EMRFD Message Archive 4627

Message Date From Subject
4627 2010-05-04 08:31:00 gi0gdp Against Ugly Construction
I build using all methods under the sun and it depends on the circumstances at the time, however sometimes ugly is bad.
If you are going to subsequently produce a PCB then you are almost 100% going to run into problems. This is a bit the same as when you put something in a box syndrome.
So there are times when i go direct to an ugly pcb. Only ugly in the sense that perhaps not alot of care has been taken when etching or you have allowed some tracks to be a bit thin or thick but never the less a pcb.
But horses for courses i suppose although over the years i do tend to produce in the first instance a pcb, perhaps because i can!,
regards
Geoff
4628 2010-05-04 11:15:19 Tim Re: Against Ugly Construction
My crudest PCB's were in fact carved out of PCB using a utility knife.

Every board in my R2Pro mainframe was made that way.

Doing 0.1" spacing for DIP's is possible with a utility knife but requires a good amount of care.

I think it's a fine technique for audio type constructi
4629 2010-05-04 11:18:10 WA0ITP Re: Against Ugly Construction
I'll put in a note in support of Manhattan. I get along better with it than ugly. Altho some of my
Manhattan stuff is pretty ugly too.
-------------------------------------------------------------------
I love this radio stuff !
72, 73 Terry, WAØITP
www.wa0itp.com
www.4sqrp.com
www.qrpspots.com



----- Original Message -----
4630 2010-05-05 09:16:54 n5emqrp Re: Against Ugly Construction
Manhattan has the advantage of helping toward pc boarc layout in advance. See Paul Hardin's excellent work -

http://www.aoc.nrao.edu/~pharden/hobby/HG-MANHAT1.pdf

http://www.aoc.nrao.edu/~pharden/hobby/HG-MANHAT2.pdf , particularly this one for migrati
4631 2010-05-05 09:52:59 drmail377 Re: Against Ugly Construction
Nice Thread, More please...

Consider this:

Just solder the parts together directly. If you have a DIP or leaded SMT device, splay the leads. Use a piece of cardboard to lay the parts out; a little dab of hot-glue here-and-there is your friend to hold parts down. No PCB's involved. You can "space-wire" some pretty high frequency stuff this way.

Another favorite is to wire-wrap female headers and/or DIP sockets to a 0.1" perf-board. DIPs are accommodated, but individual leaded components are too! (Yes you can solder plug-able leads to SMT devices.) The parts are just plugged into the headers and/or DIP sockets. Voila; no soldering. Just wrap-unwrap the connections as you design and plug/unplug different components into the sockets while testing. Yes, this isn't going to work for very high frequency stuff, But at HF and below, I've experienced good results for first-level prototyping.

Best 73's, David WB4ONA

4632 2010-05-05 10:01:46 Tayloe Dan-P26412 Re: Against Ugly Construction
Wire wrap. Boy that takes me waaaaay back.

Wire wrap never worked that well for me. Long, long, ago I wire wrapped homebrew 6809 and 68000 systems. I was always fighting wire wrap connections that went bad. These were usually the "slit & wrap" connections, not the slower strip and wrap connections.

- Dan, N7VE

________________________________

4633 2010-05-05 10:05:22 Dino Papas Re: Against Ugly Construction
No fooling, that was the truth....visually there was just no way to tell if a manual (not machine, who could afford one?) wrap was good so of course you had to go back and confirm each connection with a VOM....what a pain! Ugly is much better (but probably wouldn't have been feasible for a typical computer construction of the day, although I have seen a couple of pix on the web of guys who did it).

73 -- Dino KL0S

On 5May2010, at 1:00 PM, Tayloe Dan-P26412 wrote:

> Wire wrap. Boy that takes me waaaaay back.
>
> Wire wrap never worked that well for me. Long, long, ago I wire wrapped homebrew 6809 and 68000 systems. I was always fighting wire wrap connections that went bad. These were usually the "slit & wrap" connections, not the slower strip and wrap connections.
>
> - Dan, N7VE


[Non-text portions of this message have been removed]
4634 2010-05-05 10:42:09 WA0ITP Re: Against Ugly Construction
It was a 6800 system for me, and it looked like a nest of tarantulas when I finished it.
-------------------------------------------------------------------
I love this radio stuff !
72, 73 Terry, WAØITP
www.wa0itp.com
www.4sqrp.com
www.qrpspots.com



----- Original Message -----
4635 2010-05-05 10:50:31 Corey Minyard Re: Against Ugly Construction
I've only wire-wrapped one project, a 68000-based DSP board for my
senior project, and it worked the first time. I was very meticulous
about the whole thing and I used the "strip and wrap" method. IIRC, I
tried the more automatic guns and they were not reliable, so I did it
completely manual. So I think it can be done, though having all those
pins sticking out of the bottom of the board was a big pain.

Everything I've designed since then (all for work) has been far too
complicated and fast for wire wrap. I wouldn't want to wire-wrap a 325
pin grid array :-0.

