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* Unsolderable wire? - 24 messages, 17 authors
http://groups.google.com/group/sci.electronics.repair/t/846b59baa6a8b7e9?hl=en
* Anyone help me with component ID for X5DIJ-SX039C laptop (k501j mobo)? - 2
messages, 2 authors
http://groups.google.com/group/sci.electronics.repair/t/58fd5bf0893d5f4a?hl=en

==============================================================================
TOPIC: Unsolderable wire?
http://groups.google.com/group/sci.electronics.repair/t/846b59baa6a8b7e9?hl=en
==============================================================================

== 1 of 24 ==
Date: Sat, Jan 18 2014 8:37 pm
From: Spehro Pefhany


On Sat, 18 Jan 2014 20:22:18 -0800, the renowned Bob E.
<bespoke@invalid.tv> wrote:

>I am trying to solder some RG-6 shield to a pcb. The braid won't tin. It's
>almost like it's dissipating the heat faster than I can apply it. With both a
>temp-controlled iron (set as high as 700F) and a mondo 100W stick I finally
>tried. The solder will barely melt when touched to the braid opposite the
>iron.
>
>I've applied some Kester rosin paste flux as well using my trusty Kester
>60/40 lead-based rosin core solder. No joy. I'm not holding the braid against
>the PCB now, I'm just trying to tin the braid and then deal with melting the
>2 solders (on the PCB and the braid) together later.
>
>My first attempt--before I realized that I was overheating it--I melted the
>dielectric insulation.
>
>The mesh is made from some silver-colored braid which I thought is tinned
>copper but now I'm of the opinion that it's steel; it's certainly not
>aluminum. There is also foil which is probably aluminum but I've trimmed that
>back and it's not part of this frustrating process right now.
>
>What's the trick to getting this braid to take solder? I've never seen this
>before.
>
>Thanks.

If it's like this cr*p they sell at Home Despot, it's copper clad
steel core with an _aluminum_ braid shield:-

http://www.cerrowire.com/files/file/49223_CERRO_CoaxialCable_6U_QUADLR.pdf

That would explain the copper-like heat conduction that you're
observing.

I suppose you could try an aluminum flux, but can't you just unravel
and gather enough of the shield to crimp into a ring terminal or
something?



Best regards,
Spehro Pefhany
--
"it's the network..." "The Journey is the reward"
speff@interlog.com Info for manufacturers: http://www.trexon.com
Embedded software/hardware/analog Info for designers: http://www.speff.com




== 2 of 24 ==
Date: Sat, Jan 18 2014 8:40 pm
From: "Michael A. Terrell"



"Bob E." wrote:
>
> I am trying to solder some RG-6 shield to a pcb. The braid won't tin. It's
> almost like it's dissipating the heat faster than I can apply it. With both a
> temp-controlled iron (set as high as 700F) and a mondo 100W stick I finally
> tried. The solder will barely melt when touched to the braid opposite the
> iron.
>
> I've applied some Kester rosin paste flux as well using my trusty Kester
> 60/40 lead-based rosin core solder. No joy. I'm not holding the braid against
> the PCB now, I'm just trying to tin the braid and then deal with melting the
> 2 solders (on the PCB and the braid) together later.
>
> My first attempt--before I realized that I was overheating it--I melted the
> dielectric insulation.
>
> The mesh is made from some silver-colored braid which I thought is tinned
> copper but now I'm of the opinion that it's steel; it's certainly not
> aluminum. There is also foil which is probably aluminum but I've trimmed that
> back and it's not part of this frustrating process right now.
>
> What's the trick to getting this braid to take solder? I've never seen this
> before.

It's not made to be soldered. It's CATV cable that's made for crimp
on 'F' fittings.

--
Anyone wanting to run for any political office in the US should have to
have a DD214, and a honorable discharge.




== 3 of 24 ==
Date: Sat, Jan 18 2014 8:42 pm
From: "Phil Allison"



"Bob E."

