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Radioguy7268

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Everything posted by Radioguy7268

  1. Do yourself a favor & search the term "intermod" as it relates to RF. What you're seeing is likely a product of 2 (or more) frequencies mixing & creating an un-intended 3rd frequency. I'd bet dollars to donuts that the water tower has some high powered stuff that's throwing out birdies & mixing with something else nearby.
  2. Not applicable if you don't wish them to be applicable. Keep on arguing/discussing the meanings.
  3. They're not - which is part of the FCC's problem of using terms defined in other classes, then bringing them over to Part 95 without full definition or clarification. We've been through this all at least 4 or 5 other times. My thoughts haven't changed. https://forums.mygmrs.com/topic/4835-fixed-station-what-does-that-mean-to-fcc/?do=findComment&comment=47430
  4. A Fixed Base (FB) is transmitting on the lower (base) 462.xxx frequencies. A Fixed Base FB2 is a repeater. It listens on the higher side frequency, but re-transmits on the lower (base) side of the frequency pair. Yes - changing the frequency can change the functional definition.
  5. I think that linking 2 repeaters across a distance, when those 2 repeaters are carrying a conversation between 2 (or more) people can be a useful option. I think state-wide or regional systems with 5, 10, or more repeaters being keyed simultaneously is a waste of spectrum.
  6. OP - the cable you are showing is for making a cross-band bidirectional repeater out of a set of UHF & VHF radios. Great if you want to link 2 groups of radios, one using UHF and another using VHF. Not so great for basic UHF GMRS repeater operation. The uni-directional repeater cable is the one you want. I'd tell you to spend a few dollars more though, and get one from a guy on Ebay named Kurt Meltzer - MRE Direct. He will use the correct tabs which force (OK, actually allow) proper tab orientation, and he'll include instructions with the cable kit(s). You can reach him at: mre1032 <at> yahoo.com or look him up on Ebay. Repeater-builder.com is also a great resource for DIY radio and repeater info.
  7. Assuming you do not own the repeater, you should ask the repeater owner if the system is capable of multiple PL groups. That type of setup was commonly used back in the day for Community repeaters, where each user group (plumber, HVAC, Landscaper, etc.) had their own PL tone, but they all shared a common frequency, and each user had to monitor to make sure that the repeater was not in use by one of the other groups before they would Key up on their PL. If the repeater has Multiple group capability (Every Kenwood TKR-850/851 came with that feature right out of the box) then it's simple to just request your own separate PL tone for your group. Expect to pay for that feature if it's available. Listening to a repeater's output in Carrier Squelch would defeat the purpose of having a separate PL tone. Set up properly, your daughter would only hear you when you keyed up using the special PL tone. Other traffic on the repeater would be nothing but a flashing receive light on her radio. It's 1970's technology, so don't expect any actual privacy or miracles - but it would do what you're asking for.
  8. Be careful of aftermarket products for the XPR3000 series. Otto is probably one of the few good alternatives to Motorola OEM. The side connector on the XPR3300e series is a unique connector, and not all aftermarket products work well with that connector. I'd also comment that there are a bunch of audio profile settings in the CPS programming, along with some "licensed" audio improvements that your Dealer can license and install, and the 'out of the box' audio settings on the XPR3300e can be improved. SINC+ enhanced noise suppression is what you should ask them about. Unless the area that's giving you a problem normally requires hearing protection, a properly configured 3300e radio should be able to function quite well with just a good speaker mic.
  9. That Sirio CX455 antenna requires tuning. The center section slides in/out to adjust the tuning. What frequency did you tune it for? What did you use to adjust the tuning? If I am reading your post correctly, you've got the repeater putting out 7 watts, with a measured VSWR of 1.0:1 on 462.725 ? What's the VSWR on 467.725? Those RT97 repeaters have a really small internal duplexer with poor isolation specs. If you go above 5 watts, you pretty much guarantee desense. I'd try turning down the power to see if the overall performance & balance of the system improves.
  10. I'm sorry, but if you're using a Baofeng (or other CCR with a Direct Conversion receiver on a Chip) then you're missing half the show if you're just focused on transmit power & ERP. The real game is played on receiver selectivity & desense. Sure, the CCR's have some good/great specs (on paper) for sensitivity in a laboratory testing environment. They fall short when you start looking at adjacent channel rejection and desense. Stuff like that matters in the real world. Measure your Signal to Noise and Distortion and now you've got something worth measuring on the receive side. Do you have tools that can generate a low level calibrated output to test receiver performance? 10 watts in a handheld looks great on paper, but it doesn't take into account how well the other party receives. I'd rather have lower ERP with a more selective receiver that can actually pick out a desired signal at -120 dBm & recover it into understandable audio. If your CCR is still sitting silent in the presence of a -114 dBm signal, you're missing out on more than 6 dB in the math of Signal to Noise. The ERP side says you'd need to quadruple your transmit power to achieve the same S/N ratio. Take a look at the Motorola XPR "e" series and the Vertex EVX radios if you want to see what a SDR chip coupled with good electronics and a little filtering can look like. Heck, even the older CDM mobiles had great analog receivers with some nice audio. Focusing on transmit power alone is missing half the equation.
