JLeikhim
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Posts posted by JLeikhim
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True, they would work far much less sucky on the moon or way out in the boondocks.
In fact, Midland backs up their 32 mile claim for their GMRS radios by testing them line of sight from a huge hill way out in some wide open rural area. The lawyers are happy, but folks who now have those radios, question the claim when they barely get a half mile in a suburban area.
I have some ICOM IC4008A FRS radios that are superhet, but very basic design with little preselector filtering, just a simple coil. Better than an SOC design. They work very well out in the National Parks. But around town, not so much. I keep them because they are easy to use and the AA batteries last days when camping. My wife and son carry them because they are small.
A radio is a tool like anything else. A battery operated drill from China sold at Harbor Freight might get by for the casual home user. But I have a Japanese Makita drill I purchased in 1980 for $300 in 1980 dollars , that has outlasted all of the cheap drills I bought in the meantime. For $35 You are not getting much of a drill. Same for cheap radios.
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Cheap receivers that lose all sensitivity in urban environments. Radio works fine out in the sticks, but if you get near a bunch of tranmitter towers or downtown with many transmitters, they lose sensitivity. Hearing police transmissions at VHF in the FRS GMRS band, NOAA weather blasting Intermod.I guess you'll need to provide us with the technical definition of "suck" - because i've used/use dozens of these cheap/SOC radios and they all work just great for my needs - and millions of other people seem to agree.
That is the real world, versus hooking a signal generator up to the radio on a bench and reporting it has a terrific -122 dBm SINAD sensitivity. Real world is many signals some hotter than -40 dBM entering the receiver chip.
Also sucky are cheap radios that have very scratchy clicky picket fence noise while in motion. They lack an effective FM limiter that would normally supress the AM components of a multipath condition.
Read the complaints.
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Most of the cost of a radio goes into receiver design. All manufacturers must meet minimum FCC specs for the transmitter, so that cost is fixed. Cheap radios will have simple receivers. SOC, System on a chip receivers have a minimalistic design controlled by software commands. The main thing lacking in these designs is RF preselection . The other problem appears to be the lack of an effective FM limiter circuit. While these radios might seem very sensitive in a controlled environment, they really suck in the real world.
Commercial grade radios and public safety grade radios are tested to EIA 603D. If a radio is decent, it will have published EIA 603D performance specifications. Only a minority of the radios available for GMRS have such published specs.
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In my state, the criminal enhancement is written "use of a communications device", so it really does not matter if a CB, Ham, GMRS, cellphone, or paper cups are used in the commission of a crime. Also the state laws prohibit interference with police as well as commercial broadcast. So in effect, if you are running a pirate radio station they can bust you.
Sent from my SM-T350 using Tapatalk- Mikeam and PACNWComms
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You won't find Motorola Solutions (MSI) making or selling GMRS radios. They have licensed the production of cheap retail FRS and GMRS radios to an offshore manufacturer such as Giant. Those are crappy radios .I was on the Motorola site and couldn't find a 5 watt GMRS HT. Do you know of a model or link to one?
You will need to buy a surplus public safety or business grade radio. I use Motorola Systems Sabers which happen to have the Part 95 certification. I easily tested 2 miles simplex, on foot with another radio inside my house.
There are various Kenwood radios with Part 95 certification.
Public safety Radios with Part 90 certification are generally equivalent in specs required by Part 95.
Surplus radios are cheap and plentiful. But you will need software and a cable to program the channels.
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- DownEastNC, Lscott and PACNWComms
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These cheap radios have receivers that lack effective filtering of off channel and out of band signals. So if you are in an urban area, with powerful broadcast and communications transmitters, the receiver may get desensitized or outright interfered with by strong signals and distortion.
Imagine going to a loud concert where you cannot hear the person next to you. Or being out in bright sunlight where you can't see ahead. In this case put on some blue blockers or sunglasses and now you can see through the filtering.
Toss those cheap radios and look for some good used commercial radios like Kenwood or Motorola.
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That's good to know!No wideband key needed for APX line.
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I have not heard this. I woukd think there would be a ton of disgruntled APX users on these boards trying to get GMRS to work. They are a popular personal radio. The wide band entitlement key is required , but is free.That radio is P25 computable. Will not work on GMRS. Many states are now using P25vII witch is digital ,encrypted, trunking system's. Legally the encryption section is removed from that radio when it was taken out of service. I think it is a all digital and analog system so it is possible to work with a authorized service people. But not with GMRS in my humble option. I'm guessing of a nice looking paper weight.
