marcspaz

I didn't mention the radios because the images of spurs are not radio specific, they are symptom specific. Meaning any radio can have those spur types. Also, none of the test were conducted with coax or antennas connected. For the one that was damaged, it was a QUANTAR repeater. As mentioned in the original post, the VCO in the exciter had gone bad. It was repaired with a card swap, placing a new exciter in the radio. After 26 or 27 years in use... I'm sure some silicon-based part went Tango Uniform. The other images, from the TinySA, are from my BaoFeng BF-F8HP handheld and my Yaesu FT3DR.

Hey folks... I have discussed receive and transmit quality with many of you in the past. Especially focused around the quality of the transmit signal with regard to spurious emissions, commonly known as Spurs. I wanted to share this info because with the introduction of the TinySA, some YouTubers are using these in their tech reviews, but really don't understand what they are looking at and end up giving out bad information. Our friend NotARubicon recently reviewed the BTech GMRS 50V2 and did a great job of showing/explaining what is known as a harmonic spur. Harmonics are a subset of Spurious signals found at integer multiples of the fundamental frequency of the signal. If you haven't seen the review, I highly recommend it. BTech GMRS 50V2 - Review & Power Test - Is BTech's New GMRS 50V2 Better Than The GMRS 50X1? I got a couple of pictures I wanted to share, that relate directly to this. These images may help understand the references when you see/hear reviewers discuss this topic. I have a friend of mine who's repeater was not behaving well and upon testing with a tool called a Spectrum Analyzer, he found Spurs every 100 KHz above and below the carrier at 462.675 MHz. In the GMRS world, that translates to the signal being transmitted over and over again, every 4th channel. Below are the images he sent from both prior to the repair, and after it was fixed. Broken... Fixed.... There are many, many types of spurs that can occur. You are looking at the effects of noise generated by the exciter circuits (VCO for those familiar), known both as sideband spurs and Baseband Harmonic Images. If this doesn't make sense, its okay. Just know that if someone is doing a tech review and shows pictures or video like this, the radio is broken... not that it was designed poorly. The next two pictures are of two of my radio's signals on a TinySA. These images are great example of Phase Noise spurs. The first picture, the issues seem pretty obvious to me. The second picture shows one small spur. It's not terrible, but it really shouldn't be there. Warning... Geek Alert! Phase Noise spurs are unwanted signals that occur due to the random fluctuations in the phase of the carrier signal. Phase noise spurs can degrade the quality of the transmitted signal. Think audio and signal quality. This is a symptom of poorly/cheaply designed radios and use of low-quality parts; not something that is malfunctioning. This was by no means meant to be technical. It is just samples to help know whats broken vs. poorly designed, and a conversation starter. Let me know if there are any questions. Either myself or one of the smart people in the room will answer them the best we can.

@WRQC527, the FT-70 chews up batteries. I sold mine within a few weeks of getting it. The FT-3D and FT-5D have much better battery use and standby times. I used my FT-3DR as a remote net control operator (via my xband repeater in the truck) for a Marine Corps Marathon event. I was non-stop slammed for 5 hours, 50% duty cycle, at 5w. It also has about 6 weeks standby, with the battery in the radio, before the voltage drops to 7.2vdc. With the battery disconnected from the radio, I have no idea how long the storage time is, but I know it's more than 6 months, because that is the longest I ever went between charges on my spares. Even then, they were above 7.2vdc, and I just charged them for an event.

100% anecdotal, I personally have had great luck with the handhelds, especially my BF-F8HP. The mobiles, not so much. Though the BTech brand seems to be making moves in the right direction, based on some recent reviews I've seen on newer HTs and mobiles. For the most part, if you are trying to save money, it's hard to be the price for what you're getting.

The 400 has known audio level issues on B and only supports digital on A. While the bigger screen was gone in the 300, I feel like the correction to the audio issues and dual C4FM was an improvement. Also, rejection on the 300 is much better, allowing you to pair two 300s and two antennas as a VHF or UHF repeater. The rejection on the 400 was so bad that we had to have the transmitter and receive antennas more than 100 yards apart, just to use 5w without horrible desense issues. The 300's have no desense issues at 20w and only 100 feet between the antennas. Granted, this use case is an outlier, but it's a good reflection of the overall receiver quality differences.

