Hi

Don’t worry about it. You will be under 1 db.

Bob

Bert,

Extending the RG-6U using N-connectors should not be giving you more
than 0.20 dB, probably less. Considering that you have have 6.12 dB per
100 feet in RG-6U at 1 GHz (should be about 8 dB @ 1.575 GHz), so it
will be more. Using N-connectors to extend the cable-stretch isn't going
to be a major issue, it may be the cable length that could present an issue.

I've been fighting these issues, and used too long cable at hand (RG-58
is a terrible choice but was lying around at the time). I use LMR-400
these days, giving me about 5.1 dB per 100 feet.

If cable and connector damping causes you harm, then consider installing
an additional LNA inline with the antenna.

Hope it sort itself out for you.

Cheers,
Magnus

On 12/05/2015 09:28 PM, Bert Kehren via time-nuts wrote:

Bert did not find much that I would trust. But  the FM-FM should be about
3/4db from the various posts I have seen.
Regards
Paul
WB8TSL

On Sat, Dec 5, 2015 at 3:28 PM, Bert Kehren via time-nuts <
time-nuts@febo.com> wrote:

On 12/5/15 12:28 PM, Bert Kehren via time-nuts wrote:

The couplings have almost no loss.  The data sheet will say something
like <0.05 dB, but that's because that's what the measurement
uncertainty is.

if you have a good TDR -- you need very short 50 to 20 pico-sec. rise
time -- you could play with cable to cable, but but not having such TDR
the connector is a relative bullet prof solution
73
KJ6UHN
Alex
On 12/5/2015 1:36 PM, Bob Camp wrote:

On 12/05/2015 03:28 PM, Bert Kehren via time-nuts wrote:

My GPS aerial came with the Nortel box from the auction site.
It is connected to my RFTG-u Ref 1 using RG-6. It has standard
F video connectors at each end with an F-BNC adapter at the aerial
and F-TNC at the RFTG. I did not have to measure the losses at the
connectors and adapters. RG-6 produces a 1.4 VSWR compared to 50 ohm
cable. That is just fine.

Ian, G4ICV, AB2GR

We do splices all the time with RG11 and RG6 using F type connectors and a
barrel connector to join the two.  This is for cable tv systems.  Connectors
are cheap - if you don't have any flag down your friendly fios or comcast
truck and he will surely part with a few.  The problem is you need the
correct crimp tool if they are snap and seal or a variant.  The cable guy
may be able to lend you a tool.

73,

Bill, WA2DVU
Cape May

-----Original Message-----
From: time-nuts [mailto:time-nuts-bounces@febo.com] On Behalf Of paul swed
Sent: Saturday, December 05, 2015 5:06 PM
To: ewkehren; Discussion of precise time and frequency measurement
Subject: Re: [time-nuts] RG 6 U couplings

Bert did not find much that I would trust. But  the FM-FM should be about
3/4db from the various posts I have seen.
Regards
Paul
WB8TSL

On Sat, Dec 5, 2015 at 3:28 PM, Bert Kehren via time-nuts <
time-nuts@febo.com> wrote:

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Hi Bert and the group,

I can highly recommend the so called compression F-connectors.
There are a lot of brands out, but my personal favorite is the
Waterproof CX3 Quickmount
from Corning Cabelcon, because they have very good rf and mechanical data.
They are not only weatherproof and corrosion resistant (NiTin-alloy), but
they are really watertight (tested 8h at 30m) and accept a quite high
pull strength of up to typical 480N.
The RF shielding and impedance data are also very good.

For outside I use successful since years a black polyethylen insulated
cable
which is really weatherproof and UV resistant and triple shielded with
tinned copper
braid (I don't like aluminum braid because the low mech. performance).

Just for overview information (I have no relation to this company!):
http://www.cabelcon.dk/download/CX3Folder_May2012.pdf

One may find similar connectors made by other companies.

The only 'negative' point is the need of a compression tool.

So I think this would be a very good solution for repair and connection
in general of RG6 and similar types also for GPS use.

Kind regards

Arnold, DK2WT

Am 05.12.2015 um 21:28 schrieb Bert Kehren via time-nuts:

Hi

I agree 100% with the recommendation of compression connectors and of the
CX3 in particular. The only thing I would add is that they require a proper tool
to “compress” them. I have found that some of the tools are pretty brand specific.
You may need to match the tool to the connector.

Bob

Hi Bob,

you are correct with the special compression tool.
I did it mention as a 'negative' point.
Yes, the right tool is obligatory, but the dealers
do have normally these in the list with the connectors,
I am using the correct tool of course.

I also 'misused' these connectors for my ZS6BKW-type antenna.
I connected just the shield of a hi Q SAT cable with PE outer
insulation as areal wire - fixation and contacting via these
connectors. No changes and no damages since 2 years
out in sunhine, rain, ice, snow and heavy storms mounted up on
the hill and 10 m above ground --> 100 % mechanical
and electrical test approved as well for such not nominal use!

