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Lscott

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Everything posted by Lscott

  1. Well in reality it's no for the simple cheap ones. Of course there are some exceptions. The purpose of a charge controller is to terminate the charging phase when the battery reaches the full charge state. Some of the controllers use a "charge algorithm or profile" to controll the charging process based on the battery's terminal voltage. For the simple PWM type charge controllers they effectively connect the solar panel straight to the battery terminals. The resulting terminal voltage is whatever the internal voltage is plus the voltage rise required to overcome the internal resistance at the panel's output current. So if the solar panel can output 10 amps, for example, at 12 VDC, approximate battery terminal voltage under charge, that's what you're going to get. A MPPT by definition will try to push whatever maximum power it can squeeze out of a panel into the battery. I've attached a few of the files I have in my electronic library on solar and wind power. 91069768_WhichsolarchargecontrollerPWM-or-MPPT.pdf GrapeSolar GS-Star-100W.pdf Renogy RNG-100D June 2015.pdf 1518183678_RenogyRNG-50DLatest.pdf Renogy RNG-30D June 2015.pdf 1017403390_DesignandDevelopmentofBatteriesForSolarPhotovoltaicApplications.pdf
  2. One other issue is cops having a problem with "scanners" in vehicles. Some Hams make it a standard practice to turn off their mobile radio if they get pulled over. If the cop sees your radio "scanning" they automatically assume it's a "scanner" not a two-way radio. In some states scanners are prohibited. Having your Ham rig scanning may get you a ticket. In some very rare cases the radio was confiscated requiring a trip to traffic court to get it back. The cops in general have no clue about the exceptions so you'll find Hams that keep a copy of the local/state motor vehicle code with the specific exceptions for Hams in the glove-box.
  3. In fact many radios fail in that area, including some of the better ham gear. The typical short cuts are reducing the drive to the FM modulator to limit the deviation to 2.5KHz, and bumping up the audio gain by a factor of two. The worse part is they still use the same wide band IF filter in the RX path, cost saving, in the radio so you lose the benefit of using the closer channel spacing. The more expensive commercial radios do the same but have two sets of IF filters, one wide and the other narrow, to allow use of the closer channel spacing. After all that's why the FCC mandated narrow band in the first place. Also as some people have noticed even with properly designed narrow band radios there is some range reduction. The attached file goes into some detail on that point. For range you can use the simplified formula: (Range to optical horizon in miles) = (Antenna height above ground in feet) * squareroot(2) This would be for one radio. To get the path do the calculation for each radio and add the distances together. Narrowband vs Wideband.pdf Radio Horizon.pdf
  4. Radios fail from time to time. That's why there are repair shops. Sometimes the repair cost isn't worth it. You can spend less or about the same buying another used radio.
  5. Yup. People forget that hand held radios were never intended for high duty cycle, long winded, communications. Some work better than others in that use case. I've used a few of the palm sized radios where after a few minutes of moderate TX they were getting "uncomfortable" to hold. In the winter time they would make great hand warmers.
  6. 0ne area that doesn't get much attention is the charge rate on the battery. I was at a Ham Radio swap a year or so back where one guy was selling emergency power boxes with one or two 7AH sealed lead acid batteries in them and connected up to a 100 watt solar panel. That last bit was scary. One of the often overlooked specification on rechargeable batteries is the max charge rate. On the unambitious 7AH sealed lead acid battery that max charge rate is around 2 to 2.5 amps. Anything higher will likely result in damage to the battery, bubbles in the gel which won't go away, for the older gel-cell, to gas generation, hydrogen and oxygen, which is vented to the air and results in a permanent loss of electrolyte for AGM types. So, for a 2 amp max charge rate, and assuming a 12VDC nominal terminal voltage for a discharged battery, the max usable solar panel power is 24 watts. Your typical solar panel will usually deliver about 70% to 75% of the manufacture's STC rating. So, for 24 watts that works out to a standard panel rating of 32 watts at 75%. Doing the same calculation for 2.5 amps results in a max standard panel rating of 40 watts. You have to check the data sheet for the battery you have to figure out the max safe charge rate. BP7-12.pdf UB1272 F2.pdf
  7. Now that you did some measurements it would be a good idea to include this as part of a radio's review. The problem with hand held radios is the continuing reduction in size. Starting with with the older Motorola brick radios down to the tiny palm sized units which which have to dissipate the same power, the RF power stages haven't changed much in efficiency over the years. The smaller cases, including the radio's metal chassis, and the use of more plastic leaves less area for heat to radiate. These smaller radios have a tendency to heat-up/over-heat far quicker than the larger older designs. There are stories where some users have destroyed their radio from using it at more that a tiny TX duty cycle. The cheaper radios don't have over-temp protection. That's one area where they save money and why they're so cheap.
  8. It might be comical but it's an indication the local police are not as well trained as one would assume. Something as basic and routine as running plates and knowing the format for private, commercial, truck etc. should be number one on the list of skills and proficiency required.
  9. Lscott

