Builders