AndyW wrote:
On 16/09/2014 19:43, gareth wrote:
"Michael Black" wrote in message
news:alpine.LNX.2.02.1409161411150.29263@darkstar. example.org...
I doubt anyone's ever made coax at home.

It would be an interesting exercise to conceive of the mechanism
for weaving the braid, such that it was tight onto the dielectric

Would you need to weave braid?
Could it not be made by wrapping the dielectric in foil?
Spiral winding foil or otherwise wrapping in foil would seem to be a lot
easier than braiding on the fly.

Andy

I salvaged a load of old Rediffusion coax that was hooked to my house and
that had sheet copper wrapped around the dielectric.

--
Stephen Thomas Cole // Sent from my iPhone

On 17/09/14 01:14, Lostgallifreyan wrote:
"gareth" wrote in news:lv91j4$gv9$1@dont-
email.me:

how difficult
it is to manufacture our own plugs and sockets, despite that BNC and N have
been around for 70 years, with SMC some time later!

Why do you want to do that? Some wheels are definitely best not reinvented.
BNC's can be had on eBay as easily as used matchsticks used to be seen on a
street, it's not like we have to make do without. N connectors are expensive,
but there are likely good reasons for that, partly bulk size, precision
requirements, and a lower size of market (by far) than for BNC.

Unless you wanted a bespoke connector at great expense to either do something
really new, or to freeze out an easy chance of anyone connecting to your
stuff, there is no point, the costs are extreme.

I've thought about doing similar from time to time. Not for RF mind
you, BNC serves me well here. My needs are more for audio/control
connectors.

My connection system has varied a bit over the years. In the beginning
I used 8-pin DIN connectors, which worked okay, but didn't quite have
enough contacts to handle all the controls I wanted.

I was looking for a connector that would handle:
- stereo audio (so 3 or 4 lines, depending if they were to share a
return line)
- microphone audio (2 lines)
- PTT
- 4 direction buttons

8 pins wasn't going to suffice for this. So I moved to DB15HD
connectors. Some might recognise these on VGA video cards. I used an
opposite polarity so as to prevent confusing them with a video card.
(one of my adaptor leads allowed me to use headsets with a computer)

These were convenient being all on one connector, and small, but they do
*not* like being exposed to weather much. I was replacing them on a
regular basis. The regular DB15 might be better, I haven't tried.

My next stop has been to split it into two connectors: a DIN5 carries
headset audio (microphone and two speakers), and the PTT and buttons are
on a separate DIN6.

This is more reliable, although I note the connectors have a tendency to
come apart from time to time. I put up with it though, because the same
connectors have lasted much better than the DB15HDs did.

If I did "my own", I'd probably use 6.5mm phono plugs taped together.
Crude, but effective. Kenwood still use a similar arrangement for their
handhelds and it works well enough there.

On 17/09/14 06:04, Lostgallifreyan wrote:
Michael Black wrote in
news:alpine.LNX.2.02.1409161406070.29263@darkstar. example.org:

Yes, I'd use BNC for audio connectors (something others have done) if I
was going to change connectors (or building something new) and probably
more important, if this pile had included more female connectors.


I've used them for DC power too, sometimes. Given the quality of the pin
surface and material, and a teflon former, this isn't a bad idea, it's likely
to handle surges better, and more safely, than many connectors intended to do
it.

I've used a BNC once for power, basically in a situation where we didn't
have anything else to hand.

Probably the most inappropriate use of a connector I've seen was a pair
of Belling-Lee connectors for power. With both shell and centre
shorted, one for positive, the other for negative. Not bad for current
carrying capability, but the thought of the two meeting with a bang gave
me the willies.

My TS-120S was supplied with a cable fitted in such a manner. It was
the first "modification" I made: replacing it with 30A Anderson
powerpole connectors.

A single Belling-Lee using centre for positive, shell for negative
*might* be okay, two just using the centres might be okay too, but no
way was I going to have shells with opposing polarities in such proximity.

You mention a DB25, another favourite for me. So many pins, each can
handle over an amp, some will handle 2A each. For specialised heavy current
situations,

Yep, I use them on the bicycle mobile station. Inside a motorcycle top
box I have my FT-857D mounted with a break-out cable that takes DB25 to
a 8P8C connector for the microphone and 6P6C for the head, as well as
two 3.5mm connectors for speaker and CW key.

At the other end I have a similar break-out to plug in my headset, the
head unit and the control buttons.

The DB25-DB25 connectors are linked with 3 runs of CAT5e, giving me 24
usable pins. I did try using an old printer extension cable, but found
I got cross-talk from the head unit comms cable into the microphone.
CAT5 works well though, and isn't difficult to manufacture.

