is a pretty long run.

The only one I supremely care about is 2m, because RG8 is VERY lossy around 144 mhz.

For that run, I'm actually bidding on a remnant spool of LMR400.

From the looks of it right now, I might go ahead and do my 2m install first, and put the 10m vertical on the backburner for 2 weeks or so.

One point hardly ever mentioned is the PROPER weatherproofing of the outside coax.

http://www.eham.net/articles/17553

Dielectric grease, and tightly wrapped electrical tape. Might do some wire loom over it for good measure?

-Richard-