SteveShannon

Are you asking about the executable or the data file?

I don’t see anything there that makes me cringe. The radio is as good of a GMRS certified radio as you can get. The Midland mount is okay. It’s nice to install because it only requires a 3/8” hole. It might not be “commercial radio” quality like a police car or ambulance would get, but it should be fine. If it fails then ask one of the guys like Kenny what NMO mount they use in a public safety vehicle where price is no object and reliability is the only concern. The Melowave antenna is not one I’m familiar with, but I have seen them sold on one of the buy two way radios websites. There’s no reason to doubt it, but as far as I know it’s strictly GMRS.

You’re checking for a damaged cable or something at one end or the other that might be shorting the center conductor to the shield. It’s just a guess on my part, but maybe when you turn off your radioa relay opens up and for the next three seconds, while voltage is draining from capacitors in the power circuits that’s why it suddenly works on NOAA channels. With your multimeter you might put it on the continuity test and check to see what the resistance is between the center conductor and the shield with the NMO antenna removed. It should be very large, like in the megohms or “OL” as some meters say. If it’s a low value, there might be a short between the center conductor and the shield of the coax. That could happen at either end due to a poorly installed connector or damaged cable. An antenna analyzer is a tool some of us have that performs test on the feedline and antenna to help understand what’s happening. Don’t run out and buy one unless the bug bites you and you decide to go from GMRS into ham radio. Then, heaven help you because you’ll never stop shopping for radios and test gear (or building them yourself!)

Unscrew the pl259 on the radio end and slide it partially out so the center conductor is still connected but the shield is not. See if that makes any difference. Do you have a multimeter? Or better yet an antenna analyzer?

Good grief. That’s 100% wrong. Although it’s possible to have additional ground electrodes they are all required to be bonded together. It they are not there’s a possibility that you can have current flowing along the shield of your coax.

Yes, exactly the same way.

Don’t make a long coax run to your electrical box. Your antenna isn’t grounded to the electrical panel. Instead it is grounded to your grounding electrode outside. If anything run a bonding conductor outside the house from where your coax enters the house to your intersystem bonding terminal block. See this article: https://reeve.com/Documents/Articles Papers/Reeve_AntennaSystemGroundingRequirements.pdf

A drip loop near where you go through your wall is helpful to keep water out of your walls, but that’s at the other end of the coax. For some antennas a loop is added next to the antenna to act as a choke. The minimum radius allowed for lmr400 might not allow that. If you think you need a choke you can make on with a more flexible cable, like rg58. It’s such a short length that the losses won’t hurt. There’s really no other reason for a loop at the antenna end as far as I know. I doubt that you need it.

Why do you say dumbass judgemental things like that to people? What’s wrong with you?

No. If your radio is set without a receive tone it reproduces everything detected on that RF frequency. But if a tone is set then it must match. So by leaving the receive tone out you are able to hear everything on the repeater.

Ham Radio Outlet has the antenna for $349, not including drop-shipping. https://www.hamradio.com/detail.cfm?pid=H0-003375

In hilly terrain is where something like the j-pole will really shine. Good job!

Welcome to the forum!

Perfect is the enemy of good enough! Nice job tuning the antenna!

Agreed. And actually both excess heat from current and breakdown from excess voltage could both be happening. Even though peak voltage leads peak current by a quarter wave when they leave the transmitter, off peak current or voltage can still combine to exceed specs for the transistors. This is one time where a very lossy transmission line is a benefit!

Welcome to the forums. I can’t answer your questions about the H3 being a good first radio, but there are lots of different posts about them.

Quit lecturing people on “the info you promised you’d read”. The information on the license says absolutely nothing about repeaters and your comment is not helpful to anyone.

That’s the conventional wisdom, but I’m curious what the actual failure mechanism is. Is it an excess of voltage or an excess of current that destroys the finals? We all oversimplify it by talking about “reflected power” but in reality both voltage and current are reflected by an imperfect impedance match. Depending on the length of the transmission line, the reflected voltage or the reflected current will additively combine (constructive interference) at specific locations along the transmission line. If your transmission line is just the right length the voltage (or at a different length the current) will result in twice the value of the peak forward voltage (or current). I anticipate that’s what actually causes the destruction of the finals and why it doesn’t happen to everyone in the absence of foldback protection.

Google the service manual. Most transceivers have a transmit receive relay that connects the transmitter to the antenna and disconnects the receiver from the antenna whenever transmitting. That relay is there to prevent damage to the very sensitive receiver circuits while transmitting. It might be a simple thing to fix.

Less than we typically predict. I have said a few times that an SWR of 2.5 or so wasn’t the kiss of death commonly thought. However, I’ve also attempted to transmit eight blocks down my street on 2 meters at 20 watts, using a Midland MXTA26 antenna, which is strictly a GMRS antenna and has a high SWR (I don’t remember for certain how high now but maybe up around 10:1) at 2 meters and found that I was unable to be heard. One article that I reread from time to time in on the ARRL site has influenced my understanding of high SWR. It purports that reflected power, no matter how high, eventually reflects again at the radio, this time back towards the antenna. Each time a portion is radiated by the antenna and a portion of reflected power bounces back and forth .At the antenna for the second (or third or whatever) a portion reflects again. Each time some of the signal is attenuated in the cable between the radio and antenna, converted to heat rather than RF radiation. With a no loss cable eventually all of the RF is emitted from the antenna, even if the antenna is high SWR. Unfortunately, there’s no such thing as a zero loss cable, but shortness and higher quality help. The best available to a radio operator is to have no cable at all, such as an antenna directly connected to the radio, as in a handheld radio. This (perhaps only in my opinion) is why handheld radios, including cell phones, can get by with SWRs that are up around 5:1 or 6:1. It isn’t really that measuring the SWR of a handheld’s antenna is difficult. It’s that it matters little.

They don’t, unless the radio is transmitting digital data. Ordinarily GMRS radios have removable antennas.

Either the tone, the frequency, the cable, or the antenna is wrong. Can a friend listening on the repeater input frequency hear you transmit?

Are you on the repeater channel on your handheld or one of the simplex channels? They both receive on the same frequency but the repeater channel transmits on a different frequency.

Yes, click on their name, go to their profile, then click on the envelope below their name:

That should be right, but you can always get rid of the R-CTCSS and see if the repeater hears you. That way you’ll hear the repeater response regardless of the tone. The other thing is don’t try to talk from one radio to the repeater to the other radio that’s just a few feet away. The second radio might be overwhelmed by the power of the first radio (called desense).