WRAF213
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Posts posted by WRAF213
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Unfortunately, zero type acceptance on the RT97, despite proudly displaying the FCC logo...
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It depends on how the repeater is set up. Some have a really sensitive squelch threshold, others require a lot of quieting before the repeater unmutes. Some repeaters also have insensitive receivers, resulting in you hearing the repeater much better than it hears you. Combine a touchy squelch with a deaf receiver and you'll have a repeater that you sound very scratchy into, but you'll always hear the repeater's tail clearly.
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One of the things that seems to be fairly prevalent in the repeater listings are paper repeaters - those who are listed, but not longer online or usable. It would be nice if there was some sort of process for removing these - either by vote, requesting a review, flagged as "reported offline," or something like that.
We have a few of these in the Tucson area; their owners at times haven't logged in in almost a decade and/or their licenses expired.
And with the current system of 'hide offline repeaters' and 'hide outdated listings', a lot of the repeaters that have been around for a long time get hidden by those settings and mixed in with the dead repeaters. There absolutely needs to be a user-reported repeater status function.
Perhaps a way to add a repeater that you do not own but have found. There are several in the area that I come across while scanning the GMRS frequencies, but can't find on the website to get a tone for or permission to use because I don't know who to contact. If someone could add, for example, " Found: 550 repeater near Center City Philadelphia. Tone 141.3"
Most of the repeaters in my area aren't actually listed on MyGMRS, and those that are listed are inactive or offline. It makes frequency coordination an absolute pain. I'd consider the output tone 'public' information as well since it typically identifies a system uniquely within an a particular area and channel, and gets transmitted along with the carrier. Keeping that information hidden when reading a 'found repeater' report makes it hard to tell if that reported repeater is actually the one you're hearing. This could also help with people claiming ownership of repeaters they do not actually own.
When I first got my repeater, I used a particular frequency and tone that was in use nearby. Due to California's highly variable topography, I couldn't hear the incumbent user's repeater when I was doing frequency surveying, but the coverage area overlap was a serious issue. I had to reprogram the repeater and several radios, and get the cavities re-tuned to a different pair, because the only people currently allowed to report a repeater's existence are the owners.
Many repeater owners don't want their repeater's existence or site location to become public knowledge. I do believe it's against public interest to enable that behavior, since the 8 GMRS channels are all accessible to the public and there is no right to privacy on what information is sent over the repeater's output channel. However, there needs to be limitations on access to what specific information can be seen by other users. Frequency, output tone(s), general location, and CWID (if any) can all be narrowed down quickly with a receive-only station or two, and it may also be possible to determine whether a repeater is open or not (only the owner can give the final verdict). The user-reported repeater entries should be marked separately from owner-reported entries since there's no way to attest to the accuracy of the information, and there needs to be some inquiry as to whether there's an abuse potential for such a system that would make the risks outweigh the benefits. Personally, I think there's much more benefit than risk, and Repeaterbook uses a similar system for their ham repeater listings. Over there, change history isn't made public (allowing non-public information accidentally contributed to be removed), and the repeater owners can hide all information beyond frequency, callsign, public/private system, and on/off-air status. Unlike ham bands, there's heavy frequency reuse on GMRS because 8 channels is a lot less than several hundred channels, so there needs to be a more granular way of identifying repeaters beyond using the frequency alone. I think it could also be worth allowing 'found repeater' reports to include general comments, such as hangtime duration, activity level, or peculiarities with the repeater; but anything suggesting the input tone should be censored.
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The 771 isn't resonant on GMRS, it's typically resonant on 440 to 450 MHz for UHF. I'd expect SWR at or above 2:1 or 3:1 on GMRS frequencies. I lost the sweep results on mine but I have posted about it earlier. As a rule of thumb: longer, high-gain antennas have less bandwidth than shorter antennas.
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If I'm working simplex, I'll usually say something like "WRAF213, on 675" for the main channels, or "WRAF213, on channel 1" for the interstitials. It's a good idea to say which channel you're on so folks using scan will be able to find your transmission easily.
On repeaters, I'll include the repeater name/tone when calling someone, otherwise I just drop in my callsign or even just the suffix. If I needed to hear a monologue when someone hops on a repeater, I'd just go back to the WIN System.
I hang out on channel 1 a fair bit, but only pipe up to help people who can't get radios talking together; SDR instantly tells me their channel settings, and I only talk to the parents/adults. I scare the crap outta all the kids in a 5 mile radius whenever I get on that channel, though. It's much more fun from hilltops.
