Amplified antenna question

[Stevemc]

I have searched and read through several posts on this but not found the answers I'm looking for. We have a Cedar Creek 36ckts fifth wheel but I think the television antennas and amplifiers are about the same.
I'm not getting a signal to either tv. I'm have the trailer in our driveway and have always got a good signal here before. That's why I don't think the amplifier is working. I have verified that the button and little green light is on. I removed the plate and verified that I have 12 volts coming to it. Shouldn't I be able to read some amount of low voltage at the coax ends where they connect to the tvs? I have zero. Isn't the actual amplifier in the antenna? The plate with the little on/off button just feeds the 12 volt power to the antenna. It haven't been able to sort out where all the coaxs go that are attached to the back of the switch plate. I assume one to the antenna and one to each tv?
Thanks for any help.
Steve

[Ford Idaho]

You did not mention it so I will ask if the television is set for cable or ANT when doing a scan?

I missed this once, took me half an hour to remember....

[Stevemc]

Yes thanks for asking. I have missed that before too.

[B and B]

Correct on all accounts. You should see 12 at the antenna. Check the coax for a short, in side the screw on connector is there a piece of the shield shorting the inner conductor.

Also use a pin and put this into the the connector that leaves the power supply to make sure 12 VDC is actually leaving the box.

This can trace the coax out easy.

https://www.homedepot.ca/en/home/p.c...000751011.html

[Rbertalotto]

You should see 12 at the antenna.

Are you suggesting that he should see 12V on the coax antenna wire?

[Stevemc]

Thank you B and B. Should I get some voltage reading at the coax at the tv's if the amplifier is working?
It's cold and windy today. I'll try to get back on the roof tomorrow.
Thanks Steve

[Herk7769]

Originally Posted by Rbertalotto

Are you suggesting that he should see 12V on the coax antenna wire?

Yes, there should be 12 volt dc between the core and the shield of the coax at the roof antenna. Antenna signal is RF so it does not interfere with the 12 volt power source to the antenna amplifier on the roof.

The white box of the batwing contains the signal amplifier.

[Herk7769]

Originally Posted by Stevemc

Thank you B and B. Should I get some voltage reading at the coax at the tv's if the amplifier is working?
It's cold and windy today. I'll try to get back on the roof tomorrow.
Thanks Steve

You will not (should not anyway) see 12 volts at any TV.

The signal coming down from the antenna is RF and you would need an oscilloscope to see the waveform.

DC only goes up; RF comes down (if you will). The antenna "downlead" is the only coax that "sees" the 12 volts. The TV outputs (1 and 2) have the DC stripped out.

Set 2 cable goes to a splitter then on to the TVs in other rooms

[Stevemc]

Got it! Thank you for such a great explaination.