WRKC935

Yeah, I was down there recently myself. Had my first intercontinental chat on Echo Link. Talked to a guy in Ireland. Was very surprised with that since I didn't know the repeater was an Echo Link machine. GMRS however was flat. Nothing heard. Hope that changes some before my next trip down.

Since this was last discussed I have moved forward on getting equipment moved over to the battery plant. I am now running 3 repeaters and 5 base stations (repeaters programmed for base station operation) on the battery plant. The plant is 48 volt and has 4 strings of 75 AH batteries connected to it. I need to get out the welder and build another battery tray and increase the string count to 6 or 8, but that's a different discussion. The system is grid tie only at this point. No solar or wind equipment has been setup for it. A project for a later date. Looking at running 4 wind generators based on the plastic 55 gallon drum design. Will be building one and seeing how that works before building the other three. System as it sets is a commercial rectifier (charger / power supply) that is a modular setup with 8 40 amp switch mode supplies. These feed into the attached power distribution panel that has connections for both battery strings and loads. There are five 48 volt to 24 volt switch mode buck converters with a current capacity of 40 amps per unit connected to the plant that are paralleled output. These feed a separate power distribution panel to feed the 24 volt loads. One feed is running over to a 'sub panel' that is rated 70 amp in and has 5 15 amp breakers that are feeding the base radios and repeaters. This is their only power source and have been running in this configuration for about a month now. I am working on getting some additional cable tray in place and will then be running additional feeds to other equipment. Another project is to convert the 12 volt plant that is separate from the 48 volt plant over to that plant. This will be 48 volt to 12 volt conversion. most likely will be two 60 amp buck converters in parallel feeding another distribution panel for the 12 volt loads. I am researching the fact that Cisco had a backup power setup for some of their switches that i already have. I may be able to directly feed these switches with 12 and 48 volt power and take them off 110 all together. They are running on UPS currently but if I can move stuff over to the battery plant, then I will have less equipment to maintenance.

Oh, I certainly agree that lightning can be VERY destructive and not directly hit the equipment that it damages. Part of the R56 installation manual is the grounding and bonding section. Now the standard that this manual is detailed to the point of the minimum distance between a rack and the cable tray above it and the distance from the cable tray to the interior lights. Nothing is missed that you would find inside of a communications site. I have seen where voltages were induced on metallic but non-electrified objects like file cabinets. And yes, they are required to be grounded as well for that reason. One of my favorite lightning stories was a personal experience from back when I was working in the computer field and one of our contract customers was the Ohio department of corrections. One of their facilities had a control room that sort of stuck out off the rest of the building in an atrium sort of area, AKA "The Yard". Of course this structure had 1 inch bars over the windows and it was the most physically secure part of the whole campus. The lightning hit the outside of the building and traveled down the outside of the structure via the bars on it and then arced to the ground, which was evident by looking at the outside of the building. The current was so high in the bar's that it created enough of a magnetic field to put colored bar's in all the computer monitors. I had to go home and get a degaussing coil I had from working on television sets (old school CRT stuff) and take it there to get the screens fixed up. You could tell it was the bars on the windows because the color bars were spaced perfectly with the same spacing as the window bars. But even that HUGE magnetic field that was less than 2 feet from a half dozen computers did no damage to and of the computers in the room that were up and running at the time of the strike. Which further's my personal stance on the protection of electronic gear in a box of some sort to protect it from an EMP. And with that situation, the bars weren't acting as a faraday cage, they actually increased the "EMP" energy getting into the building via the huge magnetic pulse they created.

I realize that. Of course you're not the original poster of the thread

While that might be the case elsewhere, the linked repeater here in Columbus is the only one in the entire state that is on the link. And I provide another nonlinear repeater for those that don't want to talk to everyone else. Is it personal. Yes. The op knows me from way back. So its not like we are strangers or anything. Far as I am concerned since I am the only one doing what he's complaining about in the entire state of Ohio I am gonna guess he means it to be personal as well.

