we have no railing on the existing bridge (that has been up for probably 80 years). I have to make a trip out there to check out the existing bridge and what can be reused. I planned on putting some wood 2x6 planks across to make a track to drive over (as opposed to a cattle guard style which...
I will need some time to work through some things based on the last few posts. I am not sure if RAM Advanse will be much of an option for me as I am not familiar with the program at all. I did download an evaluation copy but its not exactly like working in AutoCAD or other such programs.
Well, first of all, this is a low priority side project to do on a family farm where we do some deer hunting. Beyond that, this is a very unique opportunity to apply some learned principles of engineering but more importantly learn much more. I am not asking anyone to do any work for me, simply...
That is an option as well. I need to take a detailed look at the span and the existing bridge (what portions can be reused etc). A welder that made some gates from the same material took a look at the span and said he could "build a bridge to support a cement truck". Being that he has made...
Well my thought was that I could use multiple long members (5.5" OD) to distribute the load. I really need to be able to drive a tractor across and some vehicles. The material I have available are these steel drill stems. Thanks for your replies.
Sorry, I should have been a bit more detailed. I am going to build a small bridge (25-30') out of some structural pipe I have. The OD ranges from 2 3/8" to 5.5". At any rate, the idea was to build a bridge based on a warren truss. Without going into extreme detailed analysis I was hoping to...
Can someone give me an idea of how to calculate load capacity on a steel pipe with a certain OD at a given length? Are there calculators online I could use?
TIA
I would like to know if anyone could recommend an oscilloscope to use in a few projects I am working on. The first one is a radio kit and some testing requires an o-scope. I was looking on e-bay and hoping I could find one I could use for a couple hundred dollars or less.
TIA
Do any of you have experience with posting a job in the Eng-tips job section? I am not in a position to hire or anything but I know we (A&E firm) are looking for a Sr. RF Engineer and before I suggest posting on this website I was wondering if there was a good deal of "qualified" traffic. We...
Thanks to you all. I went ahead and ordered Microwave and Rf Design of Wireless Systems by David M. Pozar. The TOC looks like it covers just about everything I am looking for.
Thanks for the recommendation! Actually I dont mind the math at all.
I will look through the book offerings on those sites.
Any other suggestions of textbook type material would be appreciated.
Could someone steer me to a good book on RF. I am looking for something that discusses Intermodulation and other interference, noise figure, as well as equipment like isolators, duplexers, multicouplers etc. I would like something pretty detailed as long as the math isnt too much beyond Calc III.
You can look at multicouplers or combiners. Here is an example of a combiner for 800MHz http://www.dbspectra.com/products/DBS-113AB/DBS-HC113T1-08F.pdf
Higgler,
Does that rule of thumb only work with omni antennas? Was the 2" spacing vertical or horizontal? How can you determine what the near field actually is (in meters)?
TIA
Ah, I apologize. I did a search for other posts that contained "horizontal isolation" but did not see anything that directly answered my question. That thread was not listed either. I appreciate your input and will review the thread.
I am trying to get information on what kind of separation is needed between antennas. I have found a few calculators but they seem to base "xdB" of separation requires "x ft" for omnidirectional antennas. If there is a situation where directional antennas are used how should this be appraoched...
When placing antennas close to one another (such as on an antenna farm), spacing or isolation is a concern. I think what needs to be considered is the propagation pattern of the antennas and as long as the main lobes and minimal side lobes reach an adjacent antenna, there should be adequate...
