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Old June 5th 10, 10:49 PM posted to rec.radio.amateur.antenna
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Posts: 115
Default BNC connectors 75 Ohm versus 50 Ohm?

I recently was able to use a crimp on tool for F connectors for RG-6 quad
shield coax. To make sure everyone understands, I am in Israel, and RG-6
quad shield coax is cheap and easy to find.

Any other coax is almost impossible to find. Pl-259 connectors, called
"UHF" connectors here are rare items. I can get them locally, but I have
to special order them and they are expensive. Since I can not see them
before I order them, I am as likely to get nickle plated ones with
phenolic insulation as I am to get any other kind, and once ordered are
not returnable.

BNC to PL-259 adaptors, are easy to get, and can be ordered from a reliable
local souce for a relatively small price. The same with N to PL-259.

Looking around at the crimp-on F connectors before I ordered them, I found
that you can get crimp on BNC connectors for RG-6 quad shield coax.

Here's my questions, Note when I say crimp-on, I mean the ones that crimp
from the rear, like commerical F connectors, not the ones that crimp
around the plug. I have never been able to get any of them to "fit right":

1. Can I connect a 75ohm BNC plug (which is a different size) to a
50oHm BNC socket?

2. Are there crimp on 50 ohm BNC plugs which will work with RG6 quad shield?
I know there are variations, but most are similar in size.

3. Are there crimp on N connectors that would fit the RG6 quad shield coax?
More likely due to the size a crimp on center element that screws into the
plug body?

4. Are there crimp on PL-259 connectors?

Thanks in advance,

Geoff.

--
Geoffrey S. Mendelson, Jerusalem, Israel N3OWJ/4X1GM
New word I coined 12/13/09, "Sub-Wikipedia" adj, describing knowledge or
understanding, as in he has a sub-wikipedia understanding of the situation.
i.e possessing less facts or information than can be found in the Wikipedia.
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Old June 6th 10, 12:03 AM posted to rec.radio.amateur.antenna
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Posts: 1,169
Default BNC connectors 75 Ohm versus 50 Ohm?

"Geoffrey S. Mendelson" wrote in
:

I recently was able to use a crimp on tool for F connectors for RG-6
quad shield coax. To make sure everyone understands, I am in Israel,
and RG-6 quad shield coax is cheap and easy to find.

Any other coax is almost impossible to find. Pl-259 connectors, called
"UHF" connectors here are rare items. I can get them locally, but I
have to special order them and they are expensive. Since I can not see
them before I order them, I am as likely to get nickle plated ones
with phenolic insulation as I am to get any other kind, and once
ordered are not returnable.

BNC to PL-259 adaptors, are easy to get, and can be ordered from a
reliable local souce for a relatively small price. The same with N to
PL-259.

Looking around at the crimp-on F connectors before I ordered them, I
found that you can get crimp on BNC connectors for RG-6 quad shield
coax.

Here's my questions, Note when I say crimp-on, I mean the ones that
crimp from the rear, like commerical F connectors, not the ones that
crimp around the plug. I have never been able to get any of them to
"fit right":

1. Can I connect a 75ohm BNC plug (which is a different size) to a
50oHm BNC socket?


There is such a thing as a 75 ohm BNC connector, but you are almost
certainly looking at 50 ohm connectors designed for use on 75 ohm cable.
My recollection is that the 75 ohm connectors are incompatible with the
50 ohm connectors, and in some combinations will spread the female inner
part.


2. Are there crimp on 50 ohm BNC plugs which will work with RG6 quad
shield?
I know there are variations, but most are similar in size.

Yes, see http://www.vk1od.net/transmissionline/RG6/index.htm .

3. Are there crimp on N connectors that would fit the RG6 quad shield
coax?


I haven't seen any. I use BNC compression connectors on the RG6, then
BNC/N adapters to connect to the antenna N connector. Works fine, all
waterproof.

More likely due to the size a crimp on center element that screws
into the plug body?

