My standard hurricane preps up to a few years ago included cranking my tower over, removing the antennas and leaving them on the ground, then cranking the tower back up. We haven't had a direct hit in a while, and when tropical storm Ian (a really bad hurricane over in SW Florida) came through in late September of '22 I made the mistake of not doing what I'd always done. From the looks of Milton, I'm going to go ahead and do that. Most likely that'll be Tuesday morning - and hopefully be done quickly.
I know I've said before that my antenna projects all tend to start with the words, "when it cools down." This year, I've been playing with the idea of automating something I do manually, selecting the antenna the radio will connect to automatically when I change the band I'm operating on.
Right now I use two switches, and here's a diagram I posted in June of '23 to illustrate things.
In general, I only need to change the top (antenna) selector when I'm operating. Right now, I'm looking into ways to automate that and whether or not there are advantages to doing that - besides a little convenience. There's one advantage that shows up immediately: it replaces three cables coming in through the wall with one - the output of a remote switch. Since the pipe through the wall for the bunch of cables is already there, that really doesn't buy me much. Each of those three cables would be shortened, go to a lightning protector, and then to the switch outside (possible examples of lightning protector and switch). The lightning protectors could be mounted to a separate ground rod for each antenna; I've also seen a larger chassis that more than one protector could be mounted to and that chassis mounted to a separate ground rod.
Remember, when it comes to getting rid of a lightning strike, the more ground the better. As we used to say to newbies trying to layout a printed circuit board: "groundliness is next to Godliness."
My main station radio is the IC-7610, and it has enough memories for frequency
and mode that I can press a front panel button and immediately change
frequency. The radio will remember how its antenna tuner is set, but it has no
way of selecting the antenna that it "knows" how to tune. It would be
convenient to press that button and have it select the antenna for me at the
same time. Failing that, the various pieces of software I'm running all the
time might be able to generate a command to switch the antenna.
The research aspect of this has been the most time consuming, so far.
And, yes, since I have my small machine shop, I have thought about making a
cute little robot that stands on top of the shelf where my switch is located
and just rotates the antenna switch knob for me.
Marvin the Paranoid Android - from
The Hitchhiker's Guide to the Galaxy. Image credit: Blenderartists (.org)
"I have this horrible pain in all my diodes down my left side..."
ReplyDeleteYeah, getting a discrete output for the antenna selector will go a LOOOONG way to automating things.
I'm getting started in automating mt RF/AF test gear with HPIB. Finally broke doen and bought a PCIe card, and now all my instruments show up!
ReplyDeleteOh, no... I have the PC app for the NanoVNA because it's easier to do stuff with it, and the dang thing is too small to see as well as I'd like to. But doing HPIB stuff would remind me too much of my years as bench technician. Besides, I only two things with an HPIB and I don't even know if that works.
DeleteAhh! I only have two things with an HPIB...
DeleteGood luck with the upcoming storm. The fact that there's so little divergence among the predicted track from the various models suggests that NHC has a good handle on where this is going. Regarding your antenna switching, have you looked into W2IHY's SWITCH PLUS modular family?
ReplyDeleteI'm not familiar with W2IHY's products. Need to add that to my research list.
DeleteHave a question Mr. Graybeard. Might be you come across this. Seems obscure info. By the way appreciate you, for sharing so much radio related information, learned a lot from you, thanks cause it's hard won long learned.
ReplyDeleteAnyway, this is wind turbine related; erected a permanent magnet alternator, driven by a 7ft dia, aluminum alloy 5 blade rotor, its mounted on a steel hub, to the PMA's rotor shaft, which drives 32 neodymium magnets, (fyi, no brushes or commutator, its purely magnetic flux/copper field, in a Y config, produced current), the PMA produces wild 3 phase, at the bottom of the steel tower, in an electrical enclosure, the 3 phase is rectified into 12 volt DC, that is conducted back to a battery bank, using underground conduit for welding cable, in PVC pipe. Hopefully that provides enough info, for my question I hope you could shed some light on.
About 12 years back, on a site of a fellow who sells various components for home built wind and solar, goes by Hydrogen Appliances, it was written on his website that wind turbines act as a kind of radio antenna. As an aside, due to various authoritative road blocks to erecting wind turbines in various locations, because a wind turbine is an "antenna and used as such, i guess you can not be inhibited from erecting one on your private property. Thats all I really know about that.
