Reluctance to use CTCSS/DCS

[kirk5056]

I have only been in the GMRS comunity for a year. I have noticed in this, and other forums, that people show a reluctance to use CTCSS/DCS (PL codes). Or the apparent belief that they are only for repeater use.

 

With GMRS radios we can transmit on 30 frequencies and listen on 22 frequencies. Using PL codes we increase those to 3-4,000 CHANNELS (freq + PL). Can some one enlighten me on the reluctance?

[mbrun]

I have only been in the GMRS comunity for a year. I have noticed in this, and other forums, that people show a reluctance to use CTCSS/DCS (PL codes). Or the apparent belief that they are only for repeater use.

 

With GMRS radios we can transmit on 30 frequencies and listen on 22 frequencies. Using PL codes we increase those to 3-4,000 CHANNELS (freq + PL). Can some one enlighten me on the reluctance?

Hello Kirk, and welcome to the forum!

 

I have been using FRS and GMRS off and on for nearly 20 years. This is the first time I have heard the suggestion of there being a ‘reluctance’ to use PL codes. You have me curious. What is the nature of the comments you’re hearing that give you this impression?

 

My personal perspective follows.

 

While I do use repeaters, my primary reason for having GMRS is simplex. There are times I operate both with and without PL codes. More often without them.

 

I use codes only when I am in an area where there is heavy use of the frequencies and I want to leave my radios on for extended periods but only want to hear traffic from my group. After all that is the reason PL codes came into existence in the first place. They provided a way for different businesses and other groups to share a frequency without having to listen to with each other’s conversations.

 

My personal experience has also shown that without codes, when in an area of low RF noise that the receiver will open squelch at a slightly greater distance without the code than with.

 

Then there is the “real” interference thing. Two people cannot operate on the same frequency without adversely affecting the reception by the intended listeners residing within their shared coverage area. This is true no matter how many PL codes there are. The use of codes masks the presence and use of the frequency by others. A knowledgable and respectful two-way radio user knows not to transmit when the frequency is in use. When PL codes are active it is easy to overlook the fact that someone else might be talking and complacency will result in unintentional interfering transmissions. If no PL code was being used, it would be pretty obvious if someone else nearby was using the frequency.

 

I hope this helps.

 

I look forward to hearing more about the reluctance.

 

 

Michael

WRHS965

KE8PLM

[Citizen]

No reluctance here.

 

Yes, I use repeaters with a PL to talk to friends outside my area.  But more importantly I use simplex to talk to family members (who are almost always within simplex range).  But family members just are not radio savvy, and so not to confuse things, I preset all radios to simplex with a likely unused PL.  That way I can hand anyone a radio and the only thing they have to worry about is PTT, and there I am on the other end of the line.

 

In fact, (mostly) the only time I use no PL at all, is when everyone else is asleep, and I start scanning frequencies to keep boredom at bay.

 

...

[Extreme]

They both took my answer. 

 

Coordinating PL codes can be a PITA when in a group of Jeepers, for instance.

[JohnE]

They both took my answer. 

 

Coordinating PL codes can be a PITA when in a group of Jeepers, for instance.

that is what "monitor" is for.

most radios have a button for monitoring (open channel) on them.

I do run my mobile in monitor most of the time as there are 4 other co channel users  on there.

[Extreme]

I'm not clear on your meaning.  How does this help coordinate PL codes in a group that wants to communicate among themselves?

MON on my radios is a momentary open of squelch.  How do you "run" the radio in Monitor?

 

that is what "monitor" is for.

most radios have a button for monitoring (open channel) on them.
I do run my mobile in monitor most of the time as there are 4 other co channel users  on there.

[kirk5056]

Thanks, everyone.  You make some good points.  I based my original comment, in part, on what seems to be the most made complaint on the forums: "I hear too much unwanted stuff-Christmas syndrome, businesses and highway flaggers".  I ONLY use PLs and never hear any of that.  Unless I am scanning, and then I want to hear unwanted stuff.

 

I read somewhere mostly in reference to trunked radio systems, that radios tend to be used 90-5-5%.  That is, when on, 90% do nothing, 5% listen to something you want to hear, 5% transmit.  So I have felt I am very unlikely to talk over someone on a different PL.  I hope I am not wrong, I really dont want to be impolite.  (BTW, after a whole life as an LEO, I think radio are closer to 98-1.5-.5% usage.)

 

So when I hear complaints like "I hear to much" or the the opposite "no one answers my calls" (I think because of unmatched PLs) i conclude people are reluctant to use PLs. 

 

Now I am reading about having a distress channel and usually suggested without PL.   A distress channel, also used as a "hailing" channel, is very much needed.  But no one will "watch" a channel without a PL and have to hear the other 125-150 conversations using PLs.  I have read that channel 20 (PL 22) was, or is, an unofficial distress channel.  WE should push that idea.  I "watch" that channel when I travel, just in case.

