[RFI] Observations of a low RFI Plasma TV and a very bad RFI plasma - same QTH

[Kirby Hallenbeck]

Since so much has been posted about how Plasma TV's are bad RFI generators,
the following post may be interesting to those who prefer the picture
quality of plasma and require low RFI.  Jim K9YC requested I repost it here,
from the Elecraft reflector.  Jim's comments are followed by the original
post. I will also note that another owner of the same set wrote me off list
to say he had the same low RFI experience. So perhaps the all plasmas are
bad is not true, and really comes down to how the sets are engineered. I
will also note I took apart the Samsung ( to harvest boards for resale)  Jim
refers to below and found there is a lot of long between board interconnect,
that could radiate, so Jim's theory has much merit IMO. I did have overkill
chokes and turns on every cable in and out of the bad TV  BTW. 

 

On 9/10/2012 8:12 PM, Kirby Hallenbeck wrote:

> I will also note that both sets were treated with the large ferrite cores

> K9YC did the group buy on a while back and I haven't done a before after

> cores on the Panasonic, as I just put them on when I installed it.  I did
do

> a before after on the Samsung and although it helped the Samsung was so
bad

> that I couldn't totally suppress it.

 

Kirby -- PLEASE post your excellent and detailed observations on the RFI 

reflector.

 

One observation about the result of your application of chokes. I'm 

thinking particularly of the Samsung box, but the concept applies to ALL 

equipment.  Chokes on cables leaving a noise source, or entering a 

victim, kill the part of the RFI that is conducted out of the set on 

those cables and RADIATED by those cables acting as antennas. Chokes 

cannot do anything about the trash that is radiated by WIRING INSIDE THE 

BOX. So -- the trash you heard after you applied the chokes, assuming 

that the chokes were ENOUGH to kill current those external wires, the 

remaining trash was from inside the box, and you'll never kill it 

without a major science project inside the box.

 

Original post on Elecraft Relflector

 

Message: 7

Date: Mon, 10 Sep 2012 20:12:47 -0700

From: "Kirby Hallenbeck" <1sailorman at comcast.net>

Subject: [Elecraft] K3 3 & Plasma - Panasonic owner experience

To: <elecraft at mailman.qth.net>

Message-ID: <011b01cd8fcb$524e7920$f6eb6b60$@net>

Content-Type: text/plain;     charset="us-ascii"

 

I have the predecessor of the Panasonic you are looking at, a TC-P65VT30,

which was manufactured August 2011. I can tell you that mine is surprisingly

quiet. I had a Samsung 58b860y2fxza prior to this that was unbelievably

obnoxious, to the point I had to turn it off to communicate on my morning

75m net and it splattered other bands too. I could actually here the noise

pattern change in response to changes in the raster on the TV. 

 

I was lucky, in an RF sense, my disabled son cracked the screen on the

Samsung, forcing me to re-evaluate brands. Since I put way through college

fixing TV's among other things, I have pretty extensive contacts with people

still in that business, and they all gave the nod to Panasonic, when it

comes to Plasma, from reliability, to picture, to support from the manuf.

After seeing both companies, I tend to agree. I wrote Samsung about the

issue requesting they address the issue and they didn't even respond. The

servicers don't like Samsung either, so steer clear of them. You will

absolutely love the Panny set. As a past servicer with very picky eyes that

like the CRT look, you will not have any regrets, unless you are looking for

super bright LCD fluorescent display, which to me is not the (natural) look

I like. 

 

I will also note that both sets were treated with the large ferrite cores

K9YC did the group buy on a while back and I haven't done a before after

cores on the Panasonic, as I just put them on when I installed it.  I did do

a before after on the Samsung and although it helped the Samsung was so bad

that I couldn't totally suppress it. 

 

For those not familiar with the Model numbers, the sets we are talking about

are/were the flagship models, so mileage may vary on lower end models. 

 

Kirby - AF6OP

 

> Subject: Re: [Elecraft] K3 & Plasma Question

> 

> 

>> We are now in the market for another TV, and have been looking at a very

nice Panasonic 65" Plasma set, model TC-P65VT50. I've already told the Best

Buy sales manager that IF we do buy it and IF it causes QRN to the HF bands,

it is coming right back. He said that is no problem. But, if I can query

this group to see if anyone else has one of these TV's, I may be able to

avert a lot of work ahead of time. Our second choice would be an LED set,

but after seeing plasma and LED side by side, playing the exact same

content, I want to stay with plasma - BUT ONLY IF IT DOESN"T SCREW UP THE

K3!!!

>>