>
> The mesh is made from some silver-colored braid which I thought is tinned
> copper but now I'm of the opinion that it's steel; it's certainly not
> aluminum.

** A magnet will pick up steel wire - but no Aluminium.


> What's the trick to getting this braid to take solder?


** Unplated steel or Aluminium wires are not solderable by ordinary means.




.... Phil






== 4 of 24 ==
Date: Sat, Jan 18 2014 8:43 pm
From: Tom Biasi


On 1/18/2014 11:22 PM, Bob E. wrote:
> I am trying to solder some RG-6 shield to a pcb. The braid won't tin. It's
> almost like it's dissipating the heat faster than I can apply it. With both a
> temp-controlled iron (set as high as 700F) and a mondo 100W stick I finally
> tried. The solder will barely melt when touched to the braid opposite the
> iron.
>
> I've applied some Kester rosin paste flux as well using my trusty Kester
> 60/40 lead-based rosin core solder. No joy. I'm not holding the braid against
> the PCB now, I'm just trying to tin the braid and then deal with melting the
> 2 solders (on the PCB and the braid) together later.
>
> My first attempt--before I realized that I was overheating it--I melted the
> dielectric insulation.
>
> The mesh is made from some silver-colored braid which I thought is tinned
> copper but now I'm of the opinion that it's steel; it's certainly not
> aluminum. There is also foil which is probably aluminum but I've trimmed that
> back and it's not part of this frustrating process right now.
>
> What's the trick to getting this braid to take solder? I've never seen this
> before.
>
> Thanks.
>
Twist the braid into a wire and butt splice on a copper wire. Heat
shrink over it.




== 5 of 24 ==
Date: Sat, Jan 18 2014 8:50 pm
From: Bob E.


Yes it's that crap.

> I suppose you could try an aluminum flux, but can't you just unravel
> and gather enough of the shield to crimp into a ring terminal or
> something?

Yeah, that's my next move. I just couldn't believe that something couldn't be
soldered. I guess REALLY agressive flux is required, as you say.

When it comes to broadcast TV I try to solder every connection possible.
Every crimp is one more dB lost.

Thanks.

Crimps in hand...





== 6 of 24 ==
Date: Sat, Jan 18 2014 9:09 pm
From: Spehro Pefhany


On Sat, 18 Jan 2014 20:50:34 -0800, the renowned Bob E.
<bespoke@invalid.tv> wrote:

>Yes it's that crap.
>
>> I suppose you could try an aluminum flux, but can't you just unravel
>> and gather enough of the shield to crimp into a ring terminal or
>> something?
>
>Yeah, that's my next move. I just couldn't believe that something couldn't be
>soldered. I guess REALLY agressive flux is required, as you say.
>
>When it comes to broadcast TV I try to solder every connection possible.
>Every crimp is one more dB lost.
>
>Thanks.
>
>Crimps in hand...

I guess there's always better stuff like this:-

http://nordencommunication.com/download?file=1460-RG_6u.pdf



Best regards,
Spehro Pefhany
--
"it's the network..." "The Journey is the reward"
speff@interlog.com Info for manufacturers: http://www.trexon.com
Embedded software/hardware/analog Info for designers: http://www.speff.com




== 7 of 24 ==
Date: Sat, Jan 18 2014 10:19 pm
From: "Michael A. Terrell"



"Bob E." wrote:
>
> Yes it's that crap.
>
> > I suppose you could try an aluminum flux, but can't you just unravel
> > and gather enough of the shield to crimp into a ring terminal or
> > something?
>
> Yeah, that's my next move. I just couldn't believe that something couldn't be
> soldered. I guess REALLY agressive flux is required, as you say.
>
> When it comes to broadcast TV I try to solder every connection possible.
> Every crimp is one more dB lost.


You must do lousy crimping, if you lose a dB.

--
Anyone wanting to run for any political office in the US should have to
have a DD214, and a honorable discharge.




== 8 of 24 ==
Date: Sat, Jan 18 2014 10:41 pm
From: cjt


On 01/18/2014 10:50 PM, Bob E. wrote:
> Yes it's that crap.
>
>> I suppose you could try an aluminum flux, but can't you just unravel
>> and gather enough of the shield to crimp into a ring terminal or
>> something?
>
> Yeah, that's my next move. I just couldn't believe that something couldn't be
> soldered. I guess REALLY agressive flux is required, as you say.
>
> When it comes to broadcast TV I try to solder every connection possible.
> Every crimp is one more dB lost.
>
> Thanks.
>
> Crimps in hand...
>
I would have thought every soldered joint is one more reflection.




== 9 of 24 ==
Date: Sat, Jan 18 2014 11:16 pm
From: Bob E.


>> When it comes to broadcast TV I try to solder every connection possible.
>> Every crimp is one more dB lost.

I'm no RF expert, just my impression--possibly mistaken.

Thanks.





== 10 of 24 ==
Date: Sat, Jan 18 2014 11:30 pm
From: "Michael A. Terrell"



"Bob E." wrote:
>
> >> When it comes to broadcast TV I try to solder every connection possible.
> >> Every crimp is one more dB lost.
>
> I'm no RF expert, just my impression--possibly mistaken.


The loss should be under .1 dB for a good F connector, ant they are
used into the GHz range.


--
Anyone wanting to run for any political office in the US should have to
have a DD214, and a honorable discharge.




== 11 of 24 ==
Date: Sun, Jan 19 2014 1:13 am
From: John Fields


On Sat, 18 Jan 2014 20:22:18 -0800, Bob E. <bespoke@invalid.tv>
wrote:

>I am trying to solder some RG-6 shield to a pcb. The braid won't tin. It's
>almost like it's dissipating the heat faster than I can apply it. With both a
>temp-controlled iron (set as high as 700F) and a mondo 100W stick I finally
>tried. The solder will barely melt when touched to the braid opposite the
>iron.
>
>I've applied some Kester rosin paste flux as well using my trusty Kester
>60/40 lead-based rosin core solder. No joy. I'm not holding the braid against
>the PCB now, I'm just trying to tin the braid and then deal with melting the
>2 solders (on the PCB and the braid) together later.
>
>My first attempt--before I realized that I was overheating it--I melted the
>dielectric insulation.
>
>The mesh is made from some silver-colored braid which I thought is tinned
>copper but now I'm of the opinion that it's steel; it's certainly not
>aluminum. There is also foil which is probably aluminum but I've trimmed that
>back and it's not part of this frustrating process right now.
>
>What's the trick to getting this braid to take solder? I've never seen this
>before.
>
>Thanks.

---
Use crimp ferrules.

http://www.te.com/catalog/feat/en/c/10028

11.5 at:

http://snebulos.mit.edu/projects/reference/NASA-Generic/NASA-STD-8739-4.pdf

JF




== 12 of 24 ==
Date: Sun, Jan 19 2014 2:34 am
From: Jasen Betts


On 2014-01-19, Bob E <bespoke@invalid.tv> wrote:
> I am trying to solder some RG-6 shield to a pcb.

> The mesh is made from some silver-colored braid which I thought is tinned
> copper but now I'm of the opinion that it's steel; it's certainly not
> aluminum. There is also foil which is probably aluminum but I've trimmed that
> back and it's not part of this frustrating process right now.

yeah stainless steel braid, aluminium shield and a copper-plated steel
core. most of the RG6 I've used is like that.

a solderable F connector socket is probably the best way to terminate it.

> What's the trick to getting this braid to take solder?

Give up! If you can't give up spot weld it to some tinned copper.

