dosw

Last night I hit a couple of repeaters in testing one of my radios. The first one is 43.6 miles from where I was located, on Mount Ogden Peak. The report was that I was coming in strong and clear. One person said "You must be pushing some power. What are you using?" But honestly I've hit the same repeater with a handheld Baofeng, using a good external antenna. Of course with that radio the signal report was much less impressive. On that first one, I think it's pretty clear that I'm mostly lucky to be able to get through; the mountains between where I was and Mount Ogden are not mere foothills, they're the Wasatch Front range. My signal must just be skirting along the west edge of the range, luckily finding its way to Mt Ogden. But communications was very clear; didn't hear any ghosting or skip interference. The second one is on a mountain on Promontory Point, in the north arm of the Great Salt Lake. The distance covered is 64.5 miles. For that second report, the person at the other end stated "You're coming in strong. Full quieting, no steam under you. It sounds nice." I've hit that same repeater a little further to the west, where Antelope Island is certainly in the path, but still got through with an easy to understand, slight static report. That Promontory repeater is really perfectly placed for my signal to not need to find its way over any mountains until it gets to within a few miles of the point. My strongest radio, the one I used in this test, is in my old Bronco; my camping / skiing / outdoorsing vehicle. It's the Retevis RA87, 40w GMRS radio, and it's feeding an MXTA26 antenna on a lip mount. Often a lip mount presents a bit of a compromise since it is usually used at the edge of a vehicle, with barely any ground plane on one side. I get lucky with the Bronco because it has a large cowling aft of the hood. Pictures of the install are attached. The wire coming across the top of the radio is just the data cable. And the device above the radio is a brake controller for when I tow a small RV. I've measured the amount of metal below my antenna, and the minimum is about seven inches. In my case that seems to be sufficient to get a good signal all around. I've tested simplex at 15-19 miles, with the vehicle in various orientations and haven't been able to hear any difference. Ideally the antenna would be on the roof, but I sometimes park the vehicle in the garage, and the antenna would be too tall that way. Nevertheless, I'm pretty happy with 64 miles, although, from the pictures, you can see why it's possible; a straight shot from 5200 feet to 6500 feet, with a valley floor at 4200-4800 feet, between. What interesting propagation have you been able to achieve?

And along with what type of antenna are you using, is what are its ground plane needs, and what is your ground plane?

The Retevis RA87 40w radio is listed at -32% $155.99. But that's approximately what I paid for mine, so maybe not much better than would be typically available.

UV5G Plus bundle is 25% off, including cable, two antennas for each radio, two radios. 51.99, so you're paying less than 26 per radio, two charging cords, two 771 style antennas, two 701 style antennas, two earpieces, one data cable, and of course the batteries.

Thanks. Good information. I'm using a Retevis 40w RA87 radio, and an MXTA26 antenna, most of the time. My SWR readings are very good. And people say I sound loud and clear hitting several repeaters. I just like tweaking things to see where I can make additional improvements. That's all. Thanks again.

It comes set up for the simplest cases. You could search for repeaters near you, and request access.This site has a tool for searching for repeaters. Once you have found one you're allowed to access, we'll have more to work with on helping set up the radio.

I'd be willing to just do it, risking damaging the mount and having to buy a new one. But I can't even figure out if my RG58 connectors are going to fit the cable. I don't see Midland publishing what the cable actually is. That's why I asked if anyone has experience cutting and putting new connectors on these specific mounts. I don't mind fouling it up and having to buy a new one, but if it's known to be impossible due to the low quality of the shielding of this cable I wouldn't bother. If it's RG58U it would be 2db loss over six meters, or 0.68db loss over two meters, I think, for a difference of 1.3db. That's not awful. But if I could use the last meter or so for practice I think I could get the hang of it. I have a crimping tool with jaw inserts for cable from RG6 up to LMR600, and I've used it for LMR400 already.

My lip mount is actually pretty well positioned. Old Bronco, there's eight inches of steel between the rear edge of the hood and the windshield. MXTA26 antenna, SWR under 1.2:1 across the GMRS frequencies. I'm just looking to reduce cable loss because I'm particular, not because it's not working well. Just yesterday I got 19 miles simplex, and would have gotten more were it not for a mountain.

