Ok we will give it a try but the repeater guy will not be back up there to test 
for the noise until next Tuesday. Sounds like a plan. 


----- Original Message -----

From: "Ken Hohhof" <[email protected]> 
To: [email protected] 
Sent: Thursday, July 23, 2015 5:04:02 PM 
Subject: Re: [AFMUG] 900 fsk and interference with repeaters 

When you say 2way, I think VHF, in which case maybe it’s the Ethernet causing 
problems. We used to have this all the time with OTA TV low band VHF before the 
digital transition. Have you tried forcing the Ethernet to 10BaseT? Not losing 
anything with 900 FSK because it can’t do 10 Mbps anyway. 
Sometimes POE switching power supply noise can be a problem as well. 
BTW, running coax up the tower is easier at 900 MHz than higher frequencies 
because of the lower loss per foot of cable. 
Looping the Cat5 several times through a ferrite bead could help as well, but 
the fix we always used was 10BaseT. Or at least if that make a big difference, 
you know the cause is the Ethernet not the radio. 
From: Adam Moffett 
Sent: Thursday, July 23, 2015 4:48 PM 
To: [email protected] 
Subject: Re: [AFMUG] 900 fsk and interference with repeaters 
Yeah.....I was wondering if it's 450mhz or thereabouts 

On 7/23/2015 5:41 PM, Work wrote: 



Is the two way system on a really low band that would be a harmonic of the 
frequency that you're on right now? 

— 
Sent from Mailbox 




On Thu, Jul 23, 2015 at 5:15 PM, Craig House < [email protected] > 
wrote: 

<blockquote>


We have another tower that we have installed 900 FSK equipment on that seems to 
be causing problems with a 2 way repeater system. The noise floor on the 2 way 
system is 20 db higher when the equipment is on. The down side to this is the 
tower owner is the repeater owner and without his repeater his business suffers 
and the need for the tower is gone. We have in the past had this issue and ran 
coax all the way up the tower to have only the antennas on top and it solved 
this issue but I dont want to do this for a FSK 900 radio? So my question would 
be, what are the odds that the new 450 900 mhz that is only moments away from 
being released would work without running Coax up the tower? I think this is an 
issue with the processor in the FSK board not the RF @ 900mhz that is causing 
the problem. What have others done about this. We have another tower that seems 
to be on the brink of this same issue as well and I dont want to completely 
pull off all 900 FSK but maybe I should? Should I just go to UBNT 900 until the 
450's release? 






</blockquote>


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