dosw

Birdies are usually focused on a narrow frequency, not across 1MHz of spectrum, aren't they?

What would be putting out a signal spanning so much bandwidth? Is this some device causing interference, or is it some form of spread spectrum transmission?

Consider the following graphic: In this graphic you'll see a thin red line. That's just where my SDR is tuned to listen. And then a wider red vertical band. That's how wide in terms of frequency bandwidth I have my SDR software set to listen. Within that faint red band is a jiggly band that grows wider and narrower. The bottom is the beginning of a transmission, and the top is the end of the transmission, in time. If I have my listening radio set to narrowband, that's similar to the faint red band being narrower. If that were the case, you would see some of the transmitted signal falling outside of the band in which I'm listening. So we're losing information. However, that also means that more of the faint red band is filled by radio waves (the jiggly band), so it will sound louder, though more distorted.

A couple years ago I was in a parking lot where there were parked a few plumbing vans. My 15w GMRS radio set off two of their car alarms when I pushed to talk. Strange how sensitive some things are. I never heard of GFCI plugs tripping though. That's wild.

Woah, hold your horses there pardner, you posted the same exact question three times within ten minutes. I'm sure it's a technical glitch, but whatever it is you're doing, less of that would be great. Can't answer the question, but I'm sure someone will answer one of the three instances of it.

Reach out to the owners of 2m or 70cm repeaters listed in your area; it takes a little research to find them, but they typically identify with Morse which will give you a call sign that you can use to find the owner. Or look in Repeaterbook, or on the band plan website for your region. A 2m/70cm repeater owner could help you through the process of finding a site (possibly the site they're using), getting in contact, and so on. Some hams are happy hams, and will help.

There's a spring kit available for it. https://www.dxengineering.com/parts/cma-ca-spr It's $22, which doesn't seem unreasonably expensive. It's too bad they don't sell a spring version to begin with.

I've also found that the CA2X4SR really needs a good ground plane. I tried it out with a GP01 kit from Nagoya, with the radials fully extended, and it stunk on 2m and wasn't great on GMRS. Installing it on a magnetic mount on a vehicle in the middle of the roof brought the SWR right down to where it should be. It might be because it's such a broad-band antenna, but it is not happy with a less ideal ground plane. With a good ground plane it's fantastic, covering 2m, MURS, 1.25m (even though it doesn't claim that band), 70cm, and GMRS.

DPL = Digital Private Line, which is a totally misleading name for DCS (Digital Coded Squelch). It is very similar to the also poorly named "PL" tones (Private Line, which they aren't), which are just CTCSS tones (Continuous Tone-Coded Squelcy System) tones. DCS and CTCSS are a way of layering in information to your transmissions that allows a receiving radio to hear that information and open squelch so the receiving party can hear you, and only hear people transmitting with the same tone. It works like this: Transmitting radio transmits your voice, and also a continuous "Tx tone". Receiving radio hears there is something being transmitted on the frequency. If it has an Rx tone set, it will only turn on its speaker and play what it's receiving if the Rx tone it has set is the same as the Tx tone you're transmitting. It would also turn on the speaker if it has NO Rx tone set. The Rx tone is an opt-in tool that the receiving user can set so that they don't hear everything that comes on a frequency, only those things that are accompanied with the correct tone. The tone, if it is CTCSS, is an actual sine wave tone in the lower audio-frequency range within the transmission. It will sound like a hum at a specific frequency; 123.5, for example means 123.5Hz. A DCS tone is a digital code transmitted along with the voice transmission, also in a lower audio-frequency range within the transmission. It will sound like a low-frequency buzz. Receiving radios apply a high-pass filter (low-reject filter) to make it so that you, the listener, don't actually hear the tone or code. If you were to listen through an SDR with the filter setting disabled, you would hear it. It's mildly annoying. Within DCS, N is normal, I is inverted, as has already been stated in this thread. And when the "N" isn't specified, it's implicit. Normal might mean you are transmitting 1010, and inverted would mean you're transmitting 0101. Unfortunately there are collisions, so N vs I doesn't mean a doubling of the number of possible encodings, but it does produce more than if you didn't have the option of inverting. 265, for example, may be 100001001. That would be the "N" encoding. If it were inverted (I) encoding, it would be 100100001 that gets transmitted. In reality it's not *quite* that simple of a protocol. The bit patterns contain parity bits, "always" bits, and the three-digit code, bits. https://mmi-comm.tripod.com/dcs.html . The patterns are 23 bits.

Wideband won't solve everything. When I transmit in wideband with my Retevis RA87, people sometimes tell me to speak up, that I'm coming through quietly. There's no gain control on that mic either. But you're certainly at a disadvantage right out of the gate if you have a narrowband radio transmitting to wideband radios.