Arnold, DK2WT

Am 06.12.2015 um 13:44 schrieb Bob Camp:

David,

You obviously is not working with 75 Ohm N-connectors on a regular basis.

Also, the point was to show that using proper connectors isn't going to
be a major issue in the loss process.

Cheers,
Magnus

On 12/06/2015 07:58 AM, David J Taylor wrote:

I initially had 50 feet of RG-58/U going to my GPS antenna.  The loss was likely around 12 dB.  That cable eventually failed, and all I had was a 100 foot length of the same type of cable, and surprisingly the GPSDO still worked ok.  Recently I purchased a 35 foot length of 3/8th inch hardline with factory-installed N connectors on eBay for $40.  The loss should be less then 2 dB.  Obviously it works, but I cannot tell that the 10 dB reduced loss from the original cable made any difference.  Rob, NC0B

Sent from my iPad

For those of us in the U.S., does anyone have suggestions of vendors or brands of quality connectors and installation tools?

Over the years, I worked my way up from cheap wire terminals to PIDG connectors and the correct tools.  Rather than repeat the process with F connectors, I'm willing to pay a bit more the first time to do it right.

Fred
KE6CD

Sent from my iPhone

I just /happened/ to be in Home Depot this morning, and observed that
they have a complete kit -- connectors and tool for something like $30.

It was in the electrical tools area, if this is any help.

Jim
wb4gcs@amsat.org

//
On 12/6/2015 9:25 AM, Arnold Tibus wrote:

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Hi

I’ve always shopped the auction sites. I buy both the connectors and the tool from
the same guy at the same time. So far that’s worked pretty well. It does take some
time sorting through the “almost as good as” or “better than but not that part number”
type listings. The sellers change fast enough that the guy I bought from a year ago
may be the last person on the planet you would want to use today.

Bob

Hi

Most of these antennas have 25 to 35 db of gain in their preamps. The
noise figure of most receive modules is in the ~ 1 db range. You do not
need much net gain to keep the system running. Anything over about
8 db or so is “gravy”. If you have one of the 35 db antennas, you can have
a lot of coax loss.

Indeed there are receivers out there that have much worse noise figures
on the front end. One quick hint that you have one of these is the 50 db gain
antenna that comes with it.

The bigger issue is not “what works today” but what works a few years down
the road. None of these parts get better with age. Each of them have
degradation mechanism. Having some surplus gain at the start is a rational way
to design a system that will work for a while.

Bob

Also, don't scrimp and cheap out on a cable prep / stripping tool.

I tried a couple of the inexpensive types ($5 to $10 variety), the sort
of worked but were frustrating to use and do a good job.

Best one I have found is the Cable Prep (bran name) CPT-6590 for RG59
and RG6 size cables. They also make other sizes, for example CPT-1100
for RG7 and RG11 size cables.

They are a good quality tool that will last a very long time in a home
lab and make the job much easier.

cheers, Graham ve3gtc

On 2015-12-06 15:20, F. W. Bray wrote:

Try not to laugh to hard but the compression connectors and crimper for RG6 style cables I picked up at Home Depot in Canada a few years ago seems to work quite well.

I have used high quality pro tools at work over the years (mostly though I watch other people use them on occasion these days (:  ). But the Home Depot one I purchased seems ok to me for home / hobby use.

As noted by others I believe it is important to match the tool to the connectors.

Sent from my iPhone

I use mostly Quad RG6, and I use the Ideal ratchet crimper and
fittings as are available from Lowes, or Home Despot.

It is important to note that RG58 <> RG6 <> Quad RG6.  They are
each different in diameter, loss, and shielding capability.

Each needs a different sized "F" connector, and crimping die.
Fortunately the Ideal crimping die has all three sizes.

-Chuck Harris

F. W. Bray wrote:

If you do use 75 Ohm Type N connectors, do NOT attempt to mate them with
a 50 Ohm connector.
The center pins are different diameters to get the different impedance.
To mate a 50 Ohm Type N male with a 75 Ohm female will guarantee
destruction of the female connector.
I have had to clean up behind someone that dis not know the difference
and took a large downlink dish off line as the spread fingers of the 75
Ohm Type N broke off and shouted the cable and the LNB supply voltage.

There are also 50 and 75 Ohm BNC connectors, but, they achieve the
impedance difference bu use of dielectric,
These connectors can be mated 50 to 75 Ohm with out damage.

Just to warn of the possible damage.

73
Glenn
WB4UIV

On 12/6/2015 10:16 AM, David J Taylor wrote:

--

Glenn Little                ARRL Technical Specialist  QCWA  LM 28417
Amateur Callsign:  WB4UIV            wb4uiv@arrl.net    AMSAT LM 2178
QTH:  Goose Creek, SC USA (EM92xx)  USSVI LM  NRA LM  SBE ARRL TAPR
"It is not the class of license that the Amateur holds but the class
of the Amateur that holds the license"