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W3TDH

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Everything posted by W3TDH

  1. Well great. If I make it through this pandemic alive I'll give you a call. -- Tom W3TDH
  2. I should point out that I worked as a control electrician and was good enough that other electricians would ask for my help with control wiring challenges. I've done controls for pharmaceutical laboratories that handle dangerous pathogens. I passed the field Underwriters Laboratory Inspection on both of those. I also worked for 2 years as a fire alarm installation and repair electrician which involved a lot of control work to integrate the fire detection with elevator, kitchen hood system, fire sprinkler controls, and central station signalling systems. I share all that to say to anyone reading the control schemes above that I AM, IN FACT, A PROFESSIONAL CONTROL ELECTRICIAN! Even another electrician who has not done extensive control work should not try to devise a power transfer assembly because it is literally a devastating injury and death prevention task. I'm not being arrogant in taking this task on. Life and death control systems, such as elevator control and fire alarm systems were my bread and butter for years. I know how to make and read ladder diagrams and control schematics. Attempting to design a one off power transfer control assembly would not be something most electricians would know how to do and, more importantly, know how to test. I'm not going to describe how transfer assembly testing is done less I tempt unqualified people to attempt it. It requires tools and equipment that most electricians do not have access to, let alone most AROs. As too why I left solar power for my home to last, it is because of it's cost and the amount of work required. My order of back up power improvements, to my home, is based on short term effectiveness followed by long term effectiveness but only from a continuity of emergency radio operations point of view. Making the changes in the transfer equipment would go gradually from strictly manual; which is what I have now; to remote manual. Then from remote manual to partial automatic. And from partial automatic to fully automatic transfer. Now that you made me look at this again I'm thinking that I will bypass the middle step and go to fully automatic with load shedding. That will save a lot of work and maybe lower the total costs. What may push me right back to a laboratory listed 200 ampere Automatic Transfer Switch (ATS) is the possibly prohibitive cost of 200 ampere and 30 Ampere solenoid trip breakers needed to open the Service Disconnecting Means breaker, which would disconnect the entire building from utility power; and shed the Air Conditioner load which, at least for now, would not be within the power budget of the present generator. I have not priced them yet but I seem to remember, from my working electrician days, the cost of solenoid trip breakers being quite high. I don't know if I ever told you that I've done radio equipment shelter builds from Tierra del Fuego to Alaska and from Uganda to French Frigate Shoals. Almost all of those involved a solar power array, charging controls, and battery bank. Some of the other power sources that we used were wind generation, thermal electric, and even water power on one site. Water power is a maintenance hog so we had to have a dammed good reason to resort to that. Many of the sights had some sort of Engine Alternator Set (generator) for back up power. LP gas was the fuel of choice for those. It will store without deteriorating almost forever or at least until the container corrodes through from the outside. It is also gentler on the engine itself than most other fuels and yet still has fairly high power density in Volt Amperes per pound. In the deployment arena I would prefer to add in solar as soon as possible but as I'm sure you know that is fairly pricey to do. Improving on what I already have would be more cost effective in the sort term. I have an entire box of used folding solar panels here that I obtained from the left overs of a development project. I've just never taken the time to pull them all out, test each one for function, and begin to acquire the other parts of a transportable solar charging system for batteries. Perhaps you would be willing to help me get to work on that after the pandemic crisis has abated. One of my hesitancies is a complete lack of experience with transportable systems. -- Tom Horne W3TDH
  3. Walt Starling; who was a traffic reporter in the Washington DC Area years ago; once said as a snow flurry began to fall "For you new people welcome to the nation's capital were a fella with a bad case of dandruff can lean his head out his car window, scratch his scalp, and create a five mile backup. People here cannot cope with white flakes!" -- Tom Horne W3TDH
  4. At present My first back up is a 5000 watt Engine Alternator Set (Generator to most folks). Second back up is a Honda EU2000i Inverter Generator, over 400 feet of various outdoor cords, with weather proof connection covers. Third is a "Pup" generator. That is a small engine mounted on a steel plate and fitted with an A pattern industrial belt pulley. That drives a high capacity vehicle alternator, using a A belt to another A pattern industrial pulley, which produces an effectively unlimited supply of 12 volt DC; i.e. more than I'll ever need. That will be supplemented with a large capacity sign wave inverter, once the stay at home order is lifted and I can prowl the wrecking yards for one out of a total loss service van or truck. I already have a source for a riding mower engine which is higher horsepower than the present one in case the one I have will not carry the inverter I hope to get. I plan to put together cord sets with the National Electrical Manufacturers Association (NEMA) standard connectors