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kidphc

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Posts posted by kidphc

  3. L3Harris XG-100M

    in Amateur Radio (Ham)

    Posted

    [mention=2261]kidphc[/mention] A 100M at my house arrived yesterday. Unfortunately I didn't get home until 11:30pm and promptly passed out. I hope to get some bench time with it this weekend, or in the next week.
    Awesome self Christmas gift.. enjoy

    Sent from my SM-S901U using Tapatalk

  6. best ⅝ wave GMRS high gain NMO antenna

    in Technical Discussion

    Posted

    15 minutes ago, WRZM228 said:

    Some guy just emailed me from another company about the antenna and he said i need to follow the chart and cut it. I told him not feeling confident doing that in this case. The more I pull the antenna, that's where the SWR is going down. I notice alot of people even experienced ham guys and dealers are having a rough time on GMRS antennas.

    It is rough for us Hams because the 70cm and GMRS bands are to close to use a duplexer for separate antennas. But far enough apart that anything that cover both bands, that we either sacrifice part of each band, or have silly SWR at the ends of both bands. Personally, I shoot for about 450-453 Mhz, when tuning them to try to get the most bandwidth. Usually, start ending up with 1.67-1.75 on the band edges. Acceptable, for a really compromised antenna.

    Easiest route is to go 1/4 wave for either band and usually will cover both bands with below 1.6 SWR. Lowest SWR will end up being in the commercial band.  But they are the broadest bandwith designs you will find. I don't use them because the roof rack shadows too much of the antenna, I end up with worse performance then with a 5/8 wave and coil design.

  7. best ⅝ wave GMRS high gain NMO antenna

    in Technical Discussion

    Posted

    The 4505 can be tuned. The recommend lengths for the parts below the enclosed collimator coil (where cut is ) is printed on the bag.

    The 4503 can be tuned a bit. First check the bottom of the coil to make sure they sent you the right one, and not miss packaged. If that fails contact the vendor. You maybe able to add a Laird spring, and cut the antenna to get it close to where you want it.

    If all else fails you can buy some .150  (i think that is the right size) nitinol wire/piano wire or bug a HAM for left over whips from over cutting. Then cut it first to larger then the original whip and tune for the mid of the GMRS band. With nitinol you will have a very flexible whip that will be near indestructible.  Nitinol is basically, what laird cause a super flex, STI and signal stick/signal stalk make their antennas out of. Do not user wire cutters, it will get destroyed. Best to use a cut off wheel, still takes a while. Just be aware without a corona ball glued on it will easily take an eye out.

  12. What would have to happen for GMRS to include APRS?

    in Technical Discussion

    Posted

    Looks like Midland is pushing for something like aprs, well bit by bit. Really right now, more like a mobile unit vs the currently approved hts.

    Why more then one beacon in a 30 second time frame? Is the only question I have.

    From a reddit thread (contains Midlands pettition.

    https://www.reddit.com/r/gmrs/s/aaCXcecUYt



    >To Amend the Commission’s GMRS Corporation Rules to Allow Non-Handheld Radios that Utilize a Non-Integrated Antenna to Automatically Transmit Digital Data and Digital Voice Data More than Once within a 30-second period, and to Operate at 50 Watts.

    Sounds like it's saying they want mobile units, with removable antennas and up to 50W (all already legal) to be able to do digital data more often than is currently allowed AND to be able to use digital voice. Possibly both at the same time.
    Best comment is... "gmrs needs to allocate one channel to ft8"

    Sent from my SM-S901U using Tapatalk

  13. GMRS Handbook/Primer?

    in General Discussion

    Posted

    Funny enough at dinner with a local guru/ multiple repeater owner.

    He was joking around about not doing or changing his antenna presentation. Kinda focusing on the basics. This, after hearing how Marc's presentation was received.

    I said please no.. let Marc handle the new guys. We all want to reserve you for why a bed spring may not be an optimal antennan even if resonant type questions.

    Sent from my SM-S901U using Tapatalk



  16. best ⅝ wave GMRS high gain NMO antenna

    in Technical Discussion

    Posted




    Remote heads are awesome for flexibility in mobile installs,too, which leads back to running GMRS separate, do a single band antenna appropriate for that (which will still receive NOAA alright) and set up 2m/70cm separately when you're go for that.