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Nope, Frank himself!Did Ahmet Zappa certify your Avatar?!?
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Better than 90% of the Chinese junk flooding GMRS, much of it not certified for anything. You will need the wideband entitlement ID along with the software. As long as you stay away from digital modes on GMRS you will be unnoticed.
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I have used it to optomize repeater tower placement for a project that required local in building coverage and there were tall pine trees throughout. It helped me in placing the tower where it could best serve.
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By the way, if you are planning on a super GMRS repeater, consider installing a JPS SNV-12 voter and two or three diversity antennas and receivers on site.
You can pick up 5 to 7 dB effective gain on the receive side this way.
Bear in mind, it is only practical for a single CTCSS tone unless you break out the tone path and use some transmission gates and logic to steer the tones to a community repeater panel. Your mileage may vary...
Sent from my SM-T350 using Tapatalk- gman1971 and Radioguy7268
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You need to factor in the expected tower loading into the design. You could end up with 500 feet but unusable vertical real estate because a potential customer might want dishes and several collinear antennas. Also waveguide and transmission lines eat into the loading.Preface: This question is cross-posted on the Midwest GMRS Facebook page.
EDIT: Preface 2: If this is in the wrong forum area, I apologize in advance. I wasn't 100% sure I put it in general; please move it if it's wrong.
EDIT AGAIN: I think lots are misunderstanding why we're doing this. No, we're not going to spend a million dollars to install one GMRS repeater. This will be a public tower which we will rent tower space out to for anyone who needs tower space. This is a way to make money for us but also, we'll have our own tower so why wouldn't we put up a massive repeater?
. I own Rugged 575 myself which is a 300' tall GMRS repeater and I pay tower space for that so that game I know VERY well and have well covered. This is one of the next projects we have is all.
Question to other repeater owners and more importantly tower owners about commercial tower pricing:
My business partner and I are getting quotes to build a free-standing radio tower in Magnolia, TX. I have a quote from Rohn for 300’ and 500’ self-supporting. We have enough room for a guyed tower so we’ll consider that too but we would much prefer free standing.
The 300’ one in particular isn’t as expensive as I’d thought at $133,935 + $19,980 for lighting, delivery, and anchor equipment. This also isn’t including installation which they didn’t quote me like they did on the 500’ one below. Maybe half of that would be let’s say $200,000 for the foundation + maybe $40,000 for install which brings the total roughly to $394,000
VS the 500’ is a whopping $476,920 + $46,930 for lighting, delivery and anchor equipment. They did quote $83,765 for install for the 500’ guy and $400,675 for “Foundation Installation - Drilled Pier (Caisson) based on Presumptive soil” which brings the total to $924,525 for the 500’ guy
Anyways we’re considering 500’ over the 300’ one because we want the larger tower. My question to you is, besides Rohn, what other companies can I get competitive quotes on for 300’ and 500’ towers? What brand are your towers?
Notes about the tower type:
This Structure is designed for:
Design Code: ANSI/TIA-222-H
Wind Speed: 125 MPH per ASCE 7-16
Wind Speed With Ice: 30 MPH with 1.00 inches Ice
Risk Category II
Exposure Category: C
Topographic Category: 1
Price above includes:
Tower Sections
Step Bolts for Climbing
Tuf Tug Safety Cable Type System w/o Trolley or Harness for One Leg Only
(1) 5ft Lightning Rod w/4ft Extension (no downlead)
(1) Base Grounding Lug per Leg - Grounding Materials to be supplied by Others
(1) 12-Hole Waveguide Ladder w/3ft spacing (Tower Base to Top)
Top Beacon Plate w/o Extension - see Optional Items for pricing on Lighting Kit
I have the actual PDF quote as well if anyone needs to see it as well. Please send me a PM.
We plan on using this tower not only for a big honkin' GMRS repeater, but also for private business radios, local state and federal com systems and for cell phone providers + microwave backhauls, etc.
Thanks for your time and Happy Thanksgiving!
500 feet might be attractive for a broadcast antenna but unnecessary for LMR.
You will find that larger transmission lines will be needed to have same ERP at 500 vs 300 feet. Antenna preamplifier will certainly be needed at 500 feet.