Both the MXTA27 lip mount, and the MXTA12 magnetic mount come with a length of fairly thin coax. I think they're each six meters, which is over nineteen feet. I don't know what cable they're using; they call it low profile coax. I have some PL259 crimp-on connectors that are made for RG58, and a crimper tool. Before braving ahead at cutting my MXTA27 cable at six feet, I found some old television coax around the house and cut the connector off of it, just to see if I could use it to practice adding a new connector. I found that the copper braided shield was so thin, and supplemented with even thinner foil, that I couldn't really work with it; any amount of cutting of the outer cover would ruin about half the copper braid, no matter how gentle I was. I assume this was because the cable I tested on was just super cheap stuff, not intended for modification. But that doesn't help me to know if I'm going to be successful with splicing a new connector onto a shortened MXTA27 or MXTA12 cable. Has anyone attempted this? Or am I better off just buying mounts that don't come with cable attached? Such mounts seem less common, in NMO form factor.

Is it set to GMRS mode? This radio has GMRS, Amateur, and Normal modes, right? I wonder if your reset switched it to amateur, or normal mode when you had previously been in GMRS mode.

Also extremely useful when doing range testing on simplex. Drive around and record to listen how you sounded, later.

edit|preferences|recording|sound activated recording -> enable. Set the Level (dB) to something low enough that "full quieting" hiss is enough to keep it open when squelch is open. I haven't fired up my raspberry pi in awhile, but I bet you could even run Audacity under an older pi. I'm using Audacity 3.4.2 on an Ubuntu laptop.

Shouldn't matter. If you can configure an inexpensive radio to be listening on your repeater, you're done. Plug it into the recorder or computer, set up VOX mode, check back later. I use the UV5G with Chirp, and it's pretty easy to configure.

Easiest way, IMO, is to hook up either an inexpensive digital voice recorder to an inexpensive HT radio like a UV5G with the appropriate cable, or plug the cable into the mic input of your computer and run Audacity in VOX mode.

I'm just following up in this thread to report back on my tests with the CF-4160J Diplexer (or Duplexer... which is what it's labeled as). The setup: UV5G -> Surecom SW-102 -> CF4160J -> XRDS-RF 50W Dummy Load. I put the dummy load on the "single" end of the diplexer, and connected the transmitter, through the SWR meter, to the 350-540MHz end of the diplexer. 462.xxxx: 1.01:1 SWR, and about 3.4W power output. 467.xxxx: 1.01:1 SWR, and about 3.1W power output. Next, I attached the transmitter, through the SWR meter, to 1.3-170MHz side of the diplexer and set to MURS frequencies: 151.9400: 1.01:1 SWR, and about 2W power output. Next I switched over to Marine VHF 16: Marine VHF 16 (156.8000): 1.0:1 SWR and 4.97W power output. Because I like to live dangerously, and don't care that much about a $25 radio, I keyed up on a GMRS frequency for a moment, with the transmitter feeding the 1.3-170MHz side of the diplexer. The SWR was around 11.5:1 or 12:1. The radio seemed to survive the experience, so I switched over so that the input feed was on the 350-540MHz side, and keyed up in a MURS frequency. Again, a nearly 12:1 SWR. Next I moved the SWR meter to between the diplexer and the dummy load. This will test how much power the diplexer robs from the antenna feed. At GMRS frequencies feeding into the UHF side of the diplexer, I saw no appreciable drop in power (in watts) when the SWR meter came AFTER the diplexer, feeding to the dummy load. And SWR measurements were nearly identical. At Marine VHF frequencies, I saw about a 0.25w drop in power. At MURS frequencies I saw about a 0.2w drop in power. Again, living dangerously, I keyed up on the VHF side of the diplexer at a GMRS frequency. The SWR meter, that was inline between the diplexer and the dummy load registered nothing at all. Similarly, keying up at VHF frequencies when the feed line was plugged into the UHF side, the SWR meter that came after the diplexer registered nothing at all. For another test I reversed the diplexer so that I was transmitting into the single-feed side, and had the dummy load on the UHF side. At GMRS frequencies, I saw pretty much exactly what I measured in the opposite direction; same power, same SWR. And at VHF, the results also lined up with my previous VHF tests. And as a final test, I fed from the transmitter into the diplexer, into the SWR meter on the VHF side, into the dummy load. No power registered on the SWR/power meter when I keyed up at GMRS frequencies. And swapping over so the SWR and dummy were on the UHF side, while keying up at MURS and Marine frequencies, again nothing registered on the SWR meter. Conclusion: The CF-4160J doesn't significantly alter SWR into a well matched dummy load. It also only drops transmitted power by between 1% and 10% depending on the frequency. None of those values should matter much at all, in isolation. For example, dropping from 5w to 4.75w is not going to make an appreciable difference in range or signal quality except in some ideal situation. The CF-4160J also does a good job of isolating the UHF and VHF bands; the SWR/Power meter never registered any power on the output side, if the input was going into the wrong frequency branch. And likewise with the diplexer turned around, sending input to the common branch produced no measurable output on the wrong frequency branch. In an earlier post in this thread I mentioned that at GMRS simplex 462.xxxx frequencies I was seeing a higher SWR when I ran through the diplexer feeding a Comet CA-2X4SR antenna, than when I took the diplexer out of the equation. Given the results testing the diplexer in isolation, dummy load instead of antenna, and none of the magnetic mount's RG-too-thin cable between, it seems like the diplexer isn't the source of reflected power. In a situation where someone needs to use a common feed line to one VHF and one UHF antenna, or a common antenna for one VHF and one UHF radio, I think I can say that the CF-4160J is a really good option. In fact, I read a thread elsewhere in this forum where someone was using two of these; one connected two radios to a single feed line, and the other connected the feed line to two antennas. It looked like their results were pretty good. The only down-side I see with this unit is the fact that it's not weatherproof, so if it's going on an outdoor installation it will need to be in an enclosure.