  11. If you try to go the legit way for current model software for Motorola, you're probably going to be disappointed. Motorola is not interested in supporting Ham or GMRS at a corporate level, and getting things like Wideband entitlement for CPS software is nearly impossible. The newest CPS2 software for the XPR/Trbo series is not out in the wild, and the older CPS software won't even read new radios fresh from the Factory. If you are dealing with older model analog radios like the CDM1250 mentioned above, the PM400, M1225, etc. then there are plenty of unofficial resources and available software, but it's still not 'Plug and Play'. If you are starting from nothing, you would probably be best served to purchase a radio that's already programmed for what you need, and then try to acquire the software & cables to read that radio & save a baseline profile that you can begin to experiment with.
  12. If you plan to work repeaters for most of your mobile driving, it's really hard to beat a simple 6" hatpin antenna. They're inexpensive, low profile, and they simply work. If you're trying to impress the ladies, then by all means, get the longest possible antenna.
  13. Duplexer is the preferred method for achieving isolation on repeater antenna systems. The OP is talking about a CCR portable as a fixed base - so I won't go any further off topic, but I'd still recommend a used mobile instead.
  14. My biggest gripe about using CCR's for a repeater is that most people are over-paying for under performing pieces. You can buy a decent pair of brand name used mobile radios for less than $150, spend another $15 on a cheap 'repeater maker' cable, and have something that will actually work without de-sensing itself, and put out 10-15 watts all day long without burning itself out. The trouble comes in finding software & programming, but it's not insurmountable. Or, you can keep buying more and more CCR's trying to find the next YouTuber's favorite combination, and trying to crank up 8-10 watts out of a portable until it burns up - while trying to SAVE money on cheap radios. I guess if you're learning what doesn't work, you're on the way towards learning what will work.
  15. I think this is more of a "what gives them the right?" sovereign citizen take. I'm pretty sure that the writers of the Constitution never quite envisioned the possibility of a wireless communication system back in 1789. At best, they left it up to the People and the individual States with the 9th and 10th amendments. Pretty sure nobody pays much of any attention to the 9th and 10th since the Wickard v. Filburn decision. Feel free to fight the battle. I doubt I'll invest in your fight, but I'd be thrilled to read the legal arguments once you make it to the Supreme Court. I do recall a company called TeraWave who was going to be using Infrared light as an unlicensed high bandwidth beam between buildings. They did some amazing things in the Lab, but once they got out in the real world & put up some systems on rooftops, they discovered that there are some real world problems like fog and rain that played havoc on their systems. Not sure if the FCC got involved in that one, I think all it took was economic reality. Giving up a few hundred MB of bandwidth in exchange for a licensed microwave system with Six Sigma reliability was the winner.
  16. Layering communication technology on top of a WiFi network is a really poor choice for an emergency communication channel. When things go bad, you want to count on LESS technology, not more. The more you can adhere to the KISS principle, the better off things will work once things go wrong. Keep it simple, keep it working. What happens if the school gets hit by high winds that rip the roof off? Well - at least with conventional portable radios, there's the option of simplex. What's the option with Network radios when there is no functioning Network? There's already money available for schools for communication equipment through Federal/State grants & funding. No need for Amazon.
  17. If I follow what you're asking, you would have radio users on one system (non-GMRS) with the ability to generate traffic on a GMRS repeater. It's not going to be legal. If you end up relaying their voice traffic from this 'private' system over to an analog GMRS repeater, I also question how 'private' the system would remain. You would be basically be wiretapping your own private system, and then broadcasting the audio over an open analog channel.
  18. Generally speaking, the FCC frowns on re-broadcasting from one service to another. If I understand your question, you would just want to hear what's going on with a GMRS group in a listen only mode? No ability to talk back? If so, then I'd say it would depend on what particular rules govern the service you are trying to patch into. I can tell you that most trunking system administrators would frown on anything that automatically keys up on the system & uses up airtime just from an Erlang vs. Grade of Service standpoint.
