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Lscott

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Everything posted by Lscott

  1. Lscott
    What kind of match did you get on the Diamond? The NR-770 and the SBB-5 look like a clone of the other one. Might even come off the same assembly line with a different label?
  2. Lscott
    For testing I’ve used a section of sheet metal about 36 to 40 inches square from the local hardware store specifically to simulate a ground plane when using a magnet mount. This way I don’t need to drag crap outside for testing. I can do it in the basement. The sheet metal section is about the area of a passenger vehicle roof. It’s big enough for a VHF through UHF antenna. https://forums.mygmrs.com/gallery/image/306-220-mhz-antenna-scan/?context=new I’ve also used some brass rods bent at a 45 degree angle for a cheap home made ground radial kit. The rods were held in place using a stainless steel hose clamp around a short SO-239 barrel adapter. My antennas are typically using a UHF mount. https://forums.mygmrs.com/gallery/image/268-ca-2x4sr/
  3. Lscott
    Thanks for everyone who responded. I might pick one of these up to experiment with it. The SWR numbers look encouraging.
  4. Lscott
    What kind of SWR do you get with the SBB-5 antenna on the Ham bands, MURS and GMRS? I'm still looking for a 1/2 wave ground independent antenna I can use for Ham, MURS and GMRS. I need something that will work on my luggage roof rack rail mount. The CA-2x4SR is a 5/8 wave design which requires a GOOD ground plane, which I don't have with the mount I'm using. https://forums.mygmrs.com/gallery/image/473-close-up-of-mobile-mount/?context=new https://forums.mygmrs.com/gallery/image/471-mobile-mount-with-antenna-rear-view/ https://forums.mygmrs.com/gallery/image/472-mobile-antenna-install-side-view/ Old installation on my Jeep. https://forums.mygmrs.com/gallery/image/259-ca-2x4mb-jeepjpg/ https://forums.mygmrs.com/gallery/image/282-ca-2x4mb-scansjpg/
  5. Lscott
    While not mounted on a travel trailer it is a portable antenna and mast system. https://forums.mygmrs.com/gallery/image/257-portable-mast-antenna-system/ This is compact enough to pack in the back of a small SUV.
  6. Lscott
    There are several license free radio services in the European Union, PMR446 (narrow band FM), Digital PMR446 (DMR Tier-1), dPMR446 (dPMR). These all operate from 446.0MHz to 446.2MHz. The Ham band there is only from 430MHz to 440MHz so it's outside of their segment but within ours in the US. The licensed power is only 0.5 watts like our old FRS standard. I would suspect hearing them around popular tourist destinations for international visitors. They likely would bring their radios with them unaware they would be operating in the middle of the US Ham band. There is a forum where EU radio use is discussed. Some of the old posts are fun to read. https://transmission1.net/viewforum.php?f=4&sid=a74e04a3a9d842dce32abec0669cc532 PMR446 White Paper.pdf
  7. Lscott
    Yes to both questions. You can start off with a cheap 1/4 wave magnet mount. The antenna will only be about 6 to 8 inches tall depending on the exact magnet mount used. The antenna will be short enough where you likely won’t have to worry about clearance issues parking in a garage, going through drive throughs etc. This will at least give you an idea of potential improvements with a better external antenna. https://forums.mygmrs.com/gallery/image/338-cheap-14-wave-gmrs-antenna/?context=new
  8. Lscott
    You can get a reasonable estimate for the SWR at the antenna end of the cable if you know the coax losses, from a chart of loss verses frequency for a known length of cable, and the forward and reflected power. You can calculate the loss for the exact cable length one is using at the frequency of interest. The cable loss allows one to calculate the power delivered to the antenna based on the forward power measured at the radio end. Also the reflected power measured at the radio end allows one to calculate the reflected power at the antenna end based on the cable losses. With both the calculated forward and reflected power at the antenna end of the cable is now “known” it’s now possible to calculate the SWR of the antenna itself. This saves the trouble of having to stick the SWR meter up at the antenna, which in many cases isn’t a realistic possibility. While not likely as accurate as a real reading it’s better than nothing.
  9. Lscott
    You might try something like these. They are rubber boots to protect the finish but also likely less slippy too. Most magnet mounts use a very thin sheet of plastic on the bottom. https://www.arcantenna.com/products/laird-antenex-gro-rubber-boot-for-magnetic-nmo-mount-vehicular-antenna https://strykerradios.com/product/sr-a10mm-magnetic-mount-protective-boot/ Note adding some thickness between the magnet mount base and the mounting surface will decrease the grip force. You may need a larger magnet mount base if you use the boot.
  10. Lscott

    BTECH AMP-U25D

    Lscott replied to WRQG450's topic in Guest Forum

  11. Lscott
    And IRLP, Internet Radio Linking Project. https://irlp.net/
  12. Lscott
    https://dopsys.com/fcc-selects-doppler-systems-to-provide-radio-direction-finders/ https://dopsys.com/direction-finding-products/fixed-site-direction-finders/ https://dopsys.com/direction-finding-products/packaged-direction-finding-systems/#mobile-kit https://www.dopsys.com/doppler-files/appnotes/Using Doppler Systems Radio Direction Finders to GeoLocate Transmitters.pdf
  13. Lscott
    CX-5 Antenna System Analysis.jpg