for 12 volt DC, to run to a Schlocky Diode battery isolator and a charge controller for the battery. Fourth is the 2 Absorbed Glass Mat Valve Regulated Lead Acid 100 Ampere Hour batteries. Those are under continuous charge by the station's 50 Ampere linear power supply. That leaves me set for the likely duration of power outages here at my home location. Which is to say 2 to 4 weeks maximum. What it is not completely adequate for is for a true field deployment. To be completely prepared for a prolonged field deployment I would want to add another switching power supply to the 23 Ampere one which I already have. I'd prefer a second one to a larger one so that each of the 2 readily transported radios I have will have a power supply if they need to be used apart. The other thing I'd love to be able to afford to buy would be 2 Lithium Ferro Phosphate batteries of somewhere around 50 Ampere hour capacity. Again that would provide one for each radio I might need to deploy. The reasons that I would like to obtain the LiFePh4 batteries is that they are much lighter per ampere hour than almost any other battery chemistry presently available; AGM batteries weigh 80 pounds in the 100 ampere hour capacity size; have a much flatter discharge curve; that makes it possible for a LiFePH4 battery to carry nominal 12 volt loads through almost their entire capacity without any need for a boost regulator; they are acceptable in air, and other common carrier, transportation, they are not counted in the limit on Lithium polymer capacity which is now enforced by the Transportation Security Administration (TSA); but because of inadequate training you will need to take them to the TSA office with the documentation of their acceptability well prior to your departure. That means that you don't have to go through the additional effort and high expense to ship them overnight to the deployment area when you travel by Airline, Bus, or Train. Being at the Airport much earlier than your scheduled departure means that you can run them over to an air freight office if the approval is declined. -- Tom Horne In the future I am planning to add propane / natural gas fuel capability to my larger generator set. The reason to have propane fuel supply as well is that propane, like natural gas, does not have fuel storage issues. Thus whatever sized propane tank I’m able to afford would be available to run the generator if the natural gas supply failed. When I need to replace the generator which I have now I hope to be able to buy an electric start model which could be left connected to Natural Gas so that by solenoid controlled gas flow and electric starting I could have it online without leaving the operating position. When I could afford to add an automatic transfer switch I would do so but not necessarily leave it in automatic all the time. If I bought a 200 Ampere automatic transfer switch the cost would be higher than I can justify on my family's budget. By placing the minimum critical loads in a feeder supplied panel supplied from a fifty Ampere breaker as the Feeder Over Current and Fault Protection I would only need a fifty ampere transfer switch for automatic transfer and generator control of the power to the emergency loads feeder supplied panel. The reason to leave it in manual start is to be able to use any load in the house and avoid overloading the generator by applying careful load management. a solenoid trip breaker as the Service Disconnecting Means. When I didn't need the automatic transfer capability I could have the generator connected to a different cord inlet and a generator supply relay of only 50 ampere capacity. On the closing of the starting control relay, by wireless remote, it would apply the generator’s Starting and Ignition battery's 12 volts to a solenoid trip on the Service Disconnecting Means breaker. An auxiliary contact of the shunt trip Service Disconnecting Means breaker would close when the breaker tripped and apply the generators Starting and Ignition battery power to the generator supply relay. A Normally Open auxiliary contact on the generator supply relay would then close and apply battery power to the starting solenoid of the generator. If the Service Disconnecting Means breaker fails to open, when the DC of the generator starting and ignition battery is applied to it's solenoid trip, the contact which would have supplied the 12 volt DC control power to pull in the generator supply relay remain open and the auxiliary contact on the generator supply relay would also remain open and not engage the generator starter. If we are talking about a power outage of months in duration I would like to have Solar Panels with capacity sufficient to carry the essential home loads together with a small wind generator for longer periods of cloudy whether. Those would feed the more cost effective AGM VRLA batteries in a home battery bank. If I ever got filthy rich I would use LiFePH4 batteries for the house bank as well because of the flatter discharge curve that makes more of the nominal capacity of the battery available for actual use. -- Tom Horne W3TDH
  5. Just a thought but why not change the sign to what is already undeniably true. "Emergency Radio Service Volunteer." That also avoids waiving the taunt flag at a heard of bulls. -- Tom Horne W3TDH
  6. There is a great old one out of QST. A raft is aground on a tiny island. Jeeves, the butler, is the only character you ever see in that cartoon series. Jeeves is sending with a key hunched over a battery powered radio. Out of the little shelter on the raft comes His employer's voice, "Tell them we don't have a QSL manager Jeeves and repeat the QRRR" (Amateur Radio SOS of that time now obsolete). QRRR was an amateur radio distress signal which is now strictly for land use because it's use at sea violates the International Telecommunications Union convention on distress signals.
