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Everything posted by marcspaz
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It looks like you are trying to use the Carlson Rule. Carson’s Rule is an estimation of the maximum bandwidth. The bandwidth will be proportionate with the audio signal amplitude, but with a maximum bandwidth estimated by Carson’s Rule, the bandwidth would be 2(5 kHz + 3 kHz) = 16KHz, not 15KHz. Unfortunately, on the VHF amateur bands, channel spacing is 15KHz across most of the country. This leads to a lot of bleed-over when there are conversations happening on adjacent channels. There are about 10 states that use 20KHz, which is better. UHF is 12.5KHz for NFM and 25KHz for FM on the amateur bands and GMRS, which is a bit more comfortable with regard to prevent/avoiding interference.
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The antenna will be fine... fair price. I would buy an authentic MXT400 v2 (or newer) over the 115 because if you are going to be talking to repeaters, programming the repeater channels to operate wide band will ensure your audio levels are proper and there will be less noise in your signal. Wouxun KG905g would be my recommendation. The S88g is great, too, but after taxes and shipping it may be over $150.
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You just got your GMRS license, now you want your own repeater?
marcspaz replied to coryb27's topic in General Discussion
Man, a 300 foot hill is pretty much going to be a no-go unless you put the repeater on the top of the hill. Here is a visual of what a 328' of blocking terrain looks like. I would not be very optimistic at this point. -
What are Signal Reports? What is an s-unit? Why does this matter?
marcspaz replied to marcspaz's topic in General Discussion
Man, you have no idea who you're talking to. LOL. I'm independently wealthy. I have owned my own business for decades. I have a wife, kids, grand kids that I love and spend a bunch of time with. Along with a decades of studies in my field, I spent 7 years studying Constitutional Law and the founding and framing of the US. I have dabbled in politics, contributing to State level legislation. I have been an engineer since 1984 and have more licenses and certifications than I know what to do with, including two new certifications in the last 2 months. As an independent consultant, I have 13 years supporting the Department of Homeland Security; another 10 years supporting DoJ as well as DoD and I am currently an engineer working at the Pentagon. I love long-range shooting, have participated in professional level auto racing, 4-wheeling and I have been playing radio for 35 years, including being a licensed Amateur for 2 decades. Oh! I almost forgot, I started ground school recently and I am working on getting my private pilot license. I feel like my range of knowledge, understanding and experience are fairly vast. Though, I guess I can still do more (shrug). Just a quick reminder, you are the one who's very first post in this thread was bringing BS from "the other thread". I am just playing by your rules. See below... Yeah, about that... you're still very, very wrong about s-meter calibration and it's roots. SMDH. Saying the wrong thing over and over again doesn't make it right. I'm missing how it's dishonest to recognize the confusion of the original title (something you pointed out, I may add) correcting it and then literally making a note of what I corrected and why. I really do hope you are done posting in this thread, though. All you are doing is reaffirming your lack of knowledge and derailing a thread that was actually helpful. It's a train wreck now. With any luck, Rich will clean this thread up and lock it. -
What are Signal Reports? What is an s-unit? Why does this matter?
marcspaz replied to marcspaz's topic in General Discussion
I changed the title because, as you pointed out, the title was a bit misleading. You made a valid point to which I conceded, yet you act like an ass. Stay in your lane son... the same guy who said "one s-unit is when human ear can tell the difference between levels of AM signal" has no business criticizing anyone else's understanding of technology. Updated Thread and Section titles for clarification for "Some People" to parse the information easier. -
QFT! If I may add on to this (not directed to you), I am going to play both sides of this debate. The purpose of the Amateur Radio Service (also known as "ham" radio) in the United States is to provide a hobby and public service for individuals who are interested in radio communication and electronics experimentation. The purpose of GMRS is for short-distance two-way communications of licensees and their immediate family, for business or pleasure. Based on the definitions provided by the FCC, the idea that GMRS is exclusively utilitarian is not an accurate, in my opinion. There is overlap because of the interest in radio communications, even though GMRS is so much more restricted in use of hardware, power and range. I think OP is leaning more toward operating etiquette. I could be wrong. I like the idea of community members volunteering to make an orientation video and I like the idea of new people wanting to learn and having it as a resource. It just needs to focus on things specific to rules, technology and equipment to help people on getting started; not opinions about behavior, use, etc. While I occasionally violate this myself, I believe we should speak in plain English and if you are on a wide coverage area repeater, it's not a great idea to talk for hours. I recommend against tying up the repeater and radio waves for 2,000 sq miles or more for hours a day, several days a week, is kind of greedy. That said, it's up to the operator to decide what lingo, habits, and method they use on the service. As mentioned, the purpose of GMRS is for short-distance two-way communications to ease the activities of licensees and their immediate family. If that means rag-chewing, that is up to the operators involved. It's not really up to any one of us to tell anyone else how to use their radio/license. As far as repeaters go, the owner doesn't own the airwaves, but they own the hardware and can set the rules for sharing, if they want to share at all.
