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Everything posted by SteveShannon
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Running Node on Raspberry Pi 4/Modifying Hamvoip
SteveShannon replied to FrostyFruits's question in Technical Discussion
You’re running out of memory. That’s why cron says it can’t fork. One or more of the calls allocates memory but never releases it. Added: https://stackoverflow.com/questions/37353725/cron-error-cant-fork- 39 replies
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- raspberry pi
- raspberry pi 4
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Why no state issued GMRS call sign license plates?
SteveShannon replied to Lscott's topic in General Discussion
You’re right; I didn’t use the Gordon West books. I’ve never even handled one. But I did use the HamStudy website and app which were very effective for me. Because of my background I could understand most of the answers. The flash cards have links leading to background information that helped me understand those that I didn’t understand intuitively. I studied to understand, not memorize. I’m a VE now and I see some of the new people coming in. I’m sure there are some who try to just memorize the technician pool, but there are also those who seek to learn. Getting their Technician license gets them started along that path and helps foster further learning rather than memorization. -
Many repeaters use the same tone for TX and RX, so if you scan for tone on the repeater frequency you can at least try that tone for the TX as well. If that doesn’t work try several tones above and below the RX tone. They’re usually not too far off.
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Why no state issued GMRS call sign license plates?
SteveShannon replied to Lscott's topic in General Discussion
Bullshit. That’s a cheap shot that paints all of us with the same brush. Yes, there are those that simply memorize enough to pass the Technicians test, but they don’t hang around long. There are still many who work within clubs to help provide backup long distance communications. There are hams helping out during every tornado, flood, and hurricane. -
I completely agree with this. Plus maybe it would be good to allow users to mark a site as “non-responsive” if they don’t respond to requests.
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Unfortunately, our repeater guy hasn’t been given a key to the new gate lock. So, we had to walk up the last 1,300 feet (vertical feet, many more than that horizontally through numerous switchbacks over lose shale). Here’s what it looks like from where we parked looking up at the tower. The smudge on top of that rocky bump is it. I won’t need to take a stress test.
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No, the 2900R had 75 watts; the 2980 increased the output to 80 w.
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So today I accompanied the young man who maintains our amateur radio repeater. Our repeater is at about 9700 feet MSL, which is about 4,000 above where I live. Our repeater has an amazing coverage on 2 meter, reaching nearly a hundred miles in some directions, despite being situated in a mountain range. Our repeater uses a collinear array of four folded dipoles. Because they are a phased array the coverage pattern can be electronically modified wider coverage or to tilt the pattern by adjusting the phasing harness, but of course wider coverage comes at the cost of lower gain; which is why the Comet has higher gain. Here is a picture of the tower with our antenna being the highest 4x folded dipole array and a picture of the view towards Butte from the lookout.
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That seems like a very reasonable course of action. Please be sure and let us know how you like it.
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Requiring a tone for the receiver of a repeater is normal to limit what gets re-transmitted. Having no tone on the repeater transmit side is simply a choice.
