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Trying to see if I'm hitting a repeater or not


elevate36

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I know this is probably an easy question to search for, but I can't find any that answer this specifically. I just got my GMRS license and am trying to see if I can hit any repeaters near me (in CT). I don't have a ton of hope because CT is full of hills and mountains, although I do see a few on the map that seem to cover really large ranges.  I am trying to connect to one near me after I input the Rx and Tx CTCS codes. When I hold the PTT button, it shows full signal strength on the radio, but I am unable to hear any noise/morse code, etc back from the repeater (or anyone talking on it).  Does that mean that I am not hitting the receiver? What does the full signal strength in the radio show in this sense? 

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2 minutes ago, elevate36 said:

I know this is probably an easy question to search for, but I can't find any that answer this specifically. I just got my GMRS license and am trying to see if I can hit any repeaters near me (in CT). I don't have a ton of hope because CT is full of hills and mountains, although I do see a few on the map that seem to cover really large ranges.  I am trying to connect to one near me after I input the Rx and Tx CTCS codes. When I hold the PTT button, it shows full signal strength on the radio, but I am unable to hear any noise/morse code, etc back from the repeater (or anyone talking on it).  Does that mean that I am not hitting the receiver? What does the full signal strength in the radio show in this sense? 

I'm fairly new to this, but don't be surprised if you don't hear morse code or any traffic on the repeater. The one in my area is quiet 99% of the time, but the owner does monitor it quite a bit I think...he's the only contact I've made on that repeater.

If you are hitting the repeater, you should hear some noise (the kerchunk) of the repeater after you unkey the mic. If you know you are in range of the repeater and you're outside (definitely not in a car if you're using an HT), it's a good way to tell if your radio is configured properly. Even better if you can establish line of site to a repeater. I would also suggest taking the tone off the repeater output frequency to make sure.

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19 minutes ago, elevate36 said:

I know this is probably an easy question to search for, but I can't find any that answer this specifically. I just got my GMRS license and am trying to see if I can hit any repeaters near me (in CT). I don't have a ton of hope because CT is full of hills and mountains, although I do see a few on the map that seem to cover really large ranges.  I am trying to connect to one near me after I input the Rx and Tx CTCS codes. When I hold the PTT button, it shows full signal strength on the radio, but I am unable to hear any noise/morse code, etc back from the repeater (or anyone talking on it).  Does that mean that I am not hitting the receiver? What does the full signal strength in the radio show in this sense? 

A good rule of thumb is to always leave the receive tones out when first configuring your radio for a repeater.  Any tones you enter for receive filter your reception and could hamper your ability to hear the repeater.  If you enter the correct receive frequency, but no receive tones, you will receive everything transmitted on that frequency that is within range. If you’re not sure if you’re in range, get closer.

Seeing your meter deflect while you press PTT, probably means the transmitter is transmitting, unless it’s an SWR meter during transmit. Your radio does not receive while it’s transmitting.  Seeing the meter deflect when you’re not transmitting can be an indication of signal strength, assuming that’s what your meter is set to indicate.

Knowing the radio you’re using helps us to help you more easily.

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Thanks for the replies. In messing with it further and going outside, I was able to hear the kerchunk with 1 bar of signal on my GM-15 Pro but unable to hear anything with my UV-9G. I think I may have a bad UV-9G as my NOAA and FM tones come in pretty poorly compared to the GM-15 Pro also. I'm glad I'm able to hit the repeater with one radio at least. Maybe getting a better antenna would help. 

That is an interesting note about leaving the Rx tones off as well, I didn't know that. So can one listen in to any repeater just by connecting to the correct frequency since no tones are needed? Of course transmitting requires the correct tone, just want to make sure I am understanding it correctly. 

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1 minute ago, elevate36 said:

Thanks for the replies. In messing with it further and going outside, I was able to hear the kerchunk with 1 bar of signal on my GM-15 Pro but unable to hear anything with my UV-9G. I think I may have a bad UV-9G as my NOAA and FM tones come in pretty poorly compared to the GM-15 Pro also. I'm glad I'm able to hit the repeater with one radio at least. Maybe getting a better antenna would help. 

That is an interesting note about leaving the Rx tones off as well, I didn't know that. So can one listen in to any repeater just by connecting to the correct frequency since no tones are needed? Of course transmitting requires the correct tone, just want to make sure I am understanding it correctly. 

Try exchanging the antennas to see if that helps (assuming they both use the same gender of SMA connector.)

 

Yes, the tone acts as a filter.  No set receive tone means nothing on that frequency is filtered out.