  7. We all need to be aware that answering a call out from a recognized provider such as the Amateur Radio Relay League (the League) does not guarantee good performance. When Hurricane Katrina devastated Puerto Rico the League organized a deployment based entirely on what a client asked for. I know from talking to a federal official, who was in situ and in whom I have complete confidence, that all did not go as planned. In spite of the deployment of volunteer radio operators selected and managed entirely by the League some of the operators went rogue. I do not know how many but I do know it was more than one. My informant has no reason whatsoever to make things up. I know him as a fellow Amateur Radio Operator (ARO) who has no incentive to bad mouth other AROs. He is actively engaged in attempts to gin up the capabilities and professionalism of AROs who want to do a good job when they are needed. There is presently no recognized Resource Typing in the National Incident Management System (NIMS) for radio operators as individuals or teams. A resource type has a known set of capabilities. If the client wants a communications pathway which is not dependent on the existing, and possibly unavailable, commercial communications infrastructure, that client has no mechanism to request an appropriate resource. That prospective client doesn't know what resource to ask for. All they know is they cannot communicate with people that they need to communicate with. Even if they new that radio was what they needed they would not know what kind of radio support to ask for. Don't be confused by FEMA having names for radio people. A Radio Operator is a RADO, a Communications Technician is a COMT, a Communications Leader is a COML, and so fourth. That is not the same as a resource type. Every Squad Boss on a wild fire crew is a RADO in a sense. They know how to use the radio they have been equipped with, what it will do, how to keep it working at a very basic level, and were to obtain repair or replacement. If you haven't been a wildland firefighter then you wouldn't know that. Even if you do know it that will not do you a lot of good when you need 11 mobile radios for field expedient fire engines. You also don't know and probably don't expect that one version of mobile radios is not available to you without a radio operator. The off duty firefighters who have been called back to work will be quite surprised that they are not allowed to operate the radios they have been provided with. They will be annoyed that they have to fit a third person into the front seat of the cab with them to operate the radio. In a regular fire apparatus cab there would be extra seats for people in the back seat but not in the front. With a field expedient fire engine there probably won't be a back seat. Most of the crew would be riding on the hose bed, tank top, or wherever they can hang on. Now you come along and tell the unit commander that you have to ride in front to operate the radio and they're not going to like that. Semper Gumby, meaning Always Flexible, has to be your attitude through out any operation.