The 275 doesn't have one. There's an upgraded mic you can buy for the 275 that provides "ANC" (Automatic noise cancellation), but it doesn't seem to provide AGC settings either: https://midlandusa.com/products/mxmc01-anc-microphone-for-mxt275-mxt575?variant=41996353929393 MXMC01 The reviews for this mic are quite good. But it's an expensive experiment, at $89, to find out if it actually improves the transmitting loudness. At half that price I would probably buy one to try out. I'd rather spend the $89 on a discone for my SDR.

Nooelec makes the HackRFOne, which starts around $320 and transmits at up to 15dBm (31.62mW, .032 watts, which is less than 1/10th the power of an FRS radio on channels 8-14. Any meaningful transmission would require an amplifier which will carry its own separate cost, and would mostly only be permissible on amateur radio frequencies (with appropriate amateur license).

Keep it simple: Get an SDR that allows from HF to upper UHF without needing to drop into direct sampling in the HF range. An example of that is the RTL-SDR v4. Direct sampling is poorer performance, so a model that doesn't require it for HF is nice to have. And that dongle is about $40 last time I checked. A single unit will give you 2.4MHz swaths of waterfall to watch, to see activity happening. And you can very easily move through the bands looking at the activity you might want to listen to. You'll learn to spot SSB, FM, AM, and digital transmissions; they all have characteristic looks in the waterfall. And you'll learn how to tune in and listen. There's a steep curve the first few days, and then it gets pretty easy.

Your radio transmits and receives in "narrowband" on all channels except the repeater channels, for which it shifts to wideband. I've confirmed this behavior through listening and through observing the bandwidth deviation in a TinySA spectrum analyzer. This is how the radio is designed. The net effect of this is that when you transmit to a radio in wideband mode you'll sound quieter. And when you receive from a radio in wideband mode, they will sound louder and possibly with more clipping distortion at the loud points. In repeater mode it shifts to wideband. I have heard that some people have asked Midland to reconfigure their radios for wideband only, though those discussions were a couple of years old, and even then, it seemed to differ by which support agent handled the query. These are good, solid radios. They have nice sound quality, and are very simple to use. But this is one quirk of the radio; in an effort to make it simple they precluded an option for setting wideband or narrowband yourself.

On a UV-5G or UV-5X channels 1-7 will be around 4w. Channels 8-14 will be around a half watt. Channels 15-22 will be around 4w. Your best FRS radio will be about 2w/0.5w/2w for those same channels. You get pretty good range outside the vehicle, you mentioned. And poor range inside the vehicle. A 771 antenna can help but it's not really the answer; I can't hold a 771 vertically inside my car, can you? The answer is to get an inexpensive magnetic mount antenna for each vehicle, such as https://www.amazon.com/dp/B09TPZ221K?ref=emc_s_m_5_i_atc (Nagoya UT72G). This is a 3dBi antenna, which is relatively low gain, but it's an all-in-one kit; the antenna on a magnetic mount, cable, and even an adapter for the radio, all for under $35. And it gets the antenna outside of the vehicle. Another alternative is to go all in; get an antenna such as the MXTA26 ($59), buy a mount for it ($29), and an adapter for your radio ($10), for a total of $98, per vehicle. That will get you one of the best mobile 6dBi antennas you can find for GMRS. But it's probably not necessary to go to that expense. Just getting your antenna outside of the faraday cage, known as the automobile interior, you'll achieve much better signal propagation. Mount the magnetic mount in the middle of the vehicle's roof, for each vehicle. There's no handheld that will do very well when its antenna is inside the vehicle. This all assumes, of course, that there's nothing wrong with your radios in the first place. But there probably isn't. In the end, spending more on the antenna than on the radio is rather par for the course. That's where you get the biggest improvement.

