Open repeater behavior

[WRDU469]

Will an open repeater (Repeater with no tones) be triggered by a station on the same repeater channel but with programmed tones?

I am trying to understand if two repeaters in the same area are using the same channel, but one requires tones and the other does not, will the open (NO Tone) repeater open squelch when it receives a signal from a station using a Tone and repeat that traffic.

[Socalgmrs]

Yes it will.   That’s how it works. 

[WRYZ926]

Yes it will. 

There are two repeaters on 467.550 that are 100 miles apart. Now they do not interfere with each other since they are far enough apart. But I definitely receive both being half way between both repeaters. One repeater uses tones while the other one does not. 

I receive both repeaters but I never actually hear anything from the repeater without tones since I have tones set on my radios. If I were to turn the receive tone off on my radio then I would hear both repeaters.

[WRDU469]

This is all what I thought, thank you for confirming.

The only real solution that I can see to ensure someone only hears the repeater with Tones they want, is to make sure their channel is set to T-Squelch instead of just Tone. That will allow filtering for just signals with a specific Tone. 

[SteveShannon]

29 minutes ago, WRDU469 said:

Will an open repeater (Repeater with no tones) be triggered by a station on the same repeater channel but with programmed tones?

I am trying to understand if two repeaters in the same area are using the same channel, but one requires tones and the other does not, will the open (NO Tone) repeater open squelch when it receives a signal from a station using a Tone and repeat that traffic.

Yes it will, but the FM signals may still interfere with each other.  With AM it’s possible to actually listen to two signal on the same frequency. With FM the radio attempts to capture the strongest signal. The tone doesn’t prevent that because the tone has no effect on reception, just reproduction.

[WRYZ926]

35 minutes ago, WRDU469 said:

This is all what I thought, thank you for confirming.

The only real solution that I can see to ensure someone only hears the repeater with Tones they want, is to make sure their channel is set to T-Squelch instead of just Tone. That will allow filtering for just signals with a specific Tone. 

While you will only hear the one repeater by doing that, you will still receive the signal from the other repeater. You can see it on your radio if it has a signal meter. 

It's the same way on a repeater channel with tones set and someone close by transmits on the corresponding simplex channel without any tones. You won't hear the simplex transmission but you will still see it on the radio's signal meter. 

Just because you can't hear one of the signals does not mean that it will not interfere with the other signal that you can hear.

[WRDU469]

1 minute ago, WRYZ926 said:

While you will only hear the one repeater by doing that, you will still receive the signal from the other repeater. You can see it on your radio if it has a signal meter. 

It's the same who on a repeater channel with tones set and someone close by transmits on the corresponding simplex channel without any tones. You won't hear the simplex transmission but you will still see it on the radio's signal meter. 

Just because you can't hear one of the signals does not mean that it will not interfere with the other signal that you can hear.

That is what I have noticed as well. I think all this gets me what I need to know about my repeater situation. Fortunately, the no tone repeater in my area is much weaker and 45 miles away. So it's not a problem for most my users, but some. I am just surprised anyone would setup a repeater with no tones in general.

[SteveShannon]

9 minutes ago, WRDU469 said:

That is what I have noticed as well. I think all this gets me what I need to know about my repeater situation. Fortunately, the no tone repeater in my area is much weaker and 45 miles away. So it's not a problem for most my users, but some. I am just surprised anyone would setup a repeater with no tones in general.

Even if it had tones the risk of interference doesn’t decrease.  It should be on a different frequency.  Are there any open frequencies of the eight used for repeaters?

[WRYZ926]

I would go with a different repeater channel if all possible. The reason being is that anyone in-between the two repeaters will have issues from receiving both repeaters at the same time. I go through this all of the time being halfway between two repeaters.

[WRDU469]

Short answer is I have selected a repeater channel with the least traffic in my area. I monitored and researched out channels that would be appropriate, then determined a tone that would not conflict with other repeaters. The open repeater in question is very low traffic and in the distance. There is another repeater near by on a different tone and it does not appear to be problem with ours if the radios are setup correctly. There is just no clean channel we can use due to the amount of repeaters in our area and changing channels for our entire CERT and fire district at this point would be challenging.

 

[Raybestos]

1 hour ago, WRDU469 said:

This is all what I thought, thank you for confirming.

The only real solution that I can see to ensure someone only hears the repeater with Tones they want, is to make sure their channel is set to T-Squelch instead of just Tone. That will allow filtering for just signals with a specific Tone. 

The problem with (too) many repeaters with setting T-Squelch (your radio encodes a tone on xmit and decodes a tone on receive) is that some repeater owners (for reasons that defy all logic) choose to require a tone to access the repeater, yet do not encode a tone on the repeater output which allows the end-user to set their decoder and still hear that repeater.  This forces the end-user to set their CTCSS to encode a tone only and use carrier squelch for receive.  It is as though they just did not have that additional thirty seconds it would have taken them to program a tone on the repeater output.  There are several such repeaters here in South Carolina.

I have noted this issue with ham and GMRS repeaters.  Almost thirty years ago, some ham repeater owners may have had a decent excuse in that they needed an expensive or hard-to-find board or tone reeds to cause their repeater to encode a tone on its output.  These days, repeaters are programmable, just like ht's and mobiles, and all it takes is a few seconds of your time to program a tone on the output so end-users can enjoy setting their "T-Squelch" and keeping their receiver quiet until something on the local repeater comes in.

[nokones]

4 hours ago, SteveShannon said:

Yes it will, but the FM signals may still interfere with each other.  With AM it’s possible to actually listen to two signal on the same frequency. With FM the radio attempts to capture the strongest signal. The tone doesn’t prevent that because the tone has no effect on reception, just reproduction.

If my memory serves me right from my analog conventional simulcast system days, (and that was eons ago), it takes a difference between the two signals levels of 6 dB or greater for full capture.  Anything less than that you will get the warbles and wah wahs.