  8. Thank you for the kind words. I'm trying to come up to speed on the job under these very unusual circumstances. Tom W3TDH
  9. Further thoughts on the desirable characteristics of a repeater which is realistically expected to carry emergency communications. No part of the repeater system should depend solely on the Public Switched Telephone Network (PSTN), power from a public utility, internet connectivity, or any other resource beyond the control of the repeater's operators. Remote links for reception, control, and monitoring should all be radio based but secured against unauthorized use by a digital squelched control signal receiver. The control signals themselves should be digital as working with digital media is less likely to be within the skill set of the brainless twits who engage in malicious interference with emergency communications drills and possibly even actual emergency communications. If possible that receiver should be on Federal Communications Commission Part 15 frequencies so as to make encryption of the control codes lawful. The side benefit of using Part 15 frequencies is that it may be possible to tie that control chain into an alternative internet pathway such as a radio linked IP system like the one being constructed by the Mid Atlantic Internet Protocol Network (MAIPN). FWIW Your Millage WILL Vary. Tom W3TDH
  10. From only my own point of view a repeater that is realistically expected to carry emergency communications would be running directly off of a bank of Lithium Ferro Phosphate batteries [Note 1], with no transfer mechanism that has any likelihood of failing in an open condition; Schottky barrier diodes leap to mind. The battery bank would be sized to carry the repeater at 100% duty cycle for 24 hours. The battery bank would have three sources of recharging. Solar panel array sufficient to carry the recharging at 100% duty cycle on cloudless days. A modest wind generator with sufficient output to carry the recharging at the wind speeds historically experienced on cloudy days. and a utility powered charger / conditioner. All equipment, including computers if any, able to run directly off of the 12 volt DC power supplied by the batteries or a voltage converter from 12 volts. No inverter powered equipment in the repeater system. An AC power inlet located at an accessible location for connection of a portable or mobile generator, to supply the battery charger / conditioner, fitted with a transfer mechanism Listed by a recognized testing laboratory. A utility powered visual signal, such as an always on emergency light, to show when AC power is present at the utility supply of the facility's step down transformers, were such as system is used, that supplies the circuit which carries the Charger / Conditioner. [Note 2] Explanatory notes: [1] The choice of LiFePh4 batteries is based on their; much higher number of charge/discharge cycles prior to needing replacement, much flatter discharge curve which obviates any need for voltage boosters, lighter weight for carrying beyond the top floor which has elevator access, and their inability to support combustion. [2] Larger buildings receive utility power at a variety of voltages which can be used directly to power the buildings heavier loads such as; Heating Ventilating & Air Conditioning (HVAC), Fire protection systems, production processes... In such buildings power for 120/208 volt receptacle outlets is usually produced by a transformer that is part of the facility's electrical plant. These transformers are owned and maintained by the facility's owners.
  11. The primary repeater that is used by Skywarn in the Washington Baltimore Metropolitan area and Northern Virginia ,which is the WA4TSC 147.300 repeater at Bluemont, Virginia, has battery back up power but no automatic means to recharge it. The repeater’s output power is reduced automatically when electrical utility supplied power is lost. For some types of Skywarn Activation that has meant that I have had to change the net to one or both of the Secondary Repeaters. One of those is the Montgomery Amateur Radio Club’s KV3B repeater, Which See. The WA3YOO repeater, in central Rockville, is maintained by the Montgomery County Radio Shop for use by the Auxiliary Communications Service which is a cooperating agency of the Office of Emergency Management and Homeland Security. It is hosted in a County facility which has a legally required Emergency Generator. The Montgomery Amateur Radio Club’s (MARC) KV3B repeater system is hosted at 6 sites. All of those sites have a legally required Emergency Generator but at one of the sites it has not been possible to obtain the use of a circuit which is supported by the Emergency Generator. That leaves one of the remote receiver sites of the 146.955- repeater without emergency power. Emergency Power Systems are required to pickup their full load in 10 seconds or less. The MARC Repeater Committee is attempting to bring the KV3B repeater system up to full functionality over the next 6 Months. Once that is done the committee plans to install continuously connected battery supply which will be sufficient to get the equipment located at each of the repeater sites through generator transfer without any interruption in repeater function. At the site were a circuit supported by the Emergency Generator is not available we will move toward sufficient battery capacity and solar charging capability to assure continuous operation of the repeater and the remote receiver situated there. Tom Horne W3TDH
  12. Hey Ham Community, this is an automated post on behalf of our new member: W3TDH, On behalf of Ham Community, let's give W3TDH a warm welcome. W3TDH, we encourage you to browse around and get to know the Community's many sections. If you have any questions please don't hesitate to ask, as with all things HAM, we all love to give advice 😎 For everyone's information, W3TDH joined on the 03/25/20; this is their profile: View Member.
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