Leaderboard

This is what I got. Have to be honest... it's hot, but it "feels" hotter. LOL The IR was a good idea. 5 min Standby = 71.5 (room temp) 10 min Low Pwr (30 sec on, 30 sec off) = 95.7 10 min Hi Pwr (30 sec on, 30 sec off) = 124.4

Yes, a local GMRS user in Malibu told me that the City of Malibu funds his group to build out DB20-G GoBoxes for distribution to its citizens.

Technically, there are 22 simplex FREQUENCIES, of which 8 ("GMRS Main") can operate in simplex (radio to radio) or duplex (radio to repeater to radio, simplex frequency +5MHz on transmit). In the old days, when a license only authorized two Main frequency pairs (duplex), channel numbers were meaningless -- many business band radios used for GMRS only had "A"/"B" (or 1/2) to have the licensed channels programmed into; it was common to refer to them by the suffix (.550, say). With the reorganization of 2017, the FCC defined a standard "channel number" for the basic frequency list: 1-7: original GMRS interstitials 8-14: originally only FRS, these are interstitial channels using narrow band and only 0.5W ERP; they are now available on HTs with a 0.5W low power setting. 15-22: original GMRS main channels -- were NOT legal for FRS usage prior to 2017, and are now limited to <2W FOR FRS; with a GMRS license one can go to 50W 23-30, 15r-22r, etc.: Repeater mode, transmitting on 467.xxx, receiving on 462.xxx (again, in the old days one would have a button on the radio that just toggled the channel between simplex/duplex (and maybe reverse -- where you listen on 467.xxx to see if someone else is in range to go simplex). As has been stated, "custom" channels are memory slots in which you can specify a desired GMRS frequency, CTCSS/DCS, power level, name, wide/narrow (if you have a group using NFM-only FRS units, you may want to match narrowband -- GMRS is wideband). Depending upon the radio, you may also be able to enter non-GMRS frequencies for scanning purposes, but will not be able to transmit on those frequencies.

I think that the charging stand with my GM-30 clone, the Pofung P15UV works.

LOVE that radio. Small and compact, great for go box builds!

Radioddity DB20-G as easy to use as: 1-2-3: 1) Plug into cigarette lighter; and plug in antenna; 2) Select appropriate Repeater Channel 23-30; and 3) Push FUN button, select appropriate Tone from 01:T-CTC Menu using Up and Down arrow buttons; then push FUN button to exit Menu Mode Start using your Repeater! Tons of user feedback on this Forum alone!

So the midland antenna requires a ground plane Not sure what you used with it. I would get a TRAM UHF base antenna and LMR400 for starting point. As said as high and you can go the better but keep your cable as short as possible. Dont coil 50' of cable behind the radio.

That's super common actually. Motorola repeaters are just a pair of their mobile radio boards in the same chassis, same for Yaesu being a pair of mobile boards, Wouxun's dedicated repeater, and so on. It saves a ton on development and manufacturing costs. The real enemy is heat, as you've noted. What dedicated repeaters do differently is cool the boards better - larger heatsinks, ducted fans, and forced ventilation are common in a front to back 2U 2-post chassis normally used for repeaters, while the mobile radio usually must passively sink the heat, or, at best, has a low noise 40mm fan. A 2U chassis can easily vent over 2kW of heat if designed properly (just look at servers), a couple of hundred watts for radios and control boards is basically nothing a single 60mm fan can't handle. At least, once you stop caring about the audible noise of the cooling system! If I were building a repeater on the cheap, personally I'd pick up something like this and take my tin snips to the interior: https://www.newegg.com/black-athena-power-rm-2u200h/p/N82E16811192310 It comes with two 12V fans, plenty of room for the power supply and the RX unit, in a couple of hours it could easily turn two independent mobile radios into a repeater. I'd probably throw in a temperature sensor and fan failure alarm too for my own peace of mind.

This is excellent. Thanks for sharing this tool.