Ias it possible to program my Icom 2730 to only repeat in one direction?
Icom: 2730 cross band repeat in one direction only??
- Thread starter Major146
- Start date
nd5y
Member
I don't think the IC-2730 is capable of one-way repeat like some of the Kenwood models but you can obtain the same result by how you program the channels before you put it in repeat mode.
What exactly are you trying to do?
What exactly are you trying to do?
I used to do this with Yaesu FT-8800R models.
For your local side, use a simplex channel, no big deal.
But for the distant side, do an odd-split so that crossband rig xmits to correct freq, but when it stops transmitting, it will only Rx on a freq that has no traffic. (It's not the distant repeater's normal freq config, as the Rx side is now proframmed for a fake channel.)
We used HT's with dual receivers (Baofeng) and could monitor distant repeater's output easily, but the crossband rig will only Tx when your HT's Tx and remain idle otherwise.
Play with it... it works.
nd5y
Member
That's almost what I did when I had a IC-2720. Instead of using the VFO offset for the odd split you can program TX/RX frequencies separately in a memory channel program a random DCS code on the fake RX frequency to make 99.9% sure it will never receive anything even if somebody (or noise) shows up on your "unused" RX frequency.
Also remember to always use a PL or DCS (that isn't normally used in your area) on your local frequency to help prevent problems.
OP here. I wound up using the DCS Polarity option (TN-RR, TR-RN). I set up the x-band repeater for the normal operation to be, RX on VHF and repeat TX on UHF.
The HT’s in use would have channel one with UHF Simplex so they transmit and receive on the same channel with a PL code that is the same as the one that the repeater will be transmitting from the UHF side. Then on the HT's channel 2 would be split with the VHF as the transmit channel with a PL that matches up to the VHF side of the x-band repeater and receive on the UHF channel with the same PL tone as was used for channel one. This way the HT would receive the transmission from the repeater or another HT still on simplex no matter which of the two channels they were listening to.
The repeater would be set up to receive the VHF signal from the HT’s that are on channel 2 with an RN-TR so it would receive the normal PL that the HT’s are sending but transmit a reverse PL. But it really doesn’t matter what the VHF side has for a TX PL code because it is not likely to receive a request from the UHF side to repeat a transmission.
The repeater then transmits a UHF signal with the TN-RR (transmit normal-receive reverse) This allows the transmitted PL to be normal but the receive to be reversed. So, anyone transmitting back with the same PL that the transmitter sent would not be recognized by the receiver. Example: one of the HTs did not move to channel 2 and is transmitting on channel one which is simplex with the same PL as is being sent from the repeater with normal polarity. But the repeater would not recognize it because it is looking for the reverse polarity of the PL and would not try to have the VHF side transmit.
This whole system is a real brain twister but I think it will work. I was able to do a little testing before I ran out of daylight and time today and I think it is working but will take up more testing tomorrow.
I now have to put an ice pack on my brain before it explodes.
The HT’s in use would have channel one with UHF Simplex so they transmit and receive on the same channel with a PL code that is the same as the one that the repeater will be transmitting from the UHF side. Then on the HT's channel 2 would be split with the VHF as the transmit channel with a PL that matches up to the VHF side of the x-band repeater and receive on the UHF channel with the same PL tone as was used for channel one. This way the HT would receive the transmission from the repeater or another HT still on simplex no matter which of the two channels they were listening to.
The repeater would be set up to receive the VHF signal from the HT’s that are on channel 2 with an RN-TR so it would receive the normal PL that the HT’s are sending but transmit a reverse PL. But it really doesn’t matter what the VHF side has for a TX PL code because it is not likely to receive a request from the UHF side to repeat a transmission.
The repeater then transmits a UHF signal with the TN-RR (transmit normal-receive reverse) This allows the transmitted PL to be normal but the receive to be reversed. So, anyone transmitting back with the same PL that the transmitter sent would not be recognized by the receiver. Example: one of the HTs did not move to channel 2 and is transmitting on channel one which is simplex with the same PL as is being sent from the repeater with normal polarity. But the repeater would not recognize it because it is looking for the reverse polarity of the PL and would not try to have the VHF side transmit.
This whole system is a real brain twister but I think it will work. I was able to do a little testing before I ran out of daylight and time today and I think it is working but will take up more testing tomorrow.
I now have to put an ice pack on my brain before it explodes.
nd5y
Member
None of that makes sense without including frequencies.
Why do you want to use inverted polarity DCS? What is that supposed to accomplish?
Here are some examples of how ham type crossband repeater capable radios could be used.
1. Two-way cross band repeat.
One group of users on VHF and another group on UHF.
PL/DCS optional.
Users TX --> 438.100 PL 100.0 --> XBR RX UHF
Users RX <-- 145.555 PL 123.0 <-- XBR TX VHF
Users TX --> 145.555 PL 123.0 --> XBR RX VHF
Users RX <-- 438.100 PL 100.0 <-- XBR TX UHF
2. Two-way crossband repeat.
User is too far away from distant repeater (146.76/146.76 PL 123.0)
VHF side of XBR programmed for repeater offset.