Tell you what. How about I take all my shit off the air and you can sit and listen to static. Maybe some kids once in a while on FRS. Since I am the only one in central Ohio with a linked repeater, I am obviously the one wasting the precious spectrum that no one else seems to want to bother with putting a repeater on. Balls in your court now buddy. You don't like what I provide for free. You put a repeater on the air. I will turn all this gear back into cash and make it someone else's issue. It gets old listening to others complain about what I do with no cost to others because I can. If you don't like it, don't use it. I really don't care at this point.

Well that's much easier said than done. What you are talking about is a simulcast system with multiple repeaters that would need a GPS reference to stay exactly on frequency. All the receivers being connected back to a single voter so the best signal was selected and then channel banks taking care of the audio launch times so that it would actually work as described. It's obviously possible, but silly expensive. And requires a lot of maintenance and upkeep to continue to function correctly. I am considering it as I do have the required hardware. Need to figure out sites beyond the one I have now and proper links between those sites (can't use the Internet as the latency bounces around far too much). But that's still only going to be in the central Ohio area. I guess if you don't like talking on linked repeaters, stay off them. It's really not any harder than that. For those of us that enjoy being able to have someone to talk to most of the time, we enjoy that.

Here's a slightly different take on it. Repeater owners and their desire. Meaning if YOU have a repeater and don't want people getting on it and rag chewing all the time holding in it transmit for hours at a go then tell those folks that are acting in that manner to vacate YOUR repeater. Now of course, if it's NOT your repeater, then you really don't have a dog in the fight. Not your repeater, not your choice. We as repeater owners make the decision on who uses it, how it's linked, if at all. And what sort of discussion can take place on the repeater. After all, it's our equipment and our decision. While I would like to keep all my repeater users happy, it's not a realistic goal. Meaning there are ALWAYS going to be those that want to claim this or that about proper use, linking, IDing of the repeater and the list goes on. I look at it like this. If I don't like the way someone is using MY gear, I will simply get on the air and ASK them to not operate in that manner on my repeater. If that's not sufficient to get them to either act in a manner that's more acceptable, I can ban them from the repeater. And since my repeater is 3 miles from my house, I of course can drive over, and turn the thing off. Same thing with the linked repeater. If I don't like what's coming in from elsewhere, I can open my phone and drop the link. Easy as that. Point is this, if you own a repeater or a system of repeaters, you have the final say within the limits of the FCC regulations or what's said on it and how it's used. If you are a guest on someone else's repeater, then it's their show, and you are only along for the ride. Demanding that a repeater owner deal with some issue that YOU find to be a problem when they don't see it as such is a sure fire way to get banned from their repeater completely.

Little bit of expansion on the discussion of DIY cages. I have worked with commercial Faraday cages in the past doing RF work. Reasoning was you can't truly evaluate the performance of a radio receiver when it has multiple RF signals near it. The commercially sold cages we used were a sheet metal room (technically sheet aluminum and not metal) with an aluminum frame that the outer shield was screwed to. It was also glued with a conductive construction adhesive. The door on the unit was staggered and 6 inches thick with the inner face reaching into connect to the inner shield and had finger stock that surrounded the inner part and a separate ring of finger stock on the outer ring. There was enough room in the cage for a workbench and the required test equipment, a chair for the desk and a bit of space to move around. It was probably 6 by 6 or 8 by 8, but no bigger. Special electrical filters were connected to the power feed for the interior and while there was a 'window' it was inset into the door and has copper screening on the interior and the exterior hole was also screened. So it's technically possible to have a window, it still needs to maintain the 100% shielding inside and out. Air ducts were connected to the HVAC but there were special screens that needed weekly attention to keep them clean as the screen material was a very fine mesh and collected a TON of dust and crap. Again, there is no really secret sauce for building a cage. The info is on the web.