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What are Signal Reports? What is an s-unit? Why does this matter?
marcspaz replied to marcspaz's topic in General Discussion
@WQWX838 I agree. I really think that it's in everyone's best interest to speak plainly. Unfortunately I hear a lot of lingo from Ham and firsr responders on the repeaters in the DC metro area. Many Hams use GMRS like its amateur radio, to the point where one of my friends revoked permission from a bunch of people on his repeater. -
In that map, the two radios would need to be inside both respective circles. If you are going to have either a permanent base station or a portable/temporary base station at a camp, you would be much better served with a 5w-10w mobile used as a base station, and a portable mast with a high-gain antenna on it. This will increase your range due to the base antenna being higher and the gain from the antenna helps with transmit power and receive sensitivity. Below are a couple of my portable antenna's for example.
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What are Signal Reports? What is an s-unit? Why does this matter?
marcspaz replied to marcspaz's topic in General Discussion
Alex... Man, I am trying so hard to be nice/respectful, but I am totally bewildered by every response from you and I am starting to get a little upset. Like, it's giving me a headache. I will do what I can to make this as clear as possible. Read the next two sentences very carefully, and then read it again. I am NOT discussing RST reports for CW. I am talking about a modern Signal Report for analog voice, with origins rooted in RST. This is going to be my last reply to you on this... the only two reasons I am replying at all is because I am hoping what I'm writing will finally make sense to you, and to explain to new operators and non-hams who may hear this lingo, what it is that Hams are saying to them. One more breakdown... please read carefully. The radio's s-meter is literally, exclusively reflecting the signal strength and in the current/modern Signal Report, the S represents signal strength. You get the signal strength from the s-meter. Period. End of discussion. We are not using RST for voice. The Readability (intelligibility) of the words being spoken describes how well the listener understand what you are saying. That's it. Nothing else. I am talking about modern signal reports. There is no mutually exclusivity. The s-meter literally provides you with a measured value (if the meter is properly calibrated) for 50% of the report you are delivering. Unless you are not using a modern analog voice signal report scheme, you can't provide an accurate signal report without a calibrated s-meter. The requirement for a calibrated meter is why I said it could be scientific or subjective, depending on your radio meter type and if the meter is calibrated. I don't participate in CW exchanges, so I can't speak to how the RST reports are being used today. However, I can say (agreeing with you) the original RST reporting system was created to be used with Morse Code. However, I am NOT explaining the original RST reporting system. I am explaining the current signal reporting system, that has been adopted from the original RST system, for the purpose reporting voice quality and signal strength for all analog voice communications that amateur radio operators use and that GMRS operators may be exposed to. CW RST reports have nothing to do with this, beyond the origin story. -
What are Signal Reports? What is an s-unit? Why does this matter?
marcspaz replied to marcspaz's topic in General Discussion
@axorlov, I'm not sure why you keep coming back to this. Nothing you have shared is relevant to how things are done for voice, today. Outside of a history lesson (which is actually really entertaining to read and learn about), what was created for CW 90 years ago has nothing to do with what is used for voice today. And aural has nothing to do with the signal strength in today's method. You can either choose to use the current globally accepted method used for voice or not. That doesn't change how and when it's used today. -
Honestly... that is very normal. Radio manufactures advertise "up to" a specific wattage. They don't guaranty a certain wattage. They radio may make 45w to 48w under specific conditions on a specific frequency, which may not be easily reproduced. The manufactures have to keep the power low enough below the 50w legal limit, because is a random radio gets tested and FCC finds that it exceeds the limit, the company can have the certification pulled. Also, a good portion of 50w radios I test, typically have a max power of 34w-38w... depending on the frequency used compared to the frequency tested by the manufacturer. That is just the way it is most of the time. Worth mentioning, there is a reason why other radios cost twice as much, if not more. Sometimes that few extra watts is part of it.