I have an RTL-SDR Blog V4. The V4 has one advantage over the V3: It can do HF without the pitfalls of direct sampling. It has one disadvantage as well: It requires updated drivers (free), which means a few additional steps for first-time setup. I think it's worth the trade-off to be able to do HF. There are lots of other SDRs, but most of the better ones are over $100. For "Better" you typically get broader bandwidth. The RTL-SDR, and most others in its price range will have 2.4MHz bandwidth. That means if you want to listen to GMRS in the 462 range, and in the 467 band at the same time, you would need two dongles and a way to share the antenna. For me, needing more than 2.4MHz bandwidth in my waterfall at the same time has not been a common use case. More expensive models may do better in the HF or may handle higher than 1.7GHz. They sell a version that comes with some antennas. That adds about $20 to the kit, and the antennas are worth about $20 (ie, they're not great). I use a Comet CA2x4SR for 6m-23cm (the antenna can receive okay from 50MHz to 1.25GHz). And I have a home made dipole cut for 20m that seems to work relatively well for receiving from 40m up to 10m. You will need your own cables and adapters. The basic kit is barebones; just the dongle. Software is free: SDR++, SDR#, SDRTrunk, SDRAngel, and other tools are all you'll need. But you do have to download and install it, and configure it for whatever SDR you own. A Windows or Linux computer will be fine. There is a Linux distribution that can be run from a thumb-drive, even, that is made specifically for simple SDR use. It's called DragonOS: https://www.rtl-sdr.com/dragonos-debian-linux-with-preinstalled-open-source-sdr-software/ I bought a few of the RTL-SDRv4 because I thought I was going to set up trunk-tracking for my area, and it spans more than can be covered with one or two dongles. I really don't use more than one or two, though. Almost always, one is sufficient. I've found that when I do use two, I have one set to 2m, and one set to 70cm, to listen to uplinks and downlinks simultaneously on ISS fly-overs. For antennas, a discone that covers from HF to GHz range is a really good way to go. Here's one that I am considering: https://www.amazon.com/300-Watt-Broad-Band-Scanner-Stainless-Transmit/dp/B00QVNI1V0?ref_=ast_sto_dp . Since you're only receiving with an SDR, it doesn't matter as much that the antenna has a higher SWR in bands that interest you, as long as it receives reasonably well. I also bought a few attenuators (40dB, 20dB, 10dB) so that I can plug directly into the SDR and measure power output (after calculating the power offset). But an SA like the TinySA or a power meter like the SW102 are probably easier to configure to work for this purpose. There is some overlap between a spectrum analyzer and an SDR, though. But an actual spectrum analyzer will sweep larger ranges more easily. Later I added a HamItUp Nano up-converter, even though the SDR has HF capability, because the HamItUp seemed to reach a little better into the lower ranges. You may eventually spend a little to get some band-reject filters for FM Broadcast and AM Broadcast. I don't use them all the time, but sometimes they're useful. It's just another avenue of exploring the radio hobby. You can start out with nothing more than an RTL-SDR and the antenna you already own, whatever that is, and an adapter. And then grow from there.

50w for 15-22 and repeater inputs. 5w for 1-7, 0.5w for 8-14, plus 8-14 have to be narrowband and should only be handheld. Bandwidth misconfigurations show up in the waterfall of SA or SDR equipment. But more importantly, can cause interference with the repeater inputs. Nobody can tell, if you're configured correctly.

I would have expected that laying it flat against the ground plane would cause it to reflect a lot. So I gave it a try. Standing up, at 465MHz, on a pizza-pan ground plane, it measured 1.6:1. Laid flat it measured 2.3:1. So it got worse, but not terribly so. Nevertheless, VHF and UHF FM is supposed to be vertical polarization. Orienting the antenna horizontally isn't going to really help anything except clearing your garage roof. However, at 2m, it got much, much worse. Something like 5:1. I didn't write it down. But standing in the upright position, in the 2m band, it's down to about 1.2.1. Your mileage may vary. Laying it flat against a larger ground plane, one with a radius large enough that the entire antenna is adjacent to the metal ground plane, is going to be a lot worse. Maybe bad enough that "some people" would be right. I know even in the vertical position, I was having reflection / high SWR issues when I put reflectix along side the antenna to cover the opening necessitated by a window air conditioner in sideways sliding windows.

Tones (PL, CTCSS, DCS, Tone Squelch): All of these are just names for a way to filter out unwanted transmissions so that you only hear the ones you want, and so that others only hear you if they either have no tone set, or set a tone and use the tone you're transmitting with: https://en.wikipedia.org/wiki/Continuous_Tone-Coded_Squelch_System PL: Private Line (But it's not actually private, so it's poorly named) CTCSS: Continuous Tone-Coded Squelch System DCS: Digital-Coded Squelch DPL: Digital Private Line (Not actually private. Same as DCS) TX/RX: Transmit, or Receive Often used in the context of tones: If you set a Tx tone, you transmit that tone so others can use it in filtering out those transmitting without the tone. If you set an Rx tone, you will only hear those transmitting with that same tone as their Tx tone. Repeaters usually require you to use a Tx tone so that the repeater wakes up and listens to you. Repeaters may use an Rx tone so you can set your radio to only hear a channel when the repeater is transmitting that tone. Often used in the context of reception: Example "My Rx is good, but nobody can hear me when I transmit", or "People hear me but my Tx is causing the radio to heat up." CCR: Cheap <Some country starting with "Ch"> Radio Funny thing is that almost all radios are made in that country nowadays, regardless of the price. And if not that country, some other country that is not the US. SWR: Standing Wave Ratio: https://en.wikipedia.org/wiki/Standing_wave_ratio Fars: A humorous term for describing how far a radio will communicate, paying attention to the fact that it is not typically reasonable to assert a given radio will transmit for a very specific distance in units like miles or kilometers. Rather than saying "Will transmit 38 miles", which is almost always incorrect for a given situation, people say "lots of fars" to indicate that the radio transmits about as well as any other radio, or "more fars" to indicate that with an antenna up high, the radio seems to have better propagation. Any other terms you need ad-hoc explanations for?

