What do you use - prototyping.

[cdev]

I'm using first a breadboard, then a piece of PCB inside a cardboard box to prototype.  I can then write all the pertinent notes on the outside or inside. I dont route the wires in from the top, I cut holes for them and use dip sockets and plugs which I already have.

This is new but for a long time Ive used home-made cardboard boxes to enclose projects. With RF sometimes you have to have a snug case, this is easier to get right with copper coated cardboard or foam core than anything else.

I've often tried to use metal cases but just couldn't do what I wanted to do so ended up back with cardboard and copper and foam core..

I've used foam core for antennas too.

[kalel]

I'm using first a breadboard, then a piece of PCB inside a cardboard box to prototype.  I can then write all the pertinent notes on the outside or inside. I dont route the wires in from the top, I cut holes for them and use dip sockets and plugs which I already have.

This is new but for a long time Ive used home-made cardboard boxes to enclose projects. With RF sometimes you have to have a snug case, this is easier to get right with copper coated cardboard or foam core than anything else.

I've often tried to use metal cases but just couldn't do what I wanted to do so ended up back with cardboard and copper and foam core..

I've used foam core for antennas too.

Cardboard boxes sounds great for prototyping. Have you posted an image of such a project?

[ChrisLX200]

Copper clad board and Veroboard for me. I have a few breadboards but don't get on with them too well - always seem to get bad connections, perhaps I should invest in better quality ones :-)  I use a 3D printer for most temporary boxes because it's so easy to design and print something that fits near exact.

ChrisH

[Red Squirrel]

Mostly bread boards for small stuff and crocodile clips for bigger stuff.  For more permanent stuff I'll use perf board.  I have not gotten into any complex projects or SMD stuff yet, but once I do I will probably build my own break out boards to combine certain things together into some break out boards.   

[John B]

I don't do a lot of high frequency stuff but I am experiencing the shortcomings in breadboard use, I find the soldering up of stuff a hassle - and I always muck it up.

I marvel at how tidy some people seem able to work but I have problems transferring schematic to reality so I tend to breadboard a lot.

I have used Vero but I find the copper tracks very limiting and end up cutting tracks and putting jumpers all over the place and it is useless for anything with an IC or two, I've had some that wouldn't take solder readily.

I use Express Schematic and Express PCB to help me lay out prototypes on 0.1 inch through hole board with individual plated holes, not strip board. Once you reach a certain level of complexity and number of components, I can't imagine trying to lay it out as you solder.

The up-down left-right square grid does eventually become limiting for space, density and routing options, but it should suffice for many projects which can be put into use as is.

[Howardlong]

Used to do a similar thing when I had a darkroom - digital is so much less hassle.

You don’t need a darkroom. Use decent pre-sensitised boards and peel off the protective backing just before you place them in the UV box. As long as you’re not leaving the boards out a long time unprotected or outside in direct sunlight, normal office or domestic lighting isn’t a problem.

While I understand the retiscence around the chemicals, once you have your process it’s quick and reasonably simple. Just don’t let the ferric chloride near stainless steel kitchen sink, or conduct operations in your formal wear, or you’ll have some explaining to do.

[bd139]

Good advice. My wife hasn’t forgiven me for wrecking the nice porcelain kitchen sink with ferric chloride yet. 

[tggzzz]

Good advice. My wife hasn’t forgiven me for wrecking the nice porcelain kitchen sink with ferric chloride yet. 

Old timers remember why most people swapped to stainless steel sinks as fast as possible. And it wasn't just because of our type of activity

[bd139]

Yes she dropped a glass in it a week after she mandated that it was installed and they installed it. Big crack. Looks like shit now.

Plastic trays for this stuff. I’m a fan of the Poundland Tupperware boxes. They also won’t melt if you’re doing an IPA wash.

[woody]

Using a breadboard for the first tinkering, then a cnc mill to make a working prototype. The advantage is speed; the disadvantage is that you often have to redesign the board to make the final pcb. This due to the fact that thru-holing, vias and very fine tracks are unfeasable. But for simple one-offs a mill is quite usable.

[tggzzz]

Plastic trays for this stuff. I’m a fan of the Poundland Tupperware boxes. They also won’t melt if you’re doing an IPA wash.

Oh yes indeed. They come in so many sizes that they can be used for just about anything.

But I do find the cheap ones are more brittle than desirable.

[BenKenobi]

What is kind of clear here is that there really isn't what I'd describe as an 'elegant' solution for this, that the more complex 'packaged IC' components get, the higher the frequencies get that the prototyping methods become really challenging.

I'm not dead against chemicals but I can be a real clumsy doofus with such stuff, I know the IPA story well having had the bottom drop out of a container whilst washing something - on the dining room table.

I like the idea of breakout boards for the SMD packages, I think I'll make sure to add an extra package for the making of these as I go.

I think some of the techniques used by you guys are a little tricky for one like me who lacks all the experience in build and layout strategies that you probably take for granted, I really need to force myself to learn some PCB layout stuff but I'm just not the artistic type so I struggle a lot with it.

Please keep the ideas coming, perhaps a eureka moment will occur ...

[tggzzz]

What is kind of clear here is that there really isn't what I'd describe as an 'elegant' solution for this, that the more complex 'packaged IC' components get, the higher the frequencies get that the prototyping methods become really challenging.

For theory, concentrate on the physics of the inductance of a wire (start with 1nH/mm) including the wires "inside" SMD capacitors (>1mm long!), the current needed to charge a load capacitance during the switching/transition time, and hence the voltage induced across a wireinductor. Then you will realise why short connections are essential!

For practical construction of medium frequencies (up to UHF), see how radio hams do it. Note particularly the use of ground planes.

I like the idea of breakout boards for the SMD packages, I think I'll make sure to add an extra package for the making of these as I go.

