marcspaz

Wow. I'm all for using the search feature and using existing info, but I am pretty sure reviving an 8 year old thread is a record for this forum. LOL I am pretty sure, those in the know actually prefer the legacy LMR stuff for the rock-solid performance and true full legal limit power. It's not for the faint of heart or technically challenged, though.

You have both renewed my faith in man. LOL

@Blaise... I don't know that the shield concept wouldn't work. The question would be, how much would it impact the receiver or the transmit SWR. I don't know if it would work well, even if the transmit loop is stopped. Something I think may happen is, the metal would act like a reflector and you would end up making a 2 element beam, instead. LoL Anyway, with two handheld radios, it wasn't worth the effort to try to remedy the issue. While building a quality repeater was significantly more expensive, I like it better for a bunch of reasons.

Didn't realize there are two threads... copied. I bought this exact unit from Amazon... I tried using it with two Baofeng handhelds. Even though they call it cross-band, the radios actually determine if its same band or cross-band. Bottom line... it ended up in the trash. It relies on the volume level of the radio, VOX operation, and if you try to use it on the same band, unless you have incredibly expensive radios with great filtering on the front-end, the transmitter wipes out the receiver and it gets stuck in a transmit loop until you turn off either one of the two radios. I am a geek by trade, so I ended up building a full-blown portable repeater. At this point, I would recommend you just buy a pre-programed Retevis.

I bought this exact unit from Amazon... I tried using it with two Baofeng handhelds. Even though they call it cross-band, the radios actually determine if its same band or cross-band. Bottom line... it ended up in the trash. It relies on the volume level of the radio, VOX operation, and if you try to use it on the same band, unless you have incredibly expensive radios with great filtering on the front-end, the transmitter wipes out the receiver and it gets stuck in a transmit loop until you turn off either one of the two radios. I am a geek by trade, so I ended up building a full-blown portable repeater. At this point, I would recommend you just buy a pre-programed Retevis.

The government agencies I work with usually ask volunteer civilians to partner with them, provide the hardware and human capital. I'm not aware of any of them doing it on their own, but my experience is obviously anecdotal. My team is in process of putting an amateur repeater on the county dispatch tower at the EOC. We are already approved for the antenna and radio install. I am going to see if we can put up a dual band antenna and see if we can co-locate the amateur and GMRS systems there.

I know a lot of people hate the licensing process and think there should not be any, but the FCC keeps big business and people with more money than Joe Q. User from bullying their way into radio spectrum that individual private users access. The only way the FCC can track exactly how popular the bands are and how many users are actually using it, is via the licensing process. If there isn't enough traceable activity, the FCC will sell the space to commercial users and we will lose our allocations. I only mention this because, I think if we run into people that are unlicensed in a services that they should have one, we should explain this situation to them in encourage them to spend the little bit of effort and funds so we can all continue to enjoy the services over the coming years. One is a CCR, the other is an ECR. LOL

That's greoffloading. My car club uses them for cruises, too. A lot of people use them for off-roading. I've been pleased with my Baofeng radios as well as the Cobra and Uniden blister pack radios.

80 years in prison and a $1,000,000,000 fine, or possibly a no-no letter, maybe. Most likely nothing. Depends on who you're asking.

Nevermind...

eh... this is a tricky subject because people see a huge difference in numbers of watts, but lose sight of the fact that those numbers have minimal impact on the real range and intelligibility of your signal. Bottom line is more power is not the answer. So we just deal with it... accept it... and try to get than antenna as high as possible. I ran a real world test with a radio that has 46w actual output and LMR400 cable (one of the more common in GMRS base installs). At the end of a 100 foot run, I measured 24 watts. My range was about 8.5 miles. At 8 miles away, my son said he heard me fine and he had a 4 s-unit reading on the mobile radio. In that half mile to 8.5, I disappeared. I put my amp on and ran 350 watts out. which netted me 182 watts at the input of the antenna. That was an increase in power of over 700%. At the 8 mile mark, my son said I was at 5 s-units (measurable, but not significant), but he still completely lost me about 1,000 feet further away than with 46 watts... not eve a 1/4 mile increase. On an offroad trip, I was on top of a 4,400'+ plateau, using the same 46w radio, and was able to talk to someone 168 miles away. I could hear the other station about 7 s-units. And of course there is satellite communications, were the repeaters have about 1/4 watt and sound fantastic here on earth, 200+ miles away.

