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Hey folks. I have had a small group of people ask me about tones and GMRS/FRS basics in the past week. I figured I would take one of the conversations here and share it for people new to the service. Hopefully it will help you understand Private Lines, Privacy Tones, sub-channels, tones and squelching methods, in general. I am only covering the two most popular in GMRS and FRS, but there are many others available as you move into different radio services and technology. Before we get into what all that stuff is, lets talk about why it exists. Per NOAA and the US Census Bureau, the lower 48 states is approximately 3.1 million square miles. Also, 83% of Americans live on 10% of the total available square miles and 40% of all US citizens live on the east and west coast in counties touching oceans. Following this logic, about 500,000+ licensed and unlicensed operators (estimated by me) are sharing FRS and GMRS radio space, in roughly 310,000 square miles. So, how does 500,000 people in close proximity, sharing 22 channels, all use their radios at the same time without interfering with each other? Motorola brings you PL tones! Lets get this out of the way... regardless of what the manufacturers may tell you or how they label their products, there is no privacy. Period. Private Lines (PL), Privacy Tones, Sub-channels and any other name for the same service, does not stop people from hearing you, it stops you from hearing them. I know... seems like a day in Opposite World, but that's how it works. I suppose the first thing to do is explain what the PL tones really are, what the more common types are and what each of them do. A traditional squelch is a signal level squelch. Meaning, no audio will come out of the speaker until a strong enough signal is received. Then there are also user squelch types. With analog radios, the most common type of user squelch uses encoding called Continuous Tone-Coded Squelch System or CTCSS. This feature is defined as being used to reduce the annoyance of listening to other users on a shared two-way radio channel. So, as mentioned above, its not that you as a person speaking have any type of privacy, but rather you don't have to listen to everyone on the same frequency. Hopefully the third time is a charm. Many GMRS and FRS radios only have simple CTCSS functions called Tone Squelch, often displayed as TSQL on the screen when enabled. This means two things. One is, regardless of what you do with your squelch knob or set your RF squelch to, no audio will come out of the speaker unless the tone you selected is embedded in the signal you are receiving. The other thing it does is, when you transmit, what ever tone frequency you have programed gets transmitted with/in your signal to unlock or open the squelch of other radios configured the same way. There is another method of CTCSS called "split tone". This means that you can use one tone when you transmit and another for your receive. This comes in handy when repeater owners are trying to limit who can access the repeater, as higher cost radios typically have split tone capability, compared to poorly built and inexpensive radios that would be problematic on a repeater do not. Also, this makes it a bit more difficult to "discover" the input tone by using scanning tools. Another function of split tone CTCSS is that you can also set your radio to transmit a tone to unlock a repeater or other radio, but leave your receive tone set to null (nothing). When this mode is enabled, there is typically a display on the radio that either reads TN or TONE. That means you can bring up a repeater or unlock a radio squelch, but also hear everyone else regardless of what tones they are running, if any at all. This is actually a great feature for GMRS radios since Repeater Channels share FRS frequencies and GMRS simplex frequencies. So you can tell if the frequency is in use as well as being able to talk to others who many not be using the repeater. CTCSS is an analog squelching system. There is also a digital squelching system called Digital-Code Squelch or DCS. It has similar use cases as CTCSS, but it is sending digitally embedded numeric codes instead of a sub-audible tone. I apologize in advance, but this next portion may get a little confusing. If you have questions, just ask and myself or one of the other knowledgeable members will be able to help. All of the numbers below are simply random samples I selected for example. Last I checked, there are 38 standard tones and an additional 13 expanded tones (not available on every radio) for a total possible 51 tones and 83 DCS codes. Along with the use examples above, you can get creative with DCS, because we are dealing with binary numbers instead of a tone. You can have the numbers used in a bunch of different combinations. For example, the number 411 in binary is 00110100 00110001 00110001. The reverse of this would be 11001011 11001011 11001110. So we are swapping the meaning of a 1 and a 0. So the combinations could be as follows: Normal-Normal = Transmit sends 411 and your radio squelch only opens when it receives 411 in the standard format 00110100 00110001 00110001. Reverse-Reverse = Transmit sends 411 reversed (or bit swapped) and your radio squelch only opens when it receives 411 reversed, meaning 11001011 11001011 11001110. Normal-Reverse = Transmit sends 411 standard binary format and your radio squelch only opens when it receives 411 in a reversed binary format. Reverse-Normal = Transmit sends 411 in a reversed binary format and your radio squelch only opens when it receives 411 in a standard format. Unfortunately, I am unaware of any radio's that have a DCS option to leave your user squelch open while transmitting a DCS code. If DCS is enabled, you cannot hear anyone else unless they are using the same DCS number and binary combination. CTCSS tones can also be "reversed". CTCSS tones, since its analog, we have a phase reversal, often called "reverse burst" when it is only reversed at the end of the transmission. (Something to Google in your spare time.) On some high-end radios, squelching can get really exotic. You may be able to create your own custom tone instead of using one of the standard tones. You may also be able to combine CTCSS tones and DCS codes. For example: User-CTCSS = Transmit 2600Hz tone, squelch opens with 2600Hz tone. (random number example) T-DCS = Transmit 141.3 tone, squelch opens with 411 code. DCS-T = Transmit 411 code, squelch opens with 141.3 tone. T-rDCS = Transmit 141.3 tone, squelch opens with 411 bit swapped code. rDCS-T = Transmit 411 bit swapped code, squelch opens with 141.3 tone. Now, here is the kind of disappointing part. Some manufactures try to make their equipment sound like something its not. They will use things like there own custom number code to identify a traditional CTCSS code. For example, Midland uses code number 22 (also known as a sub-channel) to indicate the tone 141.3. This makes coordination on tone selection a bit cumbersome between some brands. It also means that if your radio doesn't display the actual CTCSS tone or DCS code, you need to keep your owner's manual handy for reference. So... I don't know if that explanation made things better or worse. LOL Anyway, some companies use verbiage like "Privacy Tones" which adds to the confusion for some people. If you are using a true full CTCSS, it just means you are limited to whom you can hear, but everyone can still hear you. The examples I provided above for DCS are not what actually gets transmitted, but rather a conceptual process to help understand at a very basic level of what occurs, simply to understand the difference. DCS adds a 134.4 bps bitstream to the transmitted audio. To move past concept to the weeds, this video does a great job.

