Do I need a grounded if my tv is connected to grounded coax?

Originally Posted By: Greg Fretwell
This post was automatically imported from our archived forum.



Perhaps you should look closer to the coax connectors going into interconnected data processing equipment. There is a plastic or fiber bushing under the connector. It is grounded at the controller end but the whole DC ground is floating in a terminal. It is isolated from AC/frame ground. DC ground is also isolated in your TV.


You really want a single grounding point.


If you are trying to stop the short duration transients that fry electronics you will find they are ramping up a lot faster than 60hz. That is why the language "straight" and "short" is used.
Most stuff is fairly hardy, mostly because MOVs are cheap and people get away with terrible grounding practices (from an electronic standpoint) but if you are serious about protecting your stuff you will be bonding all of your protectors to a single point ground, not the first available grounded point in the GE system.
Lightning protection was a big part of what I did for my last 15 years at IBM. I am right across the alley from you and we have a thunderstorm almost every day here too in the summer. People don't want to close the store/office/bank and unplug everything every afternoon. We had to learn what it takes to keep them going. When you are running Cat5 and Coax through a strip mall with 4 separate electrical services and all connected to a central server you start to think a little different about bonding and grounding. It certainly isn't just what will clear a fault.


Originally Posted By: bhendry
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Hey Jerry,


Here's a blast from the past for you:

Calibrating a scope and you find a microphonic 12AU7 - not the shield - not the chassis - not the socket - just the tube is the problem.

All you have in stock are 12AX7's. Nothing to adjust on either side of the 12AU7 circuit. And no, there is not another 12AU7 in the unit in a circuit that won't care about the microphonic tube that you can swap with.

Can you just pop in a new 12AX7 and drive on?

If you want to really go back - how about replacing a 5V4 with some silicon diodes?

Regards,

Bill


Originally Posted By: jpeck
This post was automatically imported from our archived forum.



Bill,


Those memories are some I no longer have ... at least not unless I were to try to dig deeper. ![icon_biggrin.gif](upload://iKNGSw3qcRIEmXySa8gItY6Gczg.gif)


--
Jerry Peck
South Florida

Originally Posted By: bhendry
This post was automatically imported from our archived forum.



Jerry,


If I recall correctly, the 12AU7 was a medium gain (mu) tube and the 12AX7 high gain. I was setting it up so the 12AX7 would be OK as a substitute.

Most of the time you could replace a 5V4 with a couple of diodes - I've soldered them directly to the socket - you used to be able to buy a solid state replacement that plugged in - woo hoo!

Regards,

Bill

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