MTX810 Classic Talkaround Frequency Range

dittrimd · Post by **dittrimd** » Mon Oct 09, 2006 11:50 am

Hi all,

I am attempting to program some conventional talkaround frequencies into a fellow Batlab-ers MTX810 Classic Model Number H25JBF51B4BN. He wants 6 conventional and I know I can only do 5 as I cannot delete the last trunk system. My problem is when I select talkaround and go to enter the freuqency it kicks me back to 851.0000. I am attemting to program 811.2875 through 814.2875 with no PL. I have programmed many of these in conventional repeater mode with no problem. I enter the RX frequecny and it sets the TX frequency, one I recently did was in the 809 TX range. Why is it that it will not let me enter a frequency this low in the talkaround range? Am I missing something here? I have tried both standard and splinter in the channel type with no luck. I assume I am just going too low on the RX side. If anyone can please confirm I would appreciate.

Mark

dittrimd · Post by **dittrimd** » Mon Oct 09, 2006 12:25 pm

UPDATE: I used the arrow keys to scroll through the frequency list. Here is what I have found.

Talkaround Disabled/Standard Channel type allows a low of RX of 851.0125 and TX of 806.0125 and a high RX of 869.9875 and TX of 824.9875.

Talkaround Disabled/Splinter Channel type allows a low of RX of 851.0000 and TX of 806.0000 and a high RX of 869.9750 and TX of 824.9750.

Talkaround Enabled/Standard Channel type allows a low of RX of 851.0125 and TX of 851.0125 and a high RX of 869.9875 and TX of 869.9875 .

Talkaround Enabled/Splinter Channel type allows a low of RX of 851.0000 and TX of 851.0000and a high RX of 869.9750 and TX of 869.8750.

Looks like although the lower frequencies are allowed for transmit when in talkaround disabled, it will not allow RX any lower than 851.0000 when talkaround is enabled. If anyone has any other information to add please feel free.

While I am in no way asking for LAB RSS I would appreciate if anyone knows whether lab would allow you to go out of these frequency ranges as an FYI. Again I am NOT soliciting for LAB RSS just wondering if the LAB software allows you to change this frequency constraint.

Thanks

Mark

Max-trac · Post by **Max-trac** » Mon Oct 09, 2006 12:46 pm

The radio was never made to rx down low (below 851) like most radios for that band. I don't believe it will work down there even if you can get the freqs entered (just like a maxtrac).

N4KVE · Post by **N4KVE** » Mon Oct 09, 2006 12:50 pm

You can only use talk around in the RX portion. 850-870. I have 6 of those same radios & they work great in talk around. GARY N4KVE

Post by **wavetar** » Mon Oct 09, 2006 1:27 pm

N4KVE wrote:You can only use talk around in the RX portion. 850-870. I have 6 of those same radios & they work great in talk around. GARY N4KVE

This is true of any 800MHz radio...not just the MTX810. It's FCC mandated to only have talkaround in the 850-870 range. This is why it's so difficult to make a home-brewed 800MHz repeater out of, say a couple of Maxtracs or GTX. From the factory, they do not RX in the 806-825 portion of the band, neither hardware or software wise.

Todd