Stuart Longland wrote in news:ljdoeb-
:

8 pins wasn't going to suffice for this. So I moved to DB15HD
connectors. Some might recognise these on VGA video cards. I used an
opposite polarity so as to prevent confusing them with a video card.
(one of my adaptor leads allowed me to use headsets with a computer)

These were convenient being all on one connector, and small, but they do
*not* like being exposed to weather much. I was replacing them on a
regular basis. The regular DB15 might be better, I haven't tried.


I remember someone posting about a motorbike and weathering of various
plugs (maybe you?). I tried to find any stored posts but failed, having
restored a broken X-news dir from a much earlier saved copy, losing a year's
archiving in the process apparently. I can't remember the details, but I
think he found a part-answer in using lots of PFPE grease to exclude water.
The stuff is often used on vehicles because it tends to stay put and not form
a grinding paste with all the grit that lands on it.

XLR's some in multi-pin forms, mayeb more reliable than multiple 6.5mm jacks,
but I suspect too expensive and bulky if you need a lot at once. I'd probably
use DB25 with adapter as first choice. Bit of heatshrink sleeving such as
used for DIY battery packs, to seal the adapter onto the plug. When the
adapter started to fail, rework the new adapter and new sleeving, rather than
have to do any resoldering. A kind of built-in disposability to save greater
work...

I've looked at DB15HD too, but they're so fiddly to solder I decided not to
do it again.

Stuart Longland wrote in news:6meoeb-
:

I did try using an old printer extension cable, but found
I got cross-talk from the head unit comms cable into the microphone.
CAT5 works well though, and isn't difficult to manufacture.


I once found a DB25-type cable with some individually screened pairs, in a
skip. Not got it now, but I remember it being a bit thicker and less flexible
than usual. Maybe hard to find now that it's been so many years since big
firms changed to ethernet and such. There are cables used for video,
'downlink' cables and such sold by Maplin that might do for mixed signals.
Again, probably expensive... When I wanted a 5m run for keyboard, mouse,
video, I just tied three cheap lines togeher, the cost of paying to have it
done by default was horrifying.

Stuart Longland wrote in news:6meoeb-
:

replacing it with 30A Anderson
powerpole connectors.


I nearly went with those for my offgrid PV system, but decided that modifed
3-pin XLR was good enough for me. I rarely use the full 16A capability
anyway.. In the one case where I do at times, I just put two plugs on the
cable.

On Wed, 17 Sep 2014, Lordgnome wrote:

On 16/09/2014 19:10, Michael Black wrote:

Especially when you can find them lying on the sidewalk.

Some years back, I came upon a pile of junk on the sidewalk, waiting for
the garbage truck. I poke around, and find a near endless number of BNC
connectors. I grab some, then continue on my way. Coming back, the
rest were still there so I grabbed all of them. QUite a weight once
accumulated.

There were a few hundred BNC connectors.

I wonder if this was at the time when networks were moving from coax to
UTP? I still have a wonderful collection of BNC patch leads which were
surplus when my company switched over.

This had to be some individual, it was next to an apartment building, and
the connectors were all in a drawer from a bureau. There were some junk
computer boards in a box next to it.

YOu have to be in the right place at the right time, bcause otherwise you
won't see it, and chances are good no one else who can appreciate such
finds will come along while it's there.

Michael

On 18/09/14 04:52, Lostgallifreyan wrote:
These were convenient being all on one connector, and small, but they do
*not* like being exposed to weather much. I was replacing them on a
regular basis. The regular DB15 might be better, I haven't tried.

I remember someone posting about a motorbike and weathering of various
plugs (maybe you?).

Probably not me. I've been on the back of a motorcycle exactly once and
ridden a quad-bike once. My bikes are very much motor-less.

http://stuartl.longlandclan.yi.org/b.../09/vk4msl-bm/

I can't remember the details, but I
think he found a part-answer in using lots of PFPE grease to exclude water.
The stuff is often used on vehicles because it tends to stay put and not form
a grinding paste with all the grit that lands on it.

Interesting concept, I wonder how that affects conductivity…

Frank Turner-Smith G3VKI wrote:


It's illegal to text while driving, but what about using a key?

On most cars, it's compulsory. If you don't turn it, the engine won't
start.


--
Chris
G4FZN

In message , Chris Kirby
writes
Frank Turner-Smith G3VKI wrote:


It's illegal to text while driving, but what about using a key?

On most cars, it's compulsory. If you don't turn it, the engine won't
start.

There are stringent laws specifically relating to the use of phones in
vehicles. Unless the phone has a key, they won't apply. However, you
could still get got under other laws.


--
Ian