Well, if we are gonna get into 'real' Faraday Cages, then lets actually talk about their construction. First off, they are layered. There is an outer and inner layer and they are NOT connected together. Hole size in the shielding material is what sets the minimum / maximum frequency that is blocked. In other words. A fine mesh will block a higher frequency than chicken wire will with 1 inch holes in it. Consider the holes with regard to frequency wavelength. If the hole is larger than the wavelength of the frequency in question, it will pass right through like it wasn't even there. A strong understanding of the signal level and the attenuation level of the Faraday Cage needs to be taken into account. A cage is not a perfect attenuator. It has very high attenuation levels, but a signal that is strong enough will get through at a much reduced level. Proper construction. A 2X4 or 2X6 frame is sufficient spacing to get a very high attenuation level with modest materials. Those being standard wood framing and aluminum screen. For an added sense of security, thin sheet metal can be used in place of the screen. You have an inner layer and an outer layer. of the conductive screen material. And remember they can't in any way be connected or you will loose attenuation properties. The other thing you need is a GOOD earth ground. This is not the 1 or 2 ground rods that are grounding your electrical service entrance, you will need to do better and it's advisable that the grounds be kept short as possible. So if you are planning on building a cage, do it on the first floor or in the basement near an outside wall so you can get the ground wires out the wall and to the ground field withthe shortest wire possible. Longer wires equal bigger antenna's and you don't want that. To put a door on the cage, you will need to ensure that the entire perimeter of the door be connected to the screens, both inside and outside. Couple ways of dealing with this is either finger stock, copper or other metallic door trim / weather stripping, or construction methods that taper the inner and outer screens in a way that when the door / cover is in place that a 100% seal exists in all locations around the door inside and out. Again, can't say this enough, the INNER shielding material is NOT connected to ANYTHING including the outer shielding material. For those that are looking to play around and build something similar to the professional level cages, this should be a good starting point. Sure you can locate copper screen and use that. It will work the best but it's also very expensive. Not worth the money to protect your Baofeng radios. If you are REALLY wanting to go for broke and build a large cage, and be able to occupy the space, there are methods of bringing power and RF into the cage, but special filters and methods are required and are put in place outside the cage and are bonded to the same ground as the outer layer of the cage. Remember that you need both layers of screening on all sides, including the roof and floor. There is no reason that you can't set the floor screen and then sheet over it with layers of plywood or other subflooring material as long as the screening isn't molested (floating floor material.And of course you can also drywall the walls and ceiling but it's advisable to use construction cement and not screws to fasten the drywall to the framing. Screws can be used sparingly to assist in placing the drywall until the adhesive is dry but will need to be removed after that happens to ensure the best isolation. If you bring electricity into the cage, do NOT bring a ground with it and you HAVE to use an isolation transformer with proper filtering right at the entry point on the OUTSIDE of the cage, DO NOT use conductive conduit to route wiring through within the inner shield. Detailed construction instructions are available on the web for building a Faraday Cage. Study those plans carefully and scale your project to your needs.

And that was my whole point. Thing is that the South Korea and China saw no damage either. And I was at a loss to find any information on damage done in the US from tests when they were conducted, which was the point of what I said. EMP is a real thing, and I am not trying to minimize the effects of it when it comes to things like the electrical grid. But to hear some people talk about an EMP is that anyone with ear rings in will be electrocuted by the voltage induced between them across your head. We had cars with computers in the 90's. No one seemed to be effected by the EMP from any of the testing in that era. Sure those detonations were below ground. But if the EMP is that powerful to effect every car in the midwest from a high altitude air burst then how is it that no one was effected at all during any of the testing. Or were those effects just not documented? I don't know.