User TX --> 438.100 PL 100.0 --> XBR RX UHF
XBR TX VHF --> 146.16 PL 123.0 --> distant repeater RX
XBR RX VHF <-- 146.76 PL 123.0 <-- distant repeater TX
User RX <-- 438.100 PL 100.0 <-- XBR TX UHF
3. One-way crossband repeat.
Normal repeater operation. (temporary repeater for events, etc.)
XBR RX VHF is not used and can be set to unused frequency with unused PL/DCS.
XBR TX UHF is not used and can be disabled if the radio supports it.
Or it can be configured as in example #1 above and tell the users to not transmit on VHF.
Users TX --> 438.100 PL 100.0 --> XBR RX UHF
Users RX <-- 145.555 CSQ <-- XBR TX VHF (PL/DCS is optional on user's receivers)
4. One-way crossband repeat.
User can receive distant repeater (146.76/146.76 PL 123.0) but distant repeater can't receive user's HT.
User TX --> 438.100 PL 100.0 --> XBR RX UHF
XBR TX VHF --> 146.16 PL 123.0 --> distant repeater RX
XBR RX VHF is not used and can be set to unused frequency with unused PL/DCS.
User RX <-- 146.76 PL 123.0 <-- distant repeater TX (PL optional on user RX)
Why do you want to use inverted polarity DCS? What is that supposed to accomplish?
Here are some examples of how ham type crossband repeater capable radios could be used.
1. Two-way cross band repeat.
One group of users on VHF and another group on UHF.
PL/DCS optional.
Users TX --> 438.100 PL 100.0 --> XBR RX UHF
Users RX <-- 145.555 PL 123.0 <-- XBR TX VHF
Users TX --> 145.555 PL 123.0 --> XBR RX VHF
Users RX <-- 438.100 PL 100.0 <-- XBR TX UHF
2. Two-way crossband repeat.
User is too far away from distant repeater (146.76/146.76 PL 123.0)
VHF side of XBR programmed for repeater offset.
User TX --> 438.100 PL 100.0 --> XBR RX UHF
XBR TX VHF --> 146.16 PL 123.0 --> distant repeater RX
XBR RX VHF <-- 146.76 PL 123.0 <-- distant repeater TX
User RX <-- 438.100 PL 100.0 <-- XBR TX UHF
3. One-way crossband repeat.
Normal repeater operation. (temporary repeater for events, etc.)
XBR RX VHF is not used and can be set to unused frequency with unused PL/DCS.
XBR TX UHF is not used and can be disabled if the radio supports it.
Or it can be configured as in example #1 above and tell the users to not transmit on VHF.
Users TX --> 438.100 PL 100.0 --> XBR RX UHF
Users RX <-- 145.555 CSQ <-- XBR TX VHF (PL/DCS is optional on user's receivers)
4. One-way crossband repeat.
User can receive distant repeater (146.76/146.76 PL 123.0) but distant repeater can't receive user's HT.
User TX --> 438.100 PL 100.0 --> XBR RX UHF
XBR TX VHF --> 146.16 PL 123.0 --> distant repeater RX
XBR RX VHF is not used and can be set to unused frequency with unused PL/DCS.
User RX <-- 146.76 PL 123.0 <-- distant repeater TX (PL optional on user RX)
ND5Y
You seem pretty knowledgeable about using the 2730 as a x-band repeater. I have not been able to get the output of the UHF channel when in repeater mode to transmit the tone code. When I take it off the repeater function the UHF channel transmits the DCS code but not when it is in repeater mode. Any ideas why?
You seem pretty knowledgeable about using the 2730 as a x-band repeater. I have not been able to get the output of the UHF channel when in repeater mode to transmit the tone code. When I take it off the repeater function the UHF channel transmits the DCS code but not when it is in repeater mode. Any ideas why?
N4KVE
Member
Did this in the early 90’s when I had my Kenwoods. They had this in mind, so there was a tiny switch between both volume knobs for one way, or 2 way repeat. In my case, I needed my mobile radio in the car to receive the signal from my HT, & send it out to the repeater input. But my HT could receive the repeater output just fine, so only one way repeat was necessary. Can you imagine if the mobile was retransmitting everything the repeater sent out for an hour during busy times? How long would the finals last? Later on I had Yaesu, or Icom radios, but had to trick them like posted above. Eventually I converted a GE Mstr 2 to be a single band in car repeater, & that was the best solution.
nd5y
Member
I have never touched an IC-2730. I just assmed it was similar to the IC-2710 and IC-2720. I had both of those decades ago. I don't even remember if the 2710 had crossband repeat or not. The 2720 did and I never had an issue with PL or DCS.
I have no idea why DCS doesn't work on yours. Does the same thing happen with PL? What are you using to determine if it's transmitting DCS or not? Are you using inverted DCS?
I called Icom. When I first asked why it would not transmit the PL tone he was confused and had me on hold for 6 minutes while he talked to someone in the room and finally told me nope the 2730 will not transmit a PL tone when in the repeater mode. The only alternative he offered was to buy there $1000+ repeater.
So the old “It’s working as designed” answer. No matter how stupid the design is.
That't about the siz of it. Any one out there interested in building me a low power UHF repeter? I have some stuff to trade.