4. Are there crimp on PL-259 connectors?


Yes. They have most of the disadvantages of the PL-259.

If you are of the view that everything that comes out of China, leave
now.

I buy N, BNC, UHF, etc connectors that are of Chinese original that are
economical and excellent quality. But... you have to be picky, price is
not a good indicator of quality.

There is also a prejudice against RG6. Again, quality varies, and you
need to inspect carefully and test product that you might use.

Owen

Thanks in advance,

Geoff.


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Old June 6th 10, 01:04 AM posted to rec.radio.amateur.antenna
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Posts: 115
Default BNC connectors 75 Ohm versus 50 Ohm?

Owen Duffy wrote:

There is such a thing as a 75 ohm BNC connector, but you are almost
certainly looking at 50 ohm connectors designed for use on 75 ohm cable.
My recollection is that the 75 ohm connectors are incompatible with the
50 ohm connectors, and in some combinations will spread the female inner
part.


Thanks,

The ad I saw said they were 75 ohm. If they really are 50 ohm connectors
for 75 ohm cable, so much the better. Without buying them, I have no way
to tell, and it's awfully expensive to buy one or two.

Shipping from the US to here runs between $20 (USPS) and $50 (FEDEX/DHL/UPS)
for anything. I was going to buy $10 worth of soldering iron tips from
Farnell, and they wanted a flat rate of $35 to ship them. :-(

Yes, see http://www.vk1od.net/transmissionline/RG6/index.htm .

I haven't seen any. I use BNC compression connectors on the RG6, then
BNC/N adapters to connect to the antenna N connector. Works fine, all
waterproof.


Wonderful, thanks.


I buy N, BNC, UHF, etc connectors that are of Chinese original that are
economical and excellent quality. But... you have to be picky, price is
not a good indicator of quality.


URLs??? Please.

There is also a prejudice against RG6. Again, quality varies, and you
need to inspect carefully and test product that you might use.


As in everything in life. :-)

Geoff.


--
Geoffrey S. Mendelson, Jerusalem, Israel N3OWJ/4X1GM
New word I coined 12/13/09, "Sub-Wikipedia" adj, describing knowledge or
understanding, as in he has a sub-wikipedia understanding of the situation.
i.e possessing less facts or information than can be found in the Wikipedia.
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Old June 6th 10, 01:54 AM posted to rec.radio.amateur.antenna
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Posts: 1,336
Default BNC connectors 75 Ohm versus 50 Ohm?

On Sat, 5 Jun 2010 21:49:32 +0000 (UTC), "Geoffrey S. Mendelson"
wrote:

I recently was able to use a crimp on tool for F connectors for RG-6 quad
shield coax.


Hopefully, it was a "push-on" tool and connector
http://www.arrisistore.com/digicon/Digicon-F-Connector-Installation-Guide.pdf
not the piece of junk with the small crimped ring.

To make sure everyone understands, I am in Israel, and RG-6
quad shield coax is cheap and easy to find.


There's quality RG-6a/u and junk. On the left coast of the USA, we
have both in copious quantities. I obtain mine directly from a
satellite DTV install company, so the quality is more towards quality
than junk.

Pl-259 connectors, called
"UHF" connectors here are rare items.


Be thankful. I find them to be a necessary evil as most ham radios
require them. Meanwhile, commercial radios are moving away from UHF
and toward other connectors, such as Type-N, BNC, TNC, Mini-UHF, and
SMA. However, Comerica base antennas remain UHF or Type-N.

BNC to PL-259 adaptors, are easy to get, and can be ordered from a reliable
local souce for a relatively small price. The same with N to PL-259.


That's what I do. Most of my cables are NOT terminated with UHF
connectors. If I need to go to UHF, I use an adapter.

Looking around at the crimp-on F connectors before I ordered them, I found
that you can get crimp on BNC connectors for RG-6 quad shield coax.


