Topband: Verifying integrity of 75 ohm coax.

[Gary Smith]

Tom & all those that replied,

Thanks for the replies. I do have a 259B I bought off of fleabay 
several years ago & no manual came with it. I only wanted it for SWR 
readings to adjust my vertical wires since opening the box. 

I just downloaded the manual on PDF and read the "advanced" section 
dealing with distance to fault. Sorry to say I must not be as sharp 
as I used to be and I can't tell from what I've read if the RG6U 
needs a termination for this distance to fault test or if the coax is 
unterminated. Since it's the weekend I can't call MFJ but perhaps 
someone knows this answer & can let me know so I can have at it 
tomorrow.

Apparently I'll need to find the velocity factor of this particular 
RG6U and then can do the math they describe. I just need to know if I 
test this on an open coax or with a 75 ohm carbon resistor at the 
distal end of this 75 ohm coax (or 50 ohm on RG-8). And, does it 
matter if I use either of the  SO239 or the BNC ? 

Thanks for the pointers.

73

Gary
KA1J

> >I need to isolate if a problem I am having is in a faulty 75 ohm
> coax
> > (Remee RG6U flooded variety) where either a critter bit into the
> coax
> > or a Snap-&-Seal 6QS connector failed, or an electronics issue is
> the
> > culprit.
> >
> > What's my most expeditious way to prove if it is or is not the
> Coax?
> 
> MFJ analyzers, such as the MFJ-259B, have a distance-to-fault
> function. I 
> use it on my system, and can find a problem within a few feet on a
> 2000-3000 
> foot cable.
> 
> Of course a creative person could do the same thing with a simple RF
> generator, a T connector, and some way of measuring signal level at
> one port 
> of the T.
> 
> 73 Tom 
> 
> 




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