# Cost to build Scotty's spectrum analyzer ?

#### DarthVolta

Joined Jan 27, 2015
389
https://scottyspectrumanalyzer.us/
https://www.qsl.net/n9zia/scotty/index.html

I can't find a parts list or full schematic yet, there's a bunch of pages on this thing, where's the parts list ??

About what would it cost to order the parts from anywhere like mouser/digikey, and to order the PCBs from an average cost place, and get the BNC connectors/shielding/etc.

Around what price are we talking ? It would be like a super super fun kit to try and make right. But I don't have metal working tools or a even a vice.

#### dl324

Joined Mar 30, 2015
10,494

#### KeepItSimpleStupid

Joined Mar 4, 2014
4,000
Hints for the metalworking:

VSR drill
Jewlers files
DeWalt pilot point drill bits (they make round holes. Look at the tip. https://www.mscdirect.com/product/details/03801636
The set is particularly nice.
Nibbler tool: https://www.parts-express.com/nickel-plated-nibbling-tool--360-022

Optional: Dremel or Proxxon moto-tool.

You can go screw terminal to DB25.
Convert to USB
I've seen smaller lengths elsewhere.
Use a template: https://www.thingiverse.com/thing:25505
https://www.onlinelabels.com/clip-art/connector-db25-100661.htm

You can mark with a permanent ink marker Staedtler 318-9 Fine or Superfine
You can erase the marks with methanol.

Drill one mounting hole. Align and attach connector, before drilling more holes.

To mark points 1/2, 1/4 etc. Use ruler on diagonal and pick some number convenient. E.g 9" place on a diagonal and mark at 3, 6 and 9. Make marks like "V"'s

6" metal macinists ruler
Combination square
Coping saw

Automatic center punch
Digital caliper

Transfer punch. Cheap on the 'bay.

Deburring tool: https://www.mcmaster.com/deburring-scrapers

Each tool will make things more and more professional.

Where I 'worked', I had the luxury of a BNC punch, but not a D connector punch. I also had access to a full machine shop.
I bought the same Bosch jigsaw that we had a work. That can also be used. Use double stick tape on the base with the release paper left on. It won;t mar the surface.

I also have a Fein multi-master. There are knock-offs now.

With the Dremel, you can probably make an "D" type holes you need.
You could do a flange SMA so you can use a round hole and have anti-rotation.

Printing the front panel 1x made from a CAD program is really the way to go.

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#### be80be

Joined Jul 5, 2008
2,022
DeWalt pilot point drill bits Are good bits but don't last long.

#### KeepItSimpleStupid

Joined Mar 4, 2014
4,000
The pilot point bits are designed to do sheet metal, otherwise you get a triangularish type of hole.

#### KeepItSimpleStupid

Joined Mar 4, 2014
4,000
True. Guess I paid too much. https://www.automationdirect.com/adc/shopping/catalog/tools_-a-_test_equipment/hole_cutting_tools/step_drill_bits_(hss,_hss-tin_-a-_co_5)_-_fractional_size/high_speed_steel_(hss)_tin_coated/101026ustro I got a case.

#### KeepItSimpleStupid

Joined Mar 4, 2014
4,000
PCB's can be cheap or expensive. Each fabricator has it's own design rules that need to be followed. Fortunately, you don't Have to lay out the boards. Files are sent to the fabricator and they produce a quote or a list of violations. generally, you have to get more than one.

Large sizes. 5 layers are going to cost you more. The fabricator can also provide a "stencil". This can be a polymer or steel. ou then use this to squeegee solder paste through the mask. You then place the components and solder or should I say heat the pads. The simple version.

Hobbyists might modify a toaster over with the suggested heating profile.

I actually had to re-flow a formatter board for my HP printer. It was like, remove stickers, heat oven to a specific temperature. Check with thermocouple. Insert board on high standoffs. Heat at temperature for like 10 minutes. Let cool overnight.

There is a rather large IC on the board using a BGA package (ball gate array). little blobs of solder keeping all of the connections under the IC. In manufacture, some of these joints were effectively a "cold solder joint" because the temperature time profile wasn't right.

The no lead solder is harder to work with. There is a lead free alloy with a small amount of Bismuth which is pretty nice.

IC's these days can get really small. e.g 1mm x 1mm. It's also possible to have in excess of 20 layers and even components embedded inside the PCB.