Problem: Signal issues

Dear Eric,

I've a problem with my Signal:

1- Signal: I tried with my digital meter to get the best and to eleminate the message: Viterbi Error Rate as i didn't see it before on any nera terminals, but i faild, however the signal is 7.5 db which is good as the maximum i guess is 8.5 db, so baiscly increasing the signal wont remove the Viterbi Error Rate Message.

So i tried the plorization, if i turned the BUC left or to the right the singal goes down, so it is in the best position, i don't know how to remove the error message.

Viterbi Error Rate samples:

3.576 E-5
2.861 E-5
1.430 E-5
1.192 E-5
4.076 E-6
7.015 E-6

and sometimes there is not Viterbi Error Rate values.

2- Electricity: Today when i touched the tripod i felt a small current and i couldn't keep holding the tripod, i don't know from where the current is, can it be from the connectors ?

3- The signal falls dawn by 1 dB at the night but at the morning it comes back, is there any way to stablize the SNR level ?

My ODU is: 1.8m Ku- Andrew Class I
                  SPV-1SM LNB
                  NJT5037F

My modem is Nera
Cable length: 19m RG-6


Best Regards
Ahmed