2 meter simplex question

[NWI_Scanner_Guy]

I know I should probably know the answer to this question, but I'm down with the flu and my brain is not firing on all cylinders at the moment.

When using a simplex frequency, it's okay to use a PL tone, right?

I was searching through the 2 meter band earlier today, and came across a conversation on 145.7300 with a PL of 100.0. I don't think that's a repeater frequency, so the use of a PL kinda threw me off.

My flu addled brain thanks you.

 

[n5ims]

Nothing prevents the use of a PL on simplex (and at times it's a good idea), but it may limit who you're able to talk to. If you use a PL and call CQ you may get lots of responses, but only hear those that have the same PL tone you're using. When it makes sense is when you have some type of interference (intermod, for example) that might hinder your conversation. In those cases, you'll probably want to start out without a PL and turn it on once the conversation has started (along with those that you're talking with).

 

[nd5y]

There is nothing wrong with using tone squelch on simplex.
A lot of us run simplex VoIP nodes with PL or DPL.

 

[kb2vxa]

There's only one catch and here's an example. Some years ago there was a group that camped out on a frequency using PL transmit and receive, fine for them monitoring without hearing others on the air but they never turned it off to check if the frequency was in use or while in QSO. That annoyed the heck out of everybody else when they came on clobbering QSOs in progress and ignoring attempts to ask them for a break so someone could make a call, very poor operating practice if not in violation of a rule or two. There's a term that fits; lids.

I guess there is nothing wrong with using PL on simplex if you don't think being rude and disruptive isn't wrong, trouble is everyone else will disagree with you.

 

[mmckenna]

I use a PL tone on our base radio in the kitchen, but only on the RX side. We leave that radio on 146.415 simplex 24x7. We use it for calling home if on the road. We didn't want to listen to the very occasional QSO's that would pop up on that frequency. We program the rest of the radios to TX with a PL tone, but leave the RX in carrier squelch.

All of our radios are set up to switch to carrier squelch when the microphone is taken off hook. That is certainly a benefit to using commercial gear. I have not seen an amateur radio built recently that had that function.

 

[LtDoc]

Take a look at what those 'PL' tones do. Transmitting one typically turns something 'on/off'. If whatever it turns on/off needs to be turned on/off for whatever reason then it's a good thing to do. If it isn't needed it's usually not going to do anything 'wrong'. A 'received' PL tone turns YOUR receiver on/off. That means it limits what you can hear, which can certainly be a huge disadvantage at times (interfering with a conversation already there?). It does have a purpose, but it's a very limited one and in most cases a bad idea (also called that 'toned squelch').
- 'Doc

 

[NWI_Scanner_Guy]

Thanks, everyone, for the replies.

 

[Ed_Seedhouse]

The most popular use of CTCSS for simplex around here seems to be on the "family band" as most of these FB low power transceivers have tones built in. We have extensive use of simplex frequencies in my area (Victoria B.C.) for local safety communications on two meters, but CTCSS is never used for this.

 

[bill4long]

When using a simplex frequency, it's okay to use a PL tone, right?

Yes. And you can use DCS too. And you can use DTMF bursts. Etc.

 

[KB7MIB]

Wirelessly posted (Mozilla/5.0 (X11; Linux i686; U; en-US) Gecko/20081217 Vision-Browser/8.1 301x200 LG VN530)

Check with your local/regional/state coordination body. There may be a bandplan in place which puts Echolink/IRLP/etc on simplex freqs (like they do here in AZ) and they do use a CTCSS for that.

 

[bill4long]

^^^ Good advice