Yes thanks, hit it a couple days ago when initially setting up the radios. 7 min ago right at 2 pm PST I heard another transmitted voice id message though this time there was no time stamp. Thanks for the link!

Sorry, can't help with Baofeng programming, but can you hear BARN-R1? They transmit voice id message every 30 minutes or so, you'll be able to check if your receive frequency is programmed correctly, even if nobody on the repeater. Edit: SShannon posted while I was typing. Good troubleshooting steps.

don't forget your jumper from TX to the duplexer has loss. If you use a cheap jumper I have seen some with almost another DB of loss. Did the duplexer get tuned for the channel you are using ?

What does “duty cycle” mean? I bring up duty cycle every time I hear somebody talking about making a repeater out of cheap Chinese mobiles and worse any type of handhelds. Duty cycle is the maximum time an amplifier may transmit within a five minute interval, expressed as a percentage, to avoid overheating. Suppose a mobile amplifier is rated at 30% duty cycle. This means that it may transmit for no longer than 1.5 minutes and must remain off for not less than 3.5 minutes. Some people forget that a repeater is transmitting for 2 or more people, duty cycle will be reached quickly if you get into conversation. More people in the conversation just amplifies the issue. Once a radio reaches it's thermal design limits it will no longer be able to adequately cool the output transistors. Even if a radio is not hot to the touch the transistors are, in part because of the inefficient transfer of heat to the units housing or internal heat sink. The longer you exceed the duty cycle the more heat builds on the transistors, surrounding electronics and heat sink effecting it's ability to remain on frequency without spurious emissions. Exceed duty cycle long enough and you will need a new transmitter or radio. I have tested a few Baofang and TYT radios on my service monitor without great results. All of the radios started deviating outside of the allotted channel bandwidth after simulated conversation at 50% duty cycle, the longer I allowed this the worse if got. Testing was done using an Aeroflex 2975 IFR recently back from the calibration lab. GMRS is a tiny sliver of spectrum surrounded by the commercial land mobile part 90 service. It is important that any repeaters that are built or re-purposed are held to the highest standards and operated as to not cause any interference inside or outside of our allocated spectrum. I wont get into the part 90/95 debate but i do stand firm that non certified import equipment has no place on GMRS.