Here's the issue with this. We don't know what we don't know when it comes to an EMP. And much of what we do know about it, or think we know comes from Hollywood where all the battery powered everything from automobiles to wrist watches are going to throw sparks all over the place and fry in a very dramatic manner. Yet it's said that old tube gear will be fine. Which honestly makes little sense. So here's what I know about it. And this comes from being an R56 certified installer and digging deeper into the bonding and grounding aspect of it. First thing is you can't 'prevent' lightning, you can only attempt to prepare for it and hope you have done all that is needed. We all know some CB operator that disconnects his antenna cables in puts them in a glass jar. News flash on that. Lightning jumps up to 9 miles during a strike. That little bit of glass, the 6 to 8 inches of rubber on a car tire or whatever is NOT going to stop the strike. And in truth, disconnecting the antenna cable if the cable and antenna isn't grounded at all past the shield being connected to the chassis ground of the equipment actually increases the chance of a strike. Glass jar be damned. The antenna has no where to bleed off the charge that builds up on it and it actually becomes a better path to ground because it's charged and other stuff isn't. Less of a voltage difference. Yeah, you may see some arcing on the connector in the jar, but that is an indication of the very thing I am talking about. You ground and bond everything to a common point to bleed off that charge. But you also bond it all together for when it does get hit. If you have a couple radios, a computer, power supply and such all connected together as a station, and your your tower gets hit. If EVERYTHING is bonded, then all that gear jumps to several thousand volts and then back to zero,,, but it all does it at once since it's bonded together. If you remove that bonding. Lets say on the computer you are using for HF packet and the power supply. Now all of a sudden, there is several thousand volts of potential difference between the power supply the computer and the radio. Guess what happens. So back to the EMP business. An EMP is nothing more than a light lightning strike. And if you think about that statement, think about lightning and the voltages and currents present you will realize that 10 million amps across a number 2 or even a 4/0 wire is going to be THOUSANDS of volts in the wire. Yet, towers get hit all the time. R56 is a standard used for 911 centers where they CAN'T unhook their antenna's and stop working during a storm. And if there is a tower at the center with radios connected to it and the dispatch console, then there is a direct DC path (considering the voltage potential of lightning) from the top of that mast to the headset of the dispatcher. So what do we really know about an EMP? Do we need to stick radios in Faraday cages to expect them to survive the pulse? What happened to all the electronic equipment (yes it was tube back in the day) when the US and Russia would test nukes in Nevada and the island chains they were known for? And when did the testing actually stop? Well the US's last test was in 1992. And the North Korean's was in 2017. Yet there is no information available about peoples cars stopping, radios dying, or any of that. So at what point would you need to store a radio in a Faraday Cage in order to protect it? And the answer is striking. If the EMP is that strong, the radio would need to be stored 30 to 50 feet below ground in a Faraday Cage to survive because you are close enough that the blast wave will destroy it at ground level. Now of course connected to the grid, and an antenna that distance increases, but not if you have proper bonding and grounding and correct surge suppression on the equipment in question. Antenna size and type will also play a role in this. A big HF antenna like a 40 meter dipole will take a bigger induced voltage than a UHF DC grounded folded dipole Like a DB-404 or other DB series base station antenna. This is due to the design of the antenna. Folded dipoles are closed loops with one end being grounded. HF type dipoles are open ended and typically are NOT grounded. In fact the standard half wave dipole is suppose to be a balanced design. So in theory a balun of proper design can be used with an HF dipole to protect the antenna to some degree when coupled with a proper surge suppressor. A good reference for this stuff is the Military grounding and bonding manual that goes into not only lightning suppression but EMP mitigation.

