BNC installation

[JJ Sinclair]

I'm about ready to splice on a good fin & boom to a badly broken
Puchacz fuselage. Made a clean cut 56" aft of the aft lift fittings,
glued in a sleeve, jigged up the two pieces (both sides straight, top
& bottom straight, fin vertical, lift fittings horizontal), spliced
the push-rod, hooked up the TE tube, now all I have to do is splice
the radio cable, right? Always hated trying to solder that little
center post on the BNC, especially working inside a fuselage half with
short leads. Found a BNC crimper from Aircraft Spruce & Specialty for
about $200 bucks with proper die and a hand full of BNC's. Works slick
as snot, just slide on the sleeve, trim the cable as before, slip on
the center post and crimp it, then slide on the BNC body, shove the
sleeve down over the exposed shield and crimp it also. That's it, all
done!
I installed one male and one female connector (legal in all states).
Some may wish to use two females with a male to male coupler (only
legal in some states).
JJ

[raulb]

You really want that thing rattling about inside the fuselage? With
all the work you have already done on the fuselage, is it THAT much
harder to replace the entire cable?

Anyway, you could have found a much less expensive crimper at an
electronics store (Fry's, Radio Shack, Newark, etc.). I suspect that
the only ones who solders anymore is the military, and me sometimes--
and yes, I hate it too--even though I have a considerably less
expenseive crimper.



On Jun 24, 7:28*am, JJ Sinclair > wrote:
> I'm about ready to splice on a good fin & boom to a badly broken
> Puchacz fuselage. Made a clean cut 56" aft of the aft lift fittings,
> glued in a sleeve, jigged up the two pieces (both sides straight, top
> & bottom straight, fin vertical, lift fittings horizontal), spliced
> the push-rod, hooked up the TE tube, now all I have to do is splice
> the radio cable, right? *Always hated trying to solder that little
> center post on the BNC, especially working inside a fuselage half with
> short leads. Found a BNC crimper from Aircraft Spruce & Specialty for
> about $200 bucks with proper die and a hand full of BNC's. Works slick
> as snot, just slide on the sleeve, trim the cable as before, slip on
> the center post and crimp it, then slide on the BNC body, shove the
> sleeve down over the exposed shield and crimp it also. That's it, all
> done!
> I installed one male and one female connector (legal in all states).
> Some may wish to use two females with a male to male coupler (only
> legal in some states).
> JJ

[JJ Sinclair]

raulb wrote:
> You really want that thing rattling about inside the fuselage? With
> all the work you have already done on the fuselage, is it THAT much
> harder to replace the entire cable?

Most antenna cables are epoxied to the fuselage at several locations
and can't be simply "replaced", also a new cable must be secured at
several locations in order to keep it from flopping around or it could
get tangled up with the elevator push-rod, couldn't it? Also, even it
I replaced the whole cable I would still have to connect it to the
antenna with a BNC, wouldn't I? Ever try to install a BNC inside a
fin? I have and decided connecting the two cables at the point of the
repair is the best way to go.

Just before closing the two halves of the fuselage, I will goop up the
BNC's & TE tube and secure them to one side with a string that goes
outside so that I can pull them tight and they can't "rattle around"
inside the fuselage.
This is not my first rodeo,
JJ

[Vaughn Simon]

"raulb" > wrote in message
...
>Anyway, you could have found a much less expensive crimper at an
>electronics store (Fry's, Radio Shack, Newark, etc.). I suspect that
>the only ones who solders anymore is the military, and me sometimes--
>and yes, I hate it too--even though I have a considerably less
>expenseive crimper.

This is one time when you want the professional tool. (Of course, you want
to buy the professional tool at the best price, and that is probably not any
aviation supplier)

I would rather have a crimped BNC than a soldered BNC any day of the week.
There are just too many ways to do the job wrong. A crimp connector is closer
to idiot proof. Additionally, it gives you a more reliable braid connection
than the older style solder-type connectors.


Vaughn

[Nyal Williams[_2_]]

What am I missing here? What do "some states" have to do with an
aircraft antenna installation?

