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links:xband [2021/10/07 19:55] – created - external edit 127.0.0.1links:xband [2025/06/26 10:46] (current) – [Repeater Extender] va7fi
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 A crossband repeater is different from a regular repeater in two important ways: A crossband repeater is different from a regular repeater in two important ways:
-  * Where as a regular repeater uses the same band with a small offset between the tx and rx frequencies (600 kHz for VHF and 5 MHz for UHF), a crossband repeater uses two frequencies on different bands (one on VHF and the other on UHF for example). + 
-  * Where as a regular repeater always listens to the same frequency (the input of the repeater) and always transmits on the other (the output), a crossband repeater transmits on one frequency whatever it hears on the other, whichever it hears first.+^ ^  Regular Repeater  ^  Crossband Repeater  | 
 +^1. |Uses the same band with a small offset between the tx and rx frequencies (600 kHz for VHF and 5 MHz for UHF) |Uses two frequencies on different bands (one on VHF and the other on UHF for example) | 
 +^2. |Always listens to the same frequency (the input of the repeater) and always transmits on the other (the output) |Re-transmits on one frequency whatever it hears on the other, whichever it hears first. |
  
 Many higher end dualband radios are capable of doing cross-band repeat (Icom's ID-5100 or Kenwood's TM-D710G are two examples).  Below are different uses for a crossband repeater. Many higher end dualband radios are capable of doing cross-band repeat (Icom's ID-5100 or Kenwood's TM-D710G are two examples).  Below are different uses for a crossband repeater.
  
 ===== Adhoc Repeater ===== ===== Adhoc Repeater =====
 +==== Simplest ====
 +
 +The simplest way to use a crossband repeater only works for two handhelds:
 +{{ links:xband:xband1b.png?600 |}}
 +  * Here, each handheld uses a different band.
 +  * The problem is that you can't add more handhelds (unless they can already hear the others in simplex).  
 +
 +==== For more people ====
  
-Supposing you are in a remote location with no repeater and you have a few people who need to communicate with handheld radios.  You could park your car with a crossband repeater up a hill and use two simplex frequencies as follows: +If you have more than two people, everyone will have to agree to use the same "input" and "output" frequencies, but that requires more fancy dual band tx/rx: 
-{{ howto:xband:xband1.png?600 |}} +{{ links:xband:xband1.png?600 |}} 
-  * Both handhelds are set to listen to 446.100 and transmit on 145.565 so that when Unit A transmits on 145.565,+  * All handhelds are set to listen to 446.100 and transmit on 145.565 so that when Unit A transmits on 145.565,
   * The crossband repeater hears the 145.565 signal and re-transmits it on 446.100   * The crossband repeater hears the 145.565 signal and re-transmits it on 446.100
   * Which Unit B hears, and vice versa.   * Which Unit B hears, and vice versa.
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 In practice, it might be tricky to setup the handhelds to receive on one band and transmit on the other.  With Baofeng radios, I found it was easier to have receiver A set to the Tx frequency and receiver B to the Rx frequency. In practice, it might be tricky to setup the handhelds to receive on one band and transmit on the other.  With Baofeng radios, I found it was easier to have receiver A set to the Tx frequency and receiver B to the Rx frequency.
  
 +<WRAP center round info 80%>
 +But also: look for a menu called something like ''RxMode''.  The four options I have on mine are:
 +  - ''CROSS BAND'' (uses two handhelds to create a cross band repeater)
 +  - ''DUAL RX RESPOND'' (the radio switches to whichever band it hears for the next transmit)
 +  - ''MAIN ONLY'' (the radio only uses the selected band so you can't hear the second one)
 +  - ''MAIN TX / DUAL RX'' (the radio only transmits on the selected band, but can hear both)
  
-==== Adhoc Repeater Variation ==== +The last option is the right one to use for this setup
- +
-There's a simpler variation of the above scheme but it only works for two handhelds: +
-{{ howto:xband:xband1b.png?600 |}} +
-  * Here, each handheld uses a different band so there is no need for fancy dual band tx/rx. +
-  * The problem is that you can't add more handhelds (unless they can already hear the others in simplex).+
  
 +</WRAP>
  
 ===== Repeater Extender ===== ===== Repeater Extender =====
-This is a scheme I use often at home with my base station in crossband mode: I tune one receiver to our local repeater, and the other to a simplex UHF frequency.  I can then use my handheld around the house and the yard with the "power" of my base station and antenna to get into the repeater.+==== Simplest ==== 
 +This is a scheme I used to use at home with my base station in crossband mode: Tune one receiver to our local repeater, and the other to a simplex UHF frequency.  Then use the handheld around the house and the yard with the "power" of my base station and antenna to get into the repeater.
  
-{{ howto:xband:xband2.png?800 |}}+{{ links:xband:xband2.png?800 |}}
   * Unit A transmits and receives on 446.100 (with a tone).   * Unit A transmits and receives on 446.100 (with a tone).
   * The crossband repeater hears 446.100 (with a tone squelch) and re-transmits it on 147.**8**20 (the input of the repeater).   * The crossband repeater hears 446.100 (with a tone squelch) and re-transmits it on 147.**8**20 (the input of the repeater).
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 <WRAP center round important 90%> <WRAP center round important 90%>
-One thing to keep in mind with crossband repeat is that the radio doing the repeating is transmitting every time someone transmits.  Using this scheme to listen to an hour long net means that the radio would transmit at close to 100% duty cycle, which it may or may not be designed to do.  It would be best to use the lowest power setting and/or keep the use to a minimum.+The biggest flaw with this setup is that the radio doing the repeating is transmitting every time someone transmits, which means that the radio could transmit at <fc #ff0000>close to 100% duty cycle</fc>, which it may or may not be designed to do.  So it's best to use the lowest power setting and/or keep the use to a minimum.
 </WRAP> </WRAP>
    