--
For a good time: install ntp

--- news://freenews.netfront.net/ - complaints: news@netfront.net ---




== 13 of 24 ==
Date: Sun, Jan 19 2014 4:19 am
From: Syd Rumpo


On 19/01/2014 04:22, Bob E. wrote:
> I am trying to solder some RG-6 shield to a pcb. The braid won't tin. It's
> almost like it's dissipating the heat faster than I can apply it. With both a
> temp-controlled iron (set as high as 700F) and a mondo 100W stick I finally
> tried. The solder will barely melt when touched to the braid opposite the
> iron.
>
> I've applied some Kester rosin paste flux as well using my trusty Kester
> 60/40 lead-based rosin core solder. No joy. I'm not holding the braid against
> the PCB now, I'm just trying to tin the braid and then deal with melting the
> 2 solders (on the PCB and the braid) together later.
>
> My first attempt--before I realized that I was overheating it--I melted the
> dielectric insulation.
>
> The mesh is made from some silver-colored braid which I thought is tinned
> copper but now I'm of the opinion that it's steel; it's certainly not
> aluminum. There is also foil which is probably aluminum but I've trimmed that
> back and it's not part of this frustrating process right now.
>
> What's the trick to getting this braid to take solder? I've never seen this
> before.
>
> Thanks.

If it's for personal use, tightly wrap a dozen turns of tinned copper
wire (or silver plated) around the braid, twist the end together and
solder to these.

Cheers
--
Syd




== 14 of 24 ==
Date: Sun, Jan 19 2014 5:45 am
From: "William Sommerwerck"


"Spehro Pefhany" wrote in message
news:v8lmd9tfpopj1kuv72m95aouolvlduj539@4ax.com...

> If it's like this cr*p they sell at Home Despot, it's copper-
> clad steel core with an _aluminum_ braid shield.

Aluminum is a poor choice for a crimped connection. Remember the problems with
household aluminum wiring -- even when it was screwed down?





== 15 of 24 ==
Date: Sun, Jan 19 2014 6:04 am
From: "Maynard A. Philbrook Jr."


In article <0001HW.CF0092FA036D6B77B01029BF@news.eternal-september.org>,
bespoke@invalid.tv says...
>
> I am trying to solder some RG-6 shield to a pcb. The braid won't tin. It's
> almost like it's dissipating the heat faster than I can apply it. With both a
> temp-controlled iron (set as high as 700F) and a mondo 100W stick I finally
> tried. The solder will barely melt when touched to the braid opposite the
> iron.
>
> I've applied some Kester rosin paste flux as well using my trusty Kester
> 60/40 lead-based rosin core solder. No joy. I'm not holding the braid against
> the PCB now, I'm just trying to tin the braid and then deal with melting the
> 2 solders (on the PCB and the braid) together later.
>
> My first attempt--before I realized that I was overheating it--I melted the
> dielectric insulation.
>
> The mesh is made from some silver-colored braid which I thought is tinned
> copper but now I'm of the opinion that it's steel; it's certainly not
> aluminum. There is also foil which is probably aluminum but I've trimmed that
> back and it's not part of this frustrating process right now.
>
> What's the trick to getting this braid to take solder? I've never seen this
> before.
>
> Thanks.

Electroplated wire, most likely nickel.

Jamie





== 16 of 24 ==
Date: Sun, Jan 19 2014 6:38 am
From: "Tim Williams"


Well, what does it feel like?

Steel wire feels very stiff. Grab a leaded component out of the box and
ponder the leads; they're probably tin plated steel (check with a magnet).
Most resistors, capacitors and diodes are. Some smaller ceramic caps have
thicker, softer copper leads; find some if you can.

Aluminum wire is very soft, floppy stuff. It is much softer than copper,
than copper is of steel. If that's what it is... oh well.

As for soldering practice... the old saw about "apply solder to the
opposite side of the joint" is complete BS. Forget about it. Don't try
soldering as you were told, make the solder happy and good joints will
follow. First goal, get the part hot: hold the iron on the part, and
apply solder right beside the iron, or to it, so the iron heats and wets
what it's touching. On a braid, solder will spread and soon the joint
will accept solder from all sides.

Tim

--
Seven Transistor Labs
Electrical Engineering Consultation
Website: http://seventransistorlabs.com

"Bob E." <bespoke@invalid.tv> wrote in message
news:0001HW.CF0092FA036D6B77B01029BF@news.eternal-september.org...
>I am trying to solder some RG-6 shield to a pcb. The braid won't tin.
>It's
> almost like it's dissipating the heat faster than I can apply it. With
> both a
> temp-controlled iron (set as high as 700F) and a mondo 100W stick I
> finally
> tried. The solder will barely melt when touched to the braid opposite
> the
> iron.
>
> I've applied some Kester rosin paste flux as well using my trusty Kester
> 60/40 lead-based rosin core solder. No joy. I'm not holding the braid
> against
> the PCB now, I'm just trying to tin the braid and then deal with melting
> the
> 2 solders (on the PCB and the braid) together later.
>
> My first attempt--before I realized that I was overheating it--I melted
> the
> dielectric insulation.
>
> The mesh is made from some silver-colored braid which I thought is
> tinned
> copper but now I'm of the opinion that it's steel; it's certainly not
> aluminum. There is also foil which is probably aluminum but I've trimmed
> that
> back and it's not part of this frustrating process right now.
>
> What's the trick to getting this braid to take solder? I've never seen
> this
> before.
>
> Thanks.
>






== 17 of 24 ==
Date: Sun, Jan 19 2014 7:45 am
From: dave


On 01/18/2014 08:22 PM, Bob E. wrote:
> I am trying to solder some RG-6 shield to a pcb. The braid won't tin. It's
> almost like it's dissipating the heat faster than I can apply it. With both a
> temp-controlled iron (set as high as 700F) and a mondo 100W stick I finally
> tried. The solder will barely melt when touched to the braid opposite the
> iron.
>
> I've applied some Kester rosin paste flux as well using my trusty Kester
> 60/40 lead-based rosin core solder. No joy. I'm not holding the braid against
> the PCB now, I'm just trying to tin the braid and then deal with melting the
> 2 solders (on the PCB and the braid) together later.
>
> My first attempt--before I realized that I was overheating it--I melted the
> dielectric insulation.
>
> The mesh is made from some silver-colored braid which I thought is tinned
> copper but now I'm of the opinion that it's steel; it's certainly not
> aluminum. There is also foil which is probably aluminum but I've trimmed that
> back and it's not part of this frustrating process right now.
>
> What's the trick to getting this braid to take solder? I've never seen this
> before.
>
> Thanks.
>

A solder pot is preferred. Otherwise burn all the non-metallic weirdness
away with your trusty Zippo.




== 18 of 24 ==
Date: Sun, Jan 19 2014 7:49 am
From: Baron


Michael A. Terrell scribbled thus:

>
> "Bob E." wrote:
>>
>> Yes it's that crap.
>>
>> > I suppose you could try an aluminum flux, but can't you just
>> > unravel and gather enough of the shield to crimp into a ring
>> > terminal or something?
>>
>> Yeah, that's my next move. I just couldn't believe that something
>> couldn't be soldered. I guess REALLY agressive flux is required, as
>> you say.
>>
>> When it comes to broadcast TV I try to solder every connection
>> possible. Every crimp is one more dB lost.
>
>
> You must do lousy crimping, if you lose a dB.
>

I agree ! A good crimp is at least as good as the best solder joint.

--
Best Regards:
Baron.




== 19 of 24 ==
Date: Sun, Jan 19 2014 9:09 am
From: Fred Abse


On Sat, 18 Jan 2014 20:22:18 -0800, Bob E. wrote:

> I am trying to solder some RG-6 shield to a pcb. The braid won't tin. It's
> almost like it's dissipating the heat faster than I can apply it. With
> both a temp-controlled iron (set as high as 700F) and a mondo 100W stick I
> finally tried. The solder will barely melt when touched to the braid
> opposite the iron.
>
> I've applied some Kester rosin paste flux as well using my trusty Kester
> 60/40 lead-based rosin core solder. No joy. I'm not holding the braid
> against the PCB now, I'm just trying to tin the braid and then deal with
> melting the 2 solders (on the PCB and the braid) together later.
>
> My first attempt--before I realized that I was overheating it--I melted
> the dielectric insulation.

