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hum and grounding
In , on 08/18/03
at 06:35 PM, (Dave Platt) said:
[ ... ]
Well, today I had to do it again. I went to Rat Shack and bought two
baluns --
an "inline" one with a female F-connector and pigtails for the 300-ohm
lead, and a compact one with a push-on male F connector and screw
terminals for the 300-ohm side. (This type is often supplied with TV
sets.) Before hooking things up, I got out my trusty Fluke and
measured the baluns. (Gasp, what a concept!)
It turns out that the in-line one is a true transformer -- there's no
common connection between the 300 ohm and 75 ohm sides. The compact
one does have a common connection, but of course any single break in
the "ground" chain is sufficient.
[ ... ]
Years ago, I had to make my own cable TV isolators. Rather than trying
to explain to the electronics store counter person what I was
attempting to accomplish, I asked for them to fetch a pile of baluns,
which I then sorted through with my Ohmmeter. To them, all baluns were
alike (a mystery) and they could not understand why I only wanted
certain ones.
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SPAM:
wordgame:123(abc):14 9 20 5 2 9 18 4 at 22 15 9 3 5 14 5 20 dot 3 15
13 (Barry Mann)
[sorry about the puzzle, SPAMers are ruining my mailbox]
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