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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.

I like to refer to this as a radio's "sense of self preservation."

As long as the radio has fold back protection that works properly then a high SWR should not hurt the radio. Now if the fold back protection is not working or the radio does not have that, then a high SWR can and will blow the finals. When a radio folds back, it cuts the power way down to protect itself from a high SWR. Most radios will cut the power back to 1 watt or less.

You would likely avoid a lot of unnecessary confusion by initially purchasing either a GMRS radio, which has all the channels set up other than adjusting potential repeater channels to local tones; or a HAM HT. Both types of radios can be found with the ability to monitor outside of their allowable TX freqs, although "modifying" or "unlocking" either type of radio simply creates more confusion and potential problems (outside of licensing issues) for newbs. If you want to modify and experiment, the HAM route is the only route...GMRS simply is far too limited, and not offered with hobbyist radio in mind. With HAM on the other hand, you have tremendous ability and in fact encouragement to modify and experiment almost to your heart's content, within the assigned bandplan. The radios are also generally much more complex, and therefore more difficult to "learn" and utilize all available features. In general, they are also better built electronically and physically. You should also seriously consider meeting up with a local radio club (or multiple if there are choices) before purchasing anything, to learn more about what works well and what is useless in your particular region, based on your expectations. They will generally be your best and most current source for info on any local repeaters.

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.

I had a very strange experience this weekend. I wanted to share some information about antenna performance and SWR, in hopes of stimulating conversation and maybe helping debunk some common misconceptions about high SWR breaking radios. Obviously, there is a limit to this, but with the typical gear and power levels we operate at, it seems to be a non-issue. I have several radios in my Jeep, with a total of 4 antennas, depending on the band and radio being used. I went offroading this past weekend and took all my antennas off but one small rubber ducky style to use with GMRS communications while on the trails. I had this small, flexible antenna hooked up for the 5 hour trip to the park on Friday, all day wheeling Saturday and Sunday, and for the whole ride home. While on the trails, I was getting anywhere from 100 yards to 1/4 mile of range out of my radio. Most of the time, I was only using 5w, but when the terrain would cause issues, I would crank up the power to 50w. This is pretty standard while offroad and using a flexible antenna. Sunday, on the way home, I noticed I was getting less than a mile out of the radio. That had me a little concerned, but not enough to pull over and check on anything. We stopped for gas, so I decided to see if the antenna was loose and maybe check the SWR, to make sure everything was okay. However, when I went to check on the antenna, I realized the rubber ducky antenna was on the wrong mount. I had used my radio all weekend, running as much as 50w, with no antenna whatsoever on my GMRS radio. 100% of all of my communications for 3 days was all with no antenna, just radiant energy from the end of the coax... that's it. I put the antenna on the right mount and used it for the rest of the ride home... only about an hour. I got home and tested the radio. Everything was 100% perfect. The radio power output is still good, even after a 5 minute key-down on the dummy load. So, while this is 100% non-scientific, I was still able to get about 50% of my typical range in the terrain I was in, even without an antenna. With no antenna and obviously sky-high SWR, running an occasional 50w for 3 days, there was zero damage to my radio or coax. Going back to the thread title, does antenna choice and less than perfect SWR matter? I feel like the community may be overly sensitive to this issues. Thoughts? I am looking forward to some friendly discussion.

Hello to all! I am brand new to GMRS. I currently reside in WNC, and with recent events I have discovered the need for a secondary means of communication, (i.e. cell communications unavailable) I look forward to learning all I can and hope to one day build my own repeater. The radios I started off with are the Retevis HA1G (a pair of them). hopefully will get a base station at some point. My background is in A/G communications with ATC so I want to learn how other radio communities operate. 73, Josh J. WSFK616

That is exactly how it is supposed to work in the US. But for some reason there are "some people" who now think you can't do any until the gobment tells you you can. Don't get me started!

Well it certainly is possible

I saw it on the internet. It must be true.