Yes, they work. I use quite a bit of RG-6a/u and prefer to have
everything terminated by the same connector, which is the CATV
standard F connector. If I need BNC, I use an adapter.

Here's my questions, Note when I say crimp-on, I mean the ones that crimp
from the rear, like commerical F connectors, not the ones that crimp
around the plug. I have never been able to get any of them to "fit right":


Agreed. The good ones are "push on" F connectors.

1. Can I connect a 75ohm BNC plug (which is a different size) to a
50oHm BNC socket?


There are such things as real 75 ohm BNC plugs and jacks. They're
easy to recognize because they lack the PTFE dielectric. The 75 ohm
connectors will mate properly with the 50 ohm connectors. There is
little risk of VSWR problems from using 50 ohm connectors on RG-6a/u.
http://www.qsl.net/n9zia/wireless/75_ohm_hardline.html
Basically, any small loss from VSWR is compensated by the lower loss
per meter of RG-6a/u as compared to RG-58a/u. Methinks you're safe
using all 50 ohm connectors.[1]

2. Are there crimp on 50 ohm BNC plugs which will work with RG6 quad shield?
I know there are variations, but most are similar in size.


They're nearly identical in dimensions. The 50 ohm variety have some
manner of PTFE dielectric. The 75 ohm variety use a plastic disk and
no dielectric.
http://www.amphenolconnex.com/products/bnc.asp
"50 ohm and 75 ohm connectors are intermateable to ensure
non-destructive mating"
The catch is that there's no guarantee that this is true between
different manufacturers. I've blundered across mutations and
variations that are NOT interchangeable.

3. Are there crimp on N connectors that would fit the RG6 quad shield coax?
More likely due to the size a crimp on center element that screws into the
plug body?


Probably, but I wouldn't use one. Just terminate in an F connector,
and use an F to N adapter. The price will probably be the same or
less. However, if you must go direct, any N connector that will fit
RG-59a/u will usually work with RG-6a/u. The problem is that
depending on the number of shields in the RG-6a/u, the outer diameter
will vary, making the diameter of the crimp ring an issue. Doing this
is risky and may result in a non-fitting connector. I would use an
adapter, which will always work.

4. Are there crimp on PL-259 connectors?


Also probably, but again, methinks you're better off with an F
connector and an adapter.

[1] I just counted 7 assorted coaxial cables going between my roof and
various RF devices in my house. All but one are 75 ohm RG-6a/u. Some
are double shielded, while others are quad shielded. The connectors
are slightly different. All the HF and VHF/UHF antennas use 75 ohm
coax. The one 50 ohm LMR-400 run is for the 900MHz antenna.

--
Jeff Liebermann
150 Felker St #D
http://www.LearnByDestroying.com
Santa Cruz CA 95060 http://802.11junk.com
Skype: JeffLiebermann AE6KS 831-336-2558
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Old June 6th 10, 02:19 AM posted to rec.radio.amateur.antenna
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Posts: 115
Default BNC connectors 75 Ohm versus 50 Ohm?

Jeff Liebermann wrote:

Hopefully, it was a "push-on" tool and connector
http://www.arrisistore.com/digicon/Digicon-F-Connector-Installation-Guide.pdf
not the piece of junk with the small crimped ring.


Thanks,

Yes, but mine looks more like a nut cracker, however it works the same
way.

Be thankful. I find them to be a necessary evil as most ham radios
require them. Meanwhile, commercial radios are moving away from UHF
and toward other connectors, such as Type-N, BNC, TNC, Mini-UHF, and
SMA. However, Comerica base antennas remain UHF or Type-N.


Me too. Since all of the ham radios I have were either brought from the
US in 1996 when I moved here, or even older ones brought here, they use
Pl-259's or in one case an RCA jack (Drake SP-R4) for the antenna.

TV sets still use the Belling-Lee plugs (called PAL connectors in the US)
and so do VCRs. Everything else uses F connectors (cable TV, Satellite TV)
although RF outputs to TV sets have gone the way of the VCR.