At 14:28 24 June 2008, JJ Sinclair wrote:
>I'm about ready to splice on a good fin & boom to a badly broken
>Puchacz fuselage. Made a clean cut 56" aft of the aft lift fittings,
>glued in a sleeve, jigged up the two pieces (both sides straight, top
>& bottom straight, fin vertical, lift fittings horizontal), spliced
>the push-rod, hooked up the TE tube, now all I have to do is splice
>the radio cable, right? Always hated trying to solder that little
>center post on the BNC, especially working inside a fuselage half with
>short leads. Found a BNC crimper from Aircraft Spruce & Specialty for
>about $200 bucks with proper die and a hand full of BNC's. Works slick
>as snot, just slide on the sleeve, trim the cable as before, slip on
>the center post and crimp it, then slide on the BNC body, shove the
>sleeve down over the exposed shield and crimp it also. That's it, all
>done!
>I installed one male and one female connector (legal in all states).
>Some may wish to use two females with a male to male coupler (only
>legal in some states).
>JJ
>

[Bob Backer]

You obviously don't live in California.

Nyal Williams wrote:
> What am I missing here? What do "some states" have to do with an
> aircraft antenna installation?
>
> At 14:28 24 June 2008, JJ Sinclair wrote:
>> I'm about ready to splice on a good fin & boom to a badly broken
>> Puchacz fuselage. Made a clean cut 56" aft of the aft lift fittings,
>> glued in a sleeve, jigged up the two pieces (both sides straight, top
>> & bottom straight, fin vertical, lift fittings horizontal), spliced
>> the push-rod, hooked up the TE tube, now all I have to do is splice
>> the radio cable, right? Always hated trying to solder that little
>> center post on the BNC, especially working inside a fuselage half with
>> short leads. Found a BNC crimper from Aircraft Spruce & Specialty for
>> about $200 bucks with proper die and a hand full of BNC's. Works slick
>> as snot, just slide on the sleeve, trim the cable as before, slip on
>> the center post and crimp it, then slide on the BNC body, shove the
>> sleeve down over the exposed shield and crimp it also. That's it, all
>> done!
>> I installed one male and one female connector (legal in all states).
>> Some may wish to use two females with a male to male coupler (only
>> legal in some states).
>> JJ
>>

[JJ Sinclair]

On Jun 24, 1:58*pm, Nyal Williams > wrote:
> What am I missing here? *What do "some states" have to do with an
> aircraft antenna installation?

Or you could install one male with two (or more) females. Not legal in
any state, but tolerated in Nevada, Texas, Arizona and Utah!.

Think about it, Nyle. It will come to you.
:>) JJ

[COLIN LAMB]

I wish I had known about the BNC crimpers decades ago. At this point, I
would drive 100 miles to get a proper crimper instead of soldering a BNC -
they are that much better. When someone asks me to assist on their radio
installation, the first thing I look at is the BNC connector. Usually, I
can stop there.

You do not want to buy a cheap one - but electronics supply houses sell them
for under $50. Make sure it is for 50 ohm coax and not 70 ohm stuff. Many
of the good crimpers have dies that fit into the jaws for each different
type of coax.

For the price of a good steak dinner, you can make life simpler and better.

Colin Lamb

[COLIN LAMB]

I forgot one other point - get quality, name brand coax fittings. A few
years ago, some Chinese right angle coax fitting showed up. They looked
good, but used a spring of wire to connect the two terminations. Not good!
They were much easier to make.

Colin

[ContestID67]

Some comments;

1) Crimping is very much the way to go. The heat of soldering (unless
you are very careful) can easily damage the dielectric insulator.
Invariably you are then left with a blob of solder that must be
wittled away to make thing fit. Ugh.
2) The less expensive sub-$50 (but not dirt cheap) crimpers seem to
work fine. Ratcheting type is highly recommended as they enforce the
correct amount of pressure. The $200 units are made to hold up to
repeated use over years, something most of us are unlikely to need.
3) Male/Female versus Two Males with coupler (whoa!) - Stick with the
fewest possible connections. Not only for the fact that there are
fewer things to go wrong but because each extra connection looses 2db
(rule of thumb) of your power.
4) While the boom is open, think about (if possible/practical/useful)
pulling extra air lines, coax, etc.
5) Test, test, test, test and test again before buttoning this up.
Get a professional to help out. Well worth the expense. Much better
now than later.
6) If you are on the scene of a boom break (I have), resisting with
all your might the temptation of cutting all the lines (air, coax) to
speed up the removal of the dead beast from the scene of the crime.
It is much better to try to take the time to disconnect things at the
cockpit end and pull them back so that any necessary splicing is done
in a easily accessible place.