I'll bring up the theory that with modern gear more able to self-protect, high SWR is less of a danger than it used to be, especially with good quality gear. not long after i switched trucks, i moved my comet SBB5 ham antenna from a fender bracket on the ranger, to a fender bracket on the new Ram. it was great on the ranger, 1.1-1.3 across all of 2m and 70cm. few nights later, chiming in on the local linked repeater, and get a report that running mid (usual) or high power, i'm VERY scratchy, almost unreadable, even trying the other two other repeaters in the area (2 uhf & 1 vhf, which I can usually get into on a handheld with a rubber duck without issue). check SWR, and find 2.8 on UHF, and over 3 on VHF, which explains the poor signal. Hooking it up to the analyzer showed SWR is all out of whack on 2m and 70cm, but it was weirdly resonant on 220 (like 1.2 or so). Testing some other whips I had on the same mount, the 2x4SR is stellar, so I'm rolling with that. the only explanation i can see there is where the sbb5 sat fully above the hood on the Ranger, the shape of the hood on the Ram has the base sitting about an inch below the main "plane" of the hood; the radio (FTM500) has shown no ill effects after the fact. In the end, the 2x4 is the only one that reads good on that fender bracket on the Ram (though the 1/2 wave signal stalk didn't read good on the Ranger, either...tuning that is one of those ongoing to-do list items).

I have seen the protective circuits in action on a meter... watching the power get rolled back as the mismatch increases or as heat increases. Even some of my cheap radios seem to have some type of protection. I would agree, there is likely a limit to how long I can do that for before it does indeed break. Thankfully, its not a 30% duty cycle for 3 days. LOL I think there are two possible answers... one is excessive heat causing the materials to break down. Sweating a chip is always bad. LOL The other would be a voltage peak exceeding the PIV / reverse breakdown voltage, causing a collector-emitter or base-emitter current leak. In either case, we are breaking down the PN junction enough to allow current leakage and nuking the radio. I would think as long as the current levels stay low, we can get lucky and just have to replace the PA.

For years I had no access to a swr meter and just trusted that what ever antenna, single band or multi band, would work for the bands for which they were advertised. Actually I didn't trust anything, I just didn't think about it. My amateur days were utilitarian at best. Wire up a radio, install an antenna that should be good enough and use the radio. Even so, I never had an issue with any radio I ran.

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.

All interesting data points. Just to add something, years ago (50) I had a hw-16 (all tube cw only). Did not have a swr meter, but was working on 80m at the time. I probably used this for two years, then got a swr meter, (hw-16 fed a dipole) checked it, and saw a swr of 6:1. Very bad, however at the time I was in TN and contacted someone in SC at the time. 6:1 is not good of course, sold the hw-16 later, the guy who bought it had the tubes checked out, and the final output tube was a little "weak" but all still worked. So I agree, bad swr numbers are not the kiss of death. low is good, but if not its not the end of the world.. All the best regards

That kind of puts things in perspective as people fuss over .2 in SWR lol. I suppose that radios nowadays are robust enough to just pretty much handle anything..

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.

UPDATE: Talked to my friend this morning and told him there are work arounds for his issue. He said he was just going to put them back in the box until he could figure out how to do that. Then he said he just wanted to be able to talk to his family. I told him about the GMRS versions of Baofengs (he likes the price point) so he is going to send the UV5R radios back and get a couple of the GMRS versions, and, get a government permission slip. He travels with his family a lot so he can use them for car to car comms as well. Sometimes GMRS is the answer for keeping it simple.

