TV RF connector capacitor function?

M

martin king

Guest
My RF connector was ripped out of the back of the TV and the Capacitor
connected to the center lead inside a small metal box was destroyed. I
reconnected the connector without the cap and it works. What is the function
of this cap? It is a BROWN/ORANGE DISK shape approx 1/2 the size of a penny.
Ceramic?
 
"martin king" <martik@telus.net> wrote in message
news:S1pab.2417$Ph5.630@edtnps84...
My RF connector was ripped out of the back of the TV and the Capacitor
connected to the center lead inside a small metal box was destroyed. I
reconnected the connector without the cap and it works. What is the
function
of this cap? It is a BROWN/ORANGE DISK shape approx 1/2 the size of a
penny.
Ceramic?
Click to expand...
Probably a DC blocking capacitor. If so, it's there to prevent DC from
damaging the tuner. I once had a very expensive and bad experience when a
DC blocking capacitor was absent; they can be very important.
 
You should mention the make and model number of the set, in order that
someone may have information about the exact part specification.

What will work if you do not know the exact cap specifications, you can use
a 420 pF / 1KV type. This cap is necessary for antenna isolation. Any cap
from about 330 pF to about 470 pF. Make sure that the voltage rating is at
least 1KV.

--

Greetings,

Jerry Greenberg GLG Technologies GLG
=========================================
WebPage http://www.zoom-one.com
Electronics http://www.zoom-one.com/electron.htm
Instruments http://www.zoom-one.com/glgtech.htm
=========================================


"martin king" <martik@telus.net> wrote in message
news:S1pab.2417$Ph5.630@edtnps84...
My RF connector was ripped out of the back of the TV and the Capacitor
connected to the center lead inside a small metal box was destroyed. I
reconnected the connector without the cap and it works. What is the function
of this cap? It is a BROWN/ORANGE DISK shape approx 1/2 the size of a penny.
Ceramic?
 
Subject: TV RF connector capacitor function?
From: "martin king" martik@telus.net
Date: 9/18/03 5:00 PM Eastern Daylight Time
Message-id: <S1pab.2417$Ph5.630@edtnps84

My RF connector was ripped out of the back of the TV and the Capacitor
connected to the center lead inside a small metal box was destroyed. I
reconnected the connector without the cap and it works. What is the function
of this cap? It is a BROWN/ORANGE DISK shape approx 1/2 the size of a penny.
Ceramic?
Click to expand...
Well, since you posted this it means you're still alive.

That's part of the isolation system of that TV which likely has a "hot" chassis
design. It prevents serious electric shock to someone who comes in contact with
the center lead and some sort of ground.

Locate a new assy and replace it before someone gets hurt.


John Del
Wolcott, CT

"Nothing is so opportune for tyrants as a people tired of its liberty."
Alan Keyes

(remove S for email reply)
 
"Charles Schuler" <charlesschuler@comcast.net> wrote in message
"martin king" <martik@telus.net> wrote in message

Probably a DC blocking capacitor. If so, it's there to prevent DC from
damaging the tuner. I once had a very expensive and bad experience when a
DC blocking capacitor was absent; they can be very important.

.......NO, not a DC blocking capacitor, although that is what a capacitor can
Click to expand...
do, BUT it is rather a SAFETY component that isolates the television's "hot
chassis" circuitry from external metal parts and external connections such
as the antenna connector.
FIRST.... UNPLUG the television IMMEDIATELY and either replace the entire
"isolation block" (the small metal box that you described) that would
include a new antenna connector and a plug at the other end that plugs into
the tuner.... or replace the capacitor with the exact original equipment
value and rating. Again, this is a electrical shock hazard SAFETY item,
not just a tuner protection component. An omitted or wrong type of
capacitor can present a lethal and dangerous electrical shock hazard and a
fire hazard..... repair this correctly with the proper replacement
isolation block..
--
Best Regards,
Daniel Sofie
Electronics Supply & Repair
 
"Sofie" bravely wrote to "All" (18 Sep 03 17:15:48)
--- on the heady topic of "Re: TV RF connector capacitor function?"

I think this part combines a small value capacitor in parallel with a
large value resistance inside the same package. The capacitive part is
to create the RF path and the resistive part is to safely discharge the
antenna static. Some circuits vary in how complex the part is but the
voltage rating seems to be very important.


So> From: "Sofie" <sofie@olypen.com>

So> "Charles Schuler" <charlesschuler@comcast.net> wrote in message
"martin king" <martik@telus.net> wrote in message

Probably a DC blocking capacitor. If so, it's there to prevent DC from
damaging the tuner. I once had a very expensive and bad experience when a
DC blocking capacitor was absent; they can be very important.

So> ......NO, not a DC blocking capacitor, although that is what a
Click to expand...
So> capacitor can do, BUT it is rather a SAFETY component that isolates the
So> television's "hot chassis" circuitry from external metal parts and
So> external connections such as the antenna connector.
So> FIRST.... UNPLUG the television IMMEDIATELY and either replace the
So> entire "isolation block" (the small metal box that you described) that
So> would include a new antenna connector and a plug at the other end that
So> plugs into the tuner.... or replace the capacitor with the exact
So> original equipment value and rating. Again, this is a electrical
So> shock hazard SAFETY item, not just a tuner protection component. An
So> omitted or wrong type of capacitor can present a lethal and dangerous
So> electrical shock hazard and a fire hazard..... repair this correctly
So> with the proper replacement isolation block..
So> --
So> Best Regards,
So> Daniel Sofie
So> Electronics Supply & Repair

.... Letterman of Borg - "Ok, Top 10 reasons why resistance is futile:"
 
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