I have an Icom ic-7000. It was $1,500 new and is still selling used from $800 to $1,200 depending on condition. The stock microphone alone is $150. I would be thrilled to spend $2,000+ for a mobile radio if it was the build quality like what this radio was in 2005. The thought of spending $2k on a radio worth $300 is where the real headache starts. With today's tech, if you get a radio like the FT-891 (which is a bare-bones) for $650 and a FTM-300DR for $460, and you still don't have SSB on 2m or 70cm like the ic-7000 and the radios are trash compared to 20 years ago. The wild part is, go back to the days of Heathkit, Drake, Collins, Swan, Lafayette, Hallicrafters... those radios were (and still are) absolutely amazing. Even compared to 2000-ish time-frame. It seems like the more high-tech they get, the more they become disposable and unreliable.

I wouldn't be shocked. There is a lot more margin in a $5,000+ commercial radio that there is in a $170 amateur radio. If I had limited supply of common parts, I'd do the same thing.

Mostly the 65w Toshiba PA's... but pretty much any of them over 4w-5w are going to big companies. Even big brands of assembled gear is hard to find in stock unless we go north of $4k. ACOM and even the old-timer at TES are not putting out affordable gear right now. I tried to order a TES UHF amp through a local shop and they told me indefinite backorder.

I've had the same results trying to get solid-state amps. Also, one of my favorite knife makers is having trouble getting raw materials for making some of their ultra light weight versions. Specifically borax to make boron.

That's pretty cool. Some of the amateur repeaters around here do that, too. It's a great idea if someone has a truly open repeater.

I would not rule it out. The FAA, ATF and DMV in every state do it all the time.

There are "other" channels between and around the GMRS channels. There is a good possibility you are hearing digital encrypted signals related to emergency services. There is a Firehouse near me with an RF link on 462.000 MHz with a side-channel spur that wipes out channel 19 for miles in every direction.

You must have never had Samoas.

So, I am going to write something super controversial and likely going to spur some conversation... I don't know what the right answer is and don't take this as advice, but I will tell you what I do know I have seen. I know two people that collectively run over a dozen GMRS repeaters and none of them ID on their own. Also, both of them had people file complaints about the repeaters, leading to site visits by the FCC. They both were accused of using non-compliant repeaters and not ID'ing. Both of their systems and sites were found compliant and nothing changed. They still have the same hardware and still don't ID. There are several things in the rules that lead me to believe that there are many people misunderstanding when repeaters must ID on there own. Combined with what I have seen my friends go through, it just reinforces that opinion. Come to think of it... I don't recall ever hearing, first-hand, a repeater ID on it's own. Like, anywhere... ever.

I live and work in the Washington DC Metro area. The type of services I provide are with Amateur Radio Emergency Services (ARES). Though there are several other types of civilian groups doing similar work. That is the opposite experience I have had. I have actually seen a tighter integration of our team as the day-to-day communications gets more complex, relying more and more on massive underlying infrastructure, such as commercial power and the internet and cellular for most communications. Modern systems are much more susceptible to failure due to the complexity and multiple threads of 'single point of failure'. Amateurs such as myself bring a 100% standalone system that provides portable and mobile communications support for voice, data, video, networking, etc., all over radio. We are heavily engaged with the served agency for training and actual response. Some months we have several training sessions. We may be at an EOC, Hospital, Airport or some combination of all of them, plus shelters, etc. Every two months my team trains with the US Marines on Quantico and several times a year, every year for the last 20+ years, we deploy with Marines, State and/or local police, hospitals, FEMA and the Red Cross, etc. on actual live events. I think we keep getting more and more invites because, while we are aux communications designed for COOP/DR support, we still move traffic while primary systems are up, and on the regular basis the people we serve tell us we are moving more accurate information faster than the Marines, PD, etc. Some of my amateur radio peers also run the Military Auxiliary Radio Service, based out of the Pentagon. Though, I don't. Most of our operations are in the heart of urban areas in and around DC, Northern Virginia and Maryland. However, we do respond to and train in rural and hard to reach areas that present some unique obstacles to overcome. Communications (like cell service and radio coverage) does get a bit spotty in the rural areas, but we specialize in Mass Casualty / Multiple Municipality responses, which almost always occur in cities. This is how I took it... I would think most people would be comfortable with and even welcome a certain level of self-regulation. For lack of a better choice of words, discipline yourself so the world doesn't have to. Nothing wrong with a little social grooming. The best, most agreed upon methods will naturally bubble to the top as time goes on and get incorporated into SOP. I mean, that is literally what we do here every day, is it not?

