axorlov
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Posts posted by axorlov
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Simplex repeater appears not to be allowed. There are words about "store and forward" not being allowed in all Part 95. However, I actually have and I use Argent Data simplex repeater. I only use it in the mountains, never in the urban area. The ADS-SR1 can be configured in a smart way: it will not automatically blurt out anything it hears. It will record and sit quietly, until it hears DTMF "0", only then it repeats the last recorded message.
So usage mode is this: we talk on simplex with HTs, while ADS-SR1 quietly sits in the car, parked in good spot (or any available spot), connected to 40W TK-880 and efficient antenna. It does not repeat anything. Then I find myself far from the others where HTs are not picking signal. I call and wait for sufficient time to answer (say 1 minute), and then I send DTMF "0". Simplex repeater hears it and shouts out the last call (supposedly mine) with all 40W out of efficient antenna. I hear it myself, I know that now it reached recipients, most likely. This scheme works like a charm. You do not pollute the waves until really needed.
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Hamexam.org, go there, start taking practice tests. Do not order the book just yet, because there are resources to help. See how you do with the practice tests. Btw, creating an account is not needed, but if do create an account, it'll keep your statistics and point to areas where to concentrate studies for the improvement. Once you are confident that you pass, go ahead, schedule the appointment or whatever it takes these troubled days.
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If your background is in natural sciences or crafts, the test preparation will be easy. On the other hand, if you are more into philology, literature (especially english romantics of 18th century), art in general - the preparation could take like maybe the whole 4 hours!
There are helping resources on the internet. hamexam.org is one, there are plenty of others.
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I thought all rf was line of sight? So vhf can curve around the earth and go over/through mountains and stuff?
VHF and UHF and shorter frequencies are mostly line of sight. The HF (aka shortwave) is reflected from ionosphere and gives you a global reach. VHF and UHF sometimes are too reflected from atmospheric layers (tunneling) and from ionosphere (E-layer reflections), but this type of propagation is accidental, not reliable at all. VHF and UHF can be reflected and diffracted from and by any sort of things - meteors, airplanes, buildings, rocky canyons. This is how you get non- line of site communications on V- and UHF. Hams do these modes for fun, you can look up airplane scattering.
There is also a ground wave - when RF truly goes around the the curvature of this miserable planet, over the mountains and oceans. But the shorter the the wavelength, the less pronounced the effect. It's pretty much nonexistent on 40m and shorter. Best examples of ground wave are MW and LW radio broadcasts.
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4W vs 5W - negligible difference if any at all. Performance difference will come out of receiver and transmitter details, that I can't comment on because did not see schematics, tests, etc. Antenna is removable. Actually, they are interchangeable between 3170 and 3180. There are two types I own and I prefer longer antenna (KRA-27) on my 3170. And 3170 is not that much smaller than 3180. Maybe inch and a half shorter. If you already have a setup for 3180, cables and other accessories, it's not worth to move to 3170 in my opinion.
Being it fat bulky in-your-face radio may be a positive. To one crowd you may look like a cop, to another like a vigilante militiaman. Exploit possibilities!
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You can install KPG-101D without the radio to play with it, see what's available. The software is available on the internet with some searching.
Here we are discussing possible button assignment on TK-3170:
https://forums.mygmrs.com/topic/1328-kenwood-tk-880h-1/page-2?do=findComment&comment=14890
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I have 3173 and 3170. For the purpose of GMRS these two are identical, and both are programmed with KPG-101D. There is indeed an option to set CTCSS or DCS separatley for receive and transmit, so called "split tones". On the Zone/Channel screen these columns are called QT/DQT Dec (receiving tone) and QT/DQT Enc (transmitting tone). You can set tones here. Another option is to use OST feature (operator selected tone) where you can program 40 tone combinations, and program a button on the radio to invoke the OST menu. This option is in Menu -> Edit -> Optional Features -> Conventional.