    From the album: Misc. Radio Gear

    I did a bit of a detailed gain analysis of the antenna system I wanted to install on my CX-5. I ultimately went for the “C” installation. The goal was to see the tradeoffs using different antenna mounts and cable types and lengths. I had to settle for a longer lead in cable length than I had originally wanted but the hit on the gain wasn't too bad. The analysis was done using the older higher gain antenna, CA-2x4MB, which isn't manufactured any more but my old one still works and I have a new one still in the plastic bag. I had purchased two at the time, one to install and the second as a spare. I also have the Diamond SG7500, but its not as broad banded as the old antenna. The Comet CA-2x4SR would have worked provided I had a good ground plane. Since I'm using the luggage rack mount I'm stuck using a no ground plane design type so this antenna is out for the moment. https://forums.mygmrs.com/gallery/image/282-ca-2x4mb-scansjpg/?browse=1 https://diamondantenna.net/sg7500a.html https://diamondantenna.net/c213sma.html https://diamondantenna.net/c110.html
  14. Lscott
    I don’t really see any either because I normally disable JavaScript. I use a script blocker on Firefox and on the iPhone there is an option to turn it off on Safari too. This also does a good job killing annoying ads on other sites too. They also load faster on mobile devices and cuts down on your data usage.
  15. Lscott
    Interesting. I wonder if there are any rules specifically about how ID’s must be done on digital systems. I'm assuming you’re referring to repeaters exclusively, doing the CWID in analog. The question was about subscriber units, user radios, when using a repeater or in simplex mode. In my case, likely not in general, the CWID feature is only available when using NXDN on the Kenwood radios I have. For example the ND-1300, current production radio, when the NXDN version is selected in the programming software the manual CWID TX feature is available. However selecting the DMR version it’s not. I’m trying to find out is there a rule or technical reason why that’s the case. So far I haven’t found anything definitive.
  16. Lscott
    And one wonders why it's getting worse?
  17. Lscott
    That makes sense. You wouldn't want to run "narrow band" NXDN on a FCC licensed "very narrow band" frequency. I would like to know if there are any really solid technical reasons why CW ID isn't done on DMR and P25. I just wild guessed what it could be in the prior posts. I am likely wrong, but have to start somewhere.
  18. Lscott
    I've read that ID'ing on Part 90 is regularly ignored. I guess the FCC doesn't care that much about their own rule. I wasn't aware of the specific emission designation for CW ID on NXDN. Thanks.
  19. Lscott
    I was wondering the exact same thing. My NX-1300's allow CW ID function in NXDN mode but not in DMR mode. Just a wild guess on my part but I'm thinking it has to do with the TDMA nature of DMR. The radio has to kill the time slot selection, i.e. no time slots, and use straight FM to send the ID. If that was done on a repeater what happens to the other conversation on the other time slot? It gets hosed too? With NXDN I suspect it's rather trivial to switch to FM to send the ID since there is no time slot to muck things up. You only have one conversation to worry about on a repeater channel. The issue with P25 is with the newer Phase-2 mode which uses TDMA, just like DMR. And the same comments about DMR I think would apply.
  20. Lscott
    It's not even a required test element for any class of amateur license anymore.
  21. Lscott
    While the CW ID transmit isn't done on a timer, the function has to be assigned to a front panel key, it has to be manually selected each time to send. The one FM digital radio I have has the CW TX function built into the radio. The radio is also Part 95 certified too in case someone wants to know. https://forums.mygmrs.com/gallery/image/251-nx-300jpg/?context=new
  22. Lscott
    When they figured out the money stream would dry up after the market reached saturation with Win10 they had to obsolete it and force people to upgrade again. Then there is the required hardware issue crap too. I installed Win10 on an old AMD dual core PC because Kenwood blocked supporting their license manager app, KPT-300LMC on anything older. The only thing I need it for is install feature licenses to the few NX-1300 radios I own. The programming software for those radios is hacked so I don't need the license manager to activate it. All the other radio software I have works fine on Win7 Pro. I'm going to move all that to Win10. The win10 system was installed using an "activator" app. I'm not blowing money on a license for Win10 now when Microsoft is going to EOL it next year. https://learn.microsoft.com/en-us/lifecycle/products/windows-10-home-and-pro
  23. Lscott
    This project is worth keeping an eye on it. Still not ready for prime time but it's getting closer. https://reactos.org/# And if you're thinking about dumping Windows for Linux but still need to run Windows software then this project might be of interest to you. https://www.winehq.org/
  24. Lscott
    Let him try it first on his car and using his radio.
  25. Lscott
    The title of this thread could be interpreted another way. One could ask does the user care a lot about how much they spend on a radio? I know some on this forum have likely spent well past 4 figures on a portable radio. If I spent that much on a portable radio I would be reluctant to even take it out of the house. I have only purchased a few radios new over the years. The majority are clean used radios showing few signs of use. Even then I've spent maybe $200 to $250 at most on a used commercial grade radio. The more expensive used commercial ones tend to be FM/Digital types. Out of the later the FM/P25 radios seem to be noticeably more expensive than the other FM/digital types, especially the VHF models. Ham gear is a different story. Before the new TH-D75A was released the older discontinued TH-D74A was selling for a huge price premium above what they sold for new. I saw a few selling for above $1000+ on eBay. When the TH-D74A's were available one could buy it new for around $650.
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