FRS/GMRS Privacy Codes Demystified

I have a love/hate relationship with FRS/GMRS radios. They are inexpensive, and you can buy them practically anywhere. They are great for the kids to play with, and are very useful when camping, boating, hiking, or driving in a convoy with your friends. However, the range is short and the antennas are not (usually) replaceable. Nevertheless they work pretty well as long as everyone has the same brand of radio. But if you are trying to talk to people who have different a different brand of radio than yours, things can get a bit trickier.

This page will probably help you out if:

The easiest way to make different manufacturer radios talk to each other is to put them on the same channel and turn off the privacy codes (or sub codes, or interference eliminator codes, or whatever your radio calls them). If you want to use a privacy code, keep in mind that they don't give you any privacy. You can usually pick one that's less than 38 and it will work. My guess is that you already tried it and it didn't work, so you went a searching and found this page.

Channels and Frequencies

Almost all FRS and GMRS radios use channel numbers as a substitute for the frequency (the Baofeng GMRS-50X1 lets you set the frequency directly). The frequencies and channels are defined by the FCC. Note that while FRS and GMRS share the same frequencies and channels, FRS radios are limited to lower power output. If you are only communicating over short distances and there are many nearby FRS/GMRS radios, you may be better served to use channels 8-14. On the other hand, if you want to maximize the distance of your communications, you should choose channels 1-7 or 15-22.

ChannelFrequencyFRS
Power
GMRS
Power
01462.56252 W5 W
02462.58752 W5 W
03462.61252 W5 W
04462.63752 W5 W
05462.66252 W5 W
06462.68752 W5 W
07462.71252 W5 W
08467.56250.5 W0.5 W
09467.58750.5 W0.5 W
10467.61250.5 W0.5 W
11467.63750.5 W0.5 W
12467.66250.5 W0.5 W
13467.68750.5 W0.5 W
14467.71250.5 W0.5 W
15462.55002 W50 W
16462.57502 W50 W
17462.60002 W50 W
18462.62502 W50 W
19462.65002 W50 W
20462.67502 W50 W
21462.70002 W50 W
22462.72502 W50 W
 467.5500 50 W
 467.5750 50 W
 467.6000 50 W
 467.6250 50 W
 467.6500 50 W
 467.6750 50 W
 467.7000 50 W
 467.7250 50 W

Many handheld FRS/GMRS radios do not transmit at the maximum power limit. For example, a Motorola T600 has a maximum transmit power of 1.5 W. My Cobra HH450 can transmit on GMRS at 1 W, 2 W, or 3 W.

In September 2017 the FCC combined and standardized the FRS and GMRS frequencies, which codified the common practice used by most manufacturers. Most radios built before September 2017 use the modern channel frequencies in the chart above. Some older GMRS only radios, like the Midland MXT105, don't transmit on channels 8-14 because those channels were previously designated as FRS only. The good news is that most of those radios just omit those channels from their settings. Channel 20 on the MXT105 works with everybody else's channel 20.

The last 8 frequencies in the chart, the ones without channel designations, are for use as repeater input frequencies. Most GMRS radios are designed for simplex operation and can't transmit on these frequencies. Which mostly doesn't matter because there are very few GMRS repeaters out there.

What is Squelch Anyway?

GMRS/FRS channels mostly just work no matter who manufactured the radio. However, it's not so smooth when it comes to the so called privacy codes. Motorola calls them interference eliminator codes. Uniden sometimes calls them sub codes. All these words are synonyms for either analog or digital squelch, and sometimes a synonym for both, which is unfortunate. If you are a ham radio operator, you probably know what squelch means. If the word squelch makes you think of that time you almost threw up and it went all the way to the back of your throat, don't worry, it's not that. Here's a metaphor to explain.

Say you have 10 friends all in the same room at the same time. You assign two of your friends code 1, two friends code 2, two friends code 3, and so forth. Everyone starts whispering except one person, who starts talking. It's easier for you to listen to the person talking, because they are louder than everyone else. That's squelch. Now, everyone starts talking at the same time. If you are assigned to code 4, you try really hard to only listen to the other person who is assigned to code 4. That's tone squelch. But if you really want to listen to the conversation going on between the two people assigned to code 5, you could do that too. In other words, squelch just tells your radio what to listen for, it has nothing to do with what is transmitted.

You can test this out for yourself if you have two FRS/GMRS radios. Set them both to the same channel, and then set one of them to use privacy code 5. Turn off the privacy code, or set it to 0, on the other radio. When you transmit on the radio with privacy code 5, you will still be able to hear the transmission on the radio with the privacy codes off. But when you transmit on the radio with the privacy codes off, the radio set to privacy code 5 won't be able to hear. It's not that the transmission wasn't sent, it's just that the radio is ignoring all transmissions without privacy code 5.

