BoxCar

The two most common elements in the universe are hydrogen and stupidity. The ongoing debate is which is the more common.

It's probably safe to leave it in the charger, however, Lion batteries don't discharge themselves quickly like the older NiCad batteries did. I've charged up radios and let them sit for a couple of months on the shelf to find they retain 90% of their charge or greater.

The usable frequency range of the transmitter covers the Part 90 spectrum.

The manual that comes with your radio should tell you what the power draw is during transmit. Round this value up to the nearest multiple of 5 and you should be good. I personally use the Mean Well (Meanwell) brand of power supplies that can be found on Amazon as well.

Maybe start knocking on doors and asking if you could rent their attic for an antenna location. Offer them say $5 per month for the space and a little electricity to power the connected antenna and radio.

Why not help your friend get his Tech license? Then you could use the existing repeaters to stay in touch.

There is no rule about giving an existing repeater priority but there is a rule within Part 15 that states a station must avoid causing interference. That rule (admonition) is repeated in many other parts of the regulation. Simply translated into practical usage is if someone is already there, you need to go somewhere else. With only 5 channels, it can be difficult to find an unused pair, but it is the responsibility of the new station to either negotiate a sharing agreement with the incumbent or forego establishing their site.

If there are no repeaters in your area then the 5 frequencies are available. If there is a repeater operating, you are required to give that user priority for the channel and either select another channel or reach agreement to operate so not to cause interference to the existing user. The rule reads you must avoid causing interference but accept any interference from another station operating on the same frequency. Using tones or codes on a channel does not stop interference as you are both using the same channel.

Being blunt, there are no "custom channels" on GMRS or FRS radios. A channel can be "customized" by adding tones for receipt and transmission of messages between users. Adding tones means you are requiring a user to have the same tone to use the channel in the same manner as the others but does not guarantee any type of privacy or exclusive access.

I'll add my welcome as well. WRCM737, K4BJW

Almost any external speaker would work, the issue being cords between the radio and the speaker. I bought this little peaker for when I operate away from my home. AYL Mini Speaker System, Portable Plug in Speaker with 3.5mm Aux Audio Input, External Speaker for Laptop Computer, MP3 Player, iPhone, iPad, Cell Phone (Black) (amazon.com) It is amplified so its volume is independent of the radio volume meaning I can leave the radio's level set or normal use and increase or decrease the volume at the external speaker as needed.

+1 on this. Watts is output power and has no bearing (mostly) on receiving ability. The key for both is antenna height and the higher the better. Second to antenna height is the antenna itself. Antennas have a gain measurement which translates to the amount the signal at the antenna is amplified by the antenna design both outgoing and incoming. There are two scales commonly used, the dBi scale and the dBd scale. The dbi scale is how the antenna output compares to an imaginary antenna while the dBd scale is measured against real conditions. The dBi scale can be converted to dBd by subtracting 2.1 from the dBi figure.

A couple points here. Duty cycle depends on how well the transmitter can dissipate the heat generated when in use. A 100% duty cycle unit would have a large enough area that the heat generated will not degrade or shut down the transmitter. The duty cycle of a repeater will be affected by the air temperature surrounding the unit. Most are rated when the ambient air temperature is closely regulated to be about 70 degrees F. As the air temp increases, the duty cycle decreases while the inverse is also true, lower the temp and duty cycle increases. I'm going back here almost 50 years, but I remember an axiom that stated lower the junction operating temperature of a transistor by 10 degrees C and you double its life. Many of the commercial grade repeaters will incorporate the STUN/KILL mode where a specific code string can be sent to stop the transmitter until the restore code is sent. And, as to brands, there is a reason Motorola has the majority of the public safety business. It may be overpriced in comparison and incorporate proprietary software coding but, above all, its reliability is unquestioned. One of the agencies I worked with had a repeater that had been operating for close to 50 years with no failures. Around 2010 it was in an area that had a record flood and that old repeater was then stressed into operating at full capacity for a couple weeks during response and recovery. It came through with flying colors. The brand, Motorola.

Looks good to me.

And, to put a nail in that coffin, the rules plainly state NO REPEATERS are allowed on MURS.

Alternator noise usually means you need to have it checked as almost all the noise problems have been addressed by the auto manufacturers.

Many of the topics you are asking about have been addressed in the past. Several times for some of them. I suggest you look at one site frequently mentioned on these forums when the subject of repeaters, their construction and use, is asked. That site is https://www.repeater-builder.com.

The radios have to be more than 10 feet away from each other to limit receiver overload when transmitting.

My suggestion is to use a 20-25W mobile for the base station. You can find a 15A power supply on Amazon that will provide all the power you need. If you get a mobile that has a cigarette lighter plug, then a mag mount antenna is all you need for moving the radio to your car in case of SHTF. A higher power radio doesn't buy you much more than a stronger signal in the same coverage area as the lower powered one, so don't think high power. more range. It just isn't so.

There are a great many Part 90 organizations with multiple FRNs and licenses for the same physical location. Police departments are primary culprits.

Are you certain the DB-25 is putting out full power? Also, measure the power from the radio at the antenna connector. You could have a bad connector at either end of the cable.

I take it the aluminum angle work is bolted to the van roof so mounting the antenna to the center aluminum piece running crosswise would work. Virtually any metallic surface will act as a ground plane for an antenna.

Narrowbanding was mandated after 1/1/2013 so any time in 2012 works as well.

Perhaps if the major manufacturers had DMR radios the CCR market wouldn't have as deep an inroad into the ham market. Each has their own digital scheme and they are incompatible with the others. The CCRs provide hams with equipment that works across brands and, once it's configured, works well enough. Yes, they could buy public safety grade radios but they lack the flexibility to connect with a multitude of available DMR repeaters.

The money paid for spectrum, like fines and fees, goes to the treasury, not the FCC. They only get the headache of enforcing it.