DVB is just starting here and the tuners use Belling-Lee connectors. F
to Belling-Lee adaptors are common here, and even in the US, where Radio
Shack sells them.


That's what I do. Most of my cables are NOT terminated with UHF
connectors. If I need to go to UHF, I use an adapter.


They are also hard to get and expensive.


Yes, they work. I use quite a bit of RG-6a/u and prefer to have
everything terminated by the same connector, which is the CATV
standard F connector. If I need BNC, I use an adapter.


OK, So where do you get your adaptors?


Agreed. The good ones are "push on" F connectors.


I gave up about 10 years ago and used the cheap screw on ones because they
gave me a better fit than the crimp "around" types. The push on ones
are a lot better.



There are such things as real 75 ohm BNC plugs and jacks. They're
easy to recognize because they lack the PTFE dielectric. The 75 ohm
connectors will mate properly with the 50 ohm connectors. There is
little risk of VSWR problems from using 50 ohm connectors on RG-6a/u.


ok.

http://www.qsl.net/n9zia/wireless/75_ohm_hardline.html
Basically, any small loss from VSWR is compensated by the lower loss
per meter of RG-6a/u as compared to RG-58a/u. Methinks you're safe
using all 50 ohm connectors.[1]


Good, thanks.

[1] I just counted 7 assorted coaxial cables going between my roof and
various RF devices in my house. All but one are 75 ohm RG-6a/u. Some
are double shielded, while others are quad shielded. The connectors
are slightly different. All the HF and VHF/UHF antennas use 75 ohm
coax. The one 50 ohm LMR-400 run is for the 900MHz antenna.


That's not an issue, 900mHz is not a ham band here, and 1.gHz too short
range to consider using. I think there is one 1.2gHz repeater in the country,
and I can't hit the co-located 2m repeater anyway.

Geoff.


--
Geoffrey S. Mendelson, Jerusalem, Israel N3OWJ/4X1GM
New word I coined 12/13/09, "Sub-Wikipedia" adj, describing knowledge or
understanding, as in he has a sub-wikipedia understanding of the situation.
i.e possessing less facts or information than can be found in the Wikipedia.


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Old June 6th 10, 03:42 AM posted to rec.radio.amateur.antenna
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Posts: 1,336
Default BNC connectors 75 Ohm versus 50 Ohm?

On Sun, 6 Jun 2010 01:19:04 +0000 (UTC), "Geoffrey S. Mendelson"
wrote:

That's what I do. Most of my cables are NOT terminated with UHF
connectors. If I need to go to UHF, I use an adapter.


They are also hard to get and expensive.


My guess(tm) is that they are less expensive than oddities such as an
N-connector for RG-6a/u. They also have the advantage of being
reusable. When you destroy your coax cable, just unscrew the adapters
and use a new F connector.

I sometimes have to make my own adapters. It's not because the
adapter is unavailable or hard to find. It's because the accumulated
length of the connectors and adapters can get quite long. There are
also mechanical considerations, where an N to SMA adapter will surely
break at the SMA when the heavy cable is bent. For SMA and Mini-UHF
adapters, I sometimes use short pigtails to act as a strain relief.

OK, So where do you get your adaptors?


It varies. Once a year, I got to one local hamfest and stock up. I
like to see the connectors to make sure they're not junk. I typically
buy about $150 worth every year. Much of it disappears during Field
Day. The problem is that most of this stuff is nickel plated. Nickel
is fine for systems which are not potentially affected by
intermodulation issues. Therefore, I'll use them at home, Field Day,
other hams stations, and my mobile. I won't use them for repeaters,
mountain top sites, and microwave links.
http://www.amphenolrf.com/simple/PIM%20Paper.pdf
http://www.repeater-builder.com/antenna/pdf/andrew-braid-over-foil-imd.pdf
http://www.repeater-builder.com/antenna/pdf/recommended-coax-and-connectors-for-iden.pdf