Its virtually impossible to tin polyethylene coax braid without softening
the dielectric. It will re-solidify. PTFE (Teflon) is better in that
respect.

>
> The mesh is made from some silver-colored braid which I thought is
> tinned copper but now I'm of the opinion that it's steel; it's certainly
> not aluminum. There is also foil which is probably aluminum but I've
> trimmed that back and it's not part of this frustrating process right
> now.

If you think the braid is steel, try it with a magnet.

From a quick look at Belden specs, they, at least, don't make any RG6
types with steel braid. There are some versions with aluminum braid.

>
> What's the trick to getting this braid to take solder? I've never seen
> this before.
>

If it's aluminum, you can't. Either get some cable with tinned or silver
plated copper braid, or put a BNC socket on the PCB, and a crimp BNC on
the cable. (I don't trust crimping to aluminum, BTW, there's a
metallurgical creep problem)

--
"Design is the reverse of analysis"
(R.D. Middlebrook)




== 20 of 24 ==
Date: Sun, Jan 19 2014 11:57 am
From: Phil Hobbs


On 1/19/2014 2:30 AM, Michael A. Terrell wrote:
>
> "Bob E." wrote:
>>
>>>> When it comes to broadcast TV I try to solder every connection possible.
>>>> Every crimp is one more dB lost.
>>
>> I'm no RF expert, just my impression--possibly mistaken.
>
>
> The loss should be under .1 dB for a good F connector,
^^^^^^^^^^^^^^^^
Jumbo shrimp alert. ;)

Cheers

Phil Hobbs


--
Dr Philip C D Hobbs
Principal Consultant
ElectroOptical Innovations LLC
Optics, Electro-optics, Photonics, Analog Electronics

160 North State Road #203
Briarcliff Manor NY 10510

hobbs at electrooptical dot net
http://electrooptical.net




== 21 of 24 ==
Date: Sun, Jan 19 2014 2:29 pm
From: Jeff Liebermann


On Sat, 18 Jan 2014 20:50:34 -0800, Bob E. <bespoke@invalid.tv> wrote:

>When it comes to broadcast TV I try to solder every connection possible.
>Every crimp is one more dB lost.

100% of the RF connectors I use for mountain top radio sites that I
deal with are crimped, not soldered. Well, maybe a few soldered
abominations such as PL-259 connectors.

The losses per connector are quite low. For example, here's a string
of random adapters:
<http://www.learnbydestroying.com/jeffl/antennas/connector-loss/slides/Adapter%20Colluge.html>
<http://www.learnbydestroying.com/jeffl/antennas/connector-loss/>
That's about 15 assorted adapters (30 connections) showing 2dB loss at
2.4 GHz or:
2dB / 30 = 0.07 dB loss per connection.
Unless you're working with high power levels, the connector loss is
not a problem.

Unless you're working with microwave frequencies, mismatch loss is
also not much of a problem. For example, if you insert a section of
75 ohm coaxial cable into your system, a TDR would certainly show an
impedance bump far larger than what might be produced by a solder
blob. However, the losses are fairly trivial. Much depends on the
frequency of operation. If you're doing microwave, then precision is
required. If you're doing lower frequencies, you can be fairly sloppy
and things will still work quite well.

Cut-n-pasted from my previous rant on the topic from
rec.radio.amateur.antenna.

Let's pretend that I mix in a 75 ohm coax connector into a
50 ohm system. Depending on the location of this "impedance bump",
the VSWR is no more than 1.5:1 which is generally considered marginal.
That's 0.18dB of mismatch loss.
<http://www.microwaves101.com/encyclopedia/calvswr.cfm>
If you're doing satellite or microwave DX work, then 0.18dB might be
important. However, for most other applications, it's a trivial
amount.

