Jim-NN7K wrote:
One thing further- IF you check, you will see that the Physical
Size of a BNC (minus the connector locking outer ring) is the
same size as the N fitting! The "N" male will plug into a "BNC"
female,the BNC without its locking ring will plug into an "N"female!
There are temporary connectors to take advantage of this factor,
for testing (not permanent) connectors ! As info, Jim NN7K

I knew that. I have a home-made pair that I use from time-to-time in
the lab.

In article , ml
wrote:

The other thing i pondered is that it seems the don't make
Pl259/so239 connectors for hardline, so what do guys use typically for
higher power DIN?

ML-

I would expect hardline manufacturers to use a standard connector
intended for the power and frequency involved, but designed to fit the
end of their cable.

When hardline is chosen because of low loss rather than needing high
power, it is often used for long runs with a short flexible cable at the
end to connect to equipment. In this application, use of type N
connectors is common, with a female connector custom made to fit the
hardline.

You can get adapters for PL259/SO239, but those are lousy connectors for
RF. Their impedance is not constant from one end to the other!

Fred
K4DII

On Jan 10, 10:29*pm, Fred McKenzie wrote:
In article , ml
wrote:

The other * thing *i pondered * is that it seems * *the don't *make *
Pl259/so239 connectors for hardline, *so what do guys use *typically for *
higher *power * DIN?

ML-

I would expect hardline manufacturers to use a standard connector
intended for the power and frequency involved, but designed to fit the
end of their cable.

When hardline is chosen because of low loss rather than needing high
power, it is often used for long runs with a short flexible cable at the
end to connect to equipment. *In this application, use of type N
connectors is common, with a female connector custom made to fit the
hardline.

You can get adapters for PL259/SO239, but those are lousy connectors for
RF. *Their impedance is not constant from one end to the other!

Fred
K4DII

What I use on 7/8 hardline is a copper reducer with a barrel connecter
soldered
into one end and then I screw the combination over the hard line. Now
you have an output from the hardline that can fit most things . One
time I filled the copper reducer with dielectric before I inserted the
barrel connecter but could see no difference using max power.
Certainly a lot cheaper
than Andrews connectors and if the coax route is not ideal it is easy
and inexpensive to add flexible lengths at tight corners, such as
emerging from underground piping. Hardline gets extremely rigid and
the outer insulation is subject to cracking in the winter time which
is when I seem to have to work on things.
Art

"Art Unwin" wrote in message
...

"What I use on 7/8 hardline is a copper reducer with a barrel connecter
soldered into one end and then I screw the combination over the hard line.
Now you have an output from the hardline that can fit most things . One
time I filled the copper reducer with dielectric before I inserted the
barrel connecter but could see no difference using max power. Certainly a
lot cheaper than Andrews connectors and if the coax route is not ideal it
is easy and inexpensive to add flexible lengths at tight corners, such as
emerging from underground piping. Hardline gets extremely rigid and the
outer insulation is subject to cracking in the winter time which is when I
seem to have to work on things."

Just remember that the aluminum to copper galvanic couple promotes the
corrosion of the aluminum. Keep the contact areas as dry as possible if
you don't want problems. I have found that wrapping several layers of
tightly stretched vinyl electrical tape and then spraying the area with
clear Krylon® acrylic varnish does a reasonable job. But since water vapor
can diffuse through the tape, you will need to check the connection
periodically.

73, Dr. Barry L. Ornitz WA4VZQ

On Jan 11, 1:59*pm, "NoSPAM" wrote:
"Art Unwin" wrote in message

...

"What I use on 7/8 hardline is a copper reducer with a barrel connecter
soldered into one end and then I screw the combination over the hard line..
Now you have an output from the hardline that can fit most things . One
time I filled the copper reducer with dielectric before I inserted the
barrel connecter but could see no difference *using max power. *Certainly a
lot cheaper than Andrews connectors and if the coax route is not ideal it
is easy and inexpensive to add flexible lengths at tight corners, such as
emerging from underground piping. Hardline gets extremely rigid and the
outer insulation is subject to cracking in the winter time which is when I
seem to have to work on things."

Just remember that the aluminum to copper galvanic couple promotes the
corrosion of the aluminum. *Keep the contact areas as dry as possible if
you don't want problems. *I have found that wrapping several layers of
tightly stretched vinyl electrical tape and then spraying the area with
clear Krylon® acrylic varnish does a reasonable job. *But since water vapor
can diffuse through the tape, you will need to check the connection
periodically.

* * 73, *Dr. Barry L. Ornitz *WA4VZQ

All true Then copper reducer matched the copper outside of the
Andrews hardline that I use and it made its own thread as I screwed
it on. I don't believe I soldered that end like I did with the barrel
input tho I often apply a liberal spray of acrylic on those sort of
aplications to prevent the inside copper from going green not that I
have seen that sort of evidence The use of this type of connection at
points of sharp turns on the 1/2 acre
available for the tower away from the residence really works out
inexpensive compared to the Andrews connectors when connecting to
short lengths of Andrews 1/2 flexible coax.
When tussling with long heavy hardline in the winter it invariably
crackes or splits the plastic outer covering exposing the corregated
copper sheathing, so if it has to be moved or replaced it is better if
it is without bends of any sort, I have a long stretch in an
underground pipe which is easily removed as it is without kinks.As
far as the tape goes I find that the 3M professional roles become
subject to perishing so I don't use it any more tho I have plenty of
rolls on hand
Regards
Art

NoSPAM wrote:
"Art Unwin" wrote in message
...

