Has anyone ever seen this construction technique before?

[Housedad]

Just Wow.  I have never seen anything constructed like this.  It looks intrinsically very unsafe.   Has anyone ever see anything like this rat circuit construction?  Maybe I just live a cloistered life.  I saw it here:  http://qrp-popcorn.blogspot.com/2016_11_01_archive.html

[technogeeky]

Yes. This is how things were done before the invention of circuit boards (and then printed circuit boards).

It even has a name: point-to-point circuit assembly.

It's still used today, too:



This video examines this technique in this video and some of his others show it as well. I presume that this is somewhere between impractical and impossible for some high voltage circuits, but for many circuits (including RF circuits) it can be very good and very high performance.

[Richard Crowley]

It is just one type of free-form construction technique more commonly used for analog (and particularly RF) circuits.
See also:
Dead Bug:  https://www.google.com/search?q=dead+bug+construction+style&source=lnms&tbm=isch
Manhattan: https://www.google.com/search?q=manhattan+electronic+construction+style&source=lnms&tbm=isch

Not clear what appears to be "very unsafe"?

[GreggD]

Building on a ground plane, great technique. This is how the also great Jim Williams did quick development and so did I.

[edpalmer42]

My favorite name for this is "dead bug" style.

It looks like a disaster, but it gives very good performance for RF and high speed digital circuits because everything is built on the ground plane, the leads can be very short, and capacitance to ground will be very low for leads connected through the air.  I used this technique to build a circuit that squares up a 10 MHz sine wave, divides it by 10K, and then attenuates the output.  I've attached a picture of the output pulse.  The horizontal axis is sample intervals of 100 ps.  The vertical axis is volts across a 50 ohm load.

Ed

[Farley]

This is also sometimes referred to as "ugly construction." It's used for low voltage circuits, typically 12VDC or less. It works well for quick construction of RF circuits as Richard Crowley stated.

Dave Richards (AA7EE) has made an art-form of this construction technique.
For example https://aa7ee.wordpress.com/2013/10/19/the-vk3ye-micro-40-dsb-transceiver/

[ataradov]

Not only this is common in RF designs, there are even tools for cutting small island in the copper.

Can't find commercial examples at the moment, but here is an example of homemade one - http://hackaday.com/2012/07/20/cutting-islands-into-copper-clad-pcbs-with-a-drill/

[danadak]

http://makezine.com/2012/10/08/a-fine-example-of-dead-bug-style-circuit-wiring/





http://www.edn.com/Pdf/ViewPdf?contentItemId=4326598


Regards, Dana.

[Housedad]

Fascinating.  I did not ever realize this technique existed.  I can also see that there is different levels of build quality and neatness.   Thank you for the explanations!   I now have something new to research and learn, and I always love to learn something new.   You mentioned that this was a early method of construction.   I wonder if this is part and parcel with the old wood "breadboard" building.

[Housedad]

I can only figure that I never learned about this since I was mostly steeped in digital and small power circuits when I stopped electronics 25 to 30 years ago.   I never did RF or power circuits like audio amps .  I just had no exposure as everything was learned from books and there was no massive library of info at your fingertips like the internet.  The speed at which we CAN learn now is just amazing compared to just a very short few years ago.   Well, at least I will not be as ignorant about this construction method for long.

I am actually excited to learn more about this.  Something New to me.

[Richard Crowley]

Several decades ago, a company called "International Eyelets" made a set of microscopic "hole-saw" like tools. They look just like the kind you use to make giant holes in wood, except that they are just a few mm in diameter. And with a replaceable drill bit in the middle.  They cut very nice round pads in copper-clad board with a hole in the middle for thru-hole components or you can remove the drill to cut a blind pad.  I wish someone still made them   

[senso]

Search around for diamond core drill:
http://www.ebay.com/itm/THK-3mm-to-12mm-Diamond-coated-rotary-core-drill-drills-bit-hole-saw-1-8-shank-/350742800136?hash=item51a9e66708:g:g6MAAMXQAx9RRZjx

Not the finest thing, but you can still get those things.

[128er]

I could not resist to post a picture of Jim Williams desk in this topic 

[testian]

I have never seen something like this before. Looks like art to me.

[KE5FX]

Just Wow.  I have never seen anything constructed like this.  It looks intrinsically very unsafe.   Has anyone ever see anything like this rat circuit construction?  Maybe I just live a cloistered life.  I saw it here:  http://qrp-popcorn.blogspot.com/2016_11_01_archive.html

I built (almost) an entire LF-1 GHz receiver and trunk-tracking scanner that way.  It stayed online for 10 years with roughly four-nines uptime.  I only took it down when the second replacement hard drive died.

[danadak]

Then there is this (download the software and take a look) -


http://routaboard.com/





Regards, Dana.

[danadak]

Looks like they are still in business -


http://www.intl-eyelets.com/


Regards, Dana.

[Richard Crowley]

Looks like they are still in business -
http://www.intl-eyelets.com/

Yes, but they don't sell those cutters anymore.  They only sell eyelets.

It looks like they sold the product to Vector.
https://www.vectorelect.com/pad-cutters.html

Although it appears they only work with pre-drilled holes (like Vector board!)
And they no longer have replaceable center drills.
And the price has exploded to US$ 77  !   

[KE5FX]

It always amazes me to see how much trouble people will go through to avoid using the quickest, easiest, and most effective analog prototyping methodology known to man.

[edpalmer42]

Looks like they are still in business -
http://www.intl-eyelets.com/

Yes, but they don't sell those cutters anymore.  They only sell eyelets.

It looks like they sold the product to Vector.
https://www.vectorelect.com/pad-cutters.html

Although it appears they only work with pre-drilled holes (like Vector board!)
And they no longer have replaceable center drills.
And the price has exploded to US$ 77  !   

No, the pad cutter is just used to cut the traces on a Vector stripboard.  It doesn't create Manhattan-style pads.

Ed

[mtdoc]

There are plenty these kind of small hole saws available from eBay and hobby stores in various sizes that can be used for cutting pads.

[james_s]

Dead Bug construction has been around forever. I could never bring myself to build something that ugly, but it does have a lot of advantages for RF circuits. If you want to prototype something radio related it's still an excellent technique due to the large and un-interupted ground plane.

[David Hess]

It is also used for low leakage and precision circuits; air is an excellent insulator.

[eugenenine]

My favorite name for this is "dead bug" style.

Thats still on a PCB though so its not dead bug.  Dead bug's main characteristic is lack of a PCB.

[linux-works]

power designs (pdi), early build style:



for fun, I built a tiny oscillator air-wire style: