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Lscott

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Posts posted by Lscott

  1. 8 hours ago, SpeedSpeak2Me said:

    Interesting... I'm glad someone else analyzed the N9TAX Labs antennas.  I also have both the 2m/70cm and MRUS/GMRS versions, both with 16' of RG58U.  For the MURS/GMRS (on GMRS) using a RigExpert Stick Pro, with the antennas hanging about 12' AGL (away from vegetation), I got slightly better results:

    image.thumb.png.f85e630d5c07c1e0fe0ddfd7c20a5514.png

     

    2m/70cm (UHF)

    image.thumb.png.cb486ad2e801ca8605d8d74428476e25.png

     

    I also found that the Surecom SW-102's (mine is the "S" model)l are wildly inaccurate.  I know they are popular, but the readings they give can be very misleading.  As an example, it told me my Browning BR-6155 (fed with 50' of LMR400UF) has an SWR of 1.01:1 at 467.6000 MHz.  My RigExpert Stick Pro, and my friend's AA-1400 both show 1.37:1 at that frequency. 

    I used the Rigexpert AA-1000 to make my measurements. 
     

    The antennas are a bit sensitive to the environment where you make the measurements so I’m not a bit surprised by slightly different results. Also the antennas are all hand built and tuned. That can result in differences too.

    I haven’t heard good comments about the Surecom meter. Most are about the same as yours, inaccurate results. But people like them and they keep selling. 

  2. 37 minutes ago, CJK said:

    Is there a way to program the Wouxun 935G to broadcast my call sign, in Morse code, at the end of transmission?

    That would be a nice feature to have on a radio. Maybe not at the end of every transmission.

    There is a feature on one of my digital radios to do it. But it has to be manually initiated through one of the menu selections every time I want to send it. Not very convenient.

  3. 22 minutes ago, tweiss3 said:

    Also, on an HT, you never really get an accurate measurement. Sure, it comes with the ground plane plate to attach, and it helps with the measurement, but you end up using adapters, etc. and it never shows accurately. Rotate or tilt the radio 10 degrees and the readings change. 

    BTW, on an HT, you shouldn't worry about SWR, if the antenna is the correct band split for your frequencies, just go with it. 

    Also consider the environment a typical HT is used in. hand-held, mobile with external antenna, hanging on a belt, stuck in a utility vest pocket. All those will really screw up the SWR.

    I was looking at the spec's for some of the hybrid RF power blocks used in many HT's and some mobile radios a while back. The HT one's I've seen they're rated to work up to a max SWR of 20:1!! Basically no antenna. It sort has to be that way due to the highly unpredictable environment HT's have to work in without failure. See example file attached. Look at the first page at the bottom.

    M67799MA.pdf

  4. 46 minutes ago, Sshannon said:

    GMRS is subject to the restrictions listed for all the personal radio services. This is the rule that addresses scrambling:

    95.381 Voice obscuring features.

    A grant of equipment certification will not be issued for any transmitter type that incorporates one or more voice scrambling or other obscuring features for any of the Personal Radio Services that provide for voice (telephony) communications on shared channels (see § 95.359), if the application for such grant is filed on or after December 27, 2017. 

     

    This is getting a bit off topic and into the weeds a bit. But the rule specifically mentions equipment certification. Anything after the cutoff date will not get certified if it has any kind of voice obscuring features. However it’s silent about equipment that was certified before that date and no mention the feature must not be used in that case. So, it’s very possible voice scrambling in OK, BUT only on radios certified before Dec 27, 2017.

    So, my favorite Kenwood radio, TK-3170, I use for GMRS, which by the way is certified Part 95 in 2004, has analog voice scrambling so it could be legal to use that feature. Interesting thought.

  5. 1 minute ago, WRXB215 said:

    Every day I become more and more convinced that is the most likely scenario we will face. 🙁

    I'm not a conspiracy believer, but either the government has a secret "kill switch" or an understanding with the cell phone companies to turn off the service when asked/ordered to do so. If nothing else the FCC has the authority to license and control transmitters, which of course includes cell phone towers, and force the shut down.

    People forget that Ham radio was shut down during WWI and WWII by the FCC. It took a lot of lobbying to allow Ham radio to resume in a fashion like it was doing before the war. Not likely today, but that could change.

    https://bw.billl.net/wp-content/uploads/2019/11/Radio-History-03-Amateur-Radio-Before-and-During-WWII-By-Dan-Davis-W8LUX.pdf

    Then there is the question what happens to the Part 95 services? Is it also possible they too might be ordered to cease operations?

  6. 1 hour ago, tweiss3 said:

    I wonder if it could be radar, though that should stop at 450, but you know, the feds do whatever they want.

    Also could be a 2nd image of 925.225MHz, but neither would exactly explain the issue around both locations.

    Edit: 925 is part of the LTE band. ATT did just have that huge problem last week. It is possible that their outage included firmware updates for the cell tower equipment and now something is out of band/creating an image.

    Could also be some mixing products in the radio's front end. Take a frequency on 931.6MHz (public safety frequency) and mix it with 469MHz (business frequency) you get the difference of 462.6MHz right in the GMRS range.

    It could also be just the radio. My Kenwood dual band TH-G71A shows a full scale signal on channel 7. Take the antenna off, nothing. Then I tried several other radios on the same frequency. They show nothing there. So apparently it something weird with just the one radio.

  7. 10 hours ago, WSAR863 said:

    It has to either be very powerful (to penetrate canyons) or a satellite, right? My signal, on 18, appears to be coming from the direction of a cell tower, but I guess we'll find out. The one on channel 3 seems to come from everywhere, like your channel 18 signal.

    What kind of radio is being used? If it's a cheap Chinese radio they're not known for good receivers.

    Note that channel 3 is the Interstitial frequency, 462.6125, between the main channel 17, 462.6000, and main channel 18, 462.6250.

    For GMRS the channel bandwidth is 25KHz so there is considerable overlap on channel 3 with the adjacent channels 17 and 18.  If the radio doesn't have extremely good selectivity you're likely to experience significant bleed over on 17 and 18 from a strong signal on channel 3.  Also a strong signal on either channel 17 or 18 will bleed over on channel 3.

    FRS-GMRS Channels Layout.pdf

  8. 5 hours ago, WRZP493 said:

    I lucked out and snagged a couple for a great price, Had it not been for the frequency spread I'd not have bought them, and I'd have regretted it. they're a fantastic rig.

    If I have a choice I typical go for the 400MHz to 470MHz range since most of my usage is Ham so that covers the full band. It's also usable on GMRS, but as I mentioned before they're not certified for Part 95, but typically for Part 90 of course.

    When looking for used commercial grade radios there are several things I'll do before dropping my money on one.

    1. Look up the manufacture's brochure to see what features the radio has, namely number of channels, display type, frequency ranges etc. You might decide at this point it doesn't look so appealing.

    2. Look up the FCC ID's, usually on the manufactures brochures. Check to see what the certifications are for the radio, tested power levels, modulation types and frequency ranges. You need the FCC ID to verify what you're trying to buy or bid on. I frequently find sellers who get the model name wrong or frequency range wrong in the ad description. The FCC ID doesn't lie.

    3. Check and see if the programming software is obtainable. This is a big one. Sometimes it almost impossible to find. If I can't get the software the idea is dead right there. It doesn't matter how good the radio is. Commercial radios are basically useless without the programming software, you REALLY need it.

    4. Most commercial radios are firmware up-gradable. Chances are the one you're interested in will need a firmware update to make it compatible with the recent radio programming software release.

    5. Are important accessories like battery packs, chargers, programming cables, microphones, power cables etc. easy and cheaply available? There are some nice used radios out there but battery packs are almost unobtainable as an example.

    6. Then I go looking for the documentation for the radio. Important things like user manuals, service manuals, any programming tips etc.

    7. Then it comes down to just how much you want to spend. Some sellers price the radios like they are gold plated. The worse offenders are sellers of digital radios with P25 being at the top of the list. In general it seems that the VHF gear sells for a premium compared to the UHF stuff. 

     

  9. 47 minutes ago, WRYS709 said:

    Yes, that works best to remember what is programmed to each of the 16 channels.

    I got this SMA to Alligator Clips adapter 

    Screen Shot 2024-02-25 at 7.38.28 PM.png

    and unscrewed the non-standard antenna.  I put the red clip inside the non-standard antenna jack and connected the SMA to a rooftop antenna and voilå this little thing is getting great reports through a local DMR repeater and it even works Digital Simplex really well, too!

    I would like to pick up a couple more if they were available and at the $14 price point, just to program for a couple of different DMR repeaters.  And of course finding the C006D with the display would be a bonus!

    The miss match caused by the clips on the leads may eventually damage your radio. I would very seriously look for a good quality adapter for your radio. Unless it’s totally proprietary to the manufacturer you should find one.

    In the case of this cheap radio you could use it as is, or disassemble it and install the pigtail directly on the circuit board. I’ve seen this done in the past with FRS radios. There are some YouTube videos on the topic.

  10. 7 hours ago, Guest NuGMRSguy said:

    It’s not a concern. You have to specifically enable it in a radio AND have to put in the particular code to do it. Leave the code out and “turn the feature off” NOBODY will have the ability to stun or kill your radio. That’s the case for every Kenwood radio I’ve programmed.

  11. 25 minutes ago, WSAV277 said:

    Can you please tell me why you only get the kerchunk with receiving tone off and not with it on?

    Two possibilities.

    1. You are using the wrong tone.

    2. The repeater doesn't use a tone on the output. In that case no tone so your radio will never un-mute the audio.

    I almost NEVER use receive tones on my radios unless I need to REALLY block some interference from another repeater or simplex station. I just don't get the desire where people feel the need to use a receive tone when it's almost never required on their radio. It ends up leading to unnecessary problems like the above.

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