Enjoy, John DeRosa

[Darryl Ramm]

On Jun 24, 7:52*pm, ContestID67 > wrote:
> Some comments;
>
> 1) Crimping is very much the way to go. *The heat of soldering (unless
> you are very careful) can easily damage the dielectric insulator.
> Invariably you are then left with a blob of solder that must be
> wittled away to make thing fit. *Ugh.
> 2) The less expensive sub-$50 (but not dirt cheap) crimpers seem to
> work fine. *Ratcheting type is highly recommended as they enforce the
> correct amount of pressure. *The $200 units are made to hold up to
> repeated use over years, something most of us are unlikely to need.
> 3) Male/Female versus Two Males with coupler (whoa!) - Stick with the
> fewest possible connections. *Not only for the fact that there are
> fewer things to go wrong but because each extra connection looses 2db
> (rule of thumb) of your power.
> 4) While the boom is open, think about (if possible/practical/useful)
> pulling extra air lines, coax, etc.
> 5) Test, test, test, test and test again before buttoning this up.
> Get a professional to help out. *Well worth the expense. *Much better
> now than later.
> 6) If you are on the scene of a boom break (I have), resisting with
> all your might the temptation of cutting all the lines (air, coax) to
> speed up the removal of the dead beast from the scene of the crime.
> It is much better to try to take the time to disconnect things at the
> cockpit end and pull them back so that any necessary splicing is done
> in a easily accessible place.
>
> Enjoy, John DeRosa

I'd raise that price limit a bit, the < $50 crimpers I've seen will
not be able to crimp tight enough to achieve a proper connection. Will
it work most of the time. Sure. But I'd not want them in my aircraft.
The ratcheting type crimpers have enough jaw pressure to properly
crimp the wires (collapses a large % of the voids in the wire bundles,
creates cold welds). The ratchet makes sure you crimp it all the way.
And since many come with interchangeable dies once you need to crimp
more than one type of connector the total cost is not too bad. The
high end crimpers also have properly shaped hardened and polished
steel jaws that will crimp with high pressure without deforming the
connector.

BTW I like the Ideal Crimpmaster because they are reasonably priced ~
$50 for the bare handle with die sets ~$30-$40 each. Crimpmaster
handles and and a few dies are available at Home Depot etc. A great
web site with good selection of dies is http://www.mytoolstore.com/ideal/ide08-11.html

3M, Amp and Anderson also make great high end ratcheting crimp tools
for their line of crimp connectors. These are often ~$200-$300,
feature heavier duty construction, fine tuning of crimp pressure,
etc. Some crimp on connectors are more sensitive to others about
using the right crimp tool, e.g. some fully insulated spade/ring
connectors and Anderson PowerPole connectors.

Not that I think JJ was really posting to ask for any advice, ... but
I'd also not use a coupler. I'd just go inline M-BNC to F-BNC
connectors. It is never too late to cut the tail off again and do it
properly :-) Make sure they have gold plated pins for corrosion
resistance. I'd also put a sleeve of heat shrink over the connectors
to keep everything sealed from humidity/moisture etc. Some of the very
high-shrink type that fit over the connectors but shrink to the coax.

Darryl

[COLIN LAMB]

"3) Male/Female versus Two Males with coupler (whoa!) - Stick with the
fewest possible connections. Not only for the fact that there are
fewer things to go wrong but because each extra connection looses 2db
(rule of thumb) of your power."

Comment: While I am not an authority on connector loss, my opinion is that
the estimated 2 db loss per connector is high. I have built an EME (Earth -
Moon - Earth) communicatons system where an extra .1 db loss is the
difference between success and failure and carefully monitored losses. It
is easy to measure the loss in connectors and it is rare that 2 db is lost
on the relatively low frequency of 123 MHz. I think the norm is .1 to .2 db
per BNC connector. However, I had a box of short BNC jumper cables
(commercially made) and about one in 10 had a 2 db loss. I have never
determined why and simply discarded the high loss jumpers.

I checked a number of source books to see if I could find any defninitive
statement about "average" loss per connector at a certain frequency, and
could not find any.

The type of BNC connectors that are assembled by screwing together are much
more likely to have high losses than a properly crimped connector.

Colin Lamb

[Andy[_1_]]

On Jun 24, 7:52*pm, ContestID67 > wrote:
> 6) If you are on the scene of a boom break (I have), resisting with
> all your might the temptation of cutting all the lines (air, coax) to
> speed up the removal of the dead beast from the scene of the crime.
> It is much better to try to take the time to disconnect things at the
> cockpit end and pull them back so that any necessary splicing is done
> in a easily accessible place.

I too helped to retrieve a glider with a boom break. We splinted the
boom with trailer jack handles and lots of duct tape and put the
fuselage in the trailer in one piece. (Thanks to PC2 who had been
there, and done that, before.)