- Elkhunter521 and Extreme
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Part of getting Part 95 type acceptance is not having amateur frequencies available on a GMRS radio. Modifying the frequency capabilities of the radio to gain access to 70cm or whatever band would void the Part 95 type acceptance. This should also apply to Part 90 use on GMRS as well, but it's a silly rule best ignored. Part 90 operation can occur in the 420-450 MHz band (every so often you'll see a STA for that). Unfortunately, the rule specifically mentions the Amateur Service. The intent of the rule is both to segregate the services by license type and to ensure the radio is type-certified over its entire operating spectrum.
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The UV-5R, containing controls to operate the transceiver, is intended to be held. It's not protected under Nevada's hands-free laws. Whoever initiates the traffic stop might use their discretion to not issue a ticket for a radio on the hip or in a center console as the radio isn't readily accessible, but if you get caught it's probably for taking your eyes off the road to change channel or something.
Most commercial and CB radios (designed for road use) meet those legal requirements, while most ham and Part 95 GMRS radios (designed for operator convenience) do not.
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I’m not saying that they’re good at receive desnsing, but if you want bad bad, you should look at the Retevis RT-22 and its clones. I’ve never gotten the GD-77 to desense, but those do it at the drop of a hat.
Look at how little filtering the RT-22 has. There's all sorts of unpopulated pads on the production model that aren't on the FCC submitted model. I bet those harmonics aren't 50dB down on production models.
Also, my primary GMRS long range link is all done using Vertex Standard commercial gear. As I've quickly (and expensively) realized, sticking anything UHF non-commercial grade to the Diamond X50C2 (a 7.2 dBd UHF gain vertical antenna) immediately blanked out, desensed, the receiver due to the massive RFI coming from the 1400-foot Candelabra tower that is less than 2 miles from my house...
Again, you're in a highly unconventional RF environment, RF power coming from the Candelabra transmitters through a typical UHF passband (370-530 MHz) should be in the ballpark of 0dBm. Most people are around -50dBm. That's a HUGE difference.
That said, CCRs aren't meant to be used on fixed antennas; they're designed to be used as portable radios. Most handhelds will show measurable desense on a high-gain base antenna, CCR or not. The typical CCR construction with a wide-open frontend happens to have a lot more desense. In open spaces away from other transmitters, they have a slight advantage due to less filtering loss.
They have their place, and that's on-site business use on the hip; can't desense if the strongest transmitter is the repeater you're using. They also work good enough for amateur use that people keep buying them. Few people in reality will cite receive performance as a reason to upgrade from a D878UV or something to a Motorola or Kenwood, it's mostly for audio quality.
My experience with MURS has been the opposite, VHF reaches WAY further than UHF for the same amount of power.
Over here, where the noise floor is high on VHF, I get better coverage on GMRS than MURS, and better 800 MHz Part 90 reception than 460 MHz Part 90 reception. In my experiences with line-of-sight conditions, the higher gain from UHF antennas gives better audio (helps to make up for deep fades, which are briefer on UHF), while in mobile-to-mobile situations with some separation VHF has an advantage in punching through terrain. UHF has much better spot coverage. For mobile-to-mobile operation, ~50W out into a gain antenna on GMRS should give universally better coverage than your Part 95 compliant MURS setup. Portable-to-portable simplex will be much more variable due to terrain. Noise floor is also an important consideration in urban environments, and lower frequencies will have more noise than higher frequencies.
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Can you get an audio recording of it?
I'm not in the area, I'm just wildly curious.
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My personal repeater runs split tones, and several other private repeaters around me run split tones. It's almost exclusively commercial radios being used on those. That said, nearly all of the GMRS activity happens on repeaters without split tones. Having that capability isn't essential for a first radio, but a need might arise later on.
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For folk that "can't stand talking to the same people every day", there sure are a lot that get real angry if someone tries to enter a conversation.
Most 2-meter repeaters and open, linked 70cm repeater systems around here are welcoming of new users and make it pretty clear that they are. It's just a friendlier place to start out on a $25-$50 handheld.
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UHF connectors have been around for almost a century, back when VHF was called UHF because we didn't have enough frequencies above HF to need a distinction. They're cheap to make and handle a lot of power (a well-constructed connector will handle full legal power on HF amateur), so they remain popular. Unfortunately, they remain popular on radio equipment designed for frequencies well above what the UHF connector is designed for. Avoid the connector wherever possible on 220, 440, and GMRS equipment. N is a much better connector both in RF performance and weather resistance. Regardless of connector choice, pay attention to your connector's plating as well to avoid PIM. PIM shouldn't matter a whole lot unless you're full duplex, transmitting on two radios simultaneously, in a generally poor RF environment, or monitoring open channels for weak signals (like with emcomm).
