Icom: Cross-band repeat problems Icom ic-2730

[WS1L]

I'm trying to set up cross-band repeat with a new Icom ic-2730a and am running into a perplexing problem. The local radio club is supporting a 75 mile bike rally in mountainous terrain tomorrow, so having this working will be a big asset.

I can set it up to accept VHF input and link to UHF just fine. I can walk around my yard with a VHF HT and access the local UHF repeater great. That is all as expected. It works just as the (admittedly skimpy) manual addendum says. A few YouTube videos were on point and it was pretty easy.

When I try to set it up for UHF input to the ic2730 and output to VHF, something odd happens.

The ic2730 (using the local mic) with VHF selected as Main, reaches the VHF repeater fine.

Using a UHF HT the ic2730 UHF side sees the input signal, and the VHF side goes into TX. But, now the repeater won't hear it.

Monitoring the ic2730 VHF transmitted signal shows it is on the repeater input frequency and is transmitting the proper PL code. I used two separate receivers to be sure - with tone squelch applied, that transmitted signal on the repeater input frequency opens the squelch and the voice (repeated from the UHF side) comes through loud and clear on VHF.

But the local repeater won't repeat it. It repeats the signal from that side of the ic2730 using the local mic. Other radios can't tell the difference between the ic2730 VHF output using the local mic and the output being repeated from the UHF side.

I'm stumped. I found a reference to the ic2730 not transmitting Tone when in cross band repeat but that does not seem to be the case here.

I tried putting VHF/UHF on different sides of the radio, no difference.

Any help greatly appreciated.

73 de Chuck,
WS1L
WMA ARES SEC
chandlerusm@gmail.com

 

[nd5y]

Maybe the tone is distorted or the tone deviation is too low. Maybe the problem is in the repeater receiver. Does it work on other repeaters?

 

[WS1L]

Maybe the tone is distorted or the tone deviation is too low. Maybe the problem is in the repeater receiver. Does it work on other repeaters?

It does work going into the local UHF repeater.
It does work using the local mic into the VHF repeater. (With the ic2730 you can use the local mic while in cross band repeat mode.)

It does not work when repeating the UHF input in cross band repeat mode. (It does work repeating a VHF input into UHF out to a local UHF repeater.)
It is possible the ic2730 distorts the tone or otherwise is not the same when re-transmitting the UHF side. Two other radios seemed to find the tone acceptable, and the repeater seems to find the tone acceptable when using the local mic.

 

[MTS2000des]

The way Icom institutes cross band repeat is what I will call a "bent pipe". In other words, what goes in is what comes out. The problem here is that PL deviation may be too low and some repeaters require a PL deviation of at least 700Hz to unmute. If you check the Icom's output when in x-band mode, you'll see the transmit deviation purely depends on what it hears and is usually low and some repeaters thus "ignore" and won't unmute.

Icom knows this and says that "PL operation is not supported" which is a lame response but it is what it is. Other rigs like Kenwoods and Yaesu's strip off the PL and send audio through transmit pre-emphasis and tone encoding in cross band repeater mode.

 

[WS1L]

The UHF HT is a Motorola XPR6550. I just looked in CPS and there doesn't seem to be any way to boost the PL tone outside of audio enhancements.

I will try another UHF HT and see if that works. If so, this is likely to be the problem. Thanks!

 

[WS1L]

OK, success. The simplex frequencies I had programmed into the HTs had a different tone code than the repeater. I had expected the ic2730 to manage that more gracefully, but setting those to the same PL as the repeater expected has resulted in it working on the UHF HT to VHF repeater configuration.

Thanks to @MTS2000des for the explanation of how cross band repeat is handled in this rig.

 

[dxintel]

Glad you found success. I ran into the exact same problem myself. Another work around I have found (in addition to using the same PL tone as the repeater) is to set the cross band frequency to use a DCS tone this way I am able to cross band to a few different repeaters that have different PL tones set on the input frequency.

 

[ladn]

Another work around I have found (in addition to using the same PL tone as the repeater) is to set the cross band frequency to use a DCS tone this way I am able to cross band to a few different repeaters that have different PL tones set on the input frequency.

Great idea! I'll give it a try on my radios!