For repeaters, I use silver plated connectors, when I can get them.
Gold plating is an option, but under the gold is a layer of nickel,
which worries me a little (most of the RF flows on the surface). Tin
plate also works. I buy most of my connectors from RF Industries:
http://www.rfcoaxconnectors.com
Their mix is really bizarre. They offer Nickel, Tin, Silver and Gold
plating, but not in every type of connector. For example, F adapters
are available only in Nickel or Gold, while UHF connector are only
available in Nickel and Silver. Trying to avoid dissimilar metals is
difficult.

Other sources are eBay, various online dealers, the local electronics
sto
http://www.santacruzelectronics.com
the local cable company, and the local DTV satellite installation
company. The latter are my best sources of RG-6a/u and F connectors.
I once obtained a free bucket full of filthy connectors that someone
had left in the rain. Rather than clean them, they went to me,
instead of the recyclers. There were literally hundreds of F
connectors in the bucket.

If you're working on the HF and VHF bands, you can probably just
solder two connectors together to make an adapter. I have a bunch of
BNC to UHF adapter I made this way. The BNC panel jack fits nicely
into the PL-259 connector. The losses are not signifigant, even at
microwave (2.4GHz) frequencies:
http://802.11junk.com/jeffl/antennas/connector-loss/
I've done 8 ft chains of adapters with similar results.

I don't know what to suggest. It sounds like getting someone in
Europe to throw together a collection of connectors for you seems
easier than importing them one at a time.

--
Jeff Liebermann
150 Felker St #D
http://www.LearnByDestroying.com
Santa Cruz CA 95060 http://802.11junk.com
Skype: JeffLiebermann AE6KS 831-336-2558
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Old June 6th 10, 04:39 AM posted to rec.radio.amateur.antenna
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First recorded activity by RadioBanter: Nov 2009
Posts: 115
Default BNC connectors 75 Ohm versus 50 Ohm?

Jeff Liebermann wrote:

My guess(tm) is that they are less expensive than oddities such as an
N-connector for RG-6a/u. They also have the advantage of being
reusable. When you destroy your coax cable, just unscrew the adapters
and use a new F connector.


I don't know. I've never seen them.


OK, So where do you get your adaptors?


It varies. Once a year, I got to one local hamfest and stock up.


What's a hamfest? There are none here.

http://www.rfcoaxconnectors.com


I'll check them out.

Their mix is really bizarre. They offer Nickel, Tin, Silver and Gold
plating, but not in every type of connector. For example, F adapters
are available only in Nickel or Gold, while UHF connector are only
available in Nickel and Silver. Trying to avoid dissimilar metals is
difficult.


It's less important here. It rains about 14 days a year spread over 6
months. It rained for about 10 minutes in April, has looked like, but did
not rain at all in May, and won't do it again until around November 1.

http://www.santacruzelectronics.com


I'll look at them too.

I don't know what to suggest. It sounds like getting someone in
Europe to throw together a collection of connectors for you seems
easier than importing them one at a time.


Actually that's a myth. While I am geographicaly closer, postage from the
US is much cheaper than Europe. The only way shipping becomes cheaper if I
were to load a container full on a ship. Then sending it from a Mediterranean
port would be cheaper.

Sending a single package from the US is cheaper and faster than anywhere
else in the world with the usual, but not always exception of elsewhere
in Israel.

A single envelope, even one containing electronic components takes a week
from a vendor to my door. A small box takes 2-3 and I have to go pick it
up at the post office, even if they are the same cost and weight.

The same with internet access, I can download files from the US at twice
the speed from the UK, and 4-5 times that from continental Europe.

Geoff.