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Terrain effect on line-of-sight communications
marcspaz replied to Templeton's question in Technical Discussion
If there was zero other terrain? That would be correct. This is exactly why RF LOS terminates about 15% further than visual line of sight. RF is both scattered and partially refracted over the horizon. The closer to the horizon line, the more dense the scatter is. It's really hard to answer that question. For example, are we talking about a building? A small hill? or a 5,000'+ mountain? My house is in a recess in the ground by about 100 feet, with the ridge line about 150 yards away. I can stand in my driveway with a handheld radio and still reach another handheld about a mile away before the shadowing become to great. There is a way, but it is way beyond my skill set and understanding. The level of effort and all contributing factors vary too rapidly and greatly to attempt to try to calculate it in some practical time-frame, as well. To make things worse, the results would only be valid for the exact forecasted locations of the two radios. If you move either radio even an inch in any direction, the values are no loner valid. Items in the sky like rain and fog will attenuate the signal more. While diffraction, reflection and scattering of radio waves is the principle behind extending LOS, as those conditions increase, the amount of dilution increases, leading to more attenuation, not more extended range. The PPM of the photons simply drops too low to receive. -
Those are pretty slick!
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@Lscott yes, Sir! It gets a bit tricky with a mobile, though. LOL
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I don't know if Kemp Wireless does repairs for equipment they haven't sold, but it may be worth emailing or calling them to find out. They are highly recommend for sales and support.
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@WRUW275 ^^^ this is the best answer. If there was a realistic way to screw the antenna directly to the output of the radio, I would. LOL
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Popularity of GMRS with Over-The-Road Truckers?
marcspaz replied to Lscott's topic in General Discussion
A lot of amateurs use the space weather tools on the home page of QRZ. https://www.qrz.com/ Same data here, in the top, left corner. http://www.hamqsl.com/solar.html An my absolute ? favorite is Dr. Tamitha Skov, Space Weather Woman. https://www.spaceweatherwoman.com/ -
Terrain effect on line-of-sight communications
marcspaz replied to Templeton's question in Technical Discussion
I agree with Alex on all points. It's too hard to predict/calculate for all but a chosen few. And to touch a bit more or the reflection idea... think of radio waves like sunlight. There isn't perfect darkness in the shadows because the sunlight, to varying degrees, scatters off of everything around the item creating the shadow. That includes dust and other things in the air. Radio wave literally do the same thing. -
What are Signal Reports? What is an s-unit? Why does this matter?
marcspaz replied to marcspaz's topic in General Discussion
A friend of mine reminded me about something pretty important. I updated the original post, but wanted to include the update here as well. With new or non-technical operators, this is an often misunderstood concept. Repeater Caveat There are some important caveats to signal reports for repeater users. The RST style signal report is not a valid reporting method. The voice quality or 'intelligibility' of the transmission is likely not going to be valid. If the reporting operator is receiving the repeater's signal well enough that there is little to no chance that the voice quality is impaired, you may be able to give and get a valid readability report. This condition is often when you will hear signal reports such as "loud and clear" or "full-quiet." These replies indicate that you have a very good radio and voice signal into the repeater, as reported by someone who has a very good signal from the repeater. Additionally, the signal strength is not relevant through the repeater, at all. The receiver's station is going to be seeing the signal strength of the repeater, not the originating station asking for a signal report. It is not possible to know the received signal strength at the repeater site unless you are the repeater owner or admin and have the ability to see the actual repeater's receive meter. Even then, most repeaters do not have any easily visible signal strength meters. The next best method would be if the receiving station listens to the repeater input frequency (assuming the receiving radio has that feature). If the reporting station can hear you directly, they can tell you how strong your signal is at that person's location. It's still not indicative of how strong your signal is at the repeater. -
What are Signal Reports? What is an s-unit? Why does this matter?
