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Everything posted by Lscott
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Digital Direct Mode (Simplex) on 462 MHz GMRS Channels
Lscott replied to intermod's topic in General Discussion
So do I! When I was first messing with DMR my initial reaction was WTF? -
Digital Direct Mode (Simplex) on 462 MHz GMRS Channels
Lscott replied to intermod's topic in General Discussion
You're one of the examples of those that have no interest digital voice modes, at least DMR, on GMRS. That's perfectly fine. Any implementation has to take those kind of interests into consideration. Undoubtedly, and from other posts, you aren't the only one. NXDN is not very complex to use. It can be used without talk-groups, unlike DMR. That deceases the complexity for the user. The attached images are screen shots of the programming software for the example Kenwood dPMR radio in that file. As you can see it's very simple. One is for the analog channels while the other is for the digital ones. -
Digital Direct Mode (Simplex) on 462 MHz GMRS Channels
Lscott replied to intermod's topic in General Discussion
The issue you'll have the owners of those radios will soon realize the channels will become crowded with digital users rendering them almost impossible for analog FM use. That could happen quickly. Digital TV is a case in point. Also once people see no new analog FM radios are being sold they will most likely hang on to them much longer than otherwise might be the case. There are those who hate the sound quality of various digital voice modes and have zero desire to use any of them. If a large enough group objects to digital voice all over the channels, with their objection filed with the FCC, that's going to be a problem that needs a solution. I did a quick update to my opinion paper on how it could be done and some suggestions on how to deal with some of the potential objections by existing users. GMRS Digital Voice - 20231127.pdf -
Digital Direct Mode (Simplex) on 462 MHz GMRS Channels
Lscott replied to intermod's topic in General Discussion
Before even petitioning the FCC there needs to be some general concuss about how to do it. Without that the FCC mostly would just deny it at the outset. So far can't really get to that point yet. DMR might not even be the mode to use. I haven't really read any good debate if there are better digital voice modes that could potentially be used. I believe there are. I posted an opinion paper I wrote outlining my thoughts. If anyone is interested doing some searching on the forum should turn up references to it. From various posts on the Internet digital voice is being used in pockets around the country. I don't expect that to change without some huge FCC enforcement action, which at this point in time doesn't seem to be high on their agenda. What's more likely to happen is the practice will continue and grow. Once it gets out of hand the FCC can do what it's done before, throw in the towel and make it legal. They did it with the combo GMRS/FRS radio mistake. Buggered around with the rules such that what people were already doing illegally is now legal. -
Digital Direct Mode (Simplex) on 462 MHz GMRS Channels
Lscott replied to intermod's topic in General Discussion
That annex is huge. I think the relevant section starts on page 92 of the linked document. Most of that annex after that is just the specific test conditions for each mode. https://fasma.org/wp-content/uploads/TSB-88.1-D-Wireless-Communications-Systems-Performance-in-Noise-and-Interference-Limited-Situations-Part-1-Recommended-Methods-for-Technology-Independent-Performance-Modeling-Includes-Access-to-Additional-Content.pdf -
Digital Direct Mode (Simplex) on 462 MHz GMRS Channels
Lscott replied to intermod's topic in General Discussion
When the rules changed to allow license free FRS radios to run 2 watts isn't going to help matters considering business are free to use them. -
The problem with digital voice modes is there are so many of them. I have radios for D-Star, DMR, NXDN and P25 Phase 1. Nothing yet for YSF, or dPMR which is mainly an EU license free service like FRS here but digital. Haven’t seen it in North America yet. If that wasn’t enough there is a new one, M17. https://m17project.org
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Digital Direct Mode (Simplex) on 462 MHz GMRS Channels
Lscott replied to intermod's topic in General Discussion
If you’re referring to recent manufacture yes. There are some older radios that will do digital and have FCC Part 95 certification. I own a few of those. Of course I can’t use the digital part under the current rules. The attached file is the FCC grant for one of my NX-300 radios with certification for Part 95 for all modes it has the capability to transmit. The various radio features are listed in the attached brochure. NX-300 FCC Grant - 1.pdf NX-200_300.pdf -
Just about all the DMR repeaters by me are on UHF.
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1. No test required. 2. License fee is now only $35. 3. Licenses good for 10 years. 4. Cheap Chinese radios.
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VHF and UHF is much more challenging to make DX contacts. Most of the digital voice modes are on UHF. Satellite communications is really fun. Particularly when operating the sats with the linear translators for SSB. I have full privileges for HF. Just haven’t gotten the urge to bother with it in over 20 years. I operate VHF and above, mostly mobile.
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I've caught some very sporadic DMR traffic on channel 18 by me. It was a few transmissions during the day lasting a few seconds each. I haven't heard it in many months. I suspect either somebody miss programmed a radio, or did so deliberately. In any case it stopped and I suspect the local FCC might have had a hand in ending it.
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Again these aren't cheap. Petty much everything about going portable with solar isn't going to be cheap. Anyway these are good solar charge controllers. You can get them for various battery chemistries. They also do charge controllers with custom voltages. https://sunforgellc.com/genasun/#gen_product_row
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May everyone have a safe and happy holiday.