First off what is a 'channel block' forgive my ignorance. I have been a commercial radio tech for going on 15 years and a ham for 30. Never heard that term. I see things in zones and channels. If you are scanning the simplex channels with NO tone, and scanning the repeaters with tone the radio can stop on either one if a repeater is transmitting. If it's not looking for any tone, then any tone will work as well as no tone at all. Because it's not looking for it. No clue what radio you are using, so I can't even comment on the idea of priority scan. If it's a commercial radio, and it has priority scan running it will look at a channel, then the priority list, then the next channel in the scan list then the priority list again, then the next scan list member. This can slow scanning down a good bit, and commercial radios are NOT good scanners. They are not fast with standard scanning, and when you turn on priority scanning they get really slow. My advice, if you are gonna be scanning, buy a scanner. In fact as long as the stuff you are scanning is analog and not P25 trunking, buy several scanners. If you do have trunking stuff you are wanting to monitor, get a scanner for that too. Analog scanners are dirt cheap because they don't listen to the police any more in many places. But if you are wanting to monitor GMRS, ham or other analog stuff they work great. And trying to figure out what a radio in scan mode is doing by looking at percentages of when it stops and opens up isn't really gonna work out for you.

Oh it's possible. I can see a broadcaster buying / acquiring a broadcast tower from another broadcaster and getting it in the air and making money. But the key there is the money making. If you are in a good market and have a 2K per day income in advertizing dollars then spending 50 or 100K for a tower and that much again on a transmitter and studio gear to be on the air makes perfect sense. But it's gonna be rare that a HAM / GMRS operator is gonna be able to even relocate even 5 sections of Rohn 80 tower. Mine was almost 4 times that. Mind you the sections are 400 pounds for the top ones and the bottom and torque arm reinforced sections are 600 plus pounds. They are also 20 feet long which is a standard for medium rated commercial broadcast towers. Truly big commercial towers like Rohn 90 and above (some with 14 foot faces) weigh over 1000 pounds a section and are longer than 20 feet per section. But just so we are clear, I am not referencing the small TV and ham type towers that are in 10 foot sections and standing next to many houses with a TV antenna on top of them. That stuff can be lifted and moved about with one hand and only weighs 15 or so pounds per section.

My personal setup is a bit overkill for anyone new to radio. I run an APX8500 and a Comet 2X4 antenna. So that being said. A good starting configuration for the folks just getting into GMRS is gonna be an NMO mag mount with a unity gain whip. That is by far the least expensive option and will still give reasonable performance to get you on the air and talking on the local repeaters and some simplex as well. One of the things that people fail to understand, especially with mobile setups is the amount of available gain in mobile antenna's from unity gain to the highest numbers available is only about a 9 dB difference. Now while that sounds like a ton of gain, when you are looking at signal levels in a radio and what is receivable and whats solid copy all falls into a range of about 6 to 9dB. If your squelch is set to -118dBm which is pretty typical, could be as high as -110 dBm but that's pretty tight. When you are at -118dBm you are gonna be about 25% noise. But if you open the squelch up more and go down to -120dBm signal level you are now at 50% plus noise with your signal. So down at that level it matters. That being said. If you increase from -120 to -110, you are typically going to be perfect copy, and by the time you are at -107 you are solid. Any increase from there is NOT going to have any effect on your signal. You will sound the same from -105 to -50dBm. The reception just doesn't change. Point is this. If you have a local repeater that has a signal level of -100dBm in all the area's that you travel, putting a 9 dB gain antenna gets you NOTHING for increased signal. And UHF is finicky. Hills and valleys will block the signal no matter the antenna gain. I have two radios in my truck. One is an XPR4550 with a unity gain whip. The other is the 8500 with the 2X4 Comet. When I start loosing the repeater on either radio due to topography, both radios suffer equally. The signal is just blocked and there is nothing that can be done about that. And there are places that I can't talk on my repeater that are less than 10 miles from it, but there are places I can talk on my repeater that are 60 miles from it. So bear that in mind when your signal fades out and comes back and you feel you would be doing better to go drop $100 on a wiz-bang high gain mobile and antenna and mount thinking it's gonna cure all your problems.

