Lscott

Weather sucks today. I don't imagine you're going out to do any DF'ing.

I've done some technical writing for the company I work at, Power Point slide shows for training/sales, test procedures and manuals, but it's not my primary job. People think it's easy. Nope! It's boring mind numbing work and requires a lot of attention to details. People who do it full time professionally really earn their money. Doing design calculations, simulations and circuit design is much more fun, and it keeps the mind sharp too.

Yeah, programming a DMR radio is a PIA. Then again NXDN and P25 isn’t much different. I’ve done all three of the above.

Maybe. They still have to operate under US rules. Plus they need to communicate with other railroads, yards etc. That's likely going to be on VHF. Railroad - Scanner Frequencies and Radio Frequency Reference.pdf

I would not suspect the railroad. They would either be FM, or they were moving to NXDN, but that's on VHF, not UHF.

I did some checking on AAM and there is only one possible. It's an expired license and the plant is located in Three Rivers. That's a long way away. https://wireless2.fcc.gov/UlsApp/UlsSearch/licenseFreqSum.jsp?licKey=1905276 The frequency listed is 462.3125. Hum, if some radio tech miss typed the frequency entry he could have hit 462.53125, added in the extra "5" after the decimal point. Somebody could be using an unlicensed frequency, never licensed, or continues to use one on a long expired license. It happens. The FCC seems really lax in cracking down on this crap. For example the ding-dongs at the Lakeside Mall, house keeping, are doing it. They are on the same frequency as the Troy GMRS repeater but a different PL tone. Their license expired in 2015, never renewed from what I can see in the FCC database, and they still use the frequency!!! Geez!!?? Oh, if you want to "test" their, illegally operating, GMRS repeater out its 462.575MHz/467.575MHz with a PL of 186.2Hz. You can key it up about 4 to 5 miles away with an HT easy enough. Anyway you narrow the search down and locate the likely source of interference keep us informed! ULS_License - Expired Mall FCC Licenses.pdf ULS License - General Mobile Radio (GMRS) License - KAB1523 - LAKESIDE GENERAL GROWTH PROPERTIES - Administration.pdf

Gives me another frequency to look up.

Yeah, their plant is on 14 mile right next to the railroad overpass. I've been by it enough times.

I did some more searching on another site. Assuming the frequency is really 462.5125 I found the following: 462.5125 DMR MO 4 ROCK SECURITY & EVENTS INC. WRAK353 PONTIAC IG SECURITY COMPANY: RADIOS WILL BE USED FOR COMMUNICATION BETWEEN EMPLOYEES 462.5125 DMR MO 4 United Parcel Service, Inc. WPMR963 MADISON HEIGHTS IG APPLICANT IS A DELIVERY SERVICE. THE RADIOS WILL BE USED TO COORDINATE THE ESSENTIAL ACTIVITIES OF THE BUSINESS. 462.5125 DMR MO 5 X-Cel Industries, Inc. WQTT460 Southfield IG Radios used to coordinate activities around a coating facility.

In my experience it's also somewhat buggy too. Maybe by now they have more of the crappy bugs fixed. Also the firmware in the radio had some annoying quirks too. The feature I find most useful is the DMR monitoring mode in the radio. I wish my commercial radios had this, but that wasn't necessary since the market for them ends up with the radios pretty much programmed up once and that's the end of it.

Cool. Like to know what you find.

You can try removing the antenna on the radio. That's a cheap kind of signal attenuater. Do that when the signal gets real strong with the antenna connected. When you get close enough to the source the radio should respond even without the antenna connected. One other trick is flip the radio over so the antenna is horizontal. The source antenna is likely vertical and the cross polarization results in may cases another 20db attenuation. Then rotate in a circle. When the signal is minimum either the end of the antenna is point nearly towards the source or directly away from it. Try that in several locations and that can help pin down the area.

I wondered the same thing. I wouldn't be surprised if radios got swapped around between plants.

What if they don't drive?

Flex-N-Gate is licensed for 462.5125MHz per FCC database. Emission is narrow band FM. Plant location in database is BATTLE CREEK, MI CALHOUN County. https://wireless2.fcc.gov/UlsApp/UlsSearch/licenseFreqSum.jsp?licKey=3494581 I wonder if somebody was miss programming radios for DMR and they ended up at the R.O. location.