    I second this.

    Trying to find a triplexer for my for my Harris 100m. While not impossible hurts, cheaper ones are +280 and commercial ones average $600+ for used ones.

    Note:
    watch antenna spacing. My xtl5k (set for gmrs and p25 65cm/70cm) when at full tilt has blasted my ftm400. That is with the 5/8th for the xtl at the back 1/3 of the roof ND the 2/70sh on the driver front fender. Doesn't happen the other way around with the ftm400 on 70cm and the xtl5k on gmrs. The xtl is just has better selectivity. I have to turn off the ftm400, when using the xtl.

    Marc has toasted a vhf xtl. Not sure if has to do with the proximity of his uhf xtl. Maybe he can chime in.


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  19. best ⅝ wave GMRS high gain NMO antenna

    in Technical Discussion

    Posted

    Higher gain normally is going to cost you bandwidth.

    ⁵/8 over 5/8th best I have had for gmrs was my laird. But only going to do between 450-470.

    Big thing here is the more bands you add. The harder it gets, because more comprimises are added. So one band ends up at the bad end and one of the other bands is acceptable, then the last band becomes meh. Best = least comprimises.

    Closet to what to what you want is going to be something on the lines like the nmo 150/450/800 or nmo150/460/700. Note no 200mhz. They are also designed for the public safety focus (ems/fire/police). They have acceptable (depends on what think is acceptable) swr for amateur services. No, they are not tuneable.

    There is the 2x24sr. Very stiff, meh for me at least performance wise.


    You can use diplexers/triplexers and separate antennas? Are some bands listen only?


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  20. No laughing allowed...well maybe a little....

    in Technical Discussion

    Posted

    That's pretty awesome. Ya, don't let him climb that tree if you can help it. But that's impressive. I don't mind climbing but this tree is full of sap and I just don't want to be bothered. A fishing pole, slingshot and arborist line and I'm safely on the ground. Thanks for the feedback and the pic. 73' de WRWR978
    He won't listen. Still regularly tries to climb towers to help out with the repeaters around here.

    I was going to do the same as you.

    I was going to tether the base of the antenna as well. To stop the antenna from swinging. Even thought about climbing the pine tree to lash the antenna with rope. Damn hoa...

    Alas, the tree one storm decided it wanted to take a nap on the neighbors house.

    If you can get access to a bucket truck, it will make securing the antenna easier.

    Sent from my SM-S901U using Tapatalk

  21. No laughing allowed...well maybe a little....

    in Technical Discussion

    Posted

    None. It is what I recommend. If you could get it above the canopy, it would be awesome.

    Local here WRPJ758 Roland 2.. has one on top of a 100' tree, where he hoisted part of a tower, and a flag pole. One of the best stations you will here. Simplexes 18 miles easy, and hits repeater, up to 30 miles away with conditions. He is also only like 250 feet above sea level. ( rolly polly terrain of dc hampers his range)

    It is grounded properly, running heliax 50w from old motorola mobile, as well as a commercial antenna. Heliax from the antenna to his house.

    Pic is from the base ladder. Which is about 15 feet up.

    Keep in mind he was very picky with the mounting gear. He didn't want to poison and kill the tree with the bolts.

    Only maintenance, has been to redo the ground wire, with broke due to the growth of the tree. Currently, the tree has claimed it as part of its trunk.

    He wants to climb the tree to clear the canopy from around the antenna. None of us want him to, since now he is 78. The antenna use to be above the tree. Now you can barely make out the tip.

    I have more pictures at home. Old photos he gave me. Will try to post more later.http://files.mygmrs.com/forums/monthly_2023_11/IMG_20220922_164134.jpg.cd1cbfd566fdc74e1cf9b504678e9ae6.jpg

    Sent from my SM-S901U using Tapatalk





  22. Power for a mobile radio to use as a repeater on top of a building and other questions related to the same!

    in Technical Discussion

    Posted

    You could use a repeater radio = $$$. Or 2 kg100g with repeater cable, less $$$. Or old commercial radios and configure them as a repeater less $$$ (like kenwoods).