Yes, Sir. Same style for grounding and insulation. One of the things I am partial to with the XRDS is that the center lead gets soldered at the bottom of the pin. So there is no splatter in the collar threads and you don't have to worry about being sure there is no excess solder on the lip or outside edge of the tip, causing potential fitment issues. Makes life a lot easier.

Sure do. They are from XRDS -RF, on Amazon. This is the one that is $25. per pack. They also make SO-239 and N connectors, but I haven't tried them yet. https://www.amazon.com/Connectors-5-Pack-PL-259-Connector-LMR400/dp/B08PKG7XB2/ref=sr_1_3?crid=1MJEAXDHXWD02&keywords=clamp+pl-259&qid=1664290461&qu=eyJxc2MiOiIyLjAyIiwicXNhIjoiMC4wMCIsInFzcCI6IjAuMDAifQ%3D%3D&sprefix=clamp+pl-259%2Caps%2C135&sr=8-3

@Sshannon Don't laugh too hard, but I messed up a connection on my VHF/UHF cable to the point where, when it was bent a certain way, while connected to the radio, it didn't work well at all. I think there was a stray ground stand or two floating around. When I took the cable off the radio and put my meter inline, the cable bent another way, alleviated the partial short and tested out perfectly. I chased it for 2 days before I just happened to have the radio keyed, looking at the meter and moved the meter out of the way to look at my personal data sheet I had been building, to compare numbers from earlier. The SWR jumped to 19:1 for a flash. I ended up cutting the end off and installing a new clamp style PL259. I just my insertion loss in half and the radio started working like a rock star. BTW, I think the clamp style UHF connectors work pretty well for an affordable alliterative to an N type, for use on the 400-500 MHz range. Not sure if you have tried them. The US made connectors are about $100 each, but I found some really good quality Chinese units on Amazon for about $25 each.

Based on what you said on Sunday at 08:42 PM, about the receiver being excellent when the centered of the coax is hooked but, but get bad when you screw the ground collar on, I'm thinking you have a bad coax or bad mount, regardless of how good your SWR is. It indicates a possible partial short.

^^^ This is a great example of "it depends". I understand you are discussing personal experience... but there is most definitely a performance difference between a 1/4 wave and a 5/8 wave, even on a repeater. This is not a scientific test, by any means. I know my radio does not have a truly calibrated S-Unit meter. This is solely an exercise in observed differences with my personal gear.

The best antenna for you is going to vary a bit, depending on where you are going to be using the radio and what you want to accomplish. On a vehicle, a 5/8 wave antenna is going to show at least 3dB gain over a 1/4 wave, and at least 1dB of actual gain (depending on design, it can be much higher). This antenna has the least amount of elevation tolerance. So, if you live in a hilly/mountainous area, this may not be the best option, but it would be good in large geographically flat areas. A 1/2 wave doesn't require a ground plane and has about 2.1 dB of gain over a 1/4 wave, but it has no actual gain... its straight break-even. It also has a bit more tolerance to elevation. A 1/4 wave actually has a loss of about 2/10ths of a dB. While it doesn't provide as much range, in hilly or mountainous areas, its going to be the best choice due to the very high elevation tolerance. Based on this, I actually carry a 5/8 wave antenna that is about 32" tall and about 6dB gain, and a 1/4 wave antenna. Then I just swap them on and off the vehicle depending on the terrain I am in and the range needed.

I'm pretty sure your radio/antenna is already grounded. The question you should be asking is if you should have lightning protection. ? Those answers are way more entertaining.

I have no idea what network Garmin uses, so I can't really speak to that. However, my entire radio and IT career has been as successful as it has been because emergency services and government agencies found out the hard way that the hardline internet backbone and satellite communications not only don't have 100% up-time, but also happen to fail at the least convenient times. Also, if you watch the NOAA, NASA and other private space weather agencies, you will here about the outages as well as the predictions for potential outages. Most reports are released for public consumption weekly. Once in a while, something big happens and it makes regular news, like with all the StarLink satellites being damaged a couple of days/weeks ago, due to a massive storm caused by a CME. I think, maybe I am presenting my opinion in a confrontational way. If I have been, I apologize. That is actually a great idea. These are among the best options. I only have the opinion that HF radio is better because the radios are cheaper to buy, are not subject to service blackouts and don't require a paid subscription that expires in order to get help. That said, most people don't want to carry the small lifpo4 battery and a radio if they are on foot and every pound counts. If they wont carry a radio, the ease of something like InReach or PLB is light years ahead of other options and most definitely a great idea.