I live in East Tennessee. Hilly/mountainous terrain. A couple years ago I was trying out a retevis portable gmrs repeater, and I had it connected to a commercially built gmrs antenna. I was utterly dissapointed, getting only around 3 miles range. The antenna was only up about 15 feet, in a residential neighborhood so I assumed that was that. I had a couple years prior purchased a surecom simplex repeater thinking I could use it for various things, including testing range of radios etc. So, awhile back I bought a Jpole gmrs antenna from kb9vbr antennas, it arrived and I never got around to erecting it until yesterday. I mounted it to a section of chain link toprail and connected that to another section of top rail, giving me about 20' elevation for the antenna. Today I set up the simplex repeater, just tinkering around really, but had to go on an errand so I thought I would see what it could do. I have to go over a good sized hill to get to the highway from my house, so when I got to the top of the hill I gave it a try, loud and clear, no surprise there really as its really close to home and with all that elevation I expected nothing less. But then when I got to the bottom of the hill, I tried again, and again it was loud and clear. I was intriqued. So a half mile up the road or so I keyed up, and to my surprise it was nice and clear. Did this at several spots, each time getting a nice clear reply. Each time thinking theres no way it will reach this far. Finally it did fail to repeat, but not until I was almost 10.5 (10.47 measured with google earth straight line)miles away from it as the crow flies, NOT road miles mind you, I was and am IMPRESSED!! I intend to set up my duplex retevis repeater next on the antenna, as this is a really useful range at long last!!

HYS RG-58 I actually changed to a Browning 5/8 wave whip antenna today and cut it to tune to around the 465MHz range based on their guide. I’m now getting 1.3:1 on repeater channels, 1.4:1 on 467MHz and 1.5:1 on 462MHz frequencies. Perfect set-up? No but it will work for now. If I intended to keep this truck long-term I’d be more inclined to make permanent modifications to the vehicle. Thanks for helping me walk through this.

Morning all, can I get a sanity check on local freqs/tones/repeaters/nets? https://www.radioreference.com/db/browse/ctid/1946/ham Using this as reference point, for the GMRS freq at bottom of page. That's not a repeater right? That's just a freq+tone to use? Same question for the Amateur bands listed in that link? I need a GMRS Elmer to help me figure this all out haha. Have a good day folks.

Ouch. My bad. You are correct, it is not in CHIRP. I program it with the GM-30 download from Radioddity, which apparently has the same innards. I see Radioddity has a GM-30 Plus out now, but I can't vouch for that download as I have not used it. Thanks for catching my mistake.

That's a sweet package. I'll have to keep that in mind.

One of my favorites. Corollary: "If it doesn't say you can't, you can."

As an aside, this is the kind of thread that makes this forum so valuable. You guys rock. I love this bar.

I like the Wouxun KG-805g as a very solid starter radio. Should come out of the box with all of the channels ready to go, both simplex and repeater, but has 100 or so slots for you to program more if you want. The software will keep you in-bounds for GMRS, though it's not the nicest application out there, and still lets you program monitoring channels elsewhere in the UHF band. it's also IP55 rated (water resistant) and $79. Alternately, there's the KG-905g, with a little nicer display and IP66 rating for not much more money ($99). they also have a 2 pack with a storage case and charging cables for $209. If you want to receive VHF as well, it's another step up to the KG-935g, which is still less than the midland ($149), and brings a color display and the same IP66 rating as the 905g. All three ring in less expensive than the midland, and there's lots of posts on the forum of users' experiences with these three Wouxun radios.

Screw what the state emergency mismanagement agency thinks. People were on the ground going door to door helping people before EmErGeNcY MaNaGeMeNt even got out of bed. I do not care what is allowed or what is authorized. If people are needing to get in touch with their families then me and my radios are going to help. EDIT: Hang on. They were actually telling people they could not use ham radio to check on people? Because we need to stop and talk about that. Here. I can not even describe how uninterested I am in what is authorized or allowed. I am not seeking authorization in the first place.

The Wouxun KG-935G+ does. There is an icon that stays on indicating which area A or B last received a signal.

If it is that big of a hassle and it is useless, I would just pull the plug and walk away. Spend your resources on something else.

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!

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.

I think anyone who has played with radio very long has done that. Not good, but the radio designers know it’s going to happen and try to protect against it. I have a Yaesu 2 meter mobile where I kept transmitting into an antenna which I didn’t know had bad connector, now that radio won’t receive… I’m not 100% sure it’s because I transmitted into an open load, but I expect it is. thank you Joe K1VW/WSFG777

The speakers are plenty loud even driving down the road with the front windows down and the volumes just passed mid-way.

