I just removed the Antenna Tek MOD 500 from my 2009 Heartland Sundance 3300SK and replaced it with a HDTV Winegard Sensar IV HDTV antenna. I verified the Antenna Tek power supply outputs +12vdc to match the operating dc power of the Sensar. Everything works fine except when I turn on either the bathroom exhaust fan or the Fan-Tastic vent fan in the kitchen. When one of these fans are turned on we lose the picture or the picture becomes very pixelated to the point you can't watch it. With one or both fans running I measured +13.5vdc at the antenna coax connector, were on shore power now. I turned the power supply off and we lose the entire signal/picture. Any suggestions as to what I can do to fix this problem? Thanks and be safe!!

Did you measure the voltage at the head of the Batwing? If you have 13.5V on the roof with the fans running I would suspect that the power supply is wired to a dirty 12V circuit or the power supply itself needs to be replaced. If you have a way of connecting to a different circuit (or run something directly from a 12V battery/power source you could determine which is at issue.

I suspect the noise is coming from the brushes of the fan motors... Placing a ferrite bead on the 12VDC line right at the fan motor may help... I think What is happening is the brushes are modulating the primary DC line with RFI type noise.Sometimes just placing a capacitor to ground from the 12VDC line right at the fan motor might help...I was going to point my thoughts to a newly installed LED LIGHT. You don't by any chance also have a newly installed LED light coming on at the same time the fan comes on.The regulated type LED lights are known to produce RFI signals that blanks the HDTV sets as well... Just another thought... Roy Ken

For noise isolation in DC circuits in cars, two approaches are used.1. Ground the AC component from the offending motor or generator brushes through a capacitor. RF goes right through, DC is blocked from grounding. If the RF noise isn't grounded, your 12V DC wiring serves as an antenna to broadcast it.2. Block the RF AC from coming into the power supply of the electronic device using a choke. The power supply for the TV probably takes care of this, but the noise is likely coming into your antenna feed along with the 12V DC powering the signal booster. I don't know why the switch for this power lacks the choke, maybe a cost thing.

the key problem is you are using the oem install lineyou need to install the correct 'filtered' sensar power supply

Bill.Winegard wrote:Did you measure the voltage at the head of the Batwing? If you have 13.5V on the roof with the fans running I would suspect that the power supply is wired to a dirty 12V circuit or the power supply itself needs to be replaced. If you have a way of connecting to a different circuit (or run something directly from a 12V battery/power source you could determine which is at issue.I measured 13.5 at the antenna right on the coax cable. Some have suggested placing a capacitor from the +12vdc line to ground, do you think this is feasible and what size of cap would be required. I'm thinking about replacing the oem 12vdc power supply with a 120vac to 12vdc converter and running the antenna off the substituted power supply.

HDTV Receiving Interference | Good Sam Community

18 Replies

MNtundraRet
Navigator
Sep 07, 2013
As I mentioned mine was no problem since the cables are just loose in the overhead cabinet above the dinette in my Class C. Getting at cables in most Class A's is a "POS"!

I have not found the need to restring cables in the roof. The roof actually helps to shield those.
SCVJeff
Explorer
Sep 06, 2013
Yours is probably silver plated Teflon sleeve @ $15/ft. I'm jealous..
The_Works
Explorer
Sep 05, 2013
MNtundraRet wrote:
SCVJeff wrote:
Anything with brushes in it is an arc generator, and it takes very little of this to destroy any digital signal. Even the Fantastic motors are known to cause issues, but the cheap fans are worse. Gotta kill it at the source.

Up until about Spring of 2011, my Fantastic Fan would cause television signal interference. Fan was within 8 feet of the TV. Less, or no, interference on "low". Increased with "med" and "high" speeds.

I fixed that problem with using a high quality RG6, quad shielded, coaxial cable between my second amplifier and the TV. TV sits on the dinette table when used. It also cleared the microwave interference when used at the same time by DW. :B

I'm very familiar with RG6 cable, we used it on our fine U.S. Navy ships. How difficult of a job was it to install? Did you run the RG6 next to the factory cable? Thanks for the info!
SCVJeff
Explorer
Sep 05, 2013
I hate installing F connectors on that stuff
MNtundraRet
Navigator
Sep 04, 2013
SCVJeff wrote:
Anything with brushes in it is an arc generator, and it takes very little of this to destroy any digital signal. Even the Fantastic motors are known to cause issues, but the cheap fans are worse. Gotta kill it at the source.

Up until about Spring of 2011, my Fantastic Fan would cause television signal interference. Fan was within 8 feet of the TV. Less, or no, interference on "low". Increased with "med" and "high" speeds.

I fixed that problem with using a high quality RG6, quad shielded, coaxial cable between my second amplifier and the TV. TV sits on the dinette table when used. It also cleared the microwave interference when used at the same time by DW. :B
JJnLilly
Explorer
Sep 04, 2013
Had the same problem in our previous Heartland product and it was the fan in the bathroom. Under warranty they replaced the fan motor and the problem was solved.
SCVJeff
Explorer
Sep 04, 2013
Anything with brushes in it is an arc generator, and it takes very little of this to destroy any digital signal. Even the Fantastic motors are known to cause issues, but the cheap fans are worse. Gotta kill it at the source.
The_Works
Explorer
Sep 04, 2013
SCVJeff wrote:
Did you read my post above?

Jeff, Once we get back from Canada I'm headed to a electronics store to purchase the capacitor you mentioned. I talked to a factory rep in Burlington, Iowa and he suggested running a separate wire from the battery to the wall plate and the ac to dc converter. Hopefully I can get both the cap and ferrite beads, I will put both on the fan leads. I will let you know what the results are. Thanks for your input.
Bill_Satellite
Explorer II
Sep 04, 2013
I stand corrected and it does appear that as Jeff suggested it's the fan itself. It would be surprised (but certainly not impossible) if this was a Fantastic Fan unit but I would not be surprised if the fan you are talking about is one of those cheap, small noisy things that are just a motor and fan blades about 3" across.
If it does happen to be one of those crappy fans I would actually recommend that you update the fan for better circulation and noise reduction.
SCVJeff
Explorer
Sep 03, 2013
Did you read my post above?

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HDTV Receiving Interference

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