Radios with split tone capabilty using simplex

[DonErle]

This seems like an easy question, the answer eludes me. Now that I have several radios that allow split tones on repeaters w/o using programming software, what needs to be done when using simplex? Do both RX and TX codes need to bo entered? Or is changing the RX code good enough and leaving the TX code off?

[wayoverthere]

31 minutes ago, DonErle said:

So, if I understand you correctly, the answer to the above question is yes.

If you are using a RX code, the person you want to hear has to use the same TX code.

I think the best analogy is to think of the RX tone as a gate, and the tx tone as the key. No tones is like leaving the gate wide open, anyone can come in. If you want to get in when the gate is locked (RX tone set), you have to bring the right key (tx tone).

If you want to hear everything on the frequency when working simplex, you can just use no codes on either rx or tx. (The gate is open, so no key needed).

Does that make it a little clearer?

[mbrun]

This seems like an easy question, the answer eludes me. Now that I have several radios that allow split tones on repeaters w/o using programming software, what needs to be done when using simplex? Do both RX and TX codes need to bo entered? Or is changing the RX code good enough and leaving the TX code off?

Good Morning Don

Because you combined split-codes and simplex into the same question one might assume you are envisioning you have need to use split-tones while using simplex. That could be a wrong interpretation of your real question. If so, please clarify.

While split-tones have their place for repeater use, split tones are rarely (if ever) needed when operating simplex. If a tone is used when operating simplex, all radios in the group that are expected to be able to communicate with one another would typically all use the same tone and this would be used for both Tx and Rx in all radios. In this scenario everyone in the group would be able to communicate with everyone else in the group. Everyone transmits the same code, everyone’s squelch opens up when they receive a signal containing that code.

While there may be some edge/esoteric or “just because I can” reason, I can think of zero practical day-to-day reasons why someone needs (or wants) to run split-tones on simplex. If they are used, it would create a situation where only two radios could effectively communicate. Because the Rx tone on one radio would be aligned with the Tx tone on the other. Both radios are therefore are programmed differently. If you added a third radio, it then would only able to communication with one of the other two radios. Not a viable thing when communication is your goal. If you had a large group of radios programmed this way, then only one person would be able to hear all other radios and communicate with all others. Think circle/start configuration with one radio in the middle and all others on the perimeter. The person in the middle could communicate with everyone on the perimeter. Those on the perimeter could not communicate with each other, but could communicate with the person in the middle.

If you are thinking that perhaps if you used split tones that would somehow make your communications between two radios private, that would be incorrect. Tones provide zero privacy. Tones provide a mechanism to keep the squelch closed on your radio until you receive a signal containing that tone. They provide a means for you to ignore (not have to listen to) others that are not part of the group you want to listen to.

I hope this helps.


Michael
WRHS965
KE8PLM

[BoxCar]

If his tone is on receive, then your radio needs to transmit the tone. Having no tone on your radio's receive will allow you to hear him whether or not he sends a tone.

[WyoJoe]

If you have a receive code set on one radio, the other radio will require that you set the same code on transmit in order to open the squelch on the receiving radio. If you turn off the receive code, then you don't need a code on the transmitting radio either. Basically, your settings are determined by the receiving radio. If a code is set, then the radio rejects incoming transmissions unless the transmitting radio is sending the code required by the receiving radio. If the receiving radio's code is off, then it should receive any transmission on that frequency, regardless of whether or not the transmitting radio is sending a code.

[DonErle]

12 hours ago, DonErle said:

 Do both RX and TX codes need to bo entered?

So, if I understand you correctly, the answer to the above question is yes.

[DonErle]

My question was more basic. I do understand how squelch tones work. My buddy has a Midland MXT400. On those radios you can only set a single tone for a channel. Let’s say he uses a CTCSS of 118.8 on simplex channel 16. I have a KG-1000G radio. Do I need to set a CTCSS of 118.8 on both RX and TX? I was expecting a yes or no answer.

[mbrun]

My question was more basic. I do understand how squelch tones work. My buddy has a Midland MXT400. On those radios you can only set a single tone for a channel. Let’s say he uses a CTCSS of 118.8 on simplex channel 16. I have a KG-1000G radio. Do I need to set a CTCSS of 118.8 on both RX and TX? I was expecting a yes or no answer.

Yes, You need to separately set Tx and Rx tones.


Michael
WRHS965
KE8PLM

[djxs]

@DonErle: I am glad that your question was answered. Wow, I am learning so much everyday day. I would like to chime in with a question if I may? Since we now learned that the answers to @DonErlequestion : 

Quote

My question was more basic. I do understand how squelch tones work. My buddy has a Midland MXT400. On those radios you can only set a single tone for a channel. Let’s say he uses a CTCSS of 118.8 on simplex channel 16. I have a KG-1000G radio. Do I need to set a CTCSS of 118.8 on both RX and TX? I was expecting a yes or no answer.

I then have a follow up question. Are not all radios programmed with "standard" channels? I see some people refer to channels as frequencies, while others refer to them as channels? Are having "simpler" channels a way to make "newbies" more comfortable with using the GMRS radios? 

 

I was looking at this handy dandy FRS/GMRS Radio Quick Reference Card (click). It seems to show a channel and a frequency. Was it someones attempt to make it easier? Thanks everyone.

