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Hi guys .I have a small problem that i have been trying to sort out for a while now .I have 5 repeaters operating on one of my sites
3 vhf low band and 2 uhf band.The frequencies are as follows
VHF
A-TX 70.300MHZ RX 72.800MHZ fitted with 4 1.5 meter by 4 inch meter tins-most likely a notch diplexer 3db colinear ant FM828E
B-TX 70.5875MHZ RX 73.0875MHZ fitted with 4 1.5 meter by 4 inch meter tins-most likely a notch diplexer 3db colinear ant FM828E
C-TX 70.725MHZ RX 73.225MHZ fitted with a new band pass/band reject possibly a varinotch 3db colinear ant FM828E
UHF
D- TX 473.575 RX 478.775MHZ fitted with mobile notch diplexer 6mc450s 6db colinear ant MAXON PM150/SM4450SC
E- TX 489.1MHZ RX 483.900MHZ fitted with 6ld450s diplexer 6db colinear ant MAXON PM150/SM4450SC
All coaxes are Heliax from antennas to Diplexers with N connectors
Interconnecting cables between diplexers and radios are rg223u
A and B are a 1.5 meter apart with C in the middle
All antennas are mounted aprox 50 cms or more away from C or each other .
D and E have a 1.5 meter between them
ie- D
A C B
E
I am at times having desense (ie scratch ) especially in windy weather occuring on repeaters B and D.It doesn't seem to affect the desense wether the transmitters are txing or not .There isnt any problem of the repeaters affecting each other ,they all work great just the problem of scratch coming and going .A,C and E do get scratch on occasion but no where as bad as D and B.D and B works great sometimes (clear with no scratch)and then reception will slowly develope major scratch and then slowly clear up -possibly electrostatic or wind moving the antennas ?.I have been fixing loose bolts on the windmill tower to stop problems incase of tower twist and this affecting service.I am wondering if there are any futher sugestions .
Thank You,
Ian Wells,
Kerinvale Comaudio,
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