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So here are some things to consider. For many of us this is a hobby. For others it's a livelihood or a quest for the technically perfect. The Commscope DB404-B is probably a helluva antenna. It's certainly built like a tank and it looks cool; folded dipoles do. Also, according to the Commscope site it has a gain of 5.9 dBi. That's certainly not bad. JB007 is probably right in comparing it to a Lamborghini. Solid Signal has them for a little more than $426. https://www.commscope.com/product-type/antennas/base-station-antennas-equipment/base-station-antennas/itemdb404-b/ The Comet is not as unique looking. It's not sold as an amateur radio antenna. Comet does market it as a Commercial antenna. Of course anyone can say nearly anything, but remember what Ed Fong said about his confidence in their published characteristics. It has a gain of 9 dBi, which is 3.1dB better than the DB404-B. Yes, LMR 400 has higher loss than hardline. Nobody would dispute that. Your antenna is probably at the end of a 50' cable, possibly 75'. The loss for LMR400 is 2.7dB at 100 feet at 450 MHz. Hardline has losses of 1.63 dB per 100 ft for the half inch diameter, 1.12 dB for 3/4 inch cable, so for a 50 foot cable the difference is 1.1 dB. For longer distances it starts to add up, but if you're using only 50 feet you probably cannot tell the difference. Plus, the LMR 400 is already paid for. So, with a 50 foot drop, the combination of the $140 Comet antenna and LMR 400 cable that you already have still works out as 2 dB better than the Commscope antenna plus hardline. It might not be quite as durable, but the Comet is rated for up to 112 mph winds. It sounds like you're just trying to get a little bit more range from your base station. None of us can make your decision for you. A professional facility that must have 100% reliability would almost certainly go for the Commscope and hardline and I completely agree that would make sense. But they would also probably use a Motorola radio and have a very complete ground system and lightning protection as well as a tower set in a block of concrete. I guess the point I would make is simply that a person can spend a lot of money while only making incremental improvements that are not proportional to the cost. Best is the enemy of good enough. As far as the Comet antenna, other people have spoken highly of it on this forum as well:
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Concept: Dual HT repeater using MURS bridge
SteveShannon replied to WRUR259's topic in General Discussion
There are a few pretty neat mobile ham radios that can be configured as cross-band repeaters without needing two separate radios. The Yaesu FTM-6000 is an example at a price of $270. It has two separate VFOs. If you want digital modes there are models from Alinco, Anytone, and Yaesu that do that as well. -
The reason I looked at Comet was because I followed a rabbit trail that started here. I read some posts here from some highly respected people like Marc Spaz that gave high marks to the Comet CX-333 tri-band antenna. So then I searched for a review of the antenna and found a comparison test of the Ed Fong antenna to the cx-333. The Comet did a couple dB better, which is significant. Then the guy who did the tests contacted Ed Fong to get his comments. Mr. Fong spoke very highly of the Comet antenna and also of the Comet company and how accurately they advertise their products.
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It really does depend how you learn best. There’s not very many books on GMRS, like a “For Dummies” book, but many of the concepts will be very similar in ham radio and there are a buttload of books for that. I suggest visiting the public library. Another thing would be to see if there’s a local to you radio club, either GMRS or ham radio (many of us enjoy both.) And of course don’t hesitate to ask questions here.
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I can’t answer your question, but what about something like this: https://www.dxengineering.com/parts/cma-ca-712efc
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Concept: Dual HT repeater using MURS bridge
SteveShannon replied to WRUR259's topic in General Discussion
In this case Alex is right. The owner of this site probably doesn’t want to have a thread that teaches people to flagrantly disregard regulations. Now if you wanted to publish almost exactly the same thread in the ham radio area and aim it at doing a cross-band VHF/UHF repeater, nobody could complain. -
Sounds like BTech customer support needs a driver for their clown car.
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Which Yaesu 2 meter xceiver? I couldn’t zoom in enough to read it and I’m not familiar enough with the different models to know it off the top of my head. My first thought was the ft-2980r, but the specs said 80 watts.
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Why do I receive the same transmission on multiple Repeater Channel's?
SteveShannon replied to Link6950's question in Technical Discussion
It really depends on how those “channels“ are configured. A channel can refer to any combination of frequency and receive tone, so it’s possible to have numerous channels on the same frequency. Look and see what frequency GMRS-16 and RPT-1 receive on. I bet they’re the same and you have no tone set for one of them. If not, then maybe the problem MichaelLAX described is right. -
I like how they say “ferrous metals” and then say (aluminum, etc.).
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Exactly. We can educate and advise, but incessantly nagging does nothing but make the nagger and everyone around that person miserable.
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What you’re describing is necessary as well, unless you use a duplexer, but that’s for the antennas. You still need to shield the circuitry of the transmitter from the circuitry of the receiver. If you look inside a repeater, even the little Retevis 97, you’ll see that the transmitter and receiver are separated from each other within their own metal sealed compartments.
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Even then it wouldn’t happen. The beer sounds great though.