  
-===== Repeater Extender Variation===== +==== One Way Variation ====
-The following is a variation I use when I can hear the repeater with my handheld, but can't transmit to it because of the handheld's low power.  In this configuration, the crossband repeater only transmit when **I** am transmitting, not when the others are transmitting, which is much much easier on the radio.+
  
-{{ howto:xband:xband2b.png?800 |}}+The following is a variation I use more often when I can hear the repeater with my handheld, but can't transmit to it because of the handheld's low power.  In this configuration, the crossband repeater only transmit when **I** am transmitting, not when the others are transmitting, which is much much easier on the radio. 
 + 
 +{{ links:xband:xband2b.png?800 |}}
 The crossband repeater is set up with the input frequency of the repeater without the offset.  The tone is set to the repeater tone, but the tone squelch is set to something else (I'll explain in a minute). So: The crossband repeater is set up with the input frequency of the repeater without the offset.  The tone is set to the repeater tone, but the tone squelch is set to something else (I'll explain in a minute). So:
   * Unit A transmits on 446.100 and receives the repeater's output on 147.**2**20.   * Unit A transmits on 446.100 and receives the repeater's output on 147.**2**20.
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 In this configuration, the crossband repeater only re-transmits Unit A, and not everyone else on the net, keeping the duty cycle low. In this configuration, the crossband repeater only re-transmits Unit A, and not everyone else on the net, keeping the duty cycle low.
  
 +After much experimenting, I found that it's better for the second tone to be digital because a different analog tone sometimes interferes with the repeater's analog tone.  Right now, this is how I setup my frequencies:
 +=== On the Crossband Radio ===
 +  * Band A: 147.**8**20 MHz with a TONE(T)/DTCS(R) tone (it transmits an analog tone and requires a digital tone to open the squelch)
 +  * Band B: 446.100 MHz with a DTCS tone (it transmits a DTCS tone and requires one to open the squelch as well)
 +
 +=== On the Handheld ===
 +  * Band A: 446.100 MHz with a DTCS tone (for transmitting only)
 +  * Band B: regular 147.**2**20 MHz repeater frequency (for listening only)
  
 ===== Repeater Link ===== ===== Repeater Link =====
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 A crossband repeater can be used to link a VHF and UHF repeater simply by dialing both repeater frequencies (with offset and tones) on the crossband repeater. A crossband repeater can be used to link a VHF and UHF repeater simply by dialing both repeater frequencies (with offset and tones) on the crossband repeater.
  
-{{ howto:xband:xband3.png |}}+{{ links:xband:xband3.png |}}
  
 <WRAP center round important 90%> <WRAP center round important 90%>
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 To reach Unit A, Unit C would need to "impersonate" the VHF repeater and be setup as the "opposite" of Unit B. To reach Unit A, Unit C would need to "impersonate" the VHF repeater and be setup as the "opposite" of Unit B.
  
-{{ howto:xband:xband3b.png |}}+{{ links:xband:xband3b.png |}}
  
  
 ===== KT-8900 ===== ===== KT-8900 =====
 It's pretty easy to setup a cross band repeater with two KT-8900 radios. It's pretty easy to setup a cross band repeater with two KT-8900 radios.
-{{  howto:xband:kt8900corssband.jpeg  }} +{{  links:xband:kt8900corssband.jpeg  }} 
-  * The first step is to make an ethernet patch cord with this {{howto:xband:qytxbandcable.pdf |pin out}}:+  * The first step is to make an ethernet patch cord with this {{links:xband:qytxbandcable.pdf |pin out}}:
 <WRAP indent> <WRAP indent>
 |1 (Data Input) |  <->  | empty | |1 (Data Input) |  <->  | empty |
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 |8 (AF OUT)     |  <->  | 3 (MIC) | |8 (AF OUT)     |  <->  | 3 (MIC) |
 </WRAP> </WRAP>
-  * The second step is to set the menu option 43: ''REP-M'' to something like ''CTDCS''.  This will send the output of one radio to the input of the other radio only if the tone is detected.{{howto:xband:kt8900settings.png}}+  * The second step is to set the menu option 43: ''REP-M'' to something like ''CTDCS''.  This will send the output of one radio to the input of the other radio only if the tone is detected.{{links:xband:kt8900settings.png}}
   * For my setup:   * For my setup:
     * I set the UHF radio to low power because it's either going to be used on a UHF simplex frequency when I'm around the house, or by VE7SCK, which is also really close.  It's also the radio that'll be transmitting the most since it's listening to VE7RXZ (or whichever other repeater I want to crossband repeat).     * I set the UHF radio to low power because it's either going to be used on a UHF simplex frequency when I'm around the house, or by VE7SCK, which is also really close.  It's also the radio that'll be transmitting the most since it's listening to VE7RXZ (or whichever other repeater I want to crossband repeat).
     * I set the VHF radio to high power because this radio would need to reach a repeater further away.  It will also only transmit when I'm speaking on the UHF simplex frequency or when someone is using VE7SCK, which is less often.     * I set the VHF radio to high power because this radio would need to reach a repeater further away.  It will also only transmit when I'm speaking on the UHF simplex frequency or when someone is using VE7SCK, which is less often.
   * Once both radios are on their correct frequencies (one must be on UHF and the other on VHF), connect the cable to link them both.   * Once both radios are on their correct frequencies (one must be on UHF and the other on VHF), connect the cable to link them both.
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