Tag Archives: TVI

Before getting back into ham radio, I did something that I later found to be not optimal – I purchased a very nice 50″ plasma TV.  It sounds like everyone else’s YouTube video of Plasma TV RFI, but if you want to see mine, the video is below.

I’ve looked into different solutions that remove noise based on a noise antenna, like the MFJ-1025 Noise Canceler.  I believe these items work by inverting the phase of the noise and mixing it back with the signal to remove the noise. It is absolutely critical that these items have a great noise antenna in order to remove it.

The real issue I have is shown in the video above – the noise is picked up in the antenna.  I believe that it is primarily picked up by the feed line because it is near (enough) to the front of the TV.  See the diagram below:

Diagram of TV and Feedline Interaction

So in order to use a noise canceling device, I’d need an antenna along my feed line.

I decided to try something else first – shielding my coax.  I bought a pair of lengths of EMT conduit to run the coax in.  This has a second advantage of being able to run coax really quickly.  The only disadvantage is that I can’t use ladder line in it.  Given the situation, no big loss.

Basement End of Cable

So right now, this is where I’m at.  My HF feed line is crummy RG-58 that has an aluminum shield (insert angry face), so I haven’t tested it yet because I don’t have any crimp PL-259 connectors (nor do I have aluminum solder).  Additionally, if this doesn’t work like this, I will ground the conduit to see if that fixes it.  If neither does, I’m sure that conduit would be an adequate noise antenna for a noise canceling device.

In other news…

I’ve been virtually off the air because of a problem with my IC-706.  I posted something to Google+ and received a response that I need to look into, but I’m still looking for more clues as to why I’m getting major static on FM receive.

The filter sweeper is “stalled” because of work on other things.  I will be getting back into it because I may want (or need) it for that crystal IF filter problem indicated in the G+ post mentioned above.

-73-


Category: Equipment
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