 

Sorry for the rant, thanks for the insight.

 

Kirk

WRHS673

[OldRadioGuy]

PL tones only work when you are far from the interference or other radio traffic and relatively close to your contact.

This rarely happens in my world but maybe does happen in urban areas.

 

When the PL tone is off you will hear everything on a channel including people with PL enabled.

I want to know when a channel is in use because I can probably change to one that's not in use.

So we almost never us PL tones.

 

It is a myth that PL tones can effectively create more channels.

This only works when you are in well separated "clusters" with members of each cluster relatively concentrated in a smaller area.

So all of "our" signals are strong among our group and "their" signals are weak.

 

I guess the other situation is where use is very infrequent so the odds of "doubling" are near zero.

 

Some other responders have also said this - in different ways. 

 

Vince

[kirk5056]

Radioguy

 

If PLs only work when your are far from interference and other traffic  then we never need them.

 

If you believe in the 95-5-5% then we are already near zero.  If we dont use PLs we will become CB.  Wild west,  If you are really worried, most radios have a "busy channel lockout".  If someone is talking when you PTT you will get bonked.

 

Businesses have using PLs to create "channels" for 50 years.  That is how trunked radio got its inspiration.

 

Kirk

WRHS673
 

[uhfvhf500]

I'm a simplex only user. Base to mobile. 

 

I prefer not to use PL tones because I'd rather hear everything that's on the channel. If someone is calling me, I'd like to know.

 

PL tones are just a filter that restricts your receiver , not "extra channels" as some radios may be advertised...

 

: )

[kirk5056]

If you can fit 120-150 conversations on the same freq at the same time and 98% of the time they don't know the others are there then they ARE extra channels. That is the beauty of GMRS over CB.

[kirk5056]

Thanks. This is what I wanted to learn. I did not mean to ruffle any feathers.

 

I like PLs and how they expand our radios. But I now see why some don't.

 

Thanks.

[BoxCar]

You can't have more than one concurrent conversation in the same area regardless of tones. They use the same carrier frequency which interferes with others. My radio indicates the channel is busy even though I don't hear the ongoing conversation.

[mbrun]

You can't have more than one concurrent conversation in the same area regardless of tones. They use the same carrier frequency which interferes with others. My radio indicates the channel is busy even though I don't hear the ongoing conversation.

I truly believe that a visual channel busy indicator should be FCC mandated on all GMRS and FRS radios. While the monitor button is mandated, the visual indicator is not. For the purpose for which I understand the FCC requires the monitor button, a clear visual indicator, like an LED would be far more effective and useful for letting users know the frequency is being used. I would imagine that it is seldom, if ever, that the typical user presses the monitor button to check for traffic before they press the PTT button. A one-cent part could make a huge difference.

 

 

Michael

WRHS965

KE8PLM

[Blackmar401]

If you can fit 120-150 conversations on the same freq at the same time and 98% of the time they don't know the others are there then they ARE extra channels. That is the beauty of GMRS over CB.

yes but you are definitely going to know they are there when you spend an hour trying to get one transmission back and forth. Wether your radio let's you know that it can't transmit or if you just don't get a response and keep trying over and over again

[OldRadioGuy]

Radioguy

 

If PLs only work when your are far from interference and other traffic  then we never need them.

 

If you believe in the 95-5-5% then we are already near zero.  If we dont use PLs we will become CB.  Wild west,  If you are really worried, most radios have a "busy channel lockout".  If someone is talking when you PTT you will get bonked.

 

Businesses have using PLs to create "channels" for 50 years.  That is how trunked radio got its inspiration.

 

Kirk

WRHS673

 

I don't understand all of your comments but let's do the math.

 

If the signals within my "group" are all 10db above the people outside my group (due to physical separation) we could walk within our groups at the same time without interference.

So in this scenario the "virtual channels" do work. 

You could have a distant signal that is not so much intelligible as bothersome.

 

But my whole point is that this situation is rather rare in my world. 

Also, your "privacy code" does not ensure any privacy for you.

Any radio with PL tones off will hear everything you say.

So it is maybe a false sense of privacy... if that's a thing.

 

I don't see how PL tones affect manners or protocol on the radio though.

 

I'm not telling anyone what to do.  Just pointing out the limitations of PL tones.

 

Vince

[OldRadioGuy]

Here's a good illustration.

Let's say everyone in my example is using an FRS radio so similar power levels.

 

Me and Bob are on the golf course only several hundred feet apart using one PL tone.

Down the road is a garden center using FRS radios and a different PL but same channel.

 

This will behave just like we are on different channels.

When I'm talking to Bob the garden center's signals are well below mine and Bob will hear me even when they are talking at the same time.

The reciprocal is also true.  The garden center people are close to each other and their signals will dominate withing their group.