I was in SF during the Loma Prieta earthquake in '89. Working for the telco, at the time, I had some repair jobs on Treasure Island. The Bay Bridge collapse was on the Oakland side and although the bridge was closed to through traffic, the suspension span was open to Yerba Buena and Treasure Island. Only the far right lane was open and when I went over it, my telco van was the only vehicle on it.....going and coming back into the City. That felt a little strange since it was usually very busy. Pac Bell never went down, only too many people trying to get dial tone caused people to think the systems were down. Afterwords we had dozens of no dial tone tickets that were 'found ok'. There was a strong one in SF in '57 too --- I was 5yrs old........I wonder if Jerry Lee Lewis' "whole lotta shakin goin on" was inspired by that since it was written at that time.

Also make sure to have the correct tone set on your radio for transmit if the repeater is using tones. You can leave your receive tones off for now. You can hear the repeater with no receive tone set but the repeater will not hear you if it is using tones and you do not have your transmit tone set.

Thanks for the quick replies I was on a simplex channel. I see the rptr channels on there now didn't realize it made a difference. In terms of antenna I have it mounted on my truck and had it mounted on my metal roof testing as well. I'm about 13 miles from the tower. I'll try the repeater channel and offset when I get back home. I appreciate you all like I said I'm pretty green with this stuff.

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

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

What Steve said tongue and cheek is actually right and why we are going to see a ham test for at LEAST the next 10 years even if the requirements are relaxed by the FCC. I am 53 and got licensed when I was 22. Not long after the creation of the "No Code Tech" license. We only had allocation for voice above 50Mhz so we couldn't do too much damage. But others will tell you we were lepers, the bane of ham radio. We were going to bring about the end of ham radio and the hobby would be gone. That was the Fud's opinion of it anyway. The ARRL isn't going to be able to allow a test-less ham license because the old guys that are now older and much more opinionated will raise 9 kinds of hell at them for even thinking about it. Nut that mentality will fade as those guys shuffle off their mortal coil and begin fertilizing the flowers at the local cemetery. But I will say this. The test ain't that hard. And there are some here that if you put 1/10 the effort into studying for the test that they do in winding people up in here and beating dead horses, you would have your license in no time.

Damn right they do! Especially with a tube amp!

No attempt to make people jealous, just throwing out some stuff to help people with coming up with their own ideas on their mobile installations. Thanks on the comment.

Every one of those is a repeater. Nets are usually held on repeaters.

You can also fix your typo by clicking on the three dots I. The upper left corner of your post and choosing “Edit”. Small earthquakes maybe, but large ones can be just as devastating as tornadoes or hurricanes. Fortunately it has been a while since we have had one of those here in Montana.

Take the "peer group" out of the equation. You pick up a "study guide" that has the actual test questions and read at your leisure. That's not studying, that's memorizing. When I took all my CompTIA, Micro$oft and Cisco certifications, you had to know the material. The study questions were just that, to study. They weren't actual test questions. You had to know the material in order to pass the exam. Just my $0.02.

Well, lets just wait and see.

Report it.. (them)..

Because oftentimes, this is where repeaters are located: And this is where you and your friends are located Ok, I don't actually know that, but...repeaters are often powerful radios with big antennas located somewhere high up. You're holding a handset on whatever ground you're standing on. I can reach a repeater on a mountain 50 miles from my house, but if I'm hiking in a canyon, I'll be lucky to get half a mile depending on where the other radio is

An SWR of 3.0:1 isn’t as bad as you might think unless you’re using lossy cable. I would go by performance rather than SWR. If your antenna has a low SWR at a lower frequency and higher SWR at a higher frequency, shortening it is the correct adjustment. There’s really no other way to reduce the actual SWR of the antenna. Just don’t shorten it too much. Or consult the instructions for the antenna.

YES! and the FCC has really been cracking-down and issuing more fines lately. If you want to talk that far you should get a H.A.M. license, but if you are willing to take the risk of a major fine, go for it.

That happens if you haven’t installed the correct driver before plugging in the USB cable.