marcspaz

For spring protection when offroad, I use the Comet SBB-1. Its basically a taller rubber-ducky antenna good for 60w. 100% flexable and works great for MURS, 2m, 70cm, and GMRS.

There is no "limit" on antenna height from a GMRS rule perspective. If you have a 1,500 tower, from an FCC rule perspective, you are good. Now, there are registration and notification requirements for antennas near airports and for antennas over 200 feet. However, as long as there is no safety or environmental impact, they will simply process the notice/registration into the official record. There could be state, county or local restrictions, etc. If you are dealing with an HOA... have fun getting an antenna up at all. It's always a fight.

@fremont I am in agreement with @mbrun. If the cable is NOT connected to the radio nor an antenna, and you measure between the center lead of the NMO and ground (and/or the antenna mount bracket), and it shows <1 ohm, then you have a dead short in the cable or the mount. Take the coax completely off the mount and see if the short between the center lead and the outside of the cable still exist. If it does, you need a new cable. If it doesn't, its the mount, and I would still be very suspicious of the nylon isolator.

@wrop206... LOL true story.

Hmm.. odd, why did you vote down my response? You don't believe adding the spring can cause problems? I noticed @WRAM370 gave the same advice and you agreed to try removing it.

...

@DanW Yeah, like I mentioned earlier (today? don't remember. LOL) I don't think 20 is the right answer either. I really hope it gets more popular, though.

LOL... Point taken. The total population in and around the Line A is significant, for sure. I don't know if call signs start with any other letter than W, but per the FCC there are only 126,153 GMRS licenses that start with W. Seems about right since there are 842,408 actively licensed Amateurs, and ham radio is much more popular.

Oh, man! I missed the spring part. Adjusting the antenna length a couple of millimeters can throw off the SWR. Adding a 4 or 5 inch spring will definitely through it off.

There is a nylon spacer between the mount and the center feed on the 3/8x24. Make sure its aligned correctly and not crushed. If you have an ohm meter, disconnect the cable from the radio and the antenna from the mount and see if the center lead is shorted to ground.

No, I am not saying that 79 million people live above Line A. They would be packed ridiculously tight. What I am saying is, the total population of the northern states that Line A is present in, per the Census Bureau, is about 79,633,000+. That is enough people whom driving to or north of Line A is a distinct possibility, that they should be considered in a standardization proposal.

No, I'm sorry.. That is not what I am trying to say. What I mean is, none of your measurements are in agreement with one another.. Therefore I do not trust the 40 W reading. I believe that either you need to calibrate your watt meter, your amp meter, your volt meter, some combination of the three or all three.

@WROZ437... you are experiencing exactly what I would hope to avoid. Finding something other than 20 for "over the road simplex" would work much better in many cases. Maybe, there is no single channel as answer. OffRoaderX does have some entertaining content. Being a Jeep enthusiast, I love watching offroad videos.

Something I was thinking about with regard to Line A... 90% of the US population lives on the the US borders and coast lines. ~79,633,000 people live on the northern border. That means that Line A has the potential to impact communications for more than 24% of the people in the lower 48 states. As much as I like the idea of picking a channel, a channel other than 20 to avoid conflict with potential ORI type repeaters, a solution that potentially excludes almost one quarter of the population doesn't seem like a solution at all, IMHO. In fact, I would be more prone to encourage people to use 20 over 19, since many repeaters have light traffic and operators are supposed to be mindful of not causing interference as part of their license agreement, anyway. I don't know the right answer. Just thinking.

The meter should have come with a ground plate for testing HT's with antennas. I though the meter was at the base of the antenna. If you are 4 feet away, especially if the meter is inside the vehicle, that should be plenty of distance and shielding.

The number one rule of emergency communications is, the command center should never be in the affected area. If you are in the affected area, you need to have a radio relay system established to get the message to the appropriate logistics or CnC staffer inside or outside the affected area, to send help. So, if you are outside the impacted area, get the person's name, what the emergency is, where they are (to the best they can say). Basically the 5 W's. And then you or someone right next to you calls 911 and relays that information. If you are in the affected area, you gather all of the aforementioned information and then relay it through whatever stations needed or direct to CnC, logistics, or whatever unit has been established to respond to the type of emergency being experienced. If you are at an event that is just starting, you will likely be relaying that information directly to Incident Command. Yes! Exactly! Both fantastic radios. I am partial to the Icom, but you can't go wrong with either.

Eh... no one was looking for any of us. Honestly, back then it was common for me and a few friends to vanish for days or even weeks at a time while we were partying. Two days was not a red flag. These days, if grandpa is gone for more than 2 hours, my phone is ringing because the babies want to know when I'll be back. LOL

I'm going to throw this out there. I did about a year ago and it was not well received, but I hope this audience is a bit more open-minded. Just my own personal opinion, the best solution that has zero reliance on any underlying system is 40-meter Amateur radio. There are extremely lightweight, compact, battery powered radios. You can get a small foldable/roll-up solar kit for unlimited use. The antenna is just a piece of wire that only need to be a few feet off the ground. The best part is, depending on how high you make the antenna, you can talk everywhere from 1 to 10,000 miles. You are going to get help day or night and can actually talk to someone for health and welfare as well as status updates. I know we're a GMRS forum and there is some good advice on the satcom stuff, too... but I feel like they have dependencies that are failure points.

Are you using a grounding plate/shield to stop rf from the antenna soaking the meter?

@Sshannon If I were to guess, I would say it might be based on the minimum voltage needed for the radio to work. Given that they said it should be close to 8 amps (46w +/-) at full power and it has a 55% efficiency rating, the math would work out to 11.5vdc. That kind of makes sense... most 12vdc systems run on as little as 11.0vdc and max out at about 15vdc. So, you may be on to something there.

I wish I could answer that question accurately. Very little information about the radio that was given to me. As you noted, I'm not sure it matters either way, based on the math you shared.

No. Regardless of if you are using a dummy load or an antenna, there are 2 formulas used for calculating power, resistance, current and voltage. The first is Voltage / Current * Resistance. If you have any 2 of the 3, you can find the 1 unknown value. The second is Power / Voltage * Current. Again, if you have any 2 of the 3, you can find the 1 unknown value. We are going to use the second of the 2 formulas. We know you have 7.5 amps at 14.6vdc. We are going to multiply the two for a total of 109.5 watts of total consumed power by the radio. The transmitter has an efficiency rating of 55% (per the manufacturer, and a very common value). That means we are going to take 45% away from the 109.5w, being 109.5 * 0.55 = 60.225 watts out to the antenna or dummy load. If your meter is reading 40w, then either the watt meter is not correct or the measured voltage or current are not correct.

@Hunter399 at 55% efficiency, that puts you over 60 watts.

It reminded me of an old CB, too. There was just a channel dial, volume/on/off and a squelch. White plastic body and the face where the controls were had a slight angle so it was easy to see the channel selector while standing at the wheel. I am very glad I had the radio and my grandfather taught me how to use and maintain it. On an open vessel on salt water, there is a lot of different maintenance needed. compared to a land mobile or base station.

@Lscott do you remember the old white Midland marine radio with the old channel numbers fixed and a click dial? I don't remember the model. This was in 1985. My grandfather gave it to me because I had no radio, and he had to have had it for close to a decade. I also had a 7/8 wave vertical antenna mounted on the back right corner. EDIT: Now that I think about it, it may not have been a Midland... It may have been a Motorola or a Standard. It was a very long time ago.