Can't access a repeater that uses CTCSS

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KO4AXL
Posts: 6
Joined: Sat Feb 11, 2023 3:26 am

Can't access a repeater that uses CTCSS

Post by KO4AXL » Sat Feb 11, 2023 3:33 am

I'm seeing a bug on my TYT MDuv380.
If I have a channel that has a ctcss of 100hz and I turn to it, it doesnt raise the repeater.
My baofeng has no problem opening its squelch when this radio tx'es using the 100hz tone so i know its sending it...or something close enough.

If I restart the radio while on that specific channel, everything will work fine. if I switch to another channel...usually 2-3 channels away....it breaks again.
Tried reflashing firmware, redoing codeplug, etc. nothing works.

VK3KYY
Posts: 7478
Joined: Sat Nov 16, 2019 3:25 am
Location: Melbourne, Australia

Re: ALPHA version - Known problems

Post by VK3KYY » Sat Feb 11, 2023 5:08 am

KO4AXL wrote:
Sat Feb 11, 2023 3:33 am
I'm seeing a bug on my TYT MDuv380.
If I have a channel that has a ctcss of 100hz and I turn to it, it doesnt raise the repeater.
My baofeng has no problem opening its squelch when this radio tx'es using the 100hz tone so i know its sending it...or something close enough.

If I restart the radio while on that specific channel, everything will work fine. if I switch to another channel...usually 2-3 channels away....it breaks again.
Tried reflashing firmware, redoing codeplug, etc. nothing works.
Did you check the Tx power.

i.e if your Baofeng validates that the UV380 is transmitting with 100Hz CTCSS, then I don't see how this is the problem, unless you are saying that the 100Hz CTCSS is not accurate

I presume you can open the repeater using the Baofeng transmitting

Did you check the Tx frequency of the UV380 ?

PS. I removed your duplicate post in another thread

KO4AXL
Posts: 6
Joined: Sat Feb 11, 2023 3:26 am

Re: Can't access a repeater that uses CTCSS

Post by KO4AXL » Tue Feb 21, 2023 1:26 am

Sorry for the late reply.

I think the CTCSS gets a little off when changing channels somehow.

Again, if I turn back to this particular channel and restart the radio it works fine and continues working until I turn to another channel.

I have checked the power settings and they say 5W. boosting to -W+ does not help.
No other CTCSS seems to do this except for 100Hz. No other channels show this issue except for those that use 100Hz.

settings for one of these channels:

TX 449.075
RX 444.075
CTCSS 100Hz
TX power 5W

VK3KYY
Posts: 7478
Joined: Sat Nov 16, 2019 3:25 am
Location: Melbourne, Australia

Re: Can't access a repeater that uses CTCSS

Post by VK3KYY » Tue Feb 21, 2023 2:43 am

KO4AXL wrote:
Tue Feb 21, 2023 1:26 am
Sorry for the late reply.

I think the CTCSS gets a little off when changing channels somehow.

Again, if I turn back to this particular channel and restart the radio it works fine and continues working until I turn to another channel.

I have checked the power settings and they say 5W. boosting to -W+ does not help.
No other CTCSS seems to do this except for 100Hz. No other channels show this issue except for those that use 100Hz.

settings for one of these channels:

TX 449.075
RX 444.075
CTCSS 100Hz
TX power 5W
What CTCSS frequency does your test equipment show that the radio is transmitting?

ON4NSP
Posts: 3
Joined: Wed Feb 22, 2023 4:36 pm

Re: Can't access a repeater that uses CTCSS

Post by ON4NSP » Wed Feb 22, 2023 4:40 pm

I'm trying to connect to an FM repeater using 131.8hz CTCSS. My Boafeng UV-5R opens the squelch and it works same repeater and others. On my RT3S the LED lights up, showing signal received, but the squelch doesn't open on the radio. If I press the monitor button on the channel I can clearly hear the comms. If I turn down the squelch to 0% it still doesn't open to hear anything.

Works fine on my DMR hotpost and on PMR channels with no CTCSS/DTS.

Any ideas?
Radio calibration issue in the new settings?
Last edited by ON4NSP on Thu Feb 23, 2023 10:15 am, edited 1 time in total.