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UHF connectors shouldn't even be used at GMRS frequencies since they don't present 50 ohms above 100ish MHz.
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As long as everyone using it is licensed and states their call sign clearly, there no reason it needs to be a "family only" repeater.
The repeater itself doesn't need to 'id' itself.
Yes, it does. There's a million posts on this forum about it.
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"Ham radio really starts at HF" is an old-fashioned view of a dynamic hobby. Every operator I have talked to who shares that "ham radio really starts at HF" view has told me some variation of "I can't possibly sit around on a 2-meter repeater, talking to the same people every day." VHF and UHF operation have evolved rapidly this decade (first with Wouxun and Baofeng, then with entry-level radios featuring digital voice), while HF has lagged behind. Nearly all of the development on HF since 2005 has targeted high-end radios, outside the scope of what new operators will be using to experience HF for the first or second time; it's about upselling the existing products, not creating a product less expensive for the consumers. IP linking of both analog and digital VHF/UHF systems have whittled away at HF's advantages for ragchew, all while requiring much less equipment investment. You'll hear "the magic isn't there", but that's from a lack of understanding of the underlying infrastructure that all has to work together to establish that connection.
Ham radio can start anywhere. It could be on your local 2-meter repeater where a high-school student studied for their Technician license and bought an Anytone handheld to celebrate getting their first callsign. It could start with an unlicensed operator using their grandfather's radio under their supervision and callsign. It could start where my journey started, on someone else's HF receiver. It could start on a DMR hotspot, a satellite, a fresh-built uBITX, or even a packet node. But for most people entering the hobby, it's going to be on your local 2-meter repeater. Anyone who says that isn't really ham radio has lost sight of the hobby's goal.
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That radio lacks any type acceptance, even Part 15. Don't use it on a service like GMRS, where type acceptance is needed.
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I know the CTCSS-capable Motorolas will automatically pick up on the CTCSS/DCS in use on a channel while scanning, but I went through a bunch of user manuals for Midlands and didn't see that functionality. A scan talkback feature is described, so I don't know if the functionality is present but not discussed.
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Doing some research on that tower shows three UHF TV transmitters up on the top (ignoring the lower-power VHF transmitters).
WMSN-TV: 440kW at 497 MHz
WHA-TV: 200kW at 509 MHz
WKOW-TV: 800kW at 545 MHz
No wonder you're having problems. Path loss is roughly 100dB at that distance, since there doesn't appear to be any terrain obstruction anywhere within 2 miles of that tower. With transmit power in the ballpark of 80-85dBm ERP towards your elevation, that's a LOT of leftover signal that's as close as 30 MHz to GMRS (about the distance from GMRS to 70cm).
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Increasing the power beyond what the device is certified for, even if in software, voids the type acceptance. If the power were brought back down to what the certification lists, it's legal.
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The last time the Commission dealt with this kind if thing, I believe they went after the US sales representative, not the manufacturer.
Yep, it's whoever imported the devices for sale in the US in this case. The TCBs are getting lazy though.
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I have never seen a bubble pack radio programed to use a tone out of the box by default. All I have seen have carrier squelch by default, and are "preprogrammed" with tones that can be selected if desired.
Motorola's used 67.0 Hz by default, while Midland's are CSQ by default. Motorola also had an optional Quiet-Talk feature, which requires an additional tone (52 Hz) before transmissions; this went away when they introduced their current Txxx series radios because it didn't work well.
FRS isn't about communicating with everyone else on FRS, it's about selling a set of radios that work together and don't unmute on interfering signals. Look at Midland's "extra channels".
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Yeah, being within that distance of a broadcaster is the real problem at hand. Based on your symptoms, I'm assuming there's UHF TV broadcast on that tower in the 500 MHz band (which is almost all that's left of UHF TV). TV typically runs tens to hundreds of kilowatts, and any internal or external mixing products of TV broadcast may resemble noise due to the DTV modulation. FM is more easily controlled and the harmonics aren't in-band (fourth harmonic ends at 432.2 MHz), but that still requires strong filtering. To do an actual check of your RF environment and noise floor, you'd need a good spectrum analyzer that stays linear up to at least 10dBm; most quality equipment is rated up to +30dBm.