Have to disagree. We have had massive satellite communications outages (especially GPS related) due to recent CME's sending some nasty space weather our way. One network I am aware of lost 40 of it's 48 satellites in the past month, seriously debilitating the network. I read an article today that there was a massive satellite blackout to systems servicing most of the African continent due to a CME event. In fact Viasat has so many interruptions to service that they have a website dedicated to showing the services current status. Even the new Starlink system has been having outages due to space weather this year. Also, earth surface SatComms is contingent on clear view of an in-network satellite. Garmin has posted on their website that you need a clear view of the entire sky with little or no tree cover, and very heavy, solid tree cover in all directions may prevent successful communications. HF radio is not impacted by things like foliage or partial sky visibility. HF radio is impacted by space weather, but it's only diminished. There is never a blackout of communications using HF. So, in my opinion, if you can... have both. if not, at least have an HF radio. Just because satellite is easier and has more portable bells and whistles, that don't mean it's 100% up-time.

So, just for grins and giggles, I took some readings on one of my antennas... MFJ Analyzer 145.520 = 1.0:1 147.000 = 1.3:1 Nano VNA 145.520 = 1.2:1 147.000 = 1.2:1 Surecom High Power 145.520 = 1.1:1 / 46.07wFwd / 0.131wRev 147.000 = 1.08:1 / 41.22wFwd / 0.061wRev Low Power 145.520 = 1:1 / 5.1wFwd / 0wRev 147.000 = 1:1 / 4.67wFwd / 0wRev If you look at the readings, they are all close enough. The truth is, they may all be correct. It takes different cables and connectors to test with these devices and those numbers will change based on the changing of hardware. Shoot, realistically, just disconnecting and reconnecting the same gear twice could give you these kinds of variations. If we look at the Surecom reading 145.520 = 1.1:1 / 46.07wFwd / 0.131wRev... the reverse power is 0.285% of the forward power. So, if we switch over to 5w of output, I am not shocked the meter is reading a 1:1 SWR, because 0.285% of 5w is too low for the meter to read. Its about 0.014w. the scale on the device doesn't have enough place holders displayed to show the SWR... so it rounds to zero (or 1:1). I still think that TDukes needs to either calibrate the Nano VNA, the Surecom, or both. But for what we do as GMRS users, I think the device is working as intended and is "close enough" to know our stuff isn't going to break. The need to fine tune that last drop of power (maybe 40 miliwatts at 5w scale "if" his VNA is correct) is pointless except as an exercise.

The problem is, tone 11 isn't the same on every FRS/GMRS radio.

I'm not sure what your experience is, but in my experience, all meters must be calibrated. I'm sure you calibrated the Nano VNA per the directions, correct? Otherwise I wouldn't put much value in those readings. Granted, there are some meters that are sold being advertised as calibrated or not user adjustable, but a quality version costs many hundreds of dollars and should still be professionally calibrated regularly. That is just how this stuff works. Don't use it with the Nano VNA at the same time. Take the reading with the VNA and document it. Then take a reading with the Surecom, make a minor adjustment, and then retest. Just repeat that process until your readings match. If you have more than 1 antenna to test with, to ensure they are at least close to the same readings once it's calibrated, that would be a good verification. Edit: I see you're using an MFJ meter, not a Nano VNA... my mistake.

I've mentioned this before... but I may not have explained it correctly. There is likely nothing wrong with the Surecom. It is a device designed to be calibrated by the end user. While many come from the factory pretty close, you likely need to calibrated yours. Just calibrated it against the Nano VNA, if that's what you have, and check it again. Even if it's not dead perfect, it will be close enough.

I got the MFJ version. It's pretty handy if your looking for a quick deployment of a wire vertical. No, the issue is the aluminum. Conductive materials and PVC impact the performance characteristics of small and wire antennas. For example, a wire antenna would short-circuit against the pole and the metal under a small, top mounted antenna could change the shape of the far field lobes, greatly reducing range, changing the resonant frequency and driving up the SWR.