In real life, there are three basic types of squelch. The first is based on signal strength. The signal received by your radio has to be of a certain strength in order for your radio to decide it's important enough for you to hear it. Turn the squelch down and you will hear all kinds of fuzzy signals. Turn the squelch up and you will hear only the stronger signals. Most FRS and GMRS radios don't have this type of squelch setting.

The second type of squelch works by adding a low frequency tone to the transmission. The receiving radio ignores all signals that do not contain the specified tone. The tone is stripped out by the receiving radio before sending the signal to a speaker or headset. The real name for this method of transmission is Continuous Tone-Coded Squelch System or CTCSS. Most modern FRS and GMRS radios have CTCSS, but most of them don't call it CTCSS.

Digital Coded Squelch or DCS is the third type, and it works by adding a sub-audible digital bitstream to the transmitted audio. The bitstream is used to transmit a code along with the audio. The radio ignores signals that do not include a bitstream with the specified code. Many FRS and GMRS radios, especially the higher end models, have DCS, but like CTCSS, most of these radios don't call it DCS.

Privacy Codes

In an effort to avoid a long discussion like we just had about CTCSS and DCS, the FRS and GMRS radio manufacturers came up with different words to describe tone or digital squelch. Motorola uses "Private Line" or "PL" codes. They also use "interference eliminator codes". Radio Shack (remember them?) used to call them "quiet codes". Many manufacturers call them "privacy codes". These consumer friendly terms refer to both CTCSS and DCS. Which makes everything confusing when trying to figure out how to make radios from different brands talk to each other. To make the description easier from here on out, we'll just call them privacy codes. Just remember, they have nothing to do with privacy.

You don't have to use privacy codes. The easiest way to make your different brand radios talk to each other is to turn the privacy codes off. On many radios you turn the privacy code off by setting it to 0.

Some radios don't have privacy codes, like the Midland LXT118. That means you hear everyone on your channel, whether they use a privacy code or not. But it also means that nobody using a privacy code can hear you. They have to turn their codes off in order to listen to your transmission.

I love my Cobra HH450. It doesn't have the FRS-only frequencies because it has a detachable antenna; the FCC doesn't allow detachable antennas on FRS radios. It has the pre-2017 GMRS channels and it transmits and receives on the marine VHF channels. It's submersible and receives NOAA weather broadcasts. It's a great radio to take to the lake. Even better, it doesn't have "privacy codes". It has a way to turn on CTCSS and set the tone, or you can turn on DCS and set the code. This approach works great for a ham operator like me, but may be overwhelming for many who purchase these radios. So how do I know which privacy code to use on my Motorola MT351R when I set a CTCSS frequency of 88.5 Hz on the Cobra?

CTCSS-based Privacy Codes

CTCSS works by adding a low frequency tone to the transmitted signal. Radios configured to use CTCSS filter out any signals that don't contain the designated low frequency tone. There are more than 50 tone frequencies that work for CTCSS, but only 38 of them are commonly used on FRS or GMRS radios. A few radios (like the Cobra HH450, Jetstream JT270M, Baofeng GMRS-50X1 and Baofeng GMRS-V1) allow you to set the tone frequency directly. For most radios the manufacturer represents the various tone frequencies with a "privacy code". Lucky for us, they mostly chose the same assignments. The following chart shows a map between the CTCSS frequencies and privacy codes. The "Common" column is used by most manufacturers, including:

Freq (Hz)CommonCherokee
465
Motorola
Sport
Radio
Shack
Retevis
RB15
67.011 11
69.3 2   
69.4   2 
71.923 33
74.434 44
77.045A5 
79.756 6 
82.567 7 
85.478 8 
88.589B9 
91.5910 10 
94.81011 1111
97.41112C12 
100.01213 13 
103.51314 14 
107.21415D15 
110.91516 16 
114.81617 17 
118.81718E18 
123.01819 19 
127.31920F20 
131.82021 21 
136.52122G22 
141.32223 23 
146.22324 24 
151.42425 25 
156.72526 2626
159.8 27 27 
162.22628 2828
165.5   29 
167.92729 3030
171.3   31 
173.82830 3232
177.3   33 
177.8     
179.92931 3434
183.5 32 35 
186.23033 3636
189.9 34 37 
192.83135 3838
196.6 36   
199.5 37   
203.53238  41
206.5 39   
210.73340  43
218.13441  44
225.73542  45
229.1 43   
233.63644  47
241.83745  48
250.33846  49
254.1 47  

DCS-based Privacy Codes

Digital Coded Squelch works by transmitting a digital bitstream with the audio. The bitstream is encoded with error correction and can accommodate 512 different squelch codes. These codes are typically represented as an octal (base 8) number. However, because of the way the codes are packed into the bitstream, there is a possibility of misalignment errors upon decoding. To reduce the potential for decoding errors, most manufacturers only use 83 of the 512 codes. However, some Midland radios and the Baofeng radios can use any DCS code. In fact, the Baofeng and Jetstream radios can use inverted DCS codes (too complicated to explain here). Not sure why you would ever want or need that, so I've omitted them from the chart.