Your post here made me think about it, along with beginning the licensed amateur radio operator journey. Starting with 2 meter radios, HT's and a mobile, using a copper pipe J pole, and because our wind turbine is 45 tall, and on the highest point on our land, was considering mounting the 2 meter J pole on the tower, maybe using a ten foot extension, to max 2 meter range as much as possible, for the HT's. Live on a mountain ridge in WV, nothing much is flat around our AO. Looks like I got a line of sight to a buddy who wants to get his AB license, we are approx 12 miles in a straight line of sight to each-other, it is the 50ft tower that just gets above the intervening ridges between us. be pretty cool to be able to use low wattage to talk radio to radio. Just in case you know. Though there are many private run repeaters, along with all the coal mines having dedicated bands, and their 2 meter repeater stations, which are set on all the highest peaks, they use 2 meter almost exclusively, and CB's for local mining operations which they put in all surface equipment, even some underground mines have mini repeaters for 2 meter entrance to mine faces, some have cell phone boosters for underground reception also, though seems 2 meter is very popular around these parts, lot of chatter even more than CB, and that can get pretty crowded at times.
Any comments? really appreciate you, thanks much. Sorry if I blab too much.
I'm not sure I'm answering the question, but let me start here, about "... it was written on his website that wind turbines act as a kind of radio antenna."
DeleteThere's nothing that I know of that makes a wind turbine different from any other hunk of metal of the same size. What matters is how the physical size of that hunk compares to the physical size of the radio waves. A lot of people seem to have a problem with the concept of radio waves having a physical size but that's the basis of all those 1/4 wave verticals, 1/2 wave dipoles, 5/8 wave verticals and so on. The closer that metal thing is to being an odd multiple of 1/4 wave in any direction, the more likely it is to interfere with those waves.
It's also critical in building radio hardware and installing things like towers and grounds. If a wire is electrically too long, it can act like something completely different. A coax cable that's 1/8 wave long and open on the far end is perfect capacitor; if it's shorted at the far end, it's a perfect inductor - in both cases, the impedance of the inductor or cap is the impedance of the coax cable. If you're trying to ground something, that says the ground wire has to be shorter than 1/8 wave. How short? It really depends on how the impedance of the ground compares to the circuit's impedance. It can't be too short, but try to keep it under 1/20 wave long.
To me, your wind turbine at 45' tall with an extension pole sounds fine. There's no difference between a 45' tall wind turbine and a 45' tall Rohn tower or 45' tall anything made of metal.
OK thanks, appreciate you. Thats a lucid description. The verticle ground wave effects seem they are far more important.
DeleteI was only wondering if there was anything to it, for curiosity's sake. My first impression about the turbine blades have particular antenna effects struck me as advertising more than anything, aside from a trick to get around zoning and other governmental or HO obstructions putting up a wind turbine on your property. Clarification is appreciated. A small aside, when i read that quip my first thought regards would my wind turbine if I used the tower to mount a J pole atop it, would interfere somehow rather than enhance RF wave propagation. The PMA itself is a magnetic flux current generator, being it is brushless, what if any RF created by the magnetic fields could effect reception and transmission of the J pole. I'm new at this, so please excuse my ignorance, there is a lot of great things to learn, very exciting to me, sure its old hat and basic stuff to you and your vast experience, which i try to understand, but without actual hands on provides small amounts of understanding. Ordered the antenna companion book to the technicians manual, that i am looking forward to reading as it strikes me as practical git er done correctly info and tech.
The vertical ground wave antenna looks like a dandy of a system, but though we have superior elevation, our land sits on a sandstone ridge, in the best locations, there is only a foot or less soil sitting upon the sandstone, invariably the water table quickly drains off leaving the ground rather dry, though the sandstone contains high concentrations of various iron oxides such as ferric and ferris, leaving the thought of how those conductive oxides effect the ground wave propagation. cause we have perfect level runs where they can be strung. Guess just have to try to find out.
Its such a fantastic learning curve full of wondrous aspects of nature and physics. A seeming endless journey full of enjoyment and great entertainment. The world of radio waves, it is to me a most noble, and practical pass-time so to speak. I read your accounts and efforts to share with us your experience with a kind of happy envy, because I have so much to learn which is a great thing to look forward to, that led me to archive your radio related posts for future reading as I gain experience.
I believe the radio community you belong to is pretty unique, it is one of the grandest open source communities in the human sphere if activity, that really says it all in my book, so many people helping each-other in a kind of free booting style, that too gives the whole thing a legitimacy which frankly should be a model for other human activities, so much so, how do I put this to you, well briefly such co-operation and open source organization is a model for how we can live in a great prosperous society, a true sustainable civilization, free of the evil and tyranny of government as we know it. If for no other reason than free open source exchange of information is king in a civil society, it is essential in no uncertain terms. Which is surprizing, that "authorities" have yet to do to it what it attemots to or has done to almost everything it touches which is to destroy it because it has to control everything. It is almost the last of its kind left. You guys possess an almost open secret truly grass roots freedom movement. Not much of that remains in the sphere of human activity. Again it strikes me as a great model, that wonderful example which applies to many things in regards to Liberty and being Sovereign beings. Communication is everything. Over near and far distances so well established, it is just splendid and remarkable.