Author Topic: Old Harman Kardon Stereo with NO circuit boards, all hand soldered hornet's nest  (Read 6527 times)

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Offline Steve WayneTopic starter

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Just for show & share,, I thought this old (mid 1960's?) Harman Kardon SR-900 receiver was quite amazing to find it with no circuit boards and all through hole, hand soldered components.  I'm sure Dave would have enjoyed the smell, but it would cost a small fortune to ship it from the US. Take a look…
« Last Edit: May 05, 2015, 02:48:24 am by Steve Wayne »
 

Offline Len

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It's called point-to-point wiring and it's the way everything used to be done. And if you think that's a hornet's nest, take a look at a typical TV set:
DIY Eurorack Synth: https://lenp.net/synth/
 

Offline T3sl4co1l

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Shame, looks like someone pulled all the (socketed!) RF transistors.  Probably 2N3904 would work (unless they were PNP, which might well be the case if they used mesa germanium).

Seems unlikely those perfboards on the top controls are original, kind of curious what history it might have.

And yes, boys and girls, early transistor sets used output transformers to drive the speakers!

Tim
« Last Edit: May 05, 2015, 06:05:34 am by T3sl4co1l »
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Offline German_EE

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Some radio amateurs carry on a similar tradition in home construction, they call it 'ugly' construction. Tag strips are now difficult to obtain so if you have a junction suspended in mid air then solder a 1M ohm resistor from the junction to the PCB ground plane, it works just fine.

http://www.k4gc.com/ugly%20things.html

I prefer a technique called 'Manhattan' where small PCB pads are glued down to support parts

http://www.k8iqy.com/qrprigs/2n215/2n215081e.jpg
http://www.k8iqy.com/qrprigs/2n240/2n240216.jpg
« Last Edit: May 05, 2015, 06:53:49 pm by German_EE »
Should you find yourself in a chronically leaking boat, energy devoted to changing vessels is likely to be more productive than energy devoted to patching leaks.

Warren Buffett
 

Offline rolycat

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Alan Wolke (w2aew on the forum) has some good videos on construction techniques including Manhattan-style and island cutting, particularly this excellent summary:


 

Offline John Coloccia

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Some radio amateurs carry on a similar tradition in home construction, they call it 'ugly' construction. Tag strips are now difficult to obtain to if you have a junction suspended in mid air then solder a 1M ohm resistor from the junction to the PCB ground plane, it works just fine.

Standard way of doing it these days is with eyelet or turret boards.  I always thought tag strips were turret board's ugly, annoying sister, anyway.
 

Offline Sigmoid

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I prefer a technique called 'Manhattan' where small PCB pads are glued down to support parts

http://www.k8iqy.com/qrprigs/2n215/2n215081e.jpg
http://www.k8iqy.com/qrprigs/2n240/2n240216.jpg

This isn't ugly at all. It looks like a work of art. :D I knew there has to be a way to prototype RF.
 

Offline German_EE

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Manhattan works very well at RF. There is one amateur who works as an engineer at the VLA in New Mexico and he uses Manhattan PCBs well beyond 1 GHz. The large ground plane means a stable circuit.
Should you find yourself in a chronically leaking boat, energy devoted to changing vessels is likely to be more productive than energy devoted to patching leaks.

Warren Buffett
 

Offline T3sl4co1l

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I prefer a technique called 'Manhattan' where small PCB pads are glued down to support parts

http://www.k8iqy.com/qrprigs/2n215/2n215081e.jpg
http://www.k8iqy.com/qrprigs/2n240/2n240216.jpg

This isn't ugly at all. It looks like a work of art. :D I knew there has to be a way to prototype RF.

It's also translucent, http://seventransistorlabs.com/Images/Glow.jpg

Tim
Seven Transistor Labs, LLC
Electronic design, from concept to prototype.
Bringing a project to life?  Send me a message!
 


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