    CA-2x4SR

    When I lived in an apartment there wasn't much for options. VHF/UHF was about it with operation through local repeaters.
  10. Hum… I wonder if other states have similar issues or is it just particular to California?
  11. I would have though laying on the ground face down, hand cuffed and guns pointed at my head wouldn't have been all that funny given how some cops are trigger happy. If it was me I'd be pissed at their screw-up.
  12. That's sort of strange. Any Ham call plates I've seen from other states were rather distinctive. So in California they have to run the call sign plate through the system differently from other types? That seems weird the system can't figure it out on it's own. I would suspect people are telling BS stories.
  13. Lscott

    JumpCode

    The “beat shift” function has nothing to do with signal scrambling. All radios generate internal RF frequencies, from the microprocessors etc. , that can get into the radio’s receiver section. The interfering RF signals are integer multiples of the source. These signals appear as phantom signals, frequently called “birdies”, and may generate rather high signal levels on the radio’s S-meter. What the beat shift does is electronically shifts the frequency the microprocessor runs at so the interfering internal signal is moved off your desired frequency enough to make it undetectable.
  14. Lots of people talk about getting a radio(s) for emergency communications. During hurricane Ian how many really needed their radio equipment verses cell phones?
  15. I thought about the vanity plate idea. Chances are almost nobody would have a clue that the sequence of 4 letters followed by three numbers is an FCC radio call sign unless you were involve with radio communications. Anyway I've had a Ham call sign plate on my vehicles for over 20 years. So far no problems. If one were really that worried then why use your call sign on the air? Lot of people own scanners out there.
  16. That's not as cool as the license plate. I once had a car with some kids in it asking me at a traffic light what the letters and numbers mean on the plate. They were trying to figure out what it said. I told them it was a radio station call sign ID.
  17. I'm purchasing a new vehicle shortly and will transfer my Ham call sign plate from the old ride to the new one. It got me thinking about call sign license plates. I'm guessing one can get a Ham call sign license plate, they typically are distinctly marked as "Amateur Radio" etc., for any state they live in. In Michigan they are treated like a normal plate, not an expensive vanity plate, as far as fees are concerned. To get one all I had to do was show my official FCC license to the Secretary of State. What I'm puzzled by is why no GMRS call sign license plates? It's a licensed service like Ham with an official FCC issued call sign unique to an individual.
  18. That's why I got my GMRS license besides the fact it was cheap at the time, $70 for 10 years. I had another GMRS call before this one when it cost $85 for 5 years. Never used it so I let the license expire. When the cost dropped, and in particular the term increased to 10 years, I got back into it again. Now that's it dropped to $35 it's basically a no-brainer.
  19. No kidding. When I starting collecting my mostly Kenwood LMR gear, and got the programming software for them, my first impression was WTF is all this crap in the setup. The setup is even stranger for the digital stuff. It's a bit of a mind set change to get use to how commercial radio radios are setup verses ham gear. Ham gear you can program them on the fly. The commercial radios you program them once and then just turn on the radio and hit the PTT button.
  20. I've used these charge controllers for the LFP batteries. They make charge controllers for different battery types and will even design one for a custom output voltage for you. https://sunforgellc.com/product/gv-5/
  21. The above sounds right. I have another buddy that frequently volunteers for marathons, bike races etc. He either setups up his own portable repeater or the event communication's coordinator supplies some or most of the radio equipment.
  22. Have you looked at the LFP, Lithium Iron Phosphate, battery types? The capacity is good and the chemistry is far more stable than just about any of the other Lithium types. This company is friendly to communication hobbyists and has a good selection. https://www.bioennopower.com/ I also found using these power meters is helpful to keep an eye on the power usage. https://powerwerx.com/watt-meter-analyzer-inline-dc-powerpole Everything I have is terminated in Anderson Power Poles. This makes it very easy to swap around equipment. I typically use the 15 amp and 30 amp connectors. I managed to salvage some of the larger 45 amp connectors off of dead lead acid batteries our IT department trashed from the server room UPS systems. https://powerwerx.com/anderson-power-powerpole-sb-connectors
  23. I think the same logic works for private businesses. Each employee can have their own GMRS license and use the company owned repeater. The one caveat the repeater must be under the control of one of the licensed employees and ID as such.
  24. Don't have to join a forum. If they don't have a license and using GMRS equipment don't talk to them. Enough people do that they will either quit using the radios or get licensed when they run out of people to talk too. Either way it's a win.
  25. I have a number of commercial radios that are certified for both Part 90 and Part 95A, the later being the old part for GMRS. The radios haven't lost their certification. I have others as well like the NX-300(G), FM/NXDN, and the TK-5320, FM/P25, just have to restrict operation to FM until the FCC gets around to authorizing digital voice on GMRS. For example I routinely use my Kenwood TK-3170 for Ham and GMRS. It has both Part 90 and 95A certifications. While the programming software complains it will accept frequency entries down in to the ham band low enough to cover the repeater section just fine. So I have one radio where I can use it for either service without any hardware or software modifications. NX-200_300.pdf NX-300 FCC Grant - 1.pdf TK-2170_3170(K) Brochure.pdf TK-3170 Grant.pdf TK-5220_5320 Brochure - 2.pdf TK-5320 FCC Grant - 1.pdf
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