Do a market survey to see who might be a potential client and the height they desire. Otherwise you have a half million dollar hobby,
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You can buy "tell tale" temperature stickers that you install inside electronic equipment to determine the temperature extremes. While they don't tell you how long or whether internally or externally generated, they might be useful to determine if a failure was temperature related.
Commercial repeaters are rated at 100% transmit duty cycle. In Public Safety use that is a norm.. for trunking systems, it is also a norm. Ham radio repeaters are frequently subjected to 100% duty cycle for a half hour or more.
I would repeat the test over 100% key down and monitor the temperature rise vs time. Also monitor transmit power and current draw.
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Hey kids, get off my channel!
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It would be best to contact the entry point.Most likely, we will be going in and out the same entry point. Indeed, you can not broadcast on particular frequencies and above certain power ratings. The broadcasting is the prohibited act, not the possession of the hardware from what I’ve read. I have no need to use it, so I’m probably just going to pull the main transmitter (it’s a Midland Micromobile) and avoid the situation. I’d like to have the option of using it in Alaska but that’s minor. I plan to call the entry point and discuss it with an officer.
If you were for example entering Canada at one location, then exiting in Alaska, you might have a valid argument that you are simply transporting it. Honestly, If you had it disconnected and stowed away I see no reason they shoud be concerned. That said a lot of US citizens are not trustworthy in the eyes of the Canadian authorities.
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Are you entering and departing from same point?
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The FCC has clearly not thought this out and is relying on the assertions of the manufacturers. I don't believe there is a BCL lockout requirement. Only a duty cycle that is insufficient given the multitude of radios that might appear on channel in an urban area or national park.
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Geez does it ever end? The waiver granted to Motorola is not as benign as one thinks. When you add up a few dozen radios automatically reporting GPS location on one channel, the noise and interference will be horrible.
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I used to chase down such interference for Motorola and it happened many times. Bad power amps, bad isolator panels. Once a 220 MHz ham repeater plus FM broadcaster mix. Sometimes lightning damages stations and they go bananas. .And how, exactly, would that ever happen?
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Yeah if the repeater starts interfering with Public Safety after hours or on a weekend you definately need to be able to shut it down. If the FCC calls you and it is stuck on, do you have access to the repeater?You do need to maintain some form of control. Typically this is done with DTMF tones so you can shut down the transmitter, and you do need to be able to get to the site to maintain the equipment reasonably.
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Same as when I won the lotto..Until I got my GMRS license, I never realized just how many 'relatives' I had...
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It is nice that a GMRS license permits its licensee to allow their immediate family members, in-laws, and some other cases to operate a GMRS radio using the license holder's call sign. But what about friends?
If I'm visiting non-GMRS-licensed friends and one or more of them would like to transmit using my radio and call sign, would this be legal if done while they are in my presence? Amateur radio allows for this provision if this is done with the ham acting as a real-time control operator. But what about GMRS?
If this is not legal, a handy avenue for getting potential new GMRS users interested is not open.
Your freinds can use FRS equipment and you can communicate with them on a shared FRS/GMRS channel. But no, they cannot use your license. Even temporarily. They need their own license as GMRS licenses the individual and immediate family, not the station itself.
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This is what is so very confusing about the MXT400. It is not FCC certified for wideband operation.I bought my MXT400 in March/21 with the data cable and downloaded the programming software. The first time I was in programming mode, the radio was indeed already in wide band mode. I highly recommend getting the cable and download the software, it's well worth it.
Brian
WRKZ843
WB9VLW
If this software indicates anything whether narrow or wideband, 12.5 versus 25 KHz channel steps etc, . It really needs to be confirmed with a deviation meter and other measurements to confirm the radio is wideband. You could simply be toggling bits in the radio firmware that do nothing.
I don't believe these MXT400 radios are capable of wide band at all. If they are, Midland could potentially get hate mail from the FCC for releasing the software to modify a certified radio .
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FCC Power Rules
in FCC Rules Discussion
Posted
My read is that TPO is where the transmitting equipment meets the feed line. If transmitting equipment includes harmonic filter, circulator and a duplexer,, so be it, no problem. As long as the TPO is 50 watts.
The Motorola MSF5000 station integrated all of those optional components making a 100 watt station deliver 75 at the connector on the cabinet. This confused technicians who would see that the station was spec d at 100 watts without those internal options, and so they would turn the power up to squeeze 100 watts from the cabinet and that would make the PA run much harder.
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