Andy

[JJ Sinclair]

You make a very good point, the beast may be broken but it isn't
terminal if you use a little common sense getting it apart and back in
the box. I have seen a G-103 where the club members used a crow-bar to
get the wings off because the aft lift fitting carry-through tube was
bent and wouldn't release the wings. Bad way to go, the ship was
repairable before the club got there. I also have seen a Cirrus push-
rods cut with a hack-saw, right next to the Hotiellier rfittings. Use
a little common sense, the bird still has value. BTW, prop up the fin
and the radio may just work to get a message out. The Nimbus 3 that
was missing for 3 days at Uvalde had a good radio, battery and
antenna. All the pilot had to do was prop up the fin and talk to all
the folks that were looking for him.
JJ

Andy wrote:
> On Jun 24, 7:52�pm, ContestID67 > wrote:
> > 6) If you are on the scene of a boom break (I have), resisting with
> > all your might the temptation of cutting all the lines (air, coax) to
> > speed up the removal of the dead beast from the scene of the crime.
> > It is much better to try to take the time to disconnect things at the
> > cockpit end and pull them back so that any necessary splicing is done
> > in a easily accessible place.
>
> I too helped to retrieve a glider with a boom break. We splinted the
> boom with trailer jack handles and lots of duct tape and put the
> fuselage in the trailer in one piece. (Thanks to PC2 who had been
> there, and done that, before.)
>
> Andy

[Uncle Fuzzy]

On Jun 25, 7:56*am, "COLIN LAMB" > wrote:
> "3) Male/Female versus Two Males with coupler (whoa!) - Stick with the
> fewest possible connections. *Not only for the fact that there are
> fewer things to go wrong but because each extra connection looses 2db
> (rule of thumb) of your power."
>
> Comment: While I am not an authority on connector loss, my opinion is that
> the estimated 2 db loss per connector is high. *I have built an EME (Earth -
> Moon - Earth) communicatons system where an extra .1 db loss is the
> difference between success and failure and carefully monitored losses. *It
> is easy to measure the loss in connectors and it is rare that 2 db is lost
> on the relatively low frequency of 123 MHz. *I think the norm is .1 to ..2 db
> per BNC connector. *However, I had a box of short BNC jumper cables
> (commercially made) and about one in 10 had a 2 db loss. *I have never
> determined why and simply discarded the high loss jumpers.
>
> I checked a number of source books to see if I could find any defninitive
> statement about "average" loss per connector at a certain frequency, and
> could not find any.
>
> The type of BNC connectors that are assembled by screwing together are much
> more likely to have high losses than a properly crimped connector.
>
> Colin Lamb

Colin, he was making a JOKE about various Male/Female ratios etc.
I work instrumentation on military aircraft. Mil spec connectors,
crimpers, etc. Done correctly, soldered connectors and crimped
connectors are equally good. Done badly, neither is worth the trouble
they'll cause. That said, it is EASIER to assemble a soldered
connector BADLY, so crimping (with GOOD tools) would be my choice if I
actually GOT a choice.

[ContestID67]

On Jun 25, 11:38*am, Darryl Ramm > wrote:

> Make sure they have gold plated pins for corrosion
resistance.
> I'd also put a sleeve of heat shrink over the connectors
> to keep everything sealed from humidity/moisture etc. Some of the very
> high-shrink type that fit over the connectors but shrink to the coax.
>

Darryl - Good idea to use gold plated pins for corrosion resistance.
However,
I am unsure if I would put the heat shrink over the connectors. While
it might
keep dust and dirt out, it will also serve to keep any condensation
inside and not
allow evaporation, in effect accelerating corrosion.

Instead, I use a dielectric compound like Dow Corning #4 (http://
www.skygeek.com/dc4.html).
It keeps the moisture out, prevents corrosion and doesn't dry up. It
is also especially
good on trailer light connectors.

My $0.02.

- John "67" DeRosa

PS - If you must use heat shrink, avoid the cheap Radio Shack stuff
like the plague. It doesn't
shrink enough and becomes very stiff. Find a source for good quality
heat shrink and be willing
to pay $2-$4 per 3 foot piece.