So in this scenario PL tones work just the way we'd like them to.  It will be just like we are on different channels.

 

But this is probably not a real common situation.  That's my point.

 

Vince

[BoxCar]

Here's a good illustration.

Let's say everyone in my example is using an FRS radio so similar power levels.

 

Me and Bob are on the golf course only several hundred feet apart using one PL tone.

Down the road is a garden center using FRS radios and a different PL but same channel.

 

This will behave just like we are on different channels.

When I'm talking to Bob the garden center's signals are well below mine and Bob will hear me even when they are talking at the same time.

The reciprocal is also true.  The garden center people are close to each other and their signals will dominate withing their group.

So in this scenario PL tones work just the way we'd like them to.  It will be just like we are on different channels.

 

But this is probably not a real common situation.  That's my point.

 

Vince

You are both still causing interference to the other user. If the signal phases are enough out of alignment you will end up cancelling each others transmission. Yes, the field strength of the pair of transmitters in your example should overpower the other, there is no guarantee it will work as there are just too many variables to consider.

[n4gix]

All commercial radios support an "off hook" feature that will place the radio in "monitor mode" instantly whenever the microphone is picked up. This helps prevent doubling on top of ongoing communications.

[8nannyfoe]

I use a hybrid PL "system" to quiet a bunch of unwanted chatter, especially at campgrounds.  Use a channel as your "hailing" channel with your radios set to this hailing channel (simplex).   On this channel use a rare DTS PL code.  The only time anyone breaks that squelch you know exactly who it is saying "hello".   The other person quickly acknowledges they are on the air, by replying, "jump to alt"  Both parties know to go one channel down where no PL is set on that channel.  Once you are familiar with your area and channel usage you will find the correct channel setup that works.   This way we know we are not stepping all over someone else's convo during your convo because we can hear if there is another convo going on.  I tried the squelch/monitor thing in the beginning but it was somewhat inconvenient.   For some, they prefer not to listen to squelch while monitoring to see if someone is on the channel or continually holding down the monitor button.

[JohnE]

I'm not clear on your meaning.  How does this help coordinate PL codes in a group that wants to communicate among themselves?

MON on my radios is a momentary open of squelch.  How do you "run" the radio in Monitor?

it radio and program dependent.

my radios are Kenwoods and big M's all of that can be done in the RSS. also what N4GIX said.

[Extreme]

it radio and program dependent.

my radios are Kenwoods and big M's all of that can be done in the RSS. also what N4GIX said.

 

I run Kenwoods as well.  Guess I was unaware of the 'off-hook' feature.

[SteveC7010]

it radio and program dependent.

my radios are Kenwoods and big M's all of that can be done in the RSS. also what N4GIX said.

Let’s be clear, this just applies to mobile radios. It usually requires a programming change to enable or disable.

 

This same “off hook” feature can also be used to disable scan when the mic is picked up. Again it’s just an easy programming change.

 

With the exception of one public safety channel, I program Rx frequencies as CSQ which means I always monitor before transmitting. But then amateur and GMRS around here (Southern Adirondacks) is not heavily used anyway.

[OldRadioGuy]

You are both still causing interference to the other user. If the signal phases are enough out of alignment you will end up cancelling each others transmission. Yes, the field strength of the pair of transmitters in your example should overpower the other, there is no guarantee it will work as there are just too many variables to consider.

This is not AM.  It's FM and the "Capture Effect" will make one signal completely dominate unless they are very nearly equal.

Anything more than a few dB will do the trick and you will not be interfered with by the other signal.

In my example there is probably 20-40dB difference.  that would even work with AM.

 

Vince

[quarterwave]

The lovely people in the marketing departments at the manufacturers have helped muddy the waters on this subject.

 

Using PL/DPL (CTCSS/DCS) has nothing do with a channel or frequency per se. 

 

Prepackaged radios have referred to having X number of channels but what you find is the frequencies are just duplicated with different PL's. 

 

The basics are that you program a FREQUENCY into a CHANNEL on your radio and use it Carrier Squelch (Which is not the same as Open Squelch) and you can hear anyone on that FREQUENCY. They may hear you if they are not using PL.

 

If you add a PL to your programming, you will not hear anyone but your group of like programmed radios, other users will still hear you of they are running Carrier Squelch. Generally if running PL you should MONITOR (switch to Carrier Squelch or Open your squelch depending on your radio) before calling or starting a conversation. (Courtesy). 

 

In a group of multiple people, you would just designate a PL everyone would use or go Carrier Squelch. Otherwise PL, in my book, is a have-to on a repeater. Some operators prefer to use it on the input only and some prefer to mask the input PL by using a different one on the output, whereas the standard is the same in/out. It all depends on the amount of traffic, and how much you want to hear that doesn't concern you.  (Some radios do not allow split programming).