[mbrun]

[mention=4813]DonErle[/mention]: I am glad that your question was answered. Wow, I am learning so much everyday day. I would like to chime in with a question if I may? Since we now learned that the answers to [mention=4813]DonErle[/mention]question : 

My question was more basic. I do understand how squelch tones work. My buddy has a Midland MXT400. On those radios you can only set a single tone for a channel. Let’s say he uses a CTCSS of 118.8 on simplex channel 16. I have a KG-1000G radio. Do I need to set a CTCSS of 118.8 on both RX and TX? I was expecting a yes or no answer.

I then have a follow up question. Are not all radios programmed with "standard" channels? I see some people refer to channels as frequencies, while others refer to them as channels? Are having "simpler" channels a way to make "newbies" more comfortable with using the GMRS radios? 
 
I was looking at this handy dandy FRS/GMRS Radio Quick Reference Card (click). It seems to show a channel and a frequency. Was it someones attempt to make it easier? Thanks everyone.

The simple answer to your question regarding channelization is YES, channelization is an attempt to simplify radio for the masses. And it certainly has merit and works well for the masses. Channel ‘15’ is a lot easier to remember for most folks than remembering 462.5500 MHz in the GMRS. In its most simple form, a channel is a simply an alias way of express a frequency.

A channel can be more than just one frequency. Channel 15 in the Citizen’s band radio service is not the same as Channel 15 in the GMRS. Similarly, Channel 15 in terrestrial TV broadcast is different from 15 in CB, GMRS and every other RF communication service.

In its more advanced form, a channel is actually a group of settings what when used together enable some form of RF communication to occur between a transmitter and receiver. If the receivers settings complement the transmitter settings communication can occur. Depending upon the radio and service, the channel will include such things as a frequency and other factors such as modulation type (AM, FM, etc.), modulation depth (bandwidth), squelch codes (PL, DLC, CTCSS, DCS) and many other settings.

A programmable radio has memories. Memories in most cases are synonymous with ‘Channel’ as well since each memory holds a frequency assignment and all the other necessary factors to enable communications.

No, not all radios have standard channels programmed into them, but that is certainly something the FCC is trying to make happen a manufacturer wishes to get their radio certified for using in the Personal Radio Services under Part 95 of the rules. As you look at the current crop of part 95E GMRS radios you will see that they do in-fact have factory-programmed memories preset to use the standard GMRS frequencies so that no additional programming is required to use the radio. Programming of additional memory configuration (i.e. channels) becomes optional.

Hope this helps.


Michael
WRHS965
KE8PLM

[djxs]

44 minutes ago, mbrun said:

I then have a follow up question. Are not all radios programmed with "standard" channels? I see some people refer to channels as frequencies, while others refer to them as channels? Are having "simpler" channels a way to make "newbies" more comfortable with using the GMRS radios? 
 
I was looking at this handy dandy FRS/GMRS Radio Quick Reference Card (click). It seems to show a channel and a frequency. Was it someones attempt to make it easier? Thanks everyone.

The simple answer to your question regarding channelization is YES, channelization is an attempt to simplify radio for the masses. And it certainly has merit and works well for the masses. Channel ‘15’ is a lot easier to remember for most folks than remembering 462.5500 MHz in the GMRS. In its most simple form, a channel is a simply an alias way of express a frequency.

A channel can be more than just one frequency. Channel 15 in the Citizen’s band radio service is not the same as Channel 15 in the GMRS. Similarly, Channel 15 in terrestrial TV broadcast is different from 15 in CB, GMRS and every other RF communication service.

In its more advanced form, a channel is actually a group of settings what when used together enable some form of RF communication to occur between a transmitter and receiver. If the receivers settings complement the transmitter settings communication can occur. Depending upon the radio and service, the channel will include such things as a frequency and other factors such as modulation type (AM, FM, etc.), modulation depth (bandwidth), squelch codes (PL, DLC, CTCSS, DCS) and many other settings.

A programmable radio has memories. Memories in most cases are synonymous with ‘Channel’ as well since each memory holds a frequency assignment and all the other necessary factors to enable communications.

No, not all radios have standard channels programmed into them, but that is certainly something the FCC is trying to make happen a manufacturer wishes to get their radio certified for using in the Personal Radio Services under Part 95 of the rules. As you look at the current crop of part 95E GMRS radios you will see that they do in-fact have factory-programmed memories preset to use the standard GMRS frequencies so that no additional programming is required to use the radio. Programming of additional memory configuration (i.e. channels) becomes optional.

Hope this helps.


Michael
WRHS965
KE8PLM

@mbrun: Sir, your answer does in fact help me out. Thank you a million times over. What a clear explanation. I appreciate your knowledge, time and help.

[WRNA710AZ]

99.9% of the time, simplex will be used with carrier squelch, not tones at all.

[JarrGen]

Good afternoon. A little late but I was scanning the forum and thought to add this...

While the channels are being standardized or made common, the CTCSS and DCS squelch tones are not necessarily. I came across this reference which will explain multiple times better than me I think. 

Clipped from: https://www.k0tfu.org/reference/frs  (Web view) 

The title is FRS/GMRS Privacy Codes Demystified 

I copied the whole page to my OneNote where I have been keeping all of my tidbits from these forums for GMRS and now also on the ham and DMR side. When you get about half way down, it says what tone "sub-channel/privacy code" (not sure there is an agreed/common term here yet) which lays out how different manufacturers have used/not used/ assigned the frequencies to assigned numbers on their radios.