[Uncle Fuzzy]

On Jun 26, 10:40*pm, ContestID67 > wrote:
> On Jun 25, 11:38*am, Darryl Ramm > wrote:
>
>
>
> > Make sure they have gold plated pins for corrosion
> resistance.
> > I'd also put a sleeve of heat shrink over the connectors
> > to keep everything sealed from humidity/moisture etc. Some of the very
> > high-shrink type that fit over the connectors but shrink to the coax.
>
> Darryl - Good idea to use gold plated pins for corrosion resistance.
> However,
> I am unsure if I would put the heat shrink over the connectors. *While
> it might
> keep dust and dirt out, it will also serve to keep any condensation
> inside and not
> allow evaporation, in effect accelerating corrosion.
>
> Instead, I use a dielectric compound like Dow Corning #4 (http://www.skygeek.com/dc4.html).
> It keeps the moisture out, prevents corrosion and doesn't dry up. *It
> is also especially
> good on trailer light connectors.
>
> My $0.02.
>
> - John "67" DeRosa
>
> PS - If you must use heat shrink, avoid the cheap Radio Shack stuff
> like the plague. *It doesn't
> shrink enough and becomes very stiff. *Find a source for good quality
> heat shrink and be willing
> to pay $2-$4 per 3 foot piece.

To add one more penny's worth: If the connection is a straight
section that won't need flexibility, the dielectric compound for the
internals of the connector, then the high end heat shrink tubing with
the sealer/adhesive coating inside is the cat's meow.

[jcarlyle]

My 2 cents says "use connectors with gold plated internals and leave
the BNC connection bare". This opinion gained from experience in
making thousands on BNC connections and having to leave them for a few
weeks in rain, snow and ice before doing my test. Signals on the order
of microvolts were detected most cleanly when the BNC connectors were
bare - if we used any grease, tape, shrink wrap, etc. to "protect"
them we got a noisy circuit.

-John


On Jun 27, 11:51 am, Uncle Fuzzy > wrote:
> On Jun 26, 10:40 pm, ContestID67 > wrote:
>
>
>
> > On Jun 25, 11:38 am, Darryl Ramm > wrote:
>
> > > Make sure they have gold plated pins for corrosion
> > resistance.
> > > I'd also put a sleeve of heat shrink over the connectors
> > > to keep everything sealed from humidity/moisture etc. Some of the very
> > > high-shrink type that fit over the connectors but shrink to the coax.
>
> > Darryl - Good idea to use gold plated pins for corrosion resistance.
> > However,
> > I am unsure if I would put the heat shrink over the connectors. While
> > it might
> > keep dust and dirt out, it will also serve to keep any condensation
> > inside and not
> > allow evaporation, in effect accelerating corrosion.
>
> > Instead, I use a dielectric compound like Dow Corning #4 (http://www.skygeek.com/dc4.html).
> > It keeps the moisture out, prevents corrosion and doesn't dry up. It
> > is also especially
> > good on trailer light connectors.
>
> > My $0.02.
>
> > - John "67" DeRosa
>
> > PS - If you must use heat shrink, avoid the cheap Radio Shack stuff
> > like the plague. It doesn't
> > shrink enough and becomes very stiff. Find a source for good quality
> > heat shrink and be willing
> > to pay $2-$4 per 3 foot piece.
>
> To add one more penny's worth: If the connection is a straight
> section that won't need flexibility, the dielectric compound for the
> internals of the connector, then the high end heat shrink tubing with
> the sealer/adhesive coating inside is the cat's meow.

[ContestID67]

> > To add one more penny's worth: *If the connection is a straight
> > section that won't need flexibility, the dielectric compound for the
> > internals of the connector, then the high end heat shrink tubing with
> > the sealer/adhesive coating inside is the cat's meow.- Hide quoted text -
>

Thanks for the comments about gold plating. It has got me thinking
(ouch).

Next question: Being a person that likes to frequent hamfests (great
stuff for electronics nerds like myself - see http://www.arrl.org/hamfests.html
for details), I see lots of RF connectors for sale. It appears that
the connector plating material of choice is not gold but silver.
Maybe it is the cost savings but it seems counter-productive to use
silver as it obviously tarnishes quite quickly (and I assume that is
bad). Being a digital (non-RF) Electrical Engineer by training I
don't know enough about the qualities of the various plating materials
to hazard an educated opinion. Any ideas?

[Eric Greenwell]

ContestID67 wrote:

> Next question: Being a person that likes to frequent hamfests (great
> stuff for electronics nerds like myself - see http://www.arrl.org/hamfests.html
> for details), I see lots of RF connectors for sale. It appears that
> the connector plating material of choice is not gold but silver.
> Maybe it is the cost savings but it seems counter-productive to use
> silver as it obviously tarnishes quite quickly (and I assume that is
> bad).

Tarnished silver has the remarkable property of remaining conductive, so
it doesn't cause problems. The gold flashing is usually used on the
center pins only.

And to vote with John C, my experience with ungreased, unprotected BNC
connectors sitting outside is they work well for decades if they were
properly assembled to begin with. I would not be concerned with the
connector at all inside a fuselage.

--
Eric Greenwell - Washington State, USA
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