Baffled by verticals. A few questions.

[W5LZ]

I've found that the best source of information about grounding is the National Electrical Code (NEC). That includes antenna grounding and the 'how' of doing it.
How you do safety grounds depends a lot on the antenna and where it is (naturally). As already suggested, an arrestor in the feed line is a very nice thing to have. The effective ones are NOT cheap. The 'spark-gap' type are always too 'late' to provide much protection to the equipment on that feed line. All safety ground require an adequate means of dissipating current, a single ground rod is a terrible safety ground (check that NEC). The conductor used to connect to ground also needs to be capable of carrying the current to ground, which means a much larger 'wire' than commonly thought. The minimum size for those is 6 gauge or larger. The connections of that ground wire are also important. There will be lots of current, which means heat depends on just how much, and that means a good mechanical connection, not just soldering the thing (also in that NEC). And then there's the 'catch' that the length of that ground wire will be 'controlled' by the frequency of use of the antenna it's supposed to be protecting. So, electrically speaking it should be short as possible, and RF speaking it can't be particular lengths according to the frequency of use. [Getting complicated, ain't it?? It is NEVER simple.]

So would that vertical be better on the ground? Just depends on where you wanna put in the labor. Any antenna near the ground will benefit from the 'dirt' being more conductive (less ground losses). Will that ground mounted antenna beat a roof mounted one? Only if there's a lot of effort put into the ground radials used with that antenna. Or would you rather put that 'effort' in to mounting the thing on the roof? Probably the same amount of work, just in a different form. Either method will also depend on how well that antenna, in that particular location, is tuned. Which is also not exactly 'simple'.
So which is best for you? I don't have the slightest idea, and neither does anyone else here unless they have done exactly the same sort of thing in exactly the same conditions/locations/antenna. Not a very 'nice' answer huh? The nice part is that it isn't said anywhere that you only get one shot at an antenna. I know of very few people who have only had just one.
Have fun.
- 'Doc

 

[hookedon6]

Raised verticals are easier to work with as far as radials,...

Gee, i dunno. i have 3 500 ft spools of wire under my BTV.

jus fire off the gas powered sidewalk edger,
walk BACKWARDS with it,
drop wire into the slit,
and turn on the sprinkler

 

[trapland]

Raised verticals are easier to work with as far as radials, only need about four to make it work as good as 120 ground laid radials.

Maybe a small tower, 15 to 20 feet, let the wife plant some flowers around the base, and use your ground radials as guys so double duty, will work fine and wont have all those ground radials laying in the yard to mow around.

Either way the vertical will work good, just do not expect to much from it on 20 meters and above as height is might on the upper HF frequencies.

Hmm. 4 radials per band. 20 total on a BTV5 with at least 4 of them over 65 feet long! Sounds like a harder deal to work asthetically than a few dozen buried radials of whatever length is handy. I know which one the XYL would prefer. She'd prefer the antenna that doesn't make the house look like its being eaten by a giant tarantula.

Ironically, I am already getting the best performance on 20 meters with NO radials. I think the dirt here might be good.

 

[hookedon6]

... a harder deal to work asthetically than a few dozen buried radials of whatever length is handy. I know which one the XYL would prefer. She'd prefer the antenna that doesn't make the house look like its being eaten by a giant tarantula...

on the DX eng site, there are also instructions for a "flagpole" BTV

 

[wavrider]

Here is some good reading about antennas and grounds.

The ground radials only need to be as long as your antenna is tall if using a trapped or coil loaded antenna. The near field is where most of the ground loss will be located.

Radials and Grounds

Another in depth study of radial length vs radiator height

http://rudys.typepad.com/files/vertical-height-versus-radial-system-1.doc

Installing a vertical is not the hard part, making it efficient requires some effort.

A vertical radiates poorly in all directions. But they do work and are great for low band DX where height becomes a challenge.

 

[RatsoW8]

Gee, i dunno. i have 3 500 ft spools of wire under my BTV.

jus fire off the gas powered sidewalk edger,
walk BACKWARDS with it,
drop wire into the slit,
and turn on the sprinkler

Ya know if you take the wire off the spools and lay it out flat it works better.

 

[wavrider]

Gee, i dunno. i have 3 500 ft spools of wire under my BTV.

jus fire off the gas powered sidewalk edger,
walk BACKWARDS with it,
drop wire into the slit,
and turn on the sprinkler

Gas powered sidewalk edger? The cows do a great job of keeping the grass mowed in the pasture. They are sure a pain when it comes to the ground laid radials though.

 

[cbradiomagazine.com]

Just a note regarding proper grounding - worse than losing your equipment or house to a fire, in many states if you don't take proper measure to ground your equipment your home insurance may not cover any damage or loss due to fire.

If you mount your antenna on the house without running a ground wire to a ground rod you most likely aren't following proper code and your insurance may not cover you if the antenna is hit by lightning.

Ground the antenna and add a ICE box as well

 

[trapland]

I know its been a month since the last post, but someone sometime in the future may want a conclusion. Here's what I ended up doing:

Ground mount 5 band vertical. I suspect the soil is good.

700' of wire for radials. About 20-24 total. I lost count.

Radials buried 1/2"-1". I had to.

Didn't worry too much about length since the ground detunes them anyway. I did make sure that at least 4 for each band were at least 1/4 wavelength long, except 75 meters only got one due to space.

Grounded coax shield at antenna base to ground rod, then balun. Buried coax 4" deep hoping that a direct lightning strike would blow through into ground.

Another balun and ground rod right before the feedline enters the house. Dont want rf in the shack, and that ground rod can be used for DC equipment ground as well.

Antenna is about 30 feet from house, with taller trees another 50 feet away.

Results- no problem working Europe, Central-South America and of course North America. I leave the linear off alot of the time. The only downside is I can't work closer than 1000 miles very often. Sometimes I can on 80-40 meters, but 20-15-10 meters has to be a MINIMUM of 1000 miles so far.

I'm happy. The 5BTV makes a good general use antenna for me. Next will be adding a low dipole for NVIS to fill the 1000 mile gap some. By then I may have worn down the XYL enough for a Yagi.

 

[wavrider]

Thanks for the follow up report, Sounds like a great installation and the results are the proof with the contacts made.

Enjoy the vertical and solar cycle is on the upswing so getting a yagi will help but soon a wet noodle will work for making contacts.

 

[trapland]

Thanks for the follow up report, Sounds like a great installation and the results are the proof with the contacts made.

Enjoy the vertical and solar cycle is on the upswing so getting a yagi will help but soon a wet noodle will work for making contacts.

I know what you mean about the noodle. The other day I got scolded for QRM after I tuned up into an oil can!

 

[towerdog]

You cant ground it enough. The setup I was working on today for my house will have a ground on the shielding at the base of the tower (tree), then another ground before the coax goes into the house, plus ground lead on the equipment, going to a ground ring made of a fence with rods at the corners. Dont want my house to burn down. I might even add a surge suppressor but I make habit of disconnecting the radio after use.