|
New to Ham Radio?
My Profile
Community
Articles
Forums
News
Reviews
Friends Remembered
Speak Out
Strays
Survey Question
Operating
Contesting
DX Cluster Spots
Propagation
Resources
Calendar
Classifieds
Ham Exams
Ham Links
List Archives
News Articles
Product Reviews
QSL Managers
Site Info
eHam Help (FAQ)
Support the site
The eHam Team
Advertising Info
Vision Statement
About eHam.net
|
|
1-5 of 5 messages
|
Page 1 of 1
|
|
2 questions
|
Reply
|
|
by N2AMG on March 30, 2002
|
Mail this to a friend!
|
I'm putting up a small 2 element beam on a Radio Shack 36' mast. I have 2 questions..
1. How far out from the mast should I place my Guy anchors??
2. Has anyone buried RG8/u in the ground without any pipe covering it?? If I direct bury it It saves me 100+ feet from the mast to where the house is if I hang it from the trees that run along the edge of my property. The reason I say RG8/U is I have a coil of this already.
73's Rick N2AMG
|
| |
|
RE: 2 questions
|
Reply
|
|
by KF4ZGZ on April 1, 2002
|
Mail this to a friend!
|
1-Try to keep a 45 deg. angle on the guy wires. An easy way to do this...If the wire attaches 30ft. up the mast, plant it 30 ft. fom the base of the mast. 45 deg. seems to work well, any wider and you eat up real estate, any closer and the mast gains "leverage" on the anchor and can easily pull it up ( experience talkin'..hi hi ).
2-Unless the cable is labeled for direct bury, don't do it! The jacket on the cable isn't made to withstand the constant contact with dirt, moisture, etc.
3- (I know , you only had two...) GOOD LUCK!
73 de Matt, kf4zgz
|
| |
|
RE: 2 questions
|
Reply
|
|
by WB2WIK on April 1, 2002
|
Mail this to a friend!
|
You can't keep a 45 degree angle on the guy wires, and use four sets of guy wires (as is required with the R/S 36' slip-up mast) unless you have four sets of guy anchors. That's a rather complicated mess.
I'd recommend this, assuming you have the room:
-Set four guy anchors spaced 90 degrees apart (all equidistant from the base of the mast, and also equidistant from each other), 25' out from the base of the mast.
-Use guys at the top of each mast section (four places), this totals 16 guys. Note I didn't say "guy wires," because for use under a 2 element beam, it would be best if they were not wires, but rather strong ultraviolet-resistant rope like double braided Dacron polyester. The rope is nearly as strong as steel, and much easier to work with and lighter in weight. Conductive guys (metal wire) absolutely influences the performance of the antenna placed above them unless the wires are broken up in several places with insulators. More trouble than it's worth for a telescoping mast installation.
-Do use turnbuckles, one in each guy line, to take up the slack and make final tensioning adjustments. You'll need 16 turnbuckles. They should always be installed at the "bottom" of each guy line so they're easy to reach and adjust, and once adjusted, a rope or wire should be pulled through both turnbuckle eyes and through the center of the turnbuckle (open area where eyebolts screw in) to keep them from "untwisting" themselves, as does occur during normal vibration.
-Don't overtighten the guy lines. These telescoping masts are not terribly strong, and about 50% of the ones that fail do fail because they are "over-guyed." That can make them buckle between sections. The lowest section (lowest set of guys) can be made very tight, since that's the strongest, largest diameter pipe and it is strong. The next section (at the 19' level) should be tensioned more loosely than the lower set (snug but not enough to play a musical note on them!), then the next section at the 28' level should be a tad looser, and the highest section at the 36' level should be a bit looser than that. It will be obvious if you've overtensioned the guys, you'll see the mast beginning to buckle between guys. Not a good thing.
73 & good luck!
Steve, WB2WIK/6
|
| |
|
RE: 2 questions
|
Reply
|
|
by WB6BYU on April 3, 2002
|
Mail this to a friend!
|
If you are guying the mast with rope, do be careful to use the
dacron/polyester rope as Steve suggests. Nylon is NOT a good
choice here - it stretches and it decays in sunlight - neither of
which is a desirable characteristic in this application.
|
| |
|
RE: 2 questions
|
Reply
|
|
by N2AMG on April 3, 2002
|
Mail this to a friend!
|
Thanks for the responses. I'm putting it up this weekend So I'll let you know how it turns out.
73's Rick
|
| |
|
Email Subscription
You are not subscribed to this topic.
Subscribe!
My Subscriptions
Subscriptions Help
Check our help page for help using
Forum, or send questions, comments, or suggestions to the
Forum Manager.
|
|
|