Many radios just have one set of numbered privacy codes, and you have to magically know where it switches from CTCSS to DCS. This is how my Motorola MT351R works. Privacy code 38 is CTCSS with a 250.3 Hz tone, privacy code 39 is DCS using code 023. The MT351R has 121 privacy codes, 38 CTCSS tones, and 83 DCS codes.

The DCS-based privacy codes have been implemented two different ways. Uniden, Motorola, and Backcountry Access just keep the privacy code numbers going, and switch from CTCSS to DCS at code 39. Midland and Cobra have a separate DCS mode, and the privacy codes start over at 1.

In this chart the "Common" column is used by the following manufacturers radios:

DCS
Code
Baofeng
GMRS-V1
CommonCobraMidlandRetevis
RB15
023D023N39111
025D025N40222
026D026N4133 
031D031N4244 
032D032N43555
036D026N  84 
043D043N44667
047D047N45778
051D051N46889
053D053N  85 
054D054N479911
065D065N48101012
071D071N49111113
072D072N50121214
073D073N51131315
074D074N52141416
114D114N53151517
115D115N54161618
116D116N55171719
122D122N  86 
125D125N56181821
131D131N57191922
132D132N58202023
134D134N59212124
143D143N60222225
145D145N  87 
152D152N61232327
155D155N62242428
156D156N63252529
162D162N64262630
165D165N65272731
172D172N66282832
174D174N67292933
205D205N68303034
212D212N  88 
223D223N69313136
225D225N  89 
226D226N70323238
243D243N71333339
244D244N72343440
245D245N73353541
246D246N  90 
251D251N74363643
252D252N  91 
255D255N  92 
261D261N75373746
263D263N76383847
265D265N77393948
266D266N  93 
271D271N78404050
274D274N  94 
306D306N79414152
311D311N80424253
315D315N81434354
325D325N  95 
331D331N82444456
332D332N  96 
343D343N83454558
346D346N84464659
351D351N85474760
356D356N  97 
364D364N86484862
365D365N87494963
371D371N88505064
411D411N895151 
412D412N905252 
413D412N915353 
423D423N925454 
431D431N935555 
432D432N945656 
445D445N95575771
446D446N  98 
452D452N  99 
454D454N  100 
455D455N  101 
462D462N  102 
464D464N96585877
465D465N975959 
466D466N986060 
503D503N996161 
506D506N1006262 
516D516N101636382
523D523N  103 
526D526N  104 
532D532N102646485
546D546N1036565 
565D565N1046666 
606D606N1056767 
612D612N1066868 
624D624N1076969 
627D627N1087070 
631D631N1097171 
632D632N110727293
645D645N    
654D654N111737395
662D662N1127474 
664D664N1137575 
703D703N1147676 
712D712N115777799
718     
723D723N1167878100
731D731N1177979 
732D732N1188080102
734D734N1198181 
743D743N1208282104
754D754N1218383105

Some Midland radios, like the T70 series, only have 83 DCS privacy codes. Others, like the MXT105, have 104. The first 83 are the same across all Midland radios, but if you pick code 99 on your MXT105, most other radios will have to disable privacy codes in order to hear you.

Hopefully this helps make sense of the sometimes confusing so-called privacy codes on FRS and GMRS radios. If your radio isn't listed here or if you can confirm or dispute any information on this page, I'd love to hear from you. Email correspondence, suggestions, corrections, or complaints to jared@k0tfu.org.

Changelog

9 Jun 2021

  • Add Retevis RB15 CTCSS and DCS mappings provided by Tom B.
  • Add Rockie Talkie mapping confirmed by Tom B.
  • Add the Wayback Machine link to Harold Melton's original page. Thanks to Tim W for the link.

13 Dec 2019

  • Add Backcountry Access Link radios based on information received from Eric KI7WJP. He owns one of these radios, and verified the privacy codes are numbered the same way as Motorola.

Feedback and Sources

This page was inspired by work originally done by Harold Melton KV5R. Unfortunately, his original link no longer works and I can't seem to find a replacement page on his site. However, his page is preserved by the The Wayback Machine.

I only have a couple of FRS/GMRS radios to test with and the original version of this article was mostly pieced together from owners manuals. Since then several people have written with additional information on new radios and tests with their own equipment. Thanks to everyone who had contributed.

I've collected all my data in this Google Sheet, including the simplified tables published in this post. I used Tableizer to create HTML tables because embedded Google Sheets look really terrible.

Contributors

Owners Manuals

Other Sources