Oh I can't afford free towers. Especially big broadcast towers. What you end up finding out is the towers typically will not pass a structural analysis and can't be used unless extensive reinforcement is done to them, if it's possible at all. When the power that be (local building inspectors) ask for the results, you don't be a permit to stand the thing back up. And that says nothing of the cost of dismantling a standing tower, transporting it and erecting in at a new location. I personally went through this with a Rohn 80 that was only 10 years old at the time. While it would still pass analysis, the concrete alone to put it back up was going to cost me 15K. With a total cost of about 50K to get the thing standing. I didn't have enough land to do it either, which of course is a concern. Point is if a tower that costs tens or even hundred of thousands to erect is FREE, free is TOO expensive for most.

You know they make a tool for that.

I see how if you want to split hairs here that it applies. What I am saying is that if I go down to the local TV station that has two UHF MSF5000's repeaters sitting on a deck at 750 feet. Yes, they are there I have worked on them. If I get permission from them to go up there and reprogram one for a GMRS frequency, lower the power to 50 watts (100 watt stations) then I am completely legal as far as the FCC is concerned. Now that's not going to happen since they use those repeaters. But, the FCC regulations regarding GMRS don't have any restriction on me doing it. That's the point I was trying to make.

So me in the part 95 regulations where it says you can't place an antenna above X height. It's NOT there... anywhere. What you can build for a tower is going to be limited by your location with regard to airports, flight paths and other factors. And yes, getting the proper permitting for a 1000 foot tower may not may not be possible in a specific location. You may be limited to 20 feet and be required to have obstruction lighting on it even at that height if you are right off the end of a runway. But that is still not a GMRS SPECIFIC height restriction. It's a general restriction that would apply to any tower including one for a TV antenna.

Yes, this is correct. But if you either have the structure already, permission to install on a tower owned by others, or have deep enough pockets to stand up a tower there is no limit to the height of a GMRS antenna. On LMR, the coordination body / FCC limits ERP, power out and height to maintain coverage only extends to your licensed operating area. Yes, we are limited to 50 watts out on power. But we have no ERP restriction outside the 467Mhz channels that are limited to .5 watt ERP. And while the FCC has the requirements in place for obstruction marking (tower lights) in their regulations, it's the FAA that sets these standards.

The only place in the rules where ERP is even mentioned is specifically posted above regarding the 467Mhz iinterstitial channels. So a GAIN antenna can NOT be used with a .5 watt radio on those specific frequencies. And since you grasp the concept of gain and such. Most fail to realize that while we are limited to 50 watts of output at the transmitter there is zero height limitation on a GMRS base station or repeater antenna. You can go as high as you want and can afford to. Here is the reason this fact is significant. Broadcast and LMR (commercial) radio are in fact height limited. And the reason is a realized gain due to height. That gain is about 6dB for every time you double your antenna height. So if you have a repeater at your home and it's on a 20 foot roof peak. You stand up a 320 foot tower next to your house and park the antenna up there. Cable loss not considered. You have a perceived gain of 24dB. Putting that into perspective. To put out the same signal at 20 feet would require feeding the antenna 12800 watts. Again, not considering cable loss. Go from a 3dBi gain antenna on the roof to a 6dBi gain antenna on the tower in the process and it's now 25600 watts. Antenna height, to a point is the most important thing to have with a radio system of any type if you want it to have good coverage. And antenna gain, both from design and height equally effect both your receive and transmit, where increasing power output only increases the distance you can be heard. It does nothing for your ability to hear others.

OK, explain your current setup. You said you can put an antenna up on your house. But you make no mention of current antenna system, placement, height or anything else. No idea here what you are working with so it's hard to point you in a direction.

Your spelling is Wong / Wrong.... sorry, couldn't resist

Yeah, add repeaters are EXPENSIVE, hard to support, and will either bring you constant complaints that the coverage doesn't go someplace specific they want it to or that no one will ever use the thing. But it's usually both issues that arise. Obviously need to cover radio operations, passing a conversation. Waiting on others to break in. Not trying to talk over the reset tone. Roger beeps are for CB and not GMRS.

Resistance of the heating element when cold too low for the FET's to drive without going nuclear? Transformer acts as sort of an impedance match so the elements can heat up? Purely guessing here.