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xpr8400 in analoge
Posted: Sat Aug 18, 2012 7:18 am
by johnny1225
I have a XPR8400 repeater rx459.2250 tx 454.2250 TPL 110.9 using a Q3220 sinclair duplexer. They are running the repeater in analoge for now and is programmed to 12.5 khz. It is covering two towers one tower is 55 stories and the other is 28 stories. We are using 1/2" andrews foam heliax cable with about 16 3db antennas spread out in both buildings. We have moved the repeater everyhere to try and find the best spot. If i put repeater in P1 level of the 55 story building the second tower is truly amazing coverage but lack in the bigger tower. I think we made a huge mistake using 1/2", it should have been bigger like 1" or 1 1/4" cable. I am wondering if there is anything i can do to improve the coverage in the bigger 55 story tower. Can i put a second repeater in half way up with reverse frequencies?, i guest my question is is there anything i can put in the line the would make this system work better without a expensive BDA????
Any suggestions would be greatly appreciated....
Cheers
John
Re: xpr8400 in analoge
Posted: Sun Aug 19, 2012 8:03 am
by Bill_G
Haven't we talked about this before?
So, how are you doing this? Repeater in the underground parking to a splitter with one run going up each tower?
Have you swept the lines to verify there are no workmanship issues and discontinuities?
Which direction is failing - inbound (portable to rptr), outbound (rptr to portable), or both?
Re: xpr8400 in analoge
Posted: Sun Aug 19, 2012 8:51 am
by johnny1225
ya we have talked about this before,lol but is a different customer. ya the feedline is going up both towers. When you transmit from the transmitting portable it is so staticy you cant make it out on the receiving portable. Sometime it will hit the repeater and sometime it wont hit the repeater at all?
Re: xpr8400 in analoge
Posted: Sun Aug 19, 2012 10:58 am
by Bill_G
Ok. Have you swept the lines, or at least put a wattmeter at each antenna drop? Have you injected at the antennas to see what the threashold is? Have you done a desense test? Do you think you need a voting system?
Re: xpr8400 in analoge
Posted: Sun Aug 19, 2012 11:15 am
by escomm
How exactly are these 16 antennas being used? For receive or transmit? On a single repeater?
Re: xpr8400 in analoge
Posted: Sun Aug 19, 2012 3:45 pm
by johnny1225
Yes do you have a good supplier of voting system that is not to expense?
Re: xpr8400 in analoge
Posted: Sun Aug 19, 2012 5:13 pm
by d119
Have fun hooking voting to an XPR8400. You'll need a pilot tone generator as well - the thing doesn't have a native wireline I/O like MTR 3000 does.
Re: xpr8400 in analoge
Posted: Sun Aug 19, 2012 7:35 pm
by Bill_G
My bad. d119 is right. That came up not too long ago about how limited the XPR series is. Forget satellite rcvrs and a voter. Forget simulcasting it too. You're going to have to work the problem. Figure out where your losses are and try to overcome them as best you can.
Re: xpr8400 in analoge
Posted: Sun Aug 19, 2012 8:04 pm
by escomm
He won't be simulcasting with an MTR3000, either.
Re: xpr8400 in analoge
Posted: Sun Aug 19, 2012 8:31 pm
by d119
escomm wrote:He won't be simulcasting with an MTR3000, either.
Bitter much? j/k
Re: xpr8400 in analoge
Posted: Sun Aug 19, 2012 9:57 pm
by escomm
Just keeping it real and expanding on Bill's comments about the XPR. At least the sales literature finally makes it clear that feature won't work. Had a customer find that out the hard way.... luckily it was the direct team that was left holding that bag of doo-doo

Re: xpr8400 in analoge
Posted: Mon Aug 20, 2012 7:19 am
by d119
I know, Jeff. I just had to zing you with that because of what they've put you through with this product. I caught your other post on the 96-pin... I still see firmware enhancements in the future...