Friday, November 13, 2009

Manhattan Pads and the The Origin of the Term "Ugly Construction"



If you have been following along you have now completed reading most of the links on my site, you've watched a few of the Indian Institute of Technology videos and are now ready to try and actually build something. Albeit, not an actual radio yet, but you are inching to get some super glue stuck between your fingers.

Manhattan Pads - Are not New York City Apartments -- According to the QRP & Amateur and Short Wave Radio Electronics Experimenter's Web Site  

"A reference for Ugly Constructing is The 'Ugly Weekender' by Roger Hayward, KA7EXM and Wes Hayward, W7ZOI published in the August 1981 issue of QST. In fact, it was Wes and Roger who coined the term "Ugly Construction" when preparing this QST article.   
 [The article is available online to ARRL members - LINK]

A big part of the learning of the QST article was Ugly Construction! The term and the bread boarding technique emphasized the fact that there is no correlation between the "prettiness" of a construction project and the way it works. According to Wes, the goal had a couple of corollaries. 'First, people like myself who do NOT have the knack for doing pretty projects can still build successful radios. Second, is that we all need to look at our projects after the fact to discover what it is that really makes them work well. In the case of the Ugly Weekender, the thing that makes it fly is that there is a wonderful ground plane with that PC board material'. Indeed, this transmitter functions very well, especially after you temperature compensate the VFO. Wes also built versions for the 30 and 80 meter bands. This transmitter is a true QRP classic; both as a HAM radio transmitter and because it really promoted "ugly" ground-plane or dead bug bread boarding techniques to the scratch home-brew community.

OK, Hey but that is UGLY and not Manhattan, Where does that come from? Again quoting from the same QRP site
"Ugly Construction has its variations and the Manhattan Style Construction technique has become very popular. Manhattan or "paddy board" style uses small square or round pads cut or stamped from PC board which are glued copper side up on a large copper clad board which is also placed copper side up. The small pads or "islands"  are used for anchoring non-grounded components. Components soldered to the pads such as transistors or ICs are not positioned upside down like in standard Ugly Construction. Many Manhattan style builders use IC sockets as well. There is a tendency to make these projects look very nice and this is a wonderful ground-plane bread boarding technique for builders who have the time and ability to do this.

UGLY and Manhattan construction techniques benefits (also Manhattan can be beautiful )

  • A huge time and money saver for penny conscious QRPer
  • Experimenter can have total control over the design
  • Rapid and flexible bread boarding technique
  • A superior ground plane
  • No custom boards to order from QST or FAR circuits
  • No messy or dangerous chemicals
  • allows for easy re-mods and experimentation
You can see a lot of this all goes back quite a long ways and has many benefits. So now you've heard people taking about it, and you are ready to learn the details about it. First be sure and read the fantastic PRIMER "Manhattan Building Techniques by Chuck Adams, k7QO"

other sources for similar PRIMERS (also excellent, but related to only one radio project and therefore less general in scope) see;
  • Jason /nt7S Intro Paper for the Willamette Project -- PDF (nice overview of bench-tools & techniques)
  • Jim Kortge /k8IQY Notes for the IOWA-10  -- PDF  (nice organization & example of more complex project)


All done reading, Good! Now we are ready to try it ourselves.

Items required: 
  • HF Metal Punch (see text)
  • Super glue
  • some copper clad board stock (or scraps)
  • 25w-35w soldering Iron (See OSE in my Vendor List)
  • Optional - Digital Multi-Meter

Click on thumbnail pictures to make them larger


In order to make the copper pads the recommended way is to have a Deep Throat Metal Hand Punch available at Harbor Freight (ITEM 91510-2VGA). If you don't have one, I'm sure you can borrow one from one of the other build members -- As for non US builders, please email me concerning a suitable substitution in your country --

 

The various punch sets look like this, one can clearly see it just to the left of the calipers. The punch set is secured to the punch vise via a small set screw. The bigger of the fits under the punch, and the smaller on top (it makes the hole).  My Punch Kit cames with about 8 punch sets of varying sises, the second to smallest works best to make circuits pads.




Here one can see me busy punching away at the copper stock and making the actual pads. I have the larger punch, so the leverage is quite easy on the wrist, the smaller one available at harbor Freight requires a tad more muscle. For all my efforts, I will be rewarded with an easy to build and modify component to build QRP radios with. In my case, as you can see the punch is mounted on a small folding table. Works well enough and was surprisingly stable.



 And here is a close up photo the pad about to be made from the copper clad stock. The punched pads can be seen collecting at the bottom.









I would recommend this simple do-nothing circuit experiment to everyone. Take a few of your freshly prepared pads and play and experiment with the best ways to super-glue (cyanoacrylates)onto a copper board.


This will take the sting out of doing the same later on your PIXIE board, no gluing you fingers to your radio on the first try.




Hey, but wait a darn sprekenzie die Minuten here, we've just glue a copper board to a copper board??! Wont that make a short circuit?? -- Well actually no!  Notice the resistance of my fingers is 27 Mega-Ohms, and not infinity (your results may vary, please don't email me about how to calibrate yourselves to 27MO).





But when I measure from the top of the pad to the ground plain, the resistance is essentially infinity (at least far as my meter is concerned)


My meter showing the measurement, and proving the soundness of the technique to easily, cheaply and electrically safely combine boards, pads and components harmoniously.




Here one can see the soldered component on the two Manhattan pads, once you have mastered this simple skill, one will be able to build anything one can dream of. Therefore, building more and more complex circuits requires one only to repeat these same steps over and over.


If you have completed this step, please drop me an email ki4SGU@arrl.net.

Next time we will build an Audio Amplifier.

2 comments:

  1. Hi, I’ve updated my QRP website! I'm sure it's of interest to fellow shortwave radio enthusiasts.

    Here’s the link: www.stationqrp.com

    73's
    Jack

    ReplyDelete
  2. Hi, I’ve updated my QRP website! I'm sure it's of interest to fellow shortwave radio enthusiasts.

    Here’s the link: www.stationqrp.com

    73's
    Jack

    ReplyDelete