"What I use on 7/8 hardline is a copper reducer with a barrel connecter
soldered into one end and then I screw the combination over the hard
line. Now you have an output from the hardline that can fit most things
. One time I filled the copper reducer with dielectric before I inserted
the barrel connecter but could see no difference using max power.
Certainly a lot cheaper than Andrews connectors and if the coax route is
not ideal it is easy and inexpensive to add flexible lengths at tight
corners, such as emerging from underground piping. Hardline gets
extremely rigid and the outer insulation is subject to cracking in the
winter time which is when I seem to have to work on things."

Just remember that the aluminum to copper galvanic couple promotes the
corrosion of the aluminum. Keep the contact areas as dry as possible if
you don't want problems. I have found that wrapping several layers of
tightly stretched vinyl electrical tape and then spraying the area with
clear Krylon® acrylic varnish does a reasonable job. But since water
vapor can diffuse through the tape, you will need to check the
connection periodically.

73, Dr. Barry L. Ornitz WA4VZQ

Use an elbow to get tight 90s.

http://www.eaa1000.av.org/technicl/c...n/galvanic.htm

"Dave" wrote in message
...
NoSPAM wrote:
"Art Unwin" wrote in message
...

"What I use on 7/8 hardline is a copper reducer with a barrel connecter
soldered into one end and then I screw the combination over the hard
line. Now you have an output from the hardline that can fit most things
. One time I filled the copper reducer with dielectric before I inserted
the barrel connecter but could see no difference using max power.
Certainly a lot cheaper than Andrews connectors and if the coax route is
not ideal it is easy and inexpensive to add flexible lengths at tight
corners, such as emerging from underground piping. Hardline gets
extremely rigid and the outer insulation is subject to cracking in the
winter time which is when I seem to have to work on things."

Just to clarify things, the above part is from Art. The following is mine.

Just remember that the aluminum to copper galvanic couple promotes the
corrosion of the aluminum. Keep the contact areas as dry as possible if
you don't want problems. I have found that wrapping several layers of
tightly stretched vinyl electrical tape and then spraying the area with
clear Krylon® acrylic varnish does a reasonable job. But since water
vapor can diffuse through the tape, you will need to check the
connection periodically.

73, Dr. Barry L. Ornitz WA4VZQ

Use an elbow to get tight 90s.

http://www.eaa1000.av.org/technicl/c...n/galvanic.htm

This is a good list because it covers many grades of aluminum and stainless
steel (but unfortunately not the 308 stainless alloy often used in wire and
nuts, bolts, and washers found in hardware stores). I wish it listed the
actual voltages referenced to a standard electrode however. Galvanic
couples of less than a tenth of a volt corrode very slowly and are often
acceptable depending on the application. I have found the following
article useful.
http://www.ocean.udel.edu/seagrant/p...corrosion.html

Also I would like to add that the Krylon sprayed over the vinyl tape is
very important. Being an acrylic, clear Krylon protects the vinyl from
ultraviolet damage.

73, Barry WA4VZQ

I see the center pin on a typical N connector is pretty small

How much power could it hold at HF and also uhf/vhf
frequencies? Assuming a modern day high quality N connector??

The power handling capability of a connector is determined by both its voltage
limit and its current limit, whichever of the two is more constraining.

The N connector voltage limit is usually stated to be 500V (peak), corresponding
to an RF power of 2,500W over 50-Ohm impedance. Please note that the 500V limit
applies to the extreme environmental and conditions (e.g. temperature, humidity)
so, for a normal usage, the connector would well withstand more than 500V.

Conversely, I was never able to find a specification for the N connector current
limit. This will actually depend on the usage conditions, i.e. whether a
round.the-clock broadcast service, or an intermittent amateur service. With a
power of 2,500W, the rms current through the connector would be about 7A (at 50
Ohm), a value that, given the size of the inner pin, I would consider well
tolerable for amateur service. For a broadcast service instead it would perhaps
be safe not to exceed 1,000W at VHF, or somewhat less at UHF.

The other thing i pondered is that it seems the don't make
Pl259/so239 connectors for hardline, so what do guys use typically for
higher power DIN?

The PL259 connectors are low-cost connectors that are simply unknown in the
professional world. Main reasons a
- they do not offer a controlled impedance across the connector length
- they are not sealed, and hence offering no protection against humidity
- the ground connection is unsafe. If the connector does not remain well
tigthened under all operational conditions, one can never be sure on the
continuity of the ground path.

For hardlines there is a good choice of connectors, see
http://www.surplussales.com/connectors /HardLConnIndex.html

73

Tony I0JX

Without actually researching it I suspect the power handling capacity
will be similar to the 1/2" line itself. When a N plug mates with a N
socket it presents the same Z as the line with pretty well the same
diameters. ie the small pin is not carrying the whole load. The RF
losses and subsequent heating will be a function of skin effect of
course. How well the pin is soldered will probably also make a small
difference. Arcover will be an interesting discussion though as there is
an air dielectric where the pieces join..

I guess you could work it out from known resistance of metals, allowing
for skin effect and what will happen first, arcing or melting - all at
50 ohms and a bit of ohms law. Lets face it though you can go and look
at manufacturers websites for this kind of info.

Hardline of larger diameters than an N connector use DIN connectors or
anything else that is "larger". If you are really wanting to know go and
have a look at something like the andrew website for data. You can of
course also reduce to N size using a suitable fitting.

Cheers Bob VK2YQA

ml wrote:
hi

Just wondering a few things

Bob Bob wrote:
Without actually researching it I suspect the power handling capacity
will be similar to the 1/2" line itself. When a N plug mates with a N
socket it presents the same Z as the line with pretty well the same
diameters. ie the small pin is not carrying the whole load.

The little pin is only a mating guide for a much larger center conductor.

I like 7/8" "Heliax". EIA connectors.