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Tri-Band Antenna for Baofeng UV-17R Pro GPS
Lscott replied to back4more70's topic in Amateur Radio (Ham)
I have one for my Kenwood TH-D74A tri-band radio. SRH320A Triband HT Antenna.pdf -
Just because the radio says it's doing 10 watts means nothing. Put it on something like a calibrated watt meter. Some years back people were buying Baofeng radios that "claimed" to do 8 watts. Once they were tested on a watt meter the real power output was around the 5 to 6 range. Oh well just typical for a Chinese radio to over state the spec's.
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questions about entry level ham operation and testing..
Lscott replied to WRZF693's topic in Amateur Radio (Ham)
I would recommend ONLY the 706MKIIG model. There were some issues with the previous ones. I ran the IIG mobile for a number of years in a van when I had only my Tech Class license. It was a riot! I made some long range DX contacts on 6M SSB and a few on 2M SSB. At that time you needed the Tech Plus license to use anything below the 6M band. If you buy one used see if you can get the remote kit for it. The front face plate can be detached allowing the body to be located out of the way. IC-706MKIIg.pdf -
As mentioned using a Ham Radio on GMRS is not legal. On the other point about high power HT's. Most people find out the Chinese radios rarely generate the claimed power output. I've seen claims of HT's that can do 20 to 30 watts plus. Just not believable. The other point is the higher output power drains the battery pack faster resulting in far less operating time. Also the radios are not 100 percent efficient. For various reasons the real world efficiency is about 50 percent. That means if the radio is doing an honest 10 watts of output the battery is being drained at a 20 watt rate. Further the 10 watts of heat generated, 20 watts input minus the 10 watts of output, is soaked up by the tiny body of the radio. Those palm sized radios are the worse. Even a 5 watt radio turns into an uncomfortable "hand warmer" when operated at high duty cycles. A few Hams have destroyed their HT's power output stage doing this from the heat generated and the high internal temperatures. One posting else where the Ham said he did this more than once to the same radio. There is a reason why you see the duty cycle specifications of 5-5-90, 5 percent transmit - 5 percent receive - 90 percent standby.
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Using mail-in ballots?
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It's like any other hobby specific area. They all have their funny jargon. After you're in it a bit you'll pick it up quick enough. Remember just one thing, DON'T BE AFRAID TO ASK QUESTIONS! That's how you learn.
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I believe if you do a search on the forum here you'll find some threads on the topic. From what I've read, I don't own any BTW, people have had very good luck with the Motorola radios. These are "spread spectrum" frequency hopping radios and are only compatible with like/similar models from the manufacture when programmed with the same "hop set."
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Scanning for other channels from RadioReference.com .. Any one else have luck?
Lscott replied to WRZF693's question in Technical Discussion
Don't depend on the accuracy of the frequencies you see in their database. They depend on users to send them info, which they try to verify. I have noticed some retail frequencies for a local mall where the store has been out of business for a number of years yet the entry remains in their database. I had attempted to get some frequencies added a few years ago but I was told by the admin for that area he wouldn't do it without further confirmation. After that experience I just don't bother. If you're not hearing any traffic on the frequencies it's very likely they are no longer used. One fairly good check however is look to see if there is an FCC call sign listed. If so then look it up on the FCC's database. Under that call sign there is a tab for frequencies licensed. If the ones you have are not listed then for sure they aren't used any longer and you can delete them. -
There seems to be some confusion when reading the regulations. I had to re-read it several times before it made sense, at least to me, with how it was written. It made more sense when I considered the radios, the commercial ones I have, with Part 95 and 90 certification. The radios where manufactured to sell into different markets. This was before the 2017 rule changes. If the radio was programmed with Ham frequencies AND those were an exclusive allocation for Ham we would have a problem. At the time those radios were designed and certified for business use of GMRS frequencies it was legal. With the 2017 changes not anymore and why you are very unlikely to find a manufacture that will bother, no market. The FPP issue is pretty clear cut with little wiggle room. The reason why you can find it on some radios apparently there are some government agencies where it is allowed.
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A bit off topic but the above section "C" is phrased in a peculiar way with regard to what frequency, or frequencies, are programmed into a radio. The specific argument has to do with having Ham 70cm frequencies in the radio while also having GMRS frequencies at the same time. There are people who claim it isn't legal. I disagree. First off I mentioned in a post a while back that the Ham 70cm band is not an exclusive allocation. Hams only have secondary privileges. The primary users, typically government stations, are. Those frequencies are licensed and the radios require certification, even if they fall within the Ham band. Due to the statement: "unless such transmitter is also certified for use in another radio service for which the frequency is authorized and for which certification is also required" Having a "Ham" 70cm frequency in the radio along with GMRS can be argued to comply with the above quote rule section and thus legal. Where you do run afoul of the rules is with the FPP, Front Panel Programming, that allows the user to enter an arbitrary frequency into the radio. I believe that's what doomed the first generation Baofeng radios. They had Part 90 certification, BUT that also required the radios can not allow arbitrary frequency entry under Part 90. In a quick move the radios where shipped with the frequency programming functionality disabled and either required it to be enabled through a menu setting or the use of the programming software to enable it. Some of the current model LMR, commercial, type radios also allow FPP. However it has to be specifically enabled through the radio's programming software. It can't be enabled by accessing any controls the user can manipulate. The programming software has warnings about making sure the "feature" is disabled before turning over the radio to the user for normal operation.
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Don't expect much range. They are basically radiating dummy loads. IMHO they are a waste of money.