jdomer222
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Posts posted by jdomer222
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1 hour ago, gman1971 said:
If you are going to sink 400+ bucks on an antenna, get a commscope DB-404. Get this:
https://www.theantennafarm.com/catalog/index.php?main_page=product_info&products_id=4267
Don't waste your money on ANY verticals, they all suck for simplex because they are all cloud warmers, as the main lobe fires upwards with a takeoff angle and not towards horizon like half wave dipole arrays do. People will say that EZNEC says X Y Z, but then always verify with reality, sometimes those antenna modeling programs are not as accurate as real life is. I've measured RSSI strength in a Hustler G7, which the modeling curve shows almost horizontal radiation angle, its on VHF but its the same idea, its +6 dBd gain vertical antenna, but measured a whopping 18 dBm lower RSSI than a mere single half wave dipole with 1.85 dBd at the same 5 mile distance. So there you go, papers and equations can tell you whatever... real life usually disagrees, so measure everything in the real world too. If real life disagrees, means something is missing from those equations.
G.
Would I be able to put something that heavy on a mast like I am planning on erecting, or would it require a proper tower?
I guess my mast is going to be more like 30-40 ft since I am now planning to put it on top of a 25 ft roof peak rather than on the ground.
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I'm pretty new at all of this. Are UHF radios legal (within the rules) to transmit on GMRS channels? I was under the impression that it had to be an actual GMRS radio.
Sorry this has turned into a "help a newb set up a base station" thread instead of just an antenna mast thread, but I really appreciate all of the suggestions.
I think for the mast I will plan on installing on top of the roof instead so the mast doesn't have to be as tall, and I am considering either this antenna https://www.theantennafarm.com/catalog/index.php?main_page=product_info&cPath=191_193_258_976_250_1096&products_id=8031 or the shorter 5 dbd version for half the price. If I am calculating correctly either version at that height would get at least a -3db signal at about 300 ft from the house.
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24 minutes ago, gortex2 said:
And also remember the cable cost. 60' mast means at minimum 75' of cable to get you in the house. RG/LMR is most likely not the best option here. You really want LDF hardline which will cost almost or more than your mast. As was stated earlier 60' is on the edge of a mast. I would start looking at tower sections. Rohn is solid performer and 50' with a 10' mast of aluminum would be ideal. Still needs guyed but will stay up much longer than pipe bolted together. Budget everything you need and decide if 60' is really what you need.
Thank you for the cable suggestion. I want to do the install as well as I can up to a point... I haven't figured an exact total budget, but a tower will definitely be too expensive (and more of an eyesore I think). If that is what would be required I would rather just go lower.
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53 minutes ago, gman1971 said:
Hi,
60' feet above the ground, for just a mast, and not a tower, I recommend, like others, using the house or the tallest property structure for support and/or to start the mast there, so you can reduce the amount of actual mast you'll need to raise to get to the desired height. I honestly think going with a 2-bay or 4-bay folded dipole will also produce very good results even with something that isn't above 50 feet. Also I recommend acquiring a good radio to be mated to this antenna, as it will be exposed to all kinds of RF from nearby super high power transmitters, so a cheap radio might be more detrimental to your range aspirations.
If you must start on the ground, then I would use 10' foot galvanized water pipe steel sections, starting from the thickest diameter you can find, either 1 1/2 inch or 2 inch, etc, using the thicker tube as a sleeve for the next smaller section, like a telescopic antenna. At 60 feet, do not thread things with couplers, or they will snap, and trust me, its not pretty when that happens. As for guying, I would use two guy wires per direction, one at 40% of the height, and one at 95% of the height in a triangular 120 degree fashion. To raise this I would use a vehicle, along with a 10 foot section as fulcrum to get it off the ground, along with a helper so the pipe doesn't bend too much when first being raised.
Source: I've done this myself.
G.
Thank you for your suggestions.
Do you have any radio suggestions? I don't know where to find something "commercial." Right now I am thinking a Wouxun KG-1000g with power supply.
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16 minutes ago, WROZ250 said:
Unfortunately, I am not intimately familiar with chain link fencing hardware, although it looks like it would do the job...
That said, I've experimented with a lot of DIY masts using off the shelf hardware and many of these items will work. However, as strong as some material/pipe appears, once it is vertical with an antenna on it, you find out very quickly that it isn't what you expected. If you do this, guy wires are definitely going to be a 'must have' and, I think what you have planned may very well be sufficient, unless you live in an area with frequent high winds.
As PACNWComms noted, you may be better off with a mast intended for this purpose.
FWIW, my current DIY mast is only 25Ft (AGL) made from 2 inch, off the shelf 'conduit' (Home Depot), and it absolutely requires guy wires. It's predecessor of the same design, without guys, looked like it was perfect for the job, but eventually flexed so much under the load, that it snapped at the base. What is out there now still gives me concerns and ultimately it is going to be replaced with a a 25ft, free standing, Rohn tower. It's easy and financially attractive to go with other materials from the local hardware store but, in the end, it may be cheaper to just bite the bullet so to speak, spend the money and use something designed for the job.
For example, ask yourself, how much did you spend on your antenna? I watched $110 of antenna drop and get shattered. That alone was aggravation, not to mention the cost of a new (DIY) mast and the time to re-erect it. I was lucky still, as my hardline was undamaged.
Just one person's opinion (experience)...To clarify, my goal is not necessarily to go as cheap as possible, but to get to 60 ft in height with a mast.
I could use one of those telescoping poles and start it 15 feet up the side of the house, but I was hoping to have it start from the ground to be sturdier.
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9 minutes ago, PACNWComms said:
I am sure you will get an abundance of information on this site. To get you started though, use pipe that is intended for an antenna mast. Here are examples of what are easily and cheaply found online. https://www.cableandwireshop.com/50-foot-telescopic-push-up-antenna-mast-ez-tm-50.html
Thank you for your suggestion. That is exactly what I was referring to that I found, but I would prefer to figure out a way to get to 60ft rather than 44.
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I have gathered all kinds of information thus far, but one thing I am having a very hard time figuring out is how I can make a tall base station antenna mast. The city I live in allows 70ft amateur radio antennas without a special permit, and I think every foot of that would be beneficial for my local terrain. I intend to align it with the peak of my roof (25ft) resting on the concrete patio below. The first 25 ft will be held to the house with probably 3 brackets. Above that I plan to send 2 guy lines anchors to the opposite corners of the roof, and 2 more line anchors down to the ground below. I think the guys will be spaced about every 10 ft (probably 4 points on the mast for the roughly 35 ft of mast above the roof level - then a 9 ft antenna at the top).
Can I use chain link fence top rail for this and drill and but and bolt each joint? The only thing I have seen so far is a telescoping mast that reaches about 44 ft, or a 50ft fiberglass one that hits 50 ft. I cannot find any construction information for a mast this tall.
Thank you in advance for your help.
60 FT Guyed Antenna Mast Materials?
in Technical Discussion
Posted
Please excuse my ignorance, but is there a reason other than value for these radio recommendations? I have a kg-1000g in a vehicle that I like some of the features of...and I considered potentially using one as a base station radio because I couldn't find info on any 110v gmrs radios. Are all of the options going to pretty much be repurposed 12vdc mobile units for gmrs?
Thanks again for all of the help. I don't know anyone personally who is knowledgeable about radios, and though I've learned a fair amount just researching, I still feel like I know so little that I don't even know the right questions to ask yet!