    You would need a duplexer. Price will depend on if you choose a cheap Chinese brick duplexer or something like a 5 cavity duplexer.

    Plenty of youtube videos on different configurations.

    Depending on topography and antenna height. The repeater may not make 35 miles straight line.

    Most of the repeaters around me (d.c area) will generally have an 18 mile radius. These repeaters are usually minumum 100' with no obstructions using all commercial gear. From the repeater (like a quantar), antenna (lots of comwaves) to heliax feed line using cavity duplexers (for the isolation, and power handling).



    Sent from my SM-S901U using Tapatalk

  23. What would have to happen for GMRS to include APRS?

    in Technical Discussion

    Posted

    Lots of off-grid outdoor enthusiast GMRS users who would benefit from APRS (e.g., knowing the location of their party, allowing SAR to find them). I personally think APRS (or a variant) finds its way into GMRS.
    That is what is currently available. With some of the radios. Btech pro, garmin reach.

    Albeit simplex only.

    I can't see gmrs users spending the umpteen money on the digipeater or server infrastructure part of it.

    Sent from my SM-S901U using Tapatalk


  24. What would have to happen for GMRS to include APRS?

    in Technical Discussion

    Posted

    I do agree, and congratulations on testing AND passing your exam!
    I recall in the late 90's, in my area, packet weenies had much of 2m simplex polluted with their noise makers.  No joke!  Depending on the day or week, there were times you struggled to find a simplex 2m channel to yak with friends on.  It seemed as though every simpex channel was occupied by that annoying "SCREEEEECH" every few seconds.  My friends and I had to use PL to keep from hearing that.  I wound up buying a PL decoder board for my radio and had one sent to a friend whose budget didn't allow him to purchase one.  At that time, many 2m transceivers could encode a PL but you had to buy the optional board for decode (radio silence). Some jerk even had one set up on 146.52, the nationwide simplex call channel.  Thankfully, that eventually died down, or they all figured out they could run their noise makers on the same channel and not interfere with one another.
    I have some old radios like that.

    I even have one that only way to set a pl. Was to crack open the case and flip dip switches.

    Bet you have flash backs when an unaware user sets a tone on his aprs frequency which happens to be the voice alert tone, and you get the screech.

    Sent from my SM-S901U using Tapatalk

  25. What would have to happen for GMRS to include APRS?

    in Technical Discussion

    Posted

    With the radio likely plugged into the cell phone to access the GPS info.
    If not that then the extra expense of adding in the GPS RX into the radio. To save cost the GPS can be external. Some of the commercial radios have external accessible serial ports that allow such a connection. The ones I've seen the GPS RX is built in to the external speaker microphone, and those aren't cheap!!!
    https://www.ebay.com/itm/155825555327?hash=item2447ed477f:g:z~kAAOSwxxdlKEkf&amdata=enc%3AAQAIAAAAwIkCHDaeNe%2Fh%2FRcoGuerCnQe3rUMV7MdYj4Cfpaa%2Bj8Pq2US4jQ4EH%2Bxcq%2BIRl7xRC3NtGYt4naNXWFAdiPHoH0ZOe0ADAn3JxujrwUhhfiKP6NnXQS%2FQm60n64jYURsCKJNB2sejsOY6cwGztfIU9NnM%2Frx%2Fznv2YybxJWcja9vP%2B0haJyWtzX%2BQzLbTgNESSx2gTyQx6YRqHrdo3rWGpdx%2BS4NeLIjw1saNZknmmQVxYzq%2Fcax0TneBcO4TYJjKg%3D%3D|tkp%3ABk9SR_zqobTxYg
     
    KMC-47-48GPS.pdf
    To be honest I just use cell. With location tags, ie airtags and such. As well as the apps no need really.

    Been trying out civtac app, to kinda have aprs like functionality.

    Civilian version of atak. Which I think was designed to work with an mpu5 mimo radio. Nasty little rabbit hole. Thank god mpu5s are like $30k.

    Quick overview of atak/civtak:


    Atak video.


    Sent from my SM-S901U using Tapatalk


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