I'm about to start on a ham project where some of the chips will be SMT,
and I'm debating on whether to start with a circuit board or do
manhattan or dead bug. It seems you can get a small circuit board done
for well less than $100, and that's pretty attractive.

-corey - AE5KM


Dino Papas wrote:
> No fooling, that was the truth....visually there was just no way to tell if a manual (not machine, who could afford one?) wrap was good so of course you had to go back and confirm each connection with a VOM....what a pain! Ugly is much better (but probably wouldn't have been feasible for a typical computer construction of the day, although I have seen a couple of pix on the web of guys who did it).
>
> 73 -- Dino KL0S
>
> On 5May2010, at 1:00 PM, Tayloe Dan-P26412 wrote:
>
>
>> Wire wrap. Boy that takes me waaaaay back.
>>
>> Wire wrap never worked that well for me. Long, long, ago I wire wrapped homebrew 6809 and 68000 systems. I was always fighting wire wrap connections that went bad. These were usually the "slit & wrap" connections, not the slower strip and wrap connections.
>>
>> - Dan, N7VE
>>
>
>
>
4642 2010-05-05 12:37:22 chuck adams Re: Against Ugly Construction
On Wed, 2010-05-05 at 13:05 -0400, Dino Papas wrote:
>
> No fooling, that was the truth....visually there was just no way to
> tell if a manual (not machine, who could afford one?) wrap was good so
> of course you had to go back and confirm each connection with a
> VOM....what a pain! Ugly is much better (but probably wouldn't have
> been feasible for a typical computer construction of the day, although
> I have seen a couple of pix on the web of guys who did it).
>
> 73 -- Dino KL0S
>
> On 5May2010, at 1:00 PM, Tayloe Dan-P26412 wrote:
>
> > Wire wrap. Boy that takes me waaaaay back.
> >
> > Wire wrap never worked that well for me. Long, long, ago I wire
> wrapped homebrew 6809 and 68000 systems. I was always fighting wire
> wrap connections that went bad. These were usually the "slit & wrap"
> connections, not the slower strip and wrap connections.
> >
> > - Dan, N7VE
>

Dan et al,

Here is a presentation done by a former student of mine when I
was a prof at Texas A&M Univ in EE working with Jack Kilby,
whom I had worked with at TI in the '60s. I had several students
doing uP projects and software.

http://www.k7qo.net/huddlebug.ppt

It is a power point presentation. Those of you that did wire wrap
can see the huge number of points that Mike had to do. Some of
the PCB's were added since the 1970's.

I was the only person to ever get a DataSync board going and that
required stripping the board and doing wire wrap. DataSync was the
group that ripped off Wayne Green and Kilobaud for a large amount
that was due for advertising.

And then there ate the solderless prototyping boards used mainly for
digital work, but some have built 2m xcvrs on them. 0.1" centers and
you can rewire and reuse parts till you turn get tired of a project.


FYI

chuck


--
chuck adams, k7qo
http://www.k7qo.net/
chuck.adams.k7qo@gmail.com
4660 2010-05-07 01:13:46 drmail377 Re: Against Ugly Construction
Hi Dan,

Yes wire-wrap unfortunately seems to be a "lost-art" these days. But I use it regularly and I wish others would too...

Insulation Displacement (ID) wrap as you mentioned is problematic with hand wrapping but near bullet-proof in automated wrapping (if it even exists any-more). ID wrap protects the wrap from the elements pretty well and was used in hi-rel mil-spec stuff decades ago.

I strip and wrap. For digital and higher frequency stuff, I take care to route the wraps perpendicular to avoid cross-talk and parasitics, the results are impressive even compared to the likes of a carefully laid-out double-sided board with the likes of CPLD/FPGA. But it of-course is no replacement for multi-layer boards with ground planes ($$$).

Also, when you get to a near stable prototype, cut the wrap leads down to remove even more parasitics. Finally, soldering the wraps makes a prototype that can survive even the harshest environments, especially for vibration when using good quality machined-pin sockets/headers.

If you repeatedly wrap-unwrap posts however, you do diminish the connection quality somewhat as the wire won't bite into the post as well. When finished, solder the wraps into place for surety.

Years ago I bought a two thousand foot spool of wire-wrap mil-spec wire for something like ten bucks. I think it is Kapton coated, maybe that has something to do with the low price. The spool has served me well. For digital I wire-wrap the boards and bring out the GPIO pins to 0.1" machined socket headers.

Here in SE Asia hand wrap-unwrap tools with embedded strippers are dirt cheap (around $5 USD) and of high quality. No need to spend a lot of money for a hand-wrap tool. Very high quality machined-pin DIP wire-wrap sockets/headers of all sizes out here go for around $0.1 USD per pin and are used widely in Asia for prototyping (try Sun Electronics PTE LTD, Sin-Lim Tower, Singapore, sorry no URL).

Don't dismiss wire-wrap as a fast and flexible prototyping solution.

Best 73's David WB4ONA