I think some of the techniques used by you guys are a little tricky for one like me who lacks all the experience in build and layout strategies that you probably take for granted, I really need to force myself to learn some PCB layout stuff but I'm just not the artistic type so I struggle a lot with it.

Bugger artistry; physics is all that counts in this context! Short leads. Ground planes.

[bd139]

Nice PDF on it here: http://www.aoc.nrao.edu/~pharden/hobby/HG-MANHAT1.pdf and here: http://www.aoc.nrao.edu/~pharden/hobby/HG-MANHAT2.pdf

Quick excerpt:

[BenKenobi]

Happy days - that put a light on - that pad idea looks really usable .. off to buy some stuff - I'll experiment with that method for sure. You could even layer that with standoffs.

Rqd 1 Nibbler, 1 PCB shear, materials, new soldering station ... update - ouch - how much is a PCB shear  anybody got a secondhand one taking up too much space ..

[A Hellene]

I usually am too lazy not to be using solderless breadboards and stripboards.

But, where signal routing matters (because there is hundreds of amps of current flowing or there are nasty dU/dt and/or dI/dt signal change rates --especially when dt is of the order of tens of nanoseconds) I do not hesitate to make prototyping PCBs --even at home, by messing with fine transparency printed films, Positive photoresist sprays and FeCl3 on FR4 copper clads.

For example, this is my latest design of a voltage-doubler lead-acid batteries desulfator:


PCB layout.jpg


Runtime.jpg


About.jpg

And, since I am not satisfied with the real life performance of the voltage-doubler prototype, I'm now back to the drawing board for a voltage-tripler version of it, or even for one with an uCU controlled >50V voltage-booster on board...


-George

[bd139]

Happy days - that put a light on - that pad idea looks really usable .. off to buy some stuff - I'll experiment with that method for sure. You could even layer that with standoffs.

Rqd 1 Nibbler, 1 PCB shear, materials, new soldering station ... update - ouch - how much is a PCB shear  anybody got a secondhand one taking up too much space ..

I use a Stanley knife to cut the main board. Score both sides for a bit then it’ll snap cleanly. The 0.8mm strips you can cut with a pair of aviation shears pretty easily. I usually cut them into strips then skip off bits with aviation shears as and when I need them.

[tggzzz]

Nice PDF on it here: http://www.aoc.nrao.edu/~pharden/hobby/HG-MANHAT1.pdf and here: http://www.aoc.nrao.edu/~pharden/hobby/HG-MANHAT2.pdf
Quick excerpt:
(omitted for brevity)

I don't like the "gnd bus" in that particular example: it is only attached (inductively) to the plane at a single point. Why not use the ground plane directly, and completely omit the gnd bus? Fig 13 looks much cleaner in that respect.

Nonetheless, those articles are informative and a good starting point.

[bd139]

Mainly because you have to tombstone the SMD parts to get them on the ground plane and conductors.

[tggzzz]

Mainly because you have to tombstone the SMD parts to get them on the ground plane and conductors.

Prettier or electrically better: your choice. Fig 11 would be better if the gnd bus was soldered to the plane along the bus' length, not at a single point.

But there are alternatives: double sided PCB with one side a plane, and the other side "milled with a dremel".

[BenKenobi]

What about matrix board ?

I didn't pick that up on the circuit shown re the ground but yes since it is on a copper sheet aka ground plane why not go direct - I thought this was the idea.

On the desulphation project take care - excessive constant voltages on 'gel' type or glass mat batteries will not have the effect you expect, the battery will be effectively trashed if you're not careful. Such methods only work on 'liquid' lead acids because the liquid can carry stuff away from the plate more readily. For Gels and AGM's you need to consider pulsing, raise the voltage yes but do not apply it constantly to such a battery or the gas builds faster than it can dissipate / the cells overheat - the result is never good.

[A Hellene]

[...]
On the desulphation project take care - excessive constant voltages on 'gel' type or glass mat batteries will not have the effect you expect, the battery will be effectively trashed if you're not careful. Such methods only work on 'liquid' lead acids because the liquid can carry stuff away from the plate more readily. For Gels and AGM's you need to consider pulsing, raise the voltage yes but do not apply it constantly to such a battery or the gas builds faster than it can dissipate / the cells overheat - the result is never good.

That's correct!

On the flooded and glass-mat type lead-acid batteries you can do whatever you want to do, if and only if you are also monitoring their temperature changing rate. On the other hand, on the gel types you must be very careful with each pulse energy amount because you do not want to create (permanent) gas bubbles into the gel electrolyte polymer films that exist between their electrode plates. Thus the instantaneous (<0.5-10us max.) strikes of ~500A intended pulses, strictly depended on the procedure statistics by the uCU that creates them (meaning the length and the frequency of the pulses).


-George

[BenKenobi]

Well I've just added another project to my winter list ...

A 3 Axis DIY CNC Router / Mill / Engraving machine - can cut out tracks and such from copper coated boards.



Several interesting projects in one - building, coding, PCB design / production, and my favourite puzzle - debugging ....

[ChrisLX200]

Well I've just added another project to my winter list ...

A 3 Axis DIY CNC Router / Mill / Engraving machine - can cut out tracks and such from copper coated boards.

Several interesting projects in one - building, coding, PCB design / production, and my favourite puzzle - debugging ....

Yes, thinking about that one myself! Could be a very useful tool for smaller PCBs but I'm not confident of attempting to tackle anything above about 6" square. Needs a self-levelling system to work well.

ChrisH

[Red Squirrel]

Wow that little machine does look pretty cool.  Could be used to etch stuff like front panel plates for projects and stuff too.   I kinda like the idea of making PCBs at home but don't really want to invest in a chemical based setup, it looks quite involved if all I want to do is a few one ofs.