Electrical charge on digitbox

willg

Folks is it normal to feel an electric type charge at the back of a Sky Digibox ? Felt a kind of charge around the area where the coax connects from the dish the last day. Checked on my other box of the same type & model and felt nothing. I know there is a charge sent down the coax but should I feel it on the casing of the box. Could it be a grounding issue on the box ? Picture is perfect on the box same as the other .. Tony have you heard of this before. Any suggestions would be welcome.

Thanks in advance
Willg

eirlink

Hi
I bought a strong rx off tony and on the day i set it up I rang him with the exact same occurence.I got a tingle when touching the sat finder when setting up....put phase tester on it and it lit up.(now i know a phase tester will light even with ststic charge)But then i tested it with a multimeter and got 90-100volts ac across live and earth.

I rang Tony and he was off the opinion this voltage was to do with the type of power supply in this receiver?

the house wiring is fine/socket is earthed fine..so Im still at a loss as to what this charge is.Everything works but im still concerned and I will not use it.

I am going to plug in in at work some fine day and get technical dept to measure this with their test equip.

Anyone have any ideas.??
Tony ...do you still think its just a harmless voltage?...surely anything near 90 volts ac would damage the LNB.

Regards
Eirlink

beer enigma

May not be relevant, but I got this on my old Pace box.......a week before it died on me

byte

It happens me quite a lot from various receivers (make is irrelevant). Sometimes it's power leakage from the TV set's aerial socket. Sometimes it depends on how earthed I am (especially if I'm soaken wet from rain). I've never bothered to measure the current. Despite the fact it may be 90V, it would probably have a very low ampage.

Hmm...

Mike 1972

The voltage probably originates in your TV and travels to the LNB via the digibox

The electrical safety standards (And EMC standards but thats another story) for most TV sets on the market seem to be apallingly low. Most of them have a voltage on their aerial sockets. Quite a few have above ground potentials on their SCART outputs Phono sockets and Headphones as well Some even have a residual electrical charge on the pins of their plugs after theyre plugged out (Ive seen this on vacum cleaners hairdriers and photocopiers as well but TV's seem to be the worst offenders)

The sockets on TV's should be isolated and digiboxes should have additional isolation as well And the outer core of coax should be grounded (Although this is impossible with most cheapskate models since they only use two wire mains leads)

How manufacturers can legally put such badly designed crap on the market is a mystery !

Capt'n Midnight

I reckon Leakage from the TV put paid to two SKY magic eyes on me

byte

Yes, I do believe voltage leakage probably ruined some Sky eyes in the past. I've had a few occasions where a Sky Eye simply would not work when plugged into the back of some TV's. Take it out, and it works again.

Mike 1972 wrote:

Some even have a residual electrical charge on the pins of their plugs after theyre plugged out

Hmm, quite annoying when carrying a TV only for the plug to swing and hit your leg, giving a startling shock in the process!

Tony

eirlink wrote:

Anyone have any ideas.??
Tony ...do you still think its just a harmless voltage?...surely anything near 90 volts ac would damage the LNB.

Regards
Eirlink

Sorry for delay just saw this. yes I would think 90v A/c would blow any lnb, AFAIK there should only be 13/18v dc at the coax output.

Sparky

Mike 1972 wrote:

Some even have a residual electrical charge on the pins of their plugs after theyre plugged out

Yea i certenly got a whack of the plugtop when i was carrying the tv, although not as bad of a shock from mains but still enough to wake you up a bit.

Mike 1972

Or make you drop the TV

Or kill you if you had a heart condition

Good to see at least some countries are taking the issue of AV product safety seriously

Capt'n Midnight

Mike 1972 wrote:

Or make you drop the TV

Or kill you if you had a heart condition

While it's Volts that Jolts but Mills that Kills - a reminder that a lot of injuries associated with electrical shocks are secondary, caused by you banging against something as fly across the room or fall to the floor.

Ulsterman 1690

Suppose someone is working on the roof of a house and accidently touches an aerial which happens to be live as a result of being connected to a defective TV
The shock might cause them to fall off the roof or drop their tools which might in turn hit someone of damage property ?

Tony

then the lawyers get invloved

Ulsterman 1690 wrote:

Suppose someone is working on the roof of a house and accidently touches an aerial which happens to be live as a result of being connected to a defective TV
The shock might cause them to fall off the roof or drop their tools which might in turn hit someone of damage property ?

Sparky

Volts= Shock Amps= Death

And yes most accidents involving shocks are secondary. like a friend was working on a lightswitch thinking that once the light is off its ok (big mistake) he got a shock and as a result he fell half ways downthe stairs only to find he fractured his shoulder.

What a lesson he learned.

John R

Sparky_S wrote:

Volts= Shock Amps= Death

And yes most accidents involving shocks are secondary. like a friend was working on a lightswitch thinking that once the light is off its ok (big mistake) he got a shock and as a result he fell half ways downthe stairs only to find he fractured his shoulder.

What a lesson he learned.

Electricity is dangerous, Idiocy is fatal.