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Lscott

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Lscott last won the day on February 13

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    Design high power AC high frequency inverters for induction heating of metal parts. Have degrees in Electrical Engineering, Math with Computer Science.

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  1. I was at the Ham swap a while back in Fort Wayne Indiana. Part of the free test bench, used for checking used radios people buy before leaving, had a Rigol spectrum analyzer setup. The link below is the model I believe they were using at the time, DSA-815. https://www.rigolna.com/products/spectrum-analyzers/dsa800/ Some people were solicited specifically so they could test their radios as an informal survey. The results were socking for some people when they saw the results. The original classic UV-5R was well known for poor filtering of harmonics on the output. I found the attached VHF spectrum tests for one on-line and a copy of the schematic, likely the first generation design, for the radio. UV-5R VHF Harmonics Test.pdf SCHEMATIC Baofeng UV-5R.pdf
  2. You're entitled to your opinion, but public disregard for the FCC rules is discouraged on this forum.
  3. Lscott

    Misc. Radio Gear

    I have a few Motorola radios. The XPR6550 is a good choice. You can buy them for reasonable prices. They also use a standard SMA type antenna connector. The XPR7550 is a better radio, but they are expensive used and have a funky stud type antenna port. So, if you need to use an external antenna you want the XPR6550.
  4. Well, that depends on your current, future plans and interests. 1. Do you have or want to get your Ham license too? A significant number of GMRS users also have their Ham license. For example I am dual licensed. 2. If answer to #1 is yes, then do you plan on using the radio for both services? There are used commercial grade radios with Part 95 certification so they are legal to use on GMRS, and can be programmed for Ham 70cm band frequencies. I have a number of those and they each have their place and uses. When you say cost isn’t important there are some radios that run up to the high 3 figures and low to mid 4 figures, so you might want to quantify that a bit more. Those radios typically are the commercial grade types, tend to work better and have a lot of features the usual CCR’s, Cheap Chinese Radio, don’t offer.
  5. Interesting product. Didn't know anything like it existed.
  6. There is definitely capacitive coupling. It's not magnetic so the mount won't hold, but electrical it will work just fine.
  7. Yeah, having NOAA is useful if you spend a lot of time out doors. However that requires the radio to likely be based on a dual band design, a derivative of a VHF/UHF Ham type radio with GMRS specific firmware. Some of the GMRS radios are based on a single band design so that's why they don't have VHF and thus no NOAA station reception. I would just go for a good quality GMRS radio and then spend a bit extra and get a cheap Baofeng UV-5R type radio for about $25 or so and program in the NOAA weather channels in it. You're not really going to be transmitting on it, just using it as a monitor. I typically carry a TK-3170 for GMRS and UHF ham. For VHF Ham and NOAA I have the VHF version of the radio, TK-2170. https://pdfs.kenwoodproducts.com/9/TK-2170&3170Brochure.pdf Of course you have to be within range of a NOAA station. Some places aren't covered, or not very well. https://www.weather.gov/nwr/ https://www.weather.gov/nwr/Maps Another advantage of a separate radio is you might have an active "Skywarn" group in your area. During extreme weather events this maybe a better source of timely weather updates. https://www.weather.gov/skywarn/ https://www.weather.gov/sew/spotter
  8. It’s easy enough to find out once a person does the lookup the first time. The radio is required to have an FCC ID tag on the back to be legally imported/sold in the US. Then look up the ID on this site. https://fccid.io Type in the FCC ID and click the search button. Example for my TK-3170 HT Type-1 with ID ALH34713110. Then look at what’s under the Rule Parts in the grant. https://fccid.io/ALH34713110 Anything that shows Part 95 is certified for GMRS. In the example it’s Part 95A which is the pre 2017 rules, but still legal. The new rule part post 2017 in Part 95E. I do this for ALL my radios and keep PDF copies of the grants on file as part of the documentation set for that radio. That’s it.
  9. Are you sure your dummy load is spec’ed for GMRS frequencies? Some aren’t and give really crappy readings.
  10. It would be prudent to do some research first. Try to find user reviews online for the radio. Also if one has the technical background locating the service manual for the radio would be a good option. It would likely have the schematics. Looking those over would reveal how much frontend filtering is being done. For example I believe the Motorola XPR-7550e is one such example. Users swear by them and have very good frontend filtering and high sensitivity too.
  11. A mobile doesn't have the antenna height advantage a base does. I'm thinking the FCC's goal is to limit the operational area by removing the antenna height advantage a base station has since they likely assume the communication would be between the base station and hand-held or other mobile stations belonging to the same licensee. They didn't want GMRS to turn into a "Ham Lite" type of service, which it seems to be doing.
  12. Of course somebody will have to "volunteer" their time to maintain the list and weed out bad listings. This is were ideas like this usually fail nobody wants to put in the effort. Also some just don't care if their radio is Part 95 certified or not. A lot of users are operating older, and new, Part 90 only gear. So far the FCC doesn't seem to be interested in busting them. I'm not recommending the practice, but so far that seems to be the case.
  13. That's a valid point. I think a fair number of GMRS users would agree given the limited number of repeater frequency pairs available. IMHO one should look at what the original purpose of GMRS was targeted at. You get a feeling for that based on the licensing rules, basically a family with parents and siblings. The typical communication would be limited to a small area. I don't think the intended operational vision was communication over large geographical areas, such as state wide or multi-state systems. A city wide or county wide system might be more reasonable. I'm neutral on the topic. I don't have a dog in the fight, not a repeater owner/operator. I'll let others do the heavy lifting. Advice given to new attorneys by the old experienced ones : "If the law is against you, pound on the law. If the facts are against you pound on the facts. If both are against you pound on the table."
  14. Any publicly accessible radio service will have some degree of interference issue. The real question is just how much. Also remember not everyone is going to be on the air at the same time. If you're looking for a more robust plan then looking at several different radio services would be the route. Part 95 services would be GMRS.FRS, MURS and finally CB Radio. With the exception of GMRS you can buy radios for FRS, MURS and CB, use them with no license requirements. Then the final option is Ham radio Part 97. The later you need a license, each person, and have to pass an exam to get one. The Tech Class is fairly easy, however some people just don't want to be bothered. It does give you much more spectrum to operate in with and will greatly reduce the likely hood of interference. None of the two, Part 95 and 97, allow encryption. So, if you need to exchange sensitive information you'll have to either do so illegally with encryption, that's going to be a personal choice and nobody here will publicly recommend it, or find some other method to exchange the information, prearranged codes etc. I also would NOT depend on a repeater either, Ham or GMRS. Most are simply grid powered and will fail immediately on a grid-down condition. Some do have backup emergency power but may not last that long. Your best bet is assuming you're on your own using direct radio to radio, simplex, communications.
  15. A lot of mutual interference and signal jamming. That of course depends on the length of the transmissions and power levels. Long winded communications using 50 watt mobiles would be the worse case.
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