G4EML
Posts: 919
Joined: Sat Nov 16, 2019 10:01 am

Re: Can't access a repeater that uses CTCSS

Post by G4EML » Wed Feb 22, 2023 8:44 pm

ON4NSP, Your problem is not the same as described by K04AXL. Your issue is with receive, his with transmit.

Are you certain the repeater is sending the 131.8Hz tone? Your description is what I would expect if your radio was set for 131.8 RX CTCSS but the repeater was not sending the tone or was sending a different one.

I have just tested the latest release and the CTCSS is working correctly as far as I can tell.



KO4AXL,

Sorry, I can't reproduce your problem. 100Hz CTCSS appears to always be working OK here. There is nothing special about 100Hz so if it works with other tones there is no reason I can see for it to not work with 100Hz.

100Hz is rarely used in Europe because it is sensitive to the second harmonic of the 50Hz mains, so any hum on a transmission can cause problems. However if you are in the USA with 60Hz mains that should not be a problem.


Colin G4EML

ON4NSP
Posts: 3
Joined: Wed Feb 22, 2023 4:36 pm

Re: Can't access a repeater that uses CTCSS

Post by ON4NSP » Wed Feb 22, 2023 9:28 pm

Hi thanks very much for the info and clarification. I'm going to double check both the send and receive tones again on all my local repeaters and codeplug. It does indeed make sense in theory that it's not being sent on receive, so hopefully that fixes it. I'll update tomorrow.
Last edited by ON4NSP on Thu Feb 23, 2023 1:35 pm, edited 1 time in total.

VK3KYY
Posts: 7478
Joined: Sat Nov 16, 2019 3:25 am
Location: Melbourne, Australia

Re: Can't access a repeater that uses CTCSS

Post by VK3KYY » Wed Feb 22, 2023 9:38 pm

ON4NSP wrote:
Wed Feb 22, 2023 9:28 pm
Hi Colin thanks very much for the info and clarification. I'm going to double check both the send and receive tones again on all my local repeaters and codeplug. It does indeed make sense in theory that it's not being sent on receive, so hopefully that fixes it. I'll update tomorrow.
IMO, its not normally necessary to set a Rx CTSS for repeater channels,unless you have a lot of QRM

AFIK. The main reason that repeaters use CTCSS on their input is to prevent them being keyed by QRM.
Old repeaters do not always transmit CTCSS on their output. I had an old FM repeater which I hoped to use for MMDVM, and it only had a CTCSS filter module in its receiver.

ON4NSP
Posts: 3
Joined: Wed Feb 22, 2023 4:36 pm

Re: Can't access a repeater that uses CTCSS

Post by ON4NSP » Thu Feb 23, 2023 10:14 am

VK3KYY wrote:
Wed Feb 22, 2023 9:38 pm
ON4NSP wrote:
Wed Feb 22, 2023 9:28 pm
Hi Colin thanks very much for the info and clarification. I'm going to double check both the send and receive tones again on all my local repeaters and codeplug. It does indeed make sense in theory that it's not being sent on receive, so hopefully that fixes it. I'll update tomorrow.
IMO, its not normally necessary to set a Rx CTSS for repeater channels,unless you have a lot of QRM

AFIK. The main reason that repeaters use CTCSS on their input is to prevent them being keyed by QRM.
Old repeaters do not always transmit CTCSS on their output. I had an old FM repeater which I hoped to use for MMDVM, and it only had a CTCSS filter module in its receiver.
Just tested it out again this morning, and yep you're totally right, it was the RX CTCSS set on repeaters that didn't need it setting in my codeplug. I've been trying to figure this out for weeks, and now it seems totally obvious! Thanks for your insights and experience. It's all running great now. Very happy with OpenGD77 and I recommend it to as many people as possible.

KO4AXL
Posts: 6
Joined: Sat Feb 11, 2023 3:26 am

Re: Can't access a repeater that uses CTCSS

Post by KO4AXL » Tue May 09, 2023 2:19 am

Hi all! Wanted to you you all know that the issue I had with ctcss was fixed with the last couple of firmware updates. Thanks for much for all your hard work!!

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