I work as a volunteer, specializing in emergency 2-way communications, with two county EOC's as well as for the federal government. The repeaters I have can perform VHF/VHF, UHF/UHF, or Crossland (VHF/UHF). They both are capable of analog and P.25 digital, as well as performing as relaying stations. Relaying is fun, stringing the two repeaters together via RF linking, to extend range as far as 2x to 4x the distance as a single repeater. Basically putting the repeaters on the edge of each other's coverage, using them like a huge wifi range extender. Heres a great example. Let's say I am in an area that I only get 4 or 5 miles of coverage mobile to mobile. In the same area I get 15-20 satute miles of coverage from my mobile to the first repeater. The two repeaters can talk to each other from 30-40 statute miles, and then a mobile on the other end can get 15-20 statute miles from the second repeater. I've now extended my mobile range 60 to 80 statute miles on the longest path.

@Radioguy7268 to restate the obvious, is a rule unenforced, really a rule at all?

It's like being at the zoo. Don't feed the monkeys. When you do, they tend to throw more poo at you.

The only language restrictions I am aware of were on Amateur radio, which were lifted 17 years ago (2006). Looking at the old GMRS rules and the LMRS rules, there have never been spoken language restrictions that I can find. There has been a long-standing expectation that GMRS and LMRS operators in the United States use clear and concise language to promote effective communication and prevent interference. In the past, this expectation has been interpreted by some as a requirement to use English, but I believe this was never an official rule or regulation. If anyone has a link to the government website with the previous rule stating English only, I am open to correction, if I am mistaken.

As others have mentioned, codes, hidden messages and transmitting a false or deceptive communication are all rule violations. I think 10-codes are allowed because they are so heavily used, documented and well known that it's not really considered code, but more like shorthand for voice.

@kidphc I went with the VHF high power because there are a few alligator 2m repeaters around me. I normally run a 50w radio and a 300w amp, but 90w-100w gets me into the repeaters that I can hear. The thing that made me switch is, during the summer, I remove the amp so it doesn't get stolen while the roof and doors are off. With the XTL5000, I can leave it installed and not worry about theft... and I'll still have enough power to reach the repeaters. Also, going to run dual heads. Two W7's.

Oh! If you want one antenna that does it all, get the Diamond NR7900a. It is high gain. VHF/UHF power rated 250w/300w respectively, and covers everything we need to do on amateur and GMRS. Probably the best mobile antenna I ever owned. https://www.diamondantenna.net/nr7900a.html

LOL... no doubt. Mostly with getting forgiveness from my wife. LOL

@kidphc, I have a Tram/Browning 1126-b 1/4 wave NMO antenna. It has great SWR for 70cm and GMRS. Rated from 410-490mhz. I just need to find a high-gain antenna that is good for 70cm. I have the MXTA26 which is awesome for GMRS and rated for 120w, but I don't think it's tuned for 70cm. I already have the radios, and next week I will be installing a UHF XTL5000 for GMRS and 70cm, and a VHF XTL5000 for 2m. They both make a measured 110w+. The VHF unit has a pre-amp, too.

@WQWX838, Sounds like a nice collection! Honestly, I have 3 repeaters (1 fixed and 2 portable). Not only are they closed systems, they are not even on all the time. Only when I plan to use them. The rest of the time, they are off. My fix repeater only covers about a 10 mile radius, anyway. So, I use a friends repeater that covers a 40 mile radius and really would only turn mine on if his was down.