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Got it, thanks again. I just watched a video on the difference between GMRS and Repeater channels which helps make sense of how the tone filters work. Another question related to this, and maybe a bit too technical, but I understand that repeater channels have two frequencies, one for receive, one for transmit. When you choose a repeater channel, you are transmitting to their receiving channel.  It then repeats the signal and transmits it on a different frequency with a 5 mhz offset that your radio is ready to hear.  Why is it that you don't hear your own voice played back when you speak into a repeater then? Or am I misunderstanding this somehow 

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38 minutes ago, elevate36 said:

Got it, thanks again. I just watched a video on the difference between GMRS and Repeater channels which helps make sense of how the tone filters work. Another question related to this, and maybe a bit too technical, but I understand that repeater channels have two frequencies, one for receive, one for transmit. When you choose a repeater channel, you are transmitting to their receiving channel.  It then repeats the signal and transmits it on a different frequency with a 5 mhz offset that your radio is ready to hear.  Why is it that you don't hear your own voice played back when you speak into a repeater then? Or am I misunderstanding this somehow 

Handheld radios and mobile radios are not usually capable of receiving while transmitting.  In order to receive distant transmissions, the receiver circuit must be sensitive to millionths of volts.  Your transmitter is capable of putting out a lot more than that.  They're both connected to the same antenna, so when your transmitter transmits, that power would overwhelm your receiver. So, while transmitting, your receiver is effectively disabled.  Depending on the convention (and whom you're talking to) that's either called half-duplex or simplex.

Repeaters however, must be able to transmit and receive at the same time in order to do their job.  That's referred to as full-duplex.  But the problem still remains; how do you keep the transmitter power from overwhelming the receiver.  So they transmit and receive on two different frequencies and a special device called a "duplexer" provides even more isolation.

So, a repeater transmits into a duplexer.  The duplexer filters out everything except the frequency being transmitted (as much as it can) and routes that signal to the antenna.  Simultaneously, the antenna is picking up signals over a wider bandwidth, which go to the duplexer.  The duplexer filters out everything except the frequency that the repeater must receive, which it sends to the receiver.  A duplexer is like a traffic cop.  In order for the duplexer to do a good job, both sides of it must be pretty precisely tuned and it must be capable of aggressively filtering both signals.

If your handheld or mobile radio had a duplexer, you would be able to hear what the repeater is transmitting at the same time as you are transmitting. 

That should also make you appreciate the fact that cell phones are full duplex.

Does that help?

 

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48 minutes ago, Sshannon said:

Handheld radios and mobile radios are not usually capable of receiving while transmitting.  In order to receive distant transmissions, the receiver circuit must be sensitive to millionths of volts.  Your transmitter is capable of putting out a lot more than that.  They're both connected to the same antenna, so when your transmitter transmits, that power would overwhelm your receiver. So, while transmitting, your receiver is effectively disabled.  Depending on the convention (and whom you're talking to) that's either called half-duplex or simplex.

Repeaters however, must be able to transmit and receive at the same time in order to do their job.  That's referred to as full-duplex.  But the problem still remains; how do you keep the transmitter power from overwhelming the receiver.  So they transmit and receive on two different frequencies and a special device called a "duplexer" provides even more isolation.

So, a repeater transmits into a duplexer.  The duplexer filters out everything except the frequency being transmitted (as much as it can) and routes that signal to the antenna.  Simultaneously, the antenna is picking up signals over a wider bandwidth, which go to the duplexer.  The duplexer filters out everything except the frequency that the repeater must receive, which it sends to the receiver.  A duplexer is like a traffic cop.  In order for the duplexer to do a good job, both sides of it must be pretty precisely tuned and it must be capable of aggressively filtering both signals.

If your handheld or mobile radio had a duplexer, you would be able to hear what the repeater is transmitting at the same time as you are transmitting. 

That should also make you appreciate the fact that cell phones are full duplex.

Does that help?

 

Yes that helps a ton, thank you for all of the information, very informative. 

It seems I'm not able to hit any repeaters except the one with hardly any signal. Interestingly enough, the UV-9G is only able to hit it sometimes with a Nagoya 771G antenna and seemingly never with the GM-15's antenna, where the GM-15 stock antenna on the actual GM-15 radio is able to hit it consistently. I think I'll return the UV-9G and maybe keep the Nagoya antenna. Thanks again for the help.  

 

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Hi gang! I am also a new GMRS (WRWA569) just wondering if you could help me out as well?

I just want to understand if I'm properly interpreting the information for the repeater in my area to correctly set my HT. Here is a snip of the information for my local repeater

image.thumb.png.6c6314db80a533277e54c052254ac724.png

 

 

Settings for my HT (Baofeng GMRS-9r)

Frequency out (on my HT): 467.575 (Transmit CTSS Tone: 103.5)

Receive (on my HT): 462.575 (no tone)

 

 

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2 minutes ago, JayWRWA569FlagstaffAZ said:

Hi gang! I am also a new GMRS (WRWA569) just wondering if you could help me out as well?

I just want to understand if I'm properly interpreting the information for the repeater in my area to correctly set my HT. Here is a snip of the information for my local repeater

image.thumb.png.6c6314db80a533277e54c052254ac724.png

 

 

Settings for my HT (Baofeng GMRS-9r)

Frequency out (on my HT): 467.575 (Transmit CTSS Tone: 103.5)

Receive (on my HT): 462.575 (no tone)

 

 

Yes, exactly right!

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