--
Geoffrey S. Mendelson, Jerusalem, Israel N3OWJ/4X1GM
New word I coined 12/13/09, "Sub-Wikipedia" adj, describing knowledge or
understanding, as in he has a sub-wikipedia understanding of the situation.
i.e possessing less facts or information than can be found in the Wikipedia.
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Old June 6th 10, 09:45 AM posted to rec.radio.amateur.antenna
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First recorded activity by RadioBanter: Dec 2006
Posts: 1,169
Default BNC connectors 75 Ohm versus 50 Ohm?

"Geoffrey S. Mendelson" wrote in
:

....
I buy N, BNC, UHF, etc connectors that are of Chinese original that
are economical and excellent quality. But... you have to be picky,
price is not a good indicator of quality.


URLs??? Please.


Jyebao is Taiwanese, not Chinese, and excellent quality. They have an agent
in Israel.

http://www.jyebao.com.tw/agent-u.htm

Owen
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Old June 6th 10, 01:25 PM posted to rec.radio.amateur.antenna
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Posts: 115
Default BNC connectors 75 Ohm versus 50 Ohm?

Owen Duffy wrote:

Jyebao is Taiwanese, not Chinese, and excellent quality. They have an agent
in Israel.

http://www.jyebao.com.tw/agent-u.htm


Thanks. Interestingly enough, they have F-plugs to N jacks, (i.e. cables
with F plugs on them to connect to a radio with an N jack) but not
F plugs to PL-259(UHF) jacks. :-(

73,

Geoff.

--
Geoffrey S. Mendelson, Jerusalem, Israel N3OWJ/4X1GM
New word I coined 12/13/09, "Sub-Wikipedia" adj, describing knowledge or
understanding, as in he has a sub-wikipedia understanding of the situation.
i.e possessing less facts or information than can be found in the Wikipedia.
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Old June 6th 10, 04:00 PM posted to rec.radio.amateur.antenna
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Posts: 37
Default BNC connectors 75 Ohm versus 50 Ohm?

Geoffrey S. Mendelson Inscribed thus:

I recently was able to use a crimp on tool for F connectors for RG-6
quad shield coax. To make sure everyone understands, I am in Israel,
and RG-6 quad shield coax is cheap and easy to find.

Any other coax is almost impossible to find. Pl-259 connectors, called
"UHF" connectors here are rare items. I can get them locally, but I
have to special order them and they are expensive. Since I can not see
them before I order them, I am as likely to get nickle plated ones
with phenolic insulation as I am to get any other kind, and once
ordered are not returnable.

BNC to PL-259 adaptors, are easy to get, and can be ordered from a
reliable local souce for a relatively small price. The same with N to
PL-259.

Looking around at the crimp-on F connectors before I ordered them, I
found that you can get crimp on BNC connectors for RG-6 quad shield
coax.

Here's my questions, Note when I say crimp-on, I mean the ones that
crimp from the rear, like commerical F connectors, not the ones that
crimp around the plug. I have never been able to get any of them to
"fit right":

1. Can I connect a 75ohm BNC plug (which is a different size) to a
50oHm BNC socket?


The short answer is yes ! A 75 ohm BNC plug is identical to a 50 ohm
one, save that the male pin in a 75 ohm plug is smaller in diameter.
The other way round, a 50 ohm BNC plug will damage a 75 ohm BNC socket.

2. Are there crimp on 50 ohm BNC plugs which will work with RG6 quad
shield?


Yes. But you have to be careful to get the right sleeve size and
fitting them is not straightforward.

I know there are variations, but most are similar in size.

3. Are there crimp on N connectors that would fit the RG6 quad shield
coax?


There should be, but I'm not certain.

More likely due to the size a crimp on center element that screws
into the plug body?

4. Are there crimp on PL-259 connectors?


Yes ! Spit spit, yuk... I've always had trouble with these even used
indoors. Usually the plating fails and gives intermittent connections

Thanks in advance,

Geoff.


It might pay you to Google "Greenpar, Amphenol, Wellshow, Synergy" and
the like. There is a lot of good data out there.

--
Best Regards:
Baron.
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