ARRL

KD6MZC

Joined: Sat, Apr 4th 1998, 00:00 Roles: N/A Moderates: N/A

Latest Topics

Topic Created Posts Views Last Activity
Vintage TNC Jul 8th 2012, 05:40 2 736 on 8/7/12
Antenna Support Jul 7th 2012, 21:33 1 715 on 7/7/12
Antenna Support Jul 7th 2012, 21:33 7 1,117 on 17/7/12

Latest Posts

Topic Author Posted On
Antenna Support KD6MZC on 9/7/12
I will look further at the court rulings posted but it is my impression that the focus is on zoning issues. My focus is on the structural engineering of the antenna and any supporting structure.

Where there are building codes it is necessary to comply with the technical requirements in the building code. These requirements go beyond TIA/EIA 222G.

In many states for anything beyond a small to moderate size antenna a professional engineer registered in that state is supposed to prepare the drawings and any calculations for submission to the building department. My impression is that very few professional engineers have the necessary expertise. This is a niche specialty.

What probably happens is a local engineer who is not very familiar with towers prepares the calculations. This is probably not a problem in most cases unless the tower is very tall, wind loads are very high, or icing is an issue.

In many parts of the country the building codes are loosely enforced and this is especially true for antennas which many building officials are not familiar with. This goes a long ways towards explaining why this isn’t an issue in most cases.

It will be interesting to understand the ability/willingness of tower manufacturers to satisfy the requirement that the tower was designed by a professional engineer in the state it is sold. Are their engineers licensed in all states they sell towers and if they are do they take responsibility for the design of the bracing wires and the foundation structures. This gets messier when you move an antenna to a new site and the original professional engineer is not available.

I believe the liability issues of a book are manageable. Because the situations where there is a real need for the book have to do with situations where a professional engineer is involved the secret is to aim the technical portion of the book at professional engineers with a portion advising the purchaser of the tower. The book could be used by both the local engineer and the purchaser of the tower. Maybe what is needed are two booklets.

At the root of this discussion is the question of what your average ham can reasonably do and when he/she needs other expertise. There are no simple answers.

While there are a lot of nuggets of useful information in the posted information some of the “conventional wisdom” by those who have erected towers is questionable.

Mark
KD6MZC
Vintage TNC KD6MZC on 8/7/12
I have a Kantronics KPC-3 (not KPC-3+) that i would like to use. The primary issue is identifying the software should I need get to run on my computer? I will be using Windows 7 or 8.

My understanding is the lap top computer will not have a DB-9 port so I will need either a cable that goes from the DB-25 connector on the TNC to a USB connector or a cable that goes from the DB-9 on the existing cable to a USB connector. My understanding is that this is a common part so do not expect this to be a problem.

I will be operating on 2M or 440 using a hand held radio.
Antenna Support KD6MZC on 8/7/12
Zack

Useful references. There is much to learn.

Some of the references are dated in that the building code provisions have recently changed and the way wind loads are calculated are different. The final result may not be much different in most cases still one wants to comply with the current provisions.

The EIA/TIA 222-G standard is expensive.

Lack of discussion regarding need to get building department approvals, where they enforce the building code.

Some of the information I found reflects engineering knowledge while other information suggest that the author is passing along "conventional wisdom" some of which is wrong or simplistic.

Mark
KD6MZC
Antenna Support KD6MZC on 7/7/12
I am interested in information on the mechanical design of antennas and their support. Of specific interest is the basis for calculating wind loads and deflection criteria.

In my professional life I am a Structural Engineer so I would appreciate all information from the basic to detailed technical.

Given that aluminum is used a lot I would also be interested in what grades of aluminum are typically used in antenna structures.


Mark
KD6MZC
Antenna Support KD6MZC on 7/7/12
I am interested in information on the mechanical design of antennas and their support. Of specific interest is the basis for calculating wind loads and deflection criteria.

In my professional life I am a Structural Engineer so I would appreciate all information from the basic to detailed technical.

Given that aluminum is used a lot I would also be interested in what grades of aluminum are typically used in antenna structures.


Mark
KD6MZC

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