[TowerTalk] Making and testing coax jumpers with PL-259 connectors

[Tom Rauch]

> Tom, is there a simple way to perform that high voltage
test?

I use a surplus HV power supply from a junk computer
monitor. Copy machine and many other things have HV supplies
inside.

I just added an internal very sensitive current and high
voltage meter, a variable voltage supply, and a nice box and
now I have a 3-15kV high voltage testing machine.

> Could you test the jumper with high power RF to a dummy
load for a few
> seconds and monitor the SWR?

No. When connectors are properly installed, they will flash
over outside at the air gaps before arcing internally. They
will also not show a gradual increase in leakage current as
voltage is increased. A typical good PL-259 will flash over
at over 5kV dc from the pin to the shell edge.

> All my experience is with 100W or less. When I make coax
jumpers, I usually
> just visually inspect the solder joints, check for shorts
between center pin
> and shield, and check for continuity from center
pin-to-center pin, and from
> shell-to-shell.

None of that checks for the common problem of a stray
strand. You'd be suprised how many commercially manufactured
cables have loose copper strands in the connectors where you
can't see them.

73 Tom