You might be amused to know that most of my rooftop antennas are fed
with 75 ohm coax and that my favored antenna designs are also 75 ohm.
There are various reasons, but the main one is that coax cable losses
are less at 75 ohms, than at 50 ohms. 50 ohms can handle more power,
but 75 ohms has less loss.
<http://www.belden.com/blog/broadcastav/50-Ohms-The-Forgotten-Impedance.cfm>
The only problems I have with 75 ohms is finding the proper connectors
and dealing with the pads needed to make my 50 ohm test equipment look
like 75 ohms. (Actually the real reason is that the 75 ohm stuff is
mostly CATV surplus, which tends to be really cheap).

More:
<http://www.qsl.net/n9zia/wireless/75_ohm_hardline.html>

--
Jeff Liebermann jeffl@cruzio.com
150 Felker St #D http://www.LearnByDestroying.com
Santa Cruz CA 95060 http://802.11junk.com
Skype: JeffLiebermann AE6KS 831-336-2558




== 22 of 24 ==
Date: Sun, Jan 19 2014 4:01 pm
From: Bob E.


> 100% of the RF connectors I use for mountain top radio sites that I
> deal with are crimped, not soldered.

This is where the original short length of RG6 was soldered to the pcb
antenna. It's an inexpensive broadcast TV antenna for home.

Rather than make a male crimp plus a barrel to join the 2 mailes, just solder
the long run directly to the pcb. Or so I thought...

I crimped 1/2" of center solid conductor to the braid and soldered the solid
to the pcb. It seems to work but I have no way to measure any loss. I plan to
replace this when I find some REAL copper RG6.

Thanks.





== 23 of 24 ==
Date: Sun, Jan 19 2014 4:20 pm
From: "Phil Allison"



"Maynard A. Philbrook Jerkoff."

> Electroplated wire, most likely nickel.



** But nickel plated stuff solders beautifully.

Jack plugs and sockets, DC plugs etc.


.... Phil






== 24 of 24 ==
Date: Sun, Jan 19 2014 6:12 pm
From: Jeff Liebermann


On Sun, 19 Jan 2014 16:01:53 -0800, Bob E. <bespoke@invalid.tv> wrote:

>> 100% of the RF connectors I use for mountain top radio sites that I
>> deal with are crimped, not soldered.

>This is where the original short length of RG6 was soldered to the pcb
>antenna. It's an inexpensive broadcast TV antenna for home.

Thank you for disclosing what you're trying to accomplish. Context is
always important.

You're going to have corrosion problems. Note that all the
aforementioned crimped connectors have the crimped area sealed inside
the connector. In addition, they are usually wrapped in some form of
waterproofing (i.e. PTFE tape and electrical tape) to keep out the
water. Even if you solder the connections, the capillary action is
going to force the water up the braid and under the jacket. Depending
on the outer jacket slop, corrosion will rot up to several inches of
braid. You can try to seal the braid and solder connections with RTV
silicon rubber that doesn't contain acetic acid but I haven't had much
luck with that.

Using bare wires from the end of a coax cable is about as bad an
impedance bump as you can possibly create. However, it won't matter
for a TV antenna, that has wide bandwidth, but relatively little gain.
PCB TV antennas tend to be rather small, and therefore have even less
gain. Impedance discontinuities will not have a huge effect on
overall performance. Therefore, you can probably just attach some
spade lugs onto the ends of the RG-6/u coax, and use ordinary brass
screws and nuts to make the connection.

>Rather than make a male crimp plus a barrel to join the 2 mailes, just solder
>the long run directly to the pcb. Or so I thought...
>
>I crimped 1/2" of center solid conductor to the braid and soldered the solid
>to the pcb. It seems to work but I have no way to measure any loss. I plan to
>replace this when I find some REAL copper RG6.

