Is there a way to make it work or do I need to take the pl 259
connectors back? I found some r6 8/u but it is 78 cents a foot! I am
just wanting something to test some antennas but am afraid of inacurate
swr readings.

Is there a way to make it work or do I need to take the pl 259
connectors back? I found some r6 8/u but it is 78 cents a foot! I am
just wanting something to test some antennas but am afraid of inacurate
swr readings.

Stryped-

AOL doesn't have your other message about RG-6 vs RG-58, so I'll try to address
both.

When testing antennas, one measure is standing wave ratio (SWR), often read
using a "reflectometer" SWR bridge, that actually measures relative forward and
reflected power but has a scale calibrated in SWR. You may find more
information about this at the Bird Electronics web site,
http://www.bird-electronic.com/.

Such an instrument is accurate only if the cable between the bridge and the
antenna has the same characteristic impedance as the bridge. For 50 Ohm cable,
you need a 50 Ohm bridge. In this case, a resonant antenna with an impedance
of 50 Ohms, has an SWR of 1.00:1 (one-to-one).

If you do not have 50 Ohm co-ax, simply make your measurements with the SWR
bridge AT the antenna. Even if you have 50 Ohm co-ax, loss due to heating of
the cable at higher frequencies will cause the SWR to look better than it
really is. Moving the bridge closer to the antenna has an advantage in that
case as well. However, using relatively short lengths should not cause much of
a problem up to about 150 MHz.

I don't know how to attach PL-259 connectors to RG-6. To attach them to RG-58,
you need an adapter that matches the outer diameter of the cable to the inner
diameter of the connector. Since the PL-259 is so commonly used with radio
equipment, I suggest you keep them and learn about attaching them to RG-58 and
RG-8 cables.

The RG-6 is a low-loss cable commonly used in the cable TV industry. As nice
as it is, its 75 Ohm impedance will cause serious errors in your antenna
measurements if used between the instruments and the antenna. I suggest you
steer clear of it for your experimental work. (If you have a 75 Ohm bridge and
are working with a 75 Ohm antenna, that is another story!)

73, Fred, K4DII

Fred McKenzie wrote:
Is there a way to make it work or do I need to take the pl 259
connectors back? I found some r6 8/u but it is 78 cents a foot! I am
just wanting something to test some antennas but am afraid of
inacurate
swr readings.

Stryped-

AOL doesn't have your other message about RG-6 vs RG-58, so I'll try
to address
both.

When testing antennas, one measure is standing wave ratio (SWR),
often read
using a "reflectometer" SWR bridge, that actually measures relative
forward and
reflected power but has a scale calibrated in SWR. You may find more
information about this at the Bird Electronics web site,
http://www.bird-electronic.com/.

Such an instrument is accurate only if the cable between the bridge
and the
antenna has the same characteristic impedance as the bridge. For 50
Ohm cable,
you need a 50 Ohm bridge. In this case, a resonant antenna with an
impedance
of 50 Ohms, has an SWR of 1.00:1 (one-to-one).

If you do not have 50 Ohm co-ax, simply make your measurements with
the SWR
bridge AT the antenna. Even if you have 50 Ohm co-ax, loss due to
heating of
the cable at higher frequencies will cause the SWR to look better
than it
really is. Moving the bridge closer to the antenna has an advantage
in that
case as well. However, using relatively short lengths should not
cause much of
a problem up to about 150 MHz.

I don't know how to attach PL-259 connectors to RG-6. To attach them
to RG-58,
you need an adapter that matches the outer diameter of the cable to
the inner
diameter of the connector. Since the PL-259 is so commonly used with
radio
equipment, I suggest you keep them and learn about attaching them to
RG-58 and
RG-8 cables.

The RG-6 is a low-loss cable commonly used in the cable TV industry.
As nice
as it is, its 75 Ohm impedance will cause serious errors in your
antenna
measurements if used between the instruments and the antenna. I
suggest you
steer clear of it for your experimental work. (If you have a 75 Ohm
bridge and
are working with a 75 Ohm antenna, that is another story!)

73, Fred, K4DII
Forgive my ignormance, but what are you calling "bridge" the radio?

Forgive my ignormance, but what are you calling "bridge" the radio?

Stryped-

You said you wanted to make SWR readings. An instrument used to read SWR is
also called an SWR Bridge.

Perhaps it is a misnomer based on the use of a simple "balanced bridge" circuit
for measuring unknown resistances by comparing them with known standard
resistors.

73, Fred, K4DII

I don't know how to attach PL-259 connectors to RG-6. To attach them to
RG-58,
you need an adapter that matches the outer diameter of the cable to the
inner
diameter of the connector. Since the PL-259 is so commonly used with
radio
equipment, I suggest you keep them and learn about attaching them to RG-58
and
RG-8 cables.
====================
There are also PL259 connectors with internal thread to suit RG58 coax
directly .
For fitting coax strip a short length of sheath ,fold braid back over
sheath ,strip polyethylene to say 1mm from braid end ,screw coax end covered
with braid into connector ,solder centre conductor to connector tip.
I prefer this type of connector over a PL259 for 10mm (3/8inch) coax with a
screwed adaptor.

I use RG58 coax for short patch leads only.

Frank GM0CSZ / KN6WH