Is it the tkr850 that stops TX?  You may have overlooked the kenwood software timeout timer must be disabled.
I did the same thing......

--------------------------------------------
On Fri, 2/7/14, Bob Roszkowski <bob@w5evh.org> wrote:

 Subject: [App_rpt-users] Loosing TX
 To: "app_rpt mailing list" <App_rpt-users@ohnosec.org>
 Date: Friday, February 7, 2014, 4:22 PM

 Group,

 I have a site that is acting strange.  I have a
 server with a VHF(Mastr II) and UHF(TKR-850) repeater, each
 with a URI.  Both repeaters are linked together locally. 
 I noticed while someone is using the machine, the TX will
 just stop while they are talking.  If I switch to the other
 repeater, the TX is working fine.  The URIs Red LED goes
 out.  This happens to both machines.   I have swapped and
 changed URIs and cables with no change.  Any ideas?


 boB - W5EVH

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