I see several company's in that area: Flex-N-Gate (large comlex) Thierry Corp Dixon and Ryan Corp United Resin Corp ArborOakland Group Bowlero Lanes and Lounge (almost on the NW corner)

I would be interested in knowing what you find out. My work office is by 14 Mile and John-R. That's only about a half dozen miles or so from where you're looking.

To get back on track for the thread's topic there is a series of posts on radioreference.com on this exact topic. A few helpful posts shows how to look up Part 95A radios the FCC has certified. I would also imagine changing to Part 95E would also find newly certified radios as well. https://forums.radioreference.com/threads/part-95-gmrs-radio-list.275040/#post-2046099 Then the same person posted an updated procedure: ------------------------------------------------------------------------------------------------------- TThis may be slightly better than what I posted back in 2013. FCC OET Authorization Search Under Application Information: Application Status: select All Granted Statuses Under Equipment Information: Frequency Range in MHz: select 462.55 to 467.725 and uncheck Exact Match Rule Parts (up to three): select 95 and uncheck Exact Match Under Formatting Options: Show results in You can select HTML to view it on the web site or select Microsoft Excel or XML to generate a spread sheet. I just tried the Microsoft Excel format and it generates a file that your browser will want to download. I don't know how that works on a smart phone or Windows. On a Linux PC with Firefox it opens a download dialog box. If you use part 95 instead of part 95A the results could be different. It might include FRS radios too. 95A should include only GMRS radios but some of them (and FRS and CB and MURS) might have only 95 without the letter. I need to check that. Specifying the frequency range 462.55 to 467.725 should exclude MURS, CB, RC and other PRS devices. Today that returned 3969 lines. Some radios have multiple grants or permissive changes so the actual number of devices is way less.

Yes that could also work. Excellent suggestion.

The expected voltage depends on the cell chemistry. Some Lithium cells have a terminal voltage around 4+ volts at full charge.

Good guess! Boost converters can be designed and built in a very small volume these days if only a few watts are required. And as you assumed it's built into the battery pack.

That's the usual offset, however the rules don't require it. Note the FCC rules simply state what frequencies can be used for communications through a repeater, sections A and C, but don't mention a required offset. https://www.ecfr.gov/current/title-47/chapter-I/subchapter-D/part-95/subpart-E/section-95.1763 Some have used a non-standard offset, still using the official frequencies, as a means to keep many users off a repeater since many radios "assume" a fixed 5MHz offset with no option for changing it. That leaves just those people with commercial grade radios that allow programming in separate TX and RX frequencies.

There are some companies that make solar panels specifically for USB charging that would be a better choice in that case since they have done the "engineering" already. Again don't take this as a recommendation but as an example of what is available. https://www.renogy.com/e-flex-21-portable-solar-panel/

Your USB charger is a fixed 5 VDC at either 1 or 2 amps of current. You will need something to provide that. If it's 2 amps then you'll need at least a 10+ watt solar panel for power, more like 15 watts. The DC to DC converter would need to supply 5 volts DC at the required current. The input voltage range would be about the same as in the Baofeng case.

You need more than just a solar panel. The battery pack they use is a Lithium Ion type and has very specific charge requirements. That is satisfied by the charger base. You need a solar panel and some type of regulator to keep the input to the charger base within specifications. DO NOT try to charge the battery pack directly off the solar panel! Most solar panels for low to medium power applications output up to 20 to 22 volts DC, likely way to high for the charger base. You can use a DC to DC converter with a wide input voltage range and a fixed output voltage to feed the charger base. The Baofeng charger base has an input of 10 VDC, 12 VDC would likely work OK. Then you need DC to DC converter that would take a wide input voltage range from the solar panel and output a fixed 12 VDC. One example, don't take this as a recommendation, is at the following link. https://www.digikey.com/en/products/detail/mean-well-usa-inc/SPBW06F-12/7707012 Datasheet specifications. https://mm.digikey.com/Volume0/opasdata/d220001/medias/docus/2289/SPBW06%2CDPBW06_Ds.pdf The input voltage range is 9 to 36 VDC so this should cover a 5 watt solar panel. You can find some 5 watt solar panels on line. I've attached some photos of a few I have. You'll likely pay around $20 to $30 for one. You'll also need some cable and connectors to wire in the DC to DC converter and connect to the charger base. Solarverter.pdf Solarland SLP005-12.pdf 5 Watt No Name Light Aluminum Frame Solar Panel.pdf