  19. The trouble with relying on cellular phones as a primary communication device in an emergency is that every cellular service is over-subscribed by design. They make money on the idea that thousands of people might be in the vicinity of a local cellular tower, but only a few of those people will actually be trying to use their phones at any given moment. In an emergency, everyone picks up their phone and tries to call, text, livestream, or search up: "what do I do in an active shooter situation?" Any study done in the aftermath of an emergency will point out poor communication as a primary point of failure. Having a dedicated communication system with proper training and protocols is much better if there is an emergency - rather than relying on a service that piggybacks on top of an overloaded cellular service. Do NOT use Zello for emergency situations.
  20. There's a practicality point to all of this, because running multiple control heads get pretty expensive pretty quickly if you're buying them retail (or even getting new at dealer cost!). The dual control head option is neat, but if you just want to talk on a specific channel, it's much easier (and affordable) to run a remote speaker and/or mic. There's a few different builders who make remote microphone options that plug into the rear accessory connector of most of the popular mobile radios. You're not going to have channel changing options, you're not going to see the LCD display, but you'll be able to hear what's going on, and even key up to talk back. If 90% of what you want to do in the other room is monitor the radio, then the remote speaker is about the simplest and cheapest.
  21. Whoever gave you that information is flat out wrong. JVC Kenwood is still making new radios. Just delivered 25 new units the other day, and they all worked quite well.
  22. My only guess on those Hyteras (and it's totally a guess) would be that they are programmed for low power with either .5 or 1 watt on FRS channels. If your school does not have a specific frequency licensed with the FCC, some radio shops and dealers would just plug in some low power random FRS channels as a workaround instead of bothering with Licensing issues.
  23. There are lots of funds available for schools under the Safe Schools funding & government grants for security. Take a look here: schoolsafety.gov I'm not sure why those compact digital Hytera radios are being out-performed by Baofengs, but I'd definitely try out some other radios with better durability & performance specifications. Radios used for safety & security at a school should not be purchased based upon cheapest price. Repeaters are not necessary for most smaller sized buildings, but I've seen some strange stuff with newer construction with low-E glass. There are also advantages to using digital repeaters for a district-wide network that allows I'd call in a local wireless company & have them survey the building to see what works. They might also be able to help you out with some direction on grants and funding options available to schools in your State.
  24. Those Midland/Retevis repeaters have a very small internal duplexer that can barely create any decent isolation when the repeater is cranking more than 5 watts. There is no magic bullet. You are never going to find a good, cheap, compact duplexer that passes 95% of your transmitter power and still gives you 90+ dB of isolation. It doesn't exist. Every rookie with a wattmeter wants to get the MAXIMUM possible output power out of their repeater. I mean, 50 has to be better than 5, right? In my opinion, the MOST important spec in a repeater system is the isolation between transmit and receive. Especially if you're using portable radios out in the field that can talk back in with 4 or 5 watts of transmit power. What good is it to key up your repeater with 10 or 15 watts of power when you introduce 3 or 4 dB of desense into the system? 3dB of desense on the receiver just made your 4 watt portable into a 2 watt portable, and how well is that going to work? Better isolation = a better repeater. Want to have a cheap repeater? You will get what you paid for. Cheap is rarely good.
  25. Either I'm not understanding what you're saying, or there's an issue I'm not seeing. You seem to be saying that you cannot get the MTR to key (and pass audio) from a portable, but in one of your posts, you state "I can key the MTR from a radio, the "receive" light comes on and stays solid until I unkey the radio. The received audio (in BASE station mode) does not get passed the controller, into the transmitter." When that receive light comes on (I'm assuming we are talking about the Rx LED on the MTR2K) - does your MTR also have a Transmit LED? To me, "keyed" means transmitting. What I do see is that your homemade cable does not appear to be strapped for PTT. You probably need to provide me with a diagram of your cable pinout (both sides) in order to diagnose what you're doing wrong. C10 needs to be pulled to ground to key the MTR in Base mode. You also need to properly map the Wireline Audio via RSS in order to get audio to pass when using the wireline audio - and by doing it that way, you can use the MTR's internal PL/DPL. Wireline audio is the way to go. When you say that you've "attempted to adjust the audio" for the Wireline according to the Station Alignment - what did you end up with for levels? And, what did you use to input the 1000 Hz tone? There's really no attempting - you either set the levels or you do not, and you need to have a way to read exact deviation levels on the output.** I have never needed to use any external amplifier to drive the input audio on an MTR2000. The station itself is plenty sensitive and responsive. **I have found that you need to lie a little to the MTR during the wireline Station Alignment when giving the levels measured in order to actually achieve full deviation. ie: You need to understate the deviation values actually measured by a few hundred Hz when inputting your results - so that the MTR will slightly "over-drive" and give you the full deviation you desire.
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