In GMRS, there are 22 simplex channels. 462.600 corresponds with channel 17. In repeater terms, an input frequency is the frequency that a radio must transmit at to be received by the repeater. The output frequency is the frequency the radio must listen to, to hear the repeater's output transmission. Any transmission from a 2-way radio on the input frequency will be repeated back on the output frequency for other radios to hear, as long as the input uses the correct squelch tone. The GMRS repeater channels pair an input frequency 5MHz higher than the output frequency. This means that simplex channels 15-22 are the same as the eight output frequencies of GMRS repeaters. Those output channels in the 462.xxxx range get paired with input frequencies in the 467.xxxx range. So 462.7000 gets paired with 467.7000. And 462.6000 gets paired with 467.6000. Any GMRS type approved radio that can work with repeaters will automatically know the 5MHz pairing. You shouldn't have to set that part up manually. You pick RP17, or RP3 or 25R, whatever your radio calls the repeater at 462.6000. Your radio will now be listening on 462.6000, and transmitting on 467.6000. The correct name for the repeater channel at 462.6000 will be in the manual. That's the first half of the battle. Next, you need your radio to send a tone when it transmits to the repeater. This tone is how the repeater knows you are talking to it, and not to some other repeater that happens to be on the same frequency. You must be on the correct frequency, AND you must transmit the correct tone on that frequency. The tone is inaudible to people, but is heard by the repeater. The repeater recognizes the tone, and opens squelch, meaning starts listening. Whatever a repeater listens to, it retransmits 5MHz lower. So in your radio you need to program tone 141.3 as a Tx (transmit) tone. If you don't program this tone, the repeater won't wake up. It's that simple. As for how to program the transmit tone in a TD-H3, I won't deprive you the opportunity to look it up in the manual the method of programming 141.3 as a transmit tone. You'll find it there, and now that you know what it is for, you may be more successful in setting it. Now you should be able to key up the radio, and state "This is WSDK548 doing a radio check. I'm looking for a signal report if anyone is monitoring." When you release the key, you'll hear a pffffft-click, which people call a "kerchunk". If you hear this, it means the radio opened squelch while you were transmitting, which means you have the correct repeater frequency and tone. If you get a response back from a person, even better. At this point you may also notice kids playing on FRS radios on channel 17, or road crews, or whatever. That's because you only set a TX tone. You are transmitting the tone needed for the repeater to listen to you, but you are not filtering out transmissions coming back to you. You are listening "open." You may not like hearing kiddies pressing the call button and road crews letting ten more cars through the work zone. So now you need to program 141.3 as an RX tone, or an input tone. Once you've done this, things will get much quieter. You will only hear someone transmitting on 462.600 with tone 141.3. There won't be many people who just stumble into this combination, so you won't be hearing much (or any) unwanted traffic. But the repeater, when it transmits back to you or your friends, transmits that 141.3 tone. By setting that as an RX tone in your radio, your radio's squelch will open when it hears that tone, and you'll hear the repeater. ... if you're in range, if you programmed it right, if someone is hitting the repeater that you're listening to correctly. To transmit to the repeater you need the right frequency and the right tone. If you set the wrong frequency or the wrong tone, the repeater won't listen to you. To listen to the repeater you need the right frequency and NO tone, OR the right frequency and the right tone. If you set the wrong tone, your radio won't open squelch and you won't hear the repeater.