If you have a PCB, why not use a PCB mounted F connector?
<http://www.ebay.com/itm/111244951312>
<http://www.ebay.com/itm/261373960762>

I tried to find such a coax cable from my distant past. It had a
copper clad steel center conductor, aluminum foil shield, and a very
loose braid of flash galvanized steel wire braid over the shield. The
braid was only for strength and not for shielding. The zinc plating
was for galvanic compatibility with the aluminum shield. Such a cable
was not intended to be soldered, only crimped. I saw it at STV
(subscription TV) in Smog Angeles in the 1960's. However, I couldn't
find it which suggests that it's either uncommon, not in current
production, or my memory is faulty.

It would be helpful if you could provide any markings on your cable so
that it can be identified.

--
Jeff Liebermann jeffl@cruzio.com
150 Felker St #D http://www.LearnByDestroying.com
Santa Cruz CA 95060 http://802.11junk.com
Skype: JeffLiebermann AE6KS 831-336-2558





==============================================================================
TOPIC: Anyone help me with component ID for X5DIJ-SX039C laptop (k501j mobo)?
http://groups.google.com/group/sci.electronics.repair/t/58fd5bf0893d5f4a?hl=en
==============================================================================

== 1 of 2 ==
Date: Sun, Jan 19 2014 4:27 pm
From: Chris from London


Went to try to fix my daughters ASUS laptop and made it much worse :)
She did not have her power supply so I used mine - I have an ASUS netbook. The plug was not the same but the VA are so I rigged up what I thought was the correct one but when I plugged it in it would not light the "PSU connected light". Although the laptop worked, without a charger it was no use.

As it was working before I got my hands on it I assume my connector somehow caused the PSU circuit to blow. The DC Jack goes to a plug on the mobo and I tested it in situ - there was 19v at the mobo socket, so the prob is further down the line.

I had to take the laptop completely apart to get at the mobo components to test points, and cannot easily re-connect everything to test the whole. I stripped it down and sure enough there is a burnt-out component - looks like a SM cap (MLCC) but cannot be 100% certain due to ignorance.

The mobo is an asus k501j

Found the schematic (https://googledrive.com/host/0ByM1ELG0t6mgZlJsRmRZcXhSVWM/pub/asus_k40ij_k50ij_rev_1.1_sch.pdf although it is for rev 1.1 and my board is rev 2.1) so have extracted the PSU Section and added it to the photo.

It looks as if the burnt one is an MLCC - a capacitor but, as I am not sure I have got the right schematic and cannot trace the wiring on the board itself (it is too thick) I guess I can only go ahead and replace it and hope for the best.

Can I test the mobo with nothing apart from power or do I need to reassemble? Can I simply remove the component and see if the laptop works without it? There could be a further fault. Presumably I do not need a MLCC - a regular cap would do it provided it is rated at 25v? Thought I could maybe try to find one on an old computer board as it looks like you cannot easily buy just one MLCC.

Hers a photo of the mobo showing the component and the schematic:
http://i989.photobucket.com/albums/af18/zeus_1066/domtech/laptop/asus-k501j-burnt-out-schemtoo_zps3829aba0.png

Here is a bigger pic of just the mobo:
http://i989.photobucket.com/albums/af18/zeus_1066/domtech/laptop/k501jmoborear_zps25b04b6d.jpg

Any help gratefully appreciated.







== 2 of 2 ==
Date: Sun, Jan 19 2014 5:41 pm
From: "Phil Allison"



"Chris from London"


>Hers a photo of the mobo showing the component
> and the schematic:
>
>http://i989.photobucket.com/albums/af18/zeus_1066/domtech/laptop/asus-k501j-burnt-out-schemtoo_zps3829aba0.png


** What I see your arrow pointing at is a burnt looking SMD tantalum cap
(C6802) and immediately to it's left a missing part - Schottky diode
(D6801). The cap further to the left is an MLCC.

With reverse polarity at the DC jack, the diode would heat, melt the solder
and fall off the PCB - then the tantalum cops reverse voltage and
explodes.

I strongly suspect there is other damage too.



.... Phil







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