marcspaz replied to marcspaz's topic in General Discussion
Thank you so much for the kind words. It is much appreciated. I really do hope it helps. -
What are Signal Reports? What is an s-unit? Why does this matter? But, Why? First, why does any of this matter? The General Mobile Radio Service was segmented with the concept of being a short-distance two-way communications for licensees and their immediate family members. It doesn’t require any special knowledge, exams or understanding of the science behind the magic. However, you will occasionally hear both professional and amateur radio operators who are also licensed GMRS operators, who may be using lingo more common to other services. One of the most common will be an RST style signal report. I’ve noticed that many new operators will call for a radio check, especially on a repeater. They may get a 'signal report' from a Ham that sounds like this, “I copy you five nine.” Or you may hear “You are full-quiet into the repeater.” While these answers may be true and accurate, for new operators, hearing “Your radio sounds great” or “I can hear you fine, but there is a bunch of static. How far are you from me (or the repeater)” would likely be a lot more helpful. Well, in the event that you come across me or one of my well-seasoned friends and we forget that not everyone knows what we are talking about, this may help you understand what you are hearing with regard to signal reports… and if you would like to use the same method, provide you with the best guidance I can. What are RST and Signal Reports? The RST signal reporting system is primarily used by amateur radio operators and other radio hobbyists to exchange information about the quality of a radio signal being received. The original reporting system was created to be used with Morse Code, and is a three digit number. Each digit is used for conveying an assessment of a signal's Readability, Strength and Tone (RST). Over time, amateurs adopted this reporting scheme for voice communications as well, but it was modified a bit to be more friendly to reports about voice signals. Readability is still used to define how intelligible your voice is; meaning how well can I understand what you are saying. Strength of your signal is also still used, based on the meter on the receiver’s radio. However, Tone was dropped for voice reports. Though on occasion you will hear someone tell an operator, in plain language, if their transmitted signal has too high or too low of a tone, as some radios allow the owner to adjust the tone. Readability – This part of the report is subjective, but still helpful. Readability is used to define how intelligible your words are, on a scale of 1 to 5. A readability value of 1 means that I can tell you are transmitting and talking, but I can’t make out anything you are saying. A readability value of 5 means that, regardless of anything else, I can understand every word you say. A report with 2, 3 or 4 would be some variation between 1 and 5. Some examples on how I personally would rate your readability on GMRS would include a 2, meaning I may be able to hear enough of what you’re saying that in a life or death situation, it may be enough to get help going. With a 3, I may be able to understand 3 or 4 words out of every 5 words. We can talk, but it’s kind of a hassle. A 4 would be I can hear every word but there is static. Pretty straight forward. Strength – With regard to strength in a signal report, there is nothing subjective about it, sort of. Unfortunately, if it is scientific or subjective depends on your radio meter type and if the meter is calibrated. We are actually measuring the voltage of your signal on the receiver’s radio. This voltage is measured in S-units or Signal Units. Where this can get tricky with GMRS is, not every radio has a signal strength meter designed to support the common s-unit scale. You may have a display that shows 9 units on some unknown scale, or 10, or 15. I have even seen some radios that only have 4 or 5. I’ll explain the technical parts of signal strength measurements and if you have a radio that doesn’t use a traditional calibrated s-meter, you may be able to adopt the idea to your personal radio. This meter below is a classic analog meter. The top line measures the received signal strength in s-units. If the needle were to swing to 5, you would give them a 5 as the Strength portion of the report. For example, if you understand every word and the needle stops at 5, you would provide a signal report for their voice signal of “five five” or “5 5”. If you could hear all of the words they are saying with a lot of static and the needle is on the 3, you would report a “four three” or “4 3”. Below is a newer radio with a digital s-meter. It looks a little different, but the same rules apply. In this picture, my meter is showing a signal strength of about 5.5 (almost 6) s-units. If I could hear them perfectly, I would tell them their signal report is “five five plus” or “5 5 Plus”, meaning I understand everything perfectly and their signal strength