marcspaz

I agree to a certain degree, focusing exclusively on mobile comms, if we take repeaters out of the mix. My own opinion... CB is a much better stand-alone (peer-to-peer) radio service. In a mobile application, with 12.5 watts on SSB, I can talk 8x further than simplex UHF using 50 watts. Also, a few times a month, skip lets me talk around the country with 4 watts on AM. I can talk to central Texas on UHF, too, but I need to be on a mountain top, using a 5 element beam and 1,500 watts. That said, if you include repeaters, UHF FM radios provide great audio quality and coverage area. Though its still only local comms.

I have used VOX on my FRS radios with an in-ear (under helmet) speaker/mic to talk to my spotter while on road course race tracks. It's good to have comms with a spotter to tell you if you have panels coming loose, high body roll (wrong suspension tuning), smoke/liquid coming from the car, missing an apex or brake zone point, etc. I also use GMRS and FRS when we go 4-wheeling, to spot drivers or to get a spot while rock crawling. Many times, the terrain we are driving through is so complex that tire placement needs to be accurate within a few inches. Drivers typically can't see the tires and rocks under the vehicle. So, they need a competent driver/spotter to provide guidance on exactly what to do with the vehicle. That is just 2 examples. The opportunities for radio to make life safer and more entertaining are endless.

Two points that have been made, that I agree with, are that GMRS is "family" radio communications (definitely not a rag-chew community) and you can't judge its success or failure by repeater use. I would like to add that, because this is a low power, line of sight service, you can't judge the popularity by who you hear... not at all. With limited exception, UHF radio waves (where GMRS lives) either leave the atmosphere or get absorbed by the ground. Where we live, the numerically subtle elevation changes are actually somewhat drastic. There can be hills and low spots that only vary 100 feet, but that variation can occur over 200 yards of road/trail distance. So we end up with a bunch of natural earth walls blocking UHF RF paths. What all this comes down to is, depending on the noise floor and your location compared to the location of the other station, you may not hear anyone more than a mile or two from you. I am just to the south of you, in Woodbridge. When I am at my house, using 40 watts, my mobile will only get about 1 mile. However, if I drive 6 houses up the street, I go up 100 feet in elevation and can talk 5 miles on simplex or 20+ miles to a repeater in Warrenton or the Alexandria repeater. All that said, I think the radio service is increasing in popularity. Many people use FRS and GMRS for outdoor activities. I spend a lot of time camping, 4-wheeling, and at car shows. Many people are moving away from CB for camping and 4-wheeling and going to GMRS. Mostly because the GMRS radio performance is much more forgiving than CB and many people can't get their CB to work more than 100-200 yards. With some of the OTC GMRS kits that come with mag mounts, its almost impossible to screw up the install and get a couple miles of range on average. In the arena of outdoor stuff like car shows, food festivals, art festivals, etc., GMRS and FRS become a great tool for family to stay in touch. My family has 3 HT's and while we are at these events, we use the radios when someone goes on a food/water run, to go look an an exhibit without the whole group, as well as commuting to the location, allowing us to find each other to all meet back up. So, I think it is popular and gaining popularity. Just remember, use the right service for the desired purpose.

Diamond X200a.

I thought about that, too. One of the biggest things stopping me is there is no information on how big the center hole is. I need something that accommodates a 2" mast base. I can always reach out to the sellers. Just haven't yet.

I was thinking about getting one of the tripods with a 8 foot base and 5 feet high... but $200 vs the $25 for the 3 footer I have. Man.

I don't think it's going to work, regardless of where the antenna is in the house. Around here my handheld only gets out about 1 mile on average. On a great day, I'll have splashy comms at about 2.5 miles... but that is purely outdoors with minimal obstructions or elevation changes. The reason the repeater is working for you is because its using a great antenna on the roof of a building that is close to 100' above the ground. Have you done any testing yet?

I have a few questions. Are you trying to get coverage from building to building, specifically or are you looking to get coverage on the ride to/from home? Is she using a mobile or handheld? If she is using a handheld in he building, what floor is she on? Where she works... are there buildings visually blocking the path to the house? What is the elevation of the two locations. I live in Woodbridge and commute to DC on occasion. The RF noise levels are very high in our area and the radically changing elevations as we make our way north/south makes continuous comms almost impossible on UHF while driving. Point to point fixed station requires elevation and good antenna placement.

That's a good idea. It is volunteer work and it does get expensive. I may go that route if needed. I was going to use the spikes to stop sliding side to side, but I have some notched 10 lb weights I was going to drop on each foot, to help prevent tipping. The board idea sounds good, but I will lose the ability to easily transport and setup since I am using an SUV. If I had a pickup, I would just toss it in the back.

I've seen this before. I like them, but have had trouble finding one at a reasonable price. The one I have right now is supposed to be bolted/screwed down to a building's roof. So, the footprint is very small. It's not ideal for tall setups.