If you've got noise that appears to be in-band but cavity filters improve the situation, you've probably got intermod going on. Band-reject filters near the antenna can help with that. If filtering near the receiver doesn't improve in-band performance to a satisfactory level, PIM may be at play. Right now, intermod and overload effects could mask a generally crap noise floor from unintentional radiators; don't expect to dive in with hundreds of dollars of equipment and hit thermal noise floor (though you'll have to spend a little bit more to avoid PIM and ensure linearity of any active components). A noise power of -125dBm/16 kHz is pretty typical for a quiet area, compared to thermal noise floor at -131dBm/16 kHz. HDMI/DVI are particularly egregious noisemakers on UHF LMR bands, especially with AliExpress-quality cables. LMR-400 would make a mess of your RF environment.
Overload effects don't cause CCRs to not be heard, it simply knocks out their ability to hear. Any RDA1846 design will show desense on almost any rooftop antenna anyways; they're meant to be used with unity-gain antennas attached to the unit and work rather well in that scenario. Desense on the stock antenna or equivalent is only encountered in rather exceptional RF environments.
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It's an issue you should raise to the Commission; I bet this was an oversight by the TCB or (more likely) changes made illegally after certification. If this ended up getting handled properly, those radios would be recalled and Retevis fined. We both know those kinds of results never happen. If we're lucky (and the FCC does their job), the type certification may be revoked.
They're not combination FRS/GMRS radios, they're operating outside of their type acceptance. These were granted type acceptance well after the deadline for certification of combination radios.
You're probably best off getting a FCC representative on the phone. These rules are being violated:
- 95.337 (additional channels made available by modification) per 95.361(c ) and 95.563
- 95.381 (voice scrambling)
- 95.363(c ) (additional channels can be programmed into the radio, but this may not be the manufacturer's responsibility; programming software allowing this will be the issue at hand)
- 95.587(a) (radio can transmit on non-FRS channel/bandwidth).
As of right now, the users are in the wrong, but your only course of action is to tell them they're operating illegally and to contact the FCC about the above problems; you can't take matters into your own hands or jam their channel. You're a licensed user receiving harmful interference from unlicensed users operating equipment outside of type acceptance parameters. That alone should be enough. The manufacturer should have liability under 2.937.
Multiple repeater coverage areas on map
in myGMRS.com
Posted
Coverage maps are hard because GMRS is a line-of-sight communications service. There will be spots where you can be less than 5 miles away from a hilltop repeater and not be able to open its squelch, and there are spots where you're scratchy into a repeater that's 100 miles away. Coverage maps can be very reliable tools if both the mobile station and repeater's powers, losses, and thresholds are properly entered; the correct antenna patterns and heights are used; proper statistical losses are taken into account; and an effort is taken to ensure the topography in the mapping software matches real topography. In my experience, none or very few of these tasks are done when generating a coverage map. Real coverage tends to be much less than the modeled coverage, typically because statistical loss has a huge effect (mobile coverage requires staying above the signal threshold more than n% of the time (I usually model at 70% or 87% depending on band), while spot coverage (often used by default) assumes you're standing still in the peak of a fluttery signal), your antenna (especially if portable) probably has less net gain than whatever mobile station the map-maker simulated coverage with, site noise is a very real thing that will reduce repeater sensitivity, repeater owners may not realize that they are using a directional antenna or tower mounting position, and not many repeater owners are willing to admit that it's possible to have 4 dB of loss between the transmitter and the antenna. Repeater owners and users also like to see good coverage come out of the simulations, regardless of actual coverage, so there's even incentive for misleading coverage maps. So, there's a lot of ways to alter the coverage depicted on a coverage map, and there's so much room for variation (about 25 dB worth) that it's not possible to make repeater-to-repeater comparisons unless the same person made all the maps with correct information.
And unfortunately, it isn't possible for MyGMRS to generate the coverage maps accurately, as there's a lot of room for variation with repeater hardware (dinky little solar power repeater running 5W into a counterfeit Nagoya antenna duct-taped to a chain-link fence, vs. someone running 50 watts into a solid duplexer with preamplified receive and a 10 dBd gain antenna) and repeater locations on the map are not always accurate for various reasons. So, we just generalize coverage into a circle around the repeater's map position. It's easier for a repeater owner to estimate how far their repeater can cover towards population centers than for the owner to generate coverage maps that are correctly parameterized. It's easier for MyGMRS to handle circular coverage patterns than the rasterized geo-referenced images outputted by coverage mapping software.
Radio coverage in general should be taken with a heaping handful of salt due to the wide degrees of variability that are out there, and instead test your actual coverage with a second radio or a friend. And if you know or learn mapping software such as Radio Mobile, you can even make your own coverage maps for estimation if there's enough information about a repeater's location in its MyGMRS listing.