is never less than 5. Now, the next two images show a radio that I know doesn’t have a properly labeled or calibrated s-meter. This type of meter is the reason I said there is nothing subjective about it, sort of. While an s-unit is a true measurement of voltage, this radio has 10 lines and nothing in the owner’s manual tells me what the increment values are. However, you could still adapt the concept to a signal report, making it a bit subjective. In the first image, the meter is completely full. In this state, it’s very likely that I can hear the person talking perfectly and they almost certainly met or exceeded the voltage requirement of 9 s-units. So, I would tell this person that they are “five nine” (5 9) or they are “full quiet”. In the next image, below, the signal goes to the fifth line. Being familiar with this radio, there is a good possibility that I can hear everything they are saying, but with a lot of static. So, I would be providing a signal report of “four five” or “4 5”, since the meter measurement is half the total scale. In this case, the signal report is 100% based on my interpretation of what I am hearing and seeing, rather than providing a “metered result.” I hope this makes sense. For those of you who are interested in the science behind an s-unit, here is a little history and values. In the 1930s, the industry agreed that 9 s-units would correspond to 50 microvolts (50 μV) at the input of a receiver. However, based on meter design and how the value was sampled, this was not accurately measured from radio to radio because the input impedance of receivers was not standardized. This changed in 1981. The International Amateur Radio Union (IARU) agreed on a technical recommendation for S Meter calibration, separately for HF and VHF/UHF. IARU defines 9 s-units for the HF bands to be a receiver input voltage of 50.2 microvolts and impedance of the receiver of 50 ohms. For VHF and UHF bands, the IARU defines 9 s-units to be a receiver input voltage of 5.01 microvolts and impedance of the receiver of 50 ohms. For both HF and below, as well as everything over HF, the IARU defines that a difference of one S-unit corresponds to a difference of 6 decibels (dB), equivalent to a voltage ratio of two, or power ratio of four. For example, if 9 s-units equals 50.2 μV, than 8 s-units is 25.1 μV, 7 s-units is 12.6 μV, etc. Signals stronger than 9 s-units are given with an additional dB rating. For example, “20 dB over S9” or simply "20 over". You can see these values on the s-meters in the first 2 images. Repeater Caveat There are some important caveats to signal reports for repeater users. The RST style signal report is not a valid reporting method. The voice quality or 'intelligibility' of the transmission is likely not going to be valid. If the reporting operator is receiving the repeater's signal well enough that there is little to no chance that the voice quality is impaired, you may be able to give and get a valid readability report. This condition is often when you will hear signal reports such as "loud and clear" or "full-quiet." These replies indicate that you have a very good radio and voice signal into the repeater, as reported by someone who has a very good signal from the repeater. Additionally, the signal strength is not relevant through the repeater, at all. The receiver's station is going to be seeing the signal strength of the repeater, not the originating station asking for a signal report. It is not possible to know the received signal strength at the repeater site unless you are the repeater owner or admin and have the ability to see the actual repeater's receive meter. Even then, most repeaters do not have any easily visible signal strength meters. The next best method would be if the receiving station listens to the repeater input frequency (assuming the receiving radio has that feature). If the reporting station can hear you directly, they can tell you how strong your signal is at that person's location. It's still not indicative of how strong your signal is at the repeater. I hope this information helps anyone who may hear this lingo out on the General Mobile Radio Service. Quick Reference Chart for S-Units
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Looking for a good/accurate/ power/watt meter for UHF/GMRS
marcspaz replied to OffRoaderX's question in Technical Discussion
I have been using Bird, Swan, MFJ and Diamond for some time. I've heard people call MFJ Mighty Fine Junk, but I like them. My Diamond meters are pretty good too... but not pro great. I would rank mine as Bird, Swan and Diamond, with the MFJ being tied with my Surecom. On if my Diamond meters (UHF) needs to be calibrated. The downside to both the MFJ and Diamond meters I have is that they are rated for a 10% tolerance, which is a lot. -
Looking for a good/accurate/ power/watt meter for UHF/GMRS
marcspaz replied to OffRoaderX's question in Technical Discussion
I'm commenting to subscribe. I have a Bird 43. From there, I have amateur grade or less. I'm curious what the pros are using.