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Clean it, then. Ugly or not, it's subjective, though. I found BTech's look tacky. Besides, are you in for the checkers or for the ride?
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For $75 + $8 + <some elbow grease> you can have all of that and monitor 250 frequencies:
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Giga power, quite literally.
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1. Exists, called search button.1. Technical area for specific parts of understanding, purchasing and use of GMRS gear. This would cover mobile and base installs, repeater install and maintenance information.
2. Bring the linking stuff to the forefront. You mentioned doing the linking on a case by case basis. I believe that you need to spell out what the criteria are for linking. Things like other linked repeaters in the same coverage area. Overall coverage of a repeater system. Some level of a map showing the known coverage area's and what those repeaters are. And an understanding that CLOSED repeaters are NOT going to be linked. Now this is all my personal thoughts on linking, but if you take time to consider them they make sense. If there are TWO or more repeaters in the same area, then there are TWO frequencies (resources) in use in the same area. It's not a good idea to tie up more than one repeater with the same stuff.
3. A current projects forum. Have users that are implementing repeaters and the like a place to post what they are up to or more importantly what they are proposing. Reason for this would be if I am gonna put up a repeater on a big tower and it's gonna be a beast with coverage and someone see's it they may want to setup some partnership with the builder and pass their frequency off to enjoy better coverage overall.
4. possible links to audio feeds for busy GMRS repeaters or at least the link systems. Scanner guys do a lot of this. Giving the ability for someone to listen to the link systems may push them in one direction or the other on making the decision of linking vs not.
Give users some level of classifications that are based on technical knowledge vs post count or other metrics. As of now, when someone comes and asks a question, there are typically a number of different answers that range from highly informative to yeah, he really just said that. If folks were recognized as having expertise in certain aspects of radio communications then maybe that needs to be recognized. And it would help new comers that have questions on who to ask or listen to. And of course, there needs to be an OPT OUT part to that as well. If there are three guys that are antenna experts that get 20 questions a day... one of them will probably NOT what to be continuously pestered. He /she should have that ability to have their knowledge level remain private if they desire.
I will think on this some more and toss more up here most likely...
2. Who cares, really. Those who do, they use search button. CLOSED vs open, linking, and tying resource with the same stuff??? No one owes nothing to nobody.
3. Search button! Also, consider that no one owes nothing to nobody and does not have to disclose, advertise, publish or invite to anything.
4. Audio feeds are up to owners. Or listeners. No one owes anyth... but let's not repeat that again.
And the best part tonight: who is going to be a classifying body? How it is going to be created? The edict from the King? The Thunderdome fight? The communal vote? Who gets to vote? Why is this guy's vote is equal to that guy's vote? What if I don't agree, am I still wrong?
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Get outside. Hang up slim jim off the tree or fence or anything. Repeat the test.
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That's most likely the case, people do not speak loud enough for full wide-band deviation. But at any rate, even with distorted sound, speech is easy to understand.
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There is narrow-band vs wide-band issue. GXT1000 is narrow-band,while most of the repeaters are wide-band. You certainly will be able to hear repeater output, but if it is wide-band it will sound distorted on GXT1000.
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dxengineering.com has several magnetic mounts with RG8X. Also ebay.
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Sounds about right. Here is the attenuation chart, that agrees with the online calculator:
https://w4rp.com/ref/coax.html
Better cable would be RG8X and LMR-240. I tend to use LMR-240 for permanent car installs, where you do not move radio around often and NMO mount is drilled through the roof. RG8X is more robust cable, suites better temporary installs with mag-mounts, but loss is higher. RG58U is not a good cable for UHF. And if it's in a car, you certainly don't need 20'.
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Thanks! Very good hands-on. But was it narrow-band or wide-band with the 805G and Motorolas? I'm guessing narrow-band, since you have GXT1000 in the mix. Also, with the GXT1000, did you use the 5W channels or the 0.5W? I'm guessing again the full-power, judging by the results.
