BNC installation

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.

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.

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.

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?

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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