Thanks for the insight Marc! Much appreciated. I'll check out the links. Good to hear the mount will handle the power and now I have 2 alternative antennas. That's progress. Irony: I have the 771G for my HT but I think its a different connector, I'll have to look

I have no experience with the model you’re asking about, but in case you’re more interested in what the settings need to be rather than how to set them: I recommend leaving the CTCSS receive tone off until you are certain the frequency is correct. Once you’re certain the repeater is transmitting on the frequency listed you can always add the receive tone. By leaving the receive tone clear, you hear all transmissions on that frequency. Also, just in case you didn’t know, you transmit to the repeater at 467.550 MHz, 5 MHz above the frequency you receive. That’s commonly called the uplink frequency. You receive on the downlink frequency. So, to summarize, what I would do is this: 1. Simply set your receiver to listen on 462.550 MHz with no CTCSS Code. It may take some time if it’s not very active, but If the repeater is active this may confirm it. 2. Set the receive CTCSS to 141.3 Hz and listen until you’re certain you’re still receiving the repeater. If you no longer hear the repeater, turn the CTCSS tones off. You don’t need CTCSS to receive; they just filter out anyone who doesn’t send using the same CTCSS tone. 3. Finally, set the transmit frequency to 467.550 MHz with CTCSS of 141.3 Hz and transmit, using your call sign, to see if anyone hears you “This is wrph848 doing a radio check on (whatever the call sign of the repeater is)”. Listen for squelch tail, a slightly prolonged sound coming from the repeater after you let go of the PTT. Hopefully someone will hear you and tell you how you sound. I apologize if I’m misunderstanding your question. Good luck!

One antenna I like is the Comet CA-2X4SR. It's more than the MFJ but the usable bandwidth covers both ham frequencies and FRS/GMRS. It is available with either an SO239 or NMO mount option.

i'm rusty on hand programming a baofeng to say offhand what the button to push is, but after you program your receive frequency, you have to hit a button (i believe it's the asterisk), and go through the process again to program the transmit frequency (+5mhz, or 467.550). I don't see a mention of having set that separately. Miklor.com has some good step by step programming guides. https://www.miklor.com/COM/UV_ProgMem.php

Thanks to everyone that replied and offered suggestions. considering this thread closed

Michael, Please provide us with your definition of influencer. I saw the post as an announcement with nothing to indicate a person should purchase this item due to his standing in the forums.

Lower loss will require a larger duplexer. Most same size duplexers have about the same loss, in theory, that is The Fumei at 1.5dB sounds about right for a small mobile duplexer. I think the Fumei will be okay for now. (yes I said that!) 1.5 dB loss is not really much loss at all. If more range is desired, raising the antenna 10 feet would have more profound impact in range than swapping duplexer. G.

The thing about companders is that they intended to be used on all radios that are part of your communications circle. You don’t receive the full benefit except when your other party’s radios have the same feature and it is enabled their radios also. Michael WRHS965 KE8PLM

It's in your profile settings; from the "mygmrs.com" site hit edit profile, there's a toggle switch labeled "repeater access requests." turn it off (grey, to the left) and hit save profile.

You will spend more money on cable and connectors than the antenna many times. Spend more on the proper antenna. As gman1971 said terminate the cable where it breaches the building and ground with proper lightening protection (again $$) then run a smaller cable. If a short cable (under 10') is needed RG142 or similar could be used to the mobile/base/portable. With all of this said manage expectations. Using ham grade home made antenna and RG8 cable will not give you the benefits you hope for in most cases. There will be those that claim its better but YMMV. Determine your use case. If this is a repeater or abase for simplex spend the funds and do it right. If its just a way to hit a local repeater then you may not need what you are looking for.

Glad I could help, Yes, you probably don't want to run the anaconda heliax to the radio. Sorry for leaving this important bit out... what I do is run the Heliax up to the main ground plate, where all the N bulkhead connectors are (this plate is usually grounded), and on the other side of the bulkhead N connector I run short 4-feet patch cables of RG-400 with silver N-connectors to the filters, and then another 3-4 feet RG-400 from the filters to the radio/repeater. G.

Thanks for the link.

The other tell will be if you're picking up interference. I haven't found gmrs to be super prone to interference in my truck (older ranger clone), though I've heard more issues in jeeps. Power wise, that sounds about par with other reports on the mxt500's. @marcspazhas some direct experience in this thread:

Garmin already has something like this, its Tread ($800) plus Group Ride Radio ($350) https://buy.garmin.com/en-US/US/p/702373#specs https://buy.garmin.com/en-US/US/p/705043 It's based on MURS, where this is already allowed. You wouldn't be able to get the antenna to work in its current location with UHF and additional power if without exceeding RF exposure limits or making problems with the electronics.

IIRC, one is based in China, the other is the US based division - As I understand it, all the hardware comes from the same child slave-labor camp in the China desert. But I do recall reading that the slave-labor camp is now more child-friendly and every new piece of hardware is made with 25% fewer beatings. BTW - I do have an RT97 and its a great little box.