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With 5/8 wave it should be a coil that does matching, to balance out the big -jX component, but I may be wrong here - working from memory, and too lazy to check on internets. "Colinear" usually means 2 or more sections in line, but also could mean that Midland marketing dept found a cool scientific-sounding buzzword.
You are absolutely right about adjusting to minimum reflected power. I think moving antenna back and forth on a lip mount will not make a big difference, if any, but worth tying. Good practices means that your soldering and crimping is good and no sharp bends of the cable. I tend not to use RG58U in my car installs, I prefer RG8X or LMR-240. However, if you already have cable and connectors, it's fine. On 8' length difference in attenuation is negligible.
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That's something I had lingering in my mind after reading your links and studying DTR/DLR thing. I'll leave hacking for some time later.
The first thing (ok, second) is of course, to plug in simplex repeater and bring the whole contraption high up on a makeshift mast. That's could be a lot of fun, I already see it.
- DeoVindice and n1das
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But what if I want to listen to the radio from the other side of the galaxy?
And also, what would you listen to 100000 years ago?
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Am I wrong in thinking a simple indication of forward and reflected power should be a good way to check the antenna resonance and later compare different antennas?
SWR 1:1 does not necessarily means that your antenna is at resonance. It means that it's well matched. Assuming there is no big loss in your feed line (that eats up forward and reflected power), the lower SWR, or reflected power, the better the match. And antenna does not have to be resonant to be an efficient radiator. Resonant quarter-wave above ideal ground has 36 Ohm impedance and SWR 1.5:1 when connected to 50 Ohm feedline. So, tune for lowest SWR, i.e. for lowest reflected power. Use good practices to ensure minimal possible loss in the feed line.
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If you want to place stationary antenna at home, something like this should work (since you already confirmed you can connect with mag mount):
Actually, since you can connect with mag mount on the roof your truck, the simple unity gain antenna on the 10' - 20' mast above the roof of your house might be just fine. I used BR-6140 with great success:
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8180 has front-mounted speaker while 880 has side-mounted speaker, thus 8180 is easier to fit into car dashboard. 880 has to be located with speaker not blocked, or remote speaker is needed. 8180 has removable head, making it even more flexible for in-car installation.
Motorola DTR and DLR series 900MHz FHSS digital radios
in 900 MHz License-Free Radios (ISM)
Posted
The pair of DLR 1060 is here, and I had a chance to play with them in suburban environment. The setting was simple: Operator1 is riding bicycle around, Operator2 is stationary at the BBQ table at public park. Communications were happening via a pair of TK-3170 and a pair of DLRs. TK-3170 were configured at wide-band full power (4W) with DPL. DLRs are on default setting: Channel 1, no PIN. So, the DLRs did not outshoot Kenwoods, but were not than much far behind. When we lost comms on DLRs, Kenwoods demonstrated a lot of white noise, and while squelch broke reliably and spoken words were 100% discernible, my experience tells me that we would lost comms via Kenwoods in about quarter of mile. Two experiments were performed.
Experiment 1: Across the park, quarries and along the river bank with minimal obstacles. Trees are rare and foliage is not dense. Not exactly open field, but close. Comms failed when our line of sight started to go through the suburban subdivision. Distance was 1.75 miles.
Experiment 2: Through dense suburban subdivision with 1- and 2-story homes on small lots. Comms failed at approx 0.75 miles.
Unfortunately, I was not able to borrow better FRS radios like GXT1000 to make a direct comparison. But DLRs were not much worse than full-power TK-3170s, so they will leave FRS in the dust, especially crappier ones. DLR is seriously smaller and lighter than old brick TK-3170. It can sit in the front pocket of shorts and does not impede bicycle riding, while there is no way I can stuff 3170 into the pocket, it must be on the belt.
Next test is in the mountains, but it's not going to happen soon because of some time constrains in the coming month. Besides, Operator2, colleague and friend, borrowed DLRs for their family outing over the weekend.