Today, I put together a new portable repeater antenna setup together. I do a lot of work with Amateur Radio Emergency Service. Often, we need a repeater setup so our people can run around with HT's and still be able to communicate direct with everyone. The antenna is setup for 2m, 70cm and GMRS. In all services, the SWR is 1.2:1 or better. It's sitting on top of a fiberglass mast. The total height is 47 feet from the ground to the top of the antenna. The bottom of the antenna is 40' from the ground. My son Nick is next to it to use as a reference. I tested it out on 2m. Full quiet to another station 40 miles away, with only 5 watts. I'm pretty happy with that. On 70cm and GMRS, I was full quiet to a repeater 22 miles away with just 2 watts. I am pretty happy with this setup. I am going to be doing a training drill on March 28. We'll see how it goes. http://fiveguysracing.com/marc/HAM-GMRS/Pot_2m-440_Repeater_Antenna_2.jpg http://fiveguysracing.com/marc/HAM-GMRS/Pot_2m-440_Repeater_Antenna_3.jpg

Most coax doesn't have a minimum or minimum frequency cutoff. Almost all commercially available cable is usable from 0.3MHz to 3GHz. Some higher. Coax cable attenuation ratings are tested at 750MHz, for instance. The big things to be aware of is the conductor thickness for the power levels (not too thin), the impedance (which is not frequency specific), and the length of the cable. Most people have no idea how much matching the coax length to the wavelength (or half-wave length) impacts performance. However, most of the stuff we do in VHF and UHF, unless you are doing really high power (1,000-1,500 watts), the performance gain is negligible. It's most noticeable at the bottom end of VHF and lower. With GMRS, as long as the impedance is correct and you don't have some crazy types or numbers of adapters, you should be okay.

I laughed so loud I woke my wife up. A friend of mine was going to put one on his Range Rover. I told him to just give me the $10 and sell his radio, because the end result would be the same, only I will at least be able to get a cheeseburger and a coke. LOL

I wrote a couple of opinions about it in the reviews forum. Take a look. Not my cup of tea, performance wise. Lots of nice features, though.

You're welcome. Yes... the antenna works great for me on GMRS. At the power levels GMRS works at, any SWR 2.0 or less, you are safe. 1.5 or better, you should get good performance with minimal power loss.

http://fiveguysracing.com/marc/HAM-GMRS/X50a_462.jpg http://fiveguysracing.com/marc/HAM-GMRS/X50a_467.jpg

I have a Diamond X50a on the roof of my house. It's been up there on the original install for close to 20 years and it runs great. I'll hook up the antenna analyzer when I get home so you can see what it does on GMRS. I have a few Comet antennas for the mobile radios, but not for a base. Can't help there.

Welcome! There is a lot of great information here, and some very talented operators that are here that are field techs and engineers for their career. If I may... if you want to talk about the pros and cons of each service as it relates to offroading in this thread, I would be happy to give you some input. I'm sure others will too. I go wheeling out in the mountains of WV, VA and PA pretty regularly, and have some pretty capable setups. I understand about the conversations heard on the CB. I was on it today and its not kid friendly if you are anywhere near a major highway. LOL

That Tram is a monster antenna. That should do the trick. The ground plane kit is going to be a huge improvement on your side too. Good luck. Looking forward to hearing back with the results.

Wow... what a hot mess that thread turned into. Through my life, I have always heard and believed that purpose of Amateur Radio and what has become the Public Radio Service is to promote goodwill and forward the science. Those folks don't seem to be interested in anything of the sort.

I go straight to the battery because I have an insane amount of voltage drop on transmit when I use the factory common ground and B+ bus bar. Like... 14.6v in standby dropping to 12.4v (sometimes less) on transmit. Going direct to the battery, even with my 200w amp, I never see more than a 0.3v drop.

Where you been man? Haven't even seen you much on FB. Hope all is well. Depends on the wire gauge. What size it is?

It's very common in expensive and/or high power Ham radio gear (100w+) to protect the vehicle. Most radio manufacturers fuse the B+ side at the battery so if the B+ power lead gets shorted to ground, your vehicle doesn't burn down. Some also fuse the ground wire to prevent fires. This is mostly a risk for vehicles with a separate frame and body. In a vehicle, the body is typically the ground for most electronics in the vehicle. If the body has a poor ground or the chassis ground is broken all together and the radio ground lead gets shorted to the body somewhere, all of the electronics grounded to the body will then try to use that ground wire as the primary ground. Obviously the positive fuses for all the other circuits won't blow because the current on the B+ side is whats expected. The ground wire is sized for the radio and not all of your onboard electronics. So, to stop the negative lead from burning the car down, it gets fused at the battery side for the same reason as the positive lead.

Ah... got you. I thought you had a Midland radio, for some reason. I have zero experience with those. The Midland antennas are not great, unfortunately.

He brings up a good point. The Gen 1 MXT400's were problematic. My Gen 1 broke the first day I had it. It was deaf and power was weak. It dropped off 100% after a few minutes of use. most people reported all kinds of issues with the gen 1's drifting and not being able to get proper audio into repeaters. I had three Gen 2 MXT400's. All of them worked great. I get 5+ miles mobile to mobile (depending on terrain), I am full quiet into a repeater that is 22 miles from my house. Do your mics have loops for hanging or button style to go on a 2 prong hook?