Just because you hear traffic doesn't mean you're hearing the repeater. What is the frequency of the repeater output for the lowest numbered repeater (identified in your radio at R1 or 15R)? 462.5500. What is the frequency of simplex channel 15? 462.5500. They're the same frequency. If you hear traffic on a channel, it could be one of the following: (1) The repeater you want to listen to. (2) Another repeater you don't want to listen to. (3) Simplex traffic. (4) Interference. If you have an output tone set, it is less likely that you would hear random simplex traffic, but not impossible. It's possible for someone else to be using the same PL tone, for example. Nothing prevents that. If you have an output tone set you will *probably* only hear the repeater you want to hear. But you aren't guaranteed to only hear it. If you don't have the TX tone set, the repeater that you want to hit won't listen to you. You mentioned that you have everything set up correctly, but you haven't actually confirmed that by getting an acknowledgement on the repeater. But here's a way that you can tell if you're set up correctly. Set two radios up for the repeater. Give one of the radios to a family member and send them a block or so away from your home. Transmit to the repeater. If they hear you, you're set up correctly. If they don't hear you, either you're not set up correctly, or you're not in transmit range of the repeater.

In addition to this, the inverter can be built into the generator. Inverter generators produce constant 60Hz despite fluctuating RPMs. At lower RPMs they produce less amps. (And less noise, and lower fuel consumption.)

In the case of no antenna the pin at the end of the feedline connector, and the feedline itself becomes the antenna. In the case of no antenna, the pin in the center of the radio's antenna connector becomes the antenna. In either case, I would assume a very high SWR. You could test that first scenario by putting a farsometer between the radio and the feedline, with no antenna attached, and observe. My Surecom isn't handy, but if I turn on my NanoVNA with nothing connected to the S11 connection, and set the display to SWR, it registers infinity, which may not be very good for a transmitter. When I put a section of 15 feet of RG58U on it, I get something like 70:1.

When you said 25' apart, one directly over the other, I wanted to confirm what you meant: You really meant a 25 foot vertical separation? That seems like a lot. But then I looked at this: https://www.repeater-builder.com/antenna/separation.html ...and it does seem that 20' is about right for 60dB isolation. Apparently that's measured at the center of the antennas, though. So if the antennas are 36", then the actual vertical space between them would need to be a minimum of about 17 feet. Am I understanding that correctly? It does seem like using a duplexer is a more effective solution. Putting one or the other of the antennas 17 feet lower on a mast seems bad for range/reception. And a $150 duplexer isn't more expensive than two antennas with two feedlines.

With antennas you can't be sure something won't work without testing. Here's an example of my mount that definitely doesn't work... It's never successfully worked a repeater 150 miles away. But it does hit one 65 miles away. Is that good enough? I've tested this setup with five antennas. It checks out on the SWRsometer (both a NanoVNA and a Surecom SW102), and it hits a repeater more than five dozen miles away. Sure, it looks terrible because it's on my beater camping Bronco. But it works very well. Part of what helps it work well is the fact that there is metal in all directions. The Jeep shown metal in all directions too. The slight gap in the metal doesn't make it not work. As for how to keep it from tilting, I had to bend mine a little, and I put a small shim on the inside, where the set screws are, to help it tighten correctly without lifting as much. Here's my install: 19G_vg1sb1V-nOztHafhwNhtVgMN9ggFa 19G_vg1sb1V-nOztHafhwNhtVgMN9ggFa

No. Entering 441.0000 into the radio and transmitting on that frequency is illegal unless you have a ham license, because 441 is between 420-450MHz, which are amateur/ham frequencies. You will be overstepping your license privileges. Additionally, by setting your H3 in a mode that allows it to transmit outside of the specific 22 GMRS channels and eight repeater channels, you have invalidated its type-acceptance for GMRS, and it is no longer a GMRS radio (unless you reset it back). Pretty much every frequency in the UHF / VHF bands belongs to someone else. It's very risky just punching in a number that you don't hear traffic on and hitting the push-to-talk. Your confusion is why GMRS radios are not supposed to be able to transmit on anything except for GMRS channels; to keep people who don't know better from making this mistake.