Page 1 of 2

Hum

Posted: Mon Feb 23, 2009 11:37 am
by johnz8
I have a low level hum on my phone connected to the ooma hub. If I put the palm of my hand on the the top right side of the box (left of the keys) the hum goes away. I have moved the box around a bit but the hum stays. Is the box properly shielded? Do I need to take it apart and spray conductive paint or something on the inside of the housing?

Re: Hum

Posted: Mon Feb 23, 2009 12:02 pm
by WayneDsr
Try plugging the power supply to the hub in somewhere different. You might have a reverse polarity issue on your ac line.

Wayne

Re: Hum

Posted: Mon Feb 23, 2009 12:07 pm
by johnz8
WayneDsr wrote:Try plugging the power supply to the hub in somewhere different. You might have a reverse polarity issue on your ac line.

Wayne
I tried turning the plug around since it it is not polarized so you can do that. It made no difference. I am a Ham radio operator and very sensitive to RFI issues and know how my house wiring is done.

Re: Hum

Posted: Mon Feb 23, 2009 12:12 pm
by WayneDsr
Ham operator here too!

Wayne KF9MA

Re: Hum

Posted: Mon Feb 23, 2009 12:20 pm
by johnz8
WayneDsr wrote:Ham operator here too!

Wayne KF9MA

John Z KF7B here

Re: Hum

Posted: Tue Feb 24, 2009 12:21 pm
by johnz8
Joshua wrote:Hello johnz8,

I am going to have support contact you about the hum on the line.

They may need to send out a 3 prong power supply which should solve the problem.

I put the Scout in another room (my ham room and that would put it to the test) but that one is clean as can be.

Re: Hum

Posted: Tue Feb 24, 2009 12:26 pm
by murphy
The Scout has it's own power supply. This supports the possibility that the hub power supply may be defective.

Re: Hum

Posted: Tue Feb 24, 2009 12:56 pm
by johnz8
murphy wrote:The Scout has it's own power supply. This supports the possibility that the hub power supply may be defective.
So what do we do next? Do I need to return the hub. I don't want to pull the plug on my ooma VOIP. Can you just send me one if this is the problem and I can then return the old one?

Re: Hum

Posted: Tue Feb 24, 2009 1:12 pm
by murphy
I'm just another user.

Joshua already said that he was going to have someone contact you about the problem.

The hub takes 12 VDC at 1.2A according to the manual. The center conductor is +. Any chance that you have another wall wart around the house that is 12 VDC and at least 1.2 A that has a matching DC power plug? That would quickly tell you if the hub power supply is the problem. Unfortunately the Scout power supply is 5 VDC so it's not an option.

Re: Hum

Posted: Tue Feb 24, 2009 1:21 pm
by johnz8
murphy wrote:I'm just another user.

Joshua already said that he was going to have someone contact you about the problem.

The hub takes 12 VDC at 1.2A according to the manual. The center conductor is +. Any chance that you have another wall wart around the house that is 12 VDC and at least 1.2 A that has a matching DC power plug? That would quickly tell you if the hub power supply is the problem. Unfortunately the Scout power supply is 5 VDC so it's not an option.
I was not thinking when I made the last post. Stupid me. There is no internal supply. It is the adapter. Stupid stupid. Let me go see if I can find a 5 volt adapter in my junk power supply box. I have a bunch.