Do you have a squelch tone programmed on your channel 2? Anyway, if you're using your UV5G Plus in a vehicle you probably should get an adapter and a mag mounted antenna to get the most out of the radio.

I [may have] hooked a UV5G (allegedly unlocked) to a Shakespeare 6db fiberglass Marine VHF antenna on the transom of a boat, as well as to a Tram 3db Marine VHF stainless whip at masthead, then to a Comet CA-2X4SR-NMO (VHF/UHF) at masthead with 40 feet of LMR400. I [may have] been testing antenna SWR and propagation viability at Marine VHF frequencies, MURS, and in the case of the Comet antenna, GMRS. If the antenna is designed to work at the appropriate frequencies, you absolutely can use it with an HT, just as you would with a larger mobile radio. You'll still be somewhat limited by the quality (or lack thereof) of a $25 radio. But the external antenna will help a lot. Similarly, I've tested an MXTA26 6dbi GMRS antenna, MXTA25 3dbi GMRS, Comet CA-2X4SR-NMO, Laird TE B4505SN 5.1dbi GMRS, and HYS SDN1-T 3dbi GMRS antenna on my old Bronco, as well as on my trusty window air conditioner using the same UV-5G at GMRS frequencies, and in the case of the Comet, also at MURS frequencies. With the stock rubber ducky, and with a Nagoya 701G the Baofeng was barely audible five miles away with city terrain between. With the external antennas I was able to reach back home with varying levels of much better clarity than with the small HT antennas. Of course switching over to my 40w mobile made a huge improvement in this test, but it did go to show that external antennas can make a situation where an HT would barely get through into a situation where it can be heard. And finally, with a good external antenna at home hooked up to the Baofeng, I'm able to pick up simplex mobile radios ten miles away, and can work repeaters 64 miles away.

Ok that's a good reason to go with 3.

The article says this: Buy an FRS/GMRS capable radio or walkie-talkie and program the 307 channel into the radio Program to UHF 462.6125 Privacy Code 85.4 or Channel 3 and Privacy code 07 (307) Not exactly clearly written. It probably should have said: Buy an FRS or GMRS capable two-way radio. If it's a GMRS radio, get a license for your family. Set channel 3, or UHF 462.6125 Set the PL tone (privacy code, CTCSS tone) to 85.4. (07 on some radios, 307 on others). Stop by any state parks station, sheriff, police, or fire station to confirm your radio setup with a quick radio check. Switch over to a different channel and tone for your group communications, and back to this setting for emergency use. Place this sticker on your two way radio reminding you what channel and tone to use for emergencies. I wonder why they picked channel 3, limited to <=5w instead of 16, or 22, limited to <=50w. I know very few handhelds will transmit over 5w, but if a person in trouble manages to get back to their vehicle (possibly broken down), they may be able to get a signal out on 15-22 that wouldn't have been as clear on 1-7.

You can also listen to channels 15-22 Sunday afternoons, weekday evenings, and take notes if you find a net running. Sometimes they'll explain how to participate. You usually need to the squelch tones. But you may gain enough information to find someone to contact. Or if you have a scanner, you can set it to find the tones for you as you're listening to a net in progress. It takes more work, for sure. One time I heard a couple of people on a repeater say they're going to switch to simplex on 18, open. I switched over, and asked them about the repeater. They were happy to help.

No change to the ground plane when swapping in the duplexer. I do think that having an SWR <1.1 for both MURS and GMRS 467, and <1.4:1 for GMRS 462 without the duplexer is an indication that the setup is pretty well configured until I add in the duplexer.

I have a Comet CF-4160J Duplexer that accepts either two inputs (one in the 1.3MHz-170MHz range, one in the 350-540MHz range) to output to a single antenna, or that accepts one input to output to two antennas -- it works in either direction. The duplexer: Comet CF-4160J I have been testing it on a Comet CA2X4SR antenna. The antenna: Comet CA-2X4SR-NMO. With this antenna, no duplexer, in the MURS range, I get an SWR of <1.1:1. In the GMRS mains I get an SWR of <1.4:1. In the GMRS repeater inputs & interstitials, I get an SWR of <1.1:1. So pretty darn good results. Now add the duplexer. Antenna plugged into the duplexer. The radio plugged into one of the two frequency-ranged inputs. So plug the radio into the VHF side and test MURS: I get <1.2:1 SWR. Now plug the radio into the UHF side of the duplexer. In the main 467 frequencies, I get an SWR <2.3:1. In the repeater/interstitial frequencies, I get <1.1:1. My Surecom SR-102 is located inline between the radio and the duplexer. Here are the results in a more tabular format. SWR Meter between Radio and Antenna (NO DUPLEXER): MURS: <1.1:1 GMRS 462: <1.4:1 GMRS 467: <1.1:1 SWR Meter between Radio and Duplexer: MURS: Duplexer: <1.2:1. GMRS 462: Duplexer: <2.4:1 GMRS 467: Duplexer: <1.1:1. 2.4:1 is survivable. But it's strange that the duplexer seems to have very little effect on SWR at MURS frequencies, and at the 467s, but at the 462s it is markedly worse performing. Now if I move the Surecom to be inline between the duplexer and the antenna, instead of between the radio and the duplexer, I get the following results: SWR Meter between Duplexer and Antenna: MURS: <1.1:1 GMRS 462: <1.4:1 GMRS 467: <1.1:1 So the outlier is the GMRS mains in the 462 range, between the radio and the duplexer. Do I have a defective duplexer, or is this a pretty typical experience; that there may be rough spots at random places in the spectrum when using the duplexer?

If you know the frequency of the repeaters you're interested in gaining access to, you might try keeping your radio tuned to one or two of them (if it's dual-watch) in the evenings. Popular "net" times in my area seem to be evenings between 7pm and 9:30pm, and Sundays around 4-8pm. I know that's a lot of time to cover, but if you can just leave the radio on as you go about your day, you might hear a net start up. It's common during weekly nets for the net control operator to ask if there are any visitors wanting to check in. That's your invitation to state your call sign and introduce yourself, even if you haven't officially been granted access. And at that point you can ask what is needed to gain permission to use the repeater. If there are no nets, and the owner never responds to your request on mygmrs.com, but you DO know the CTCSS or DCS tone for the repeater, you can listen for traffic, and if you find someone having an idle conversation, wait your turn, and then state your call sign and ask how you might gain approval to use the repeater. If they tell you you're not welcome, you just apologize and go on with life. If someone announces their call sign and states "monitoring", that's also a way that people say they're looking for conversation. You can say "<your call sign> here, my name is <first name> from <city name>. I wanted to inquire about how to get approved to use this repeater.", and just see what happens. If you are polite, they may get you hooked up. Or they may tell you to not use the repeater, but it's worth a try.

Yeah, the limits of 5w in 462 interstitial, 0.5w in 467 interstitial, and 50w in the 462 mains are not necessarily desirable in a handheld. Nobody wants 50w next to their ear. But I think the assertion "most power allowed by law" on a radio that outputs (as their answer says) nearly 3w is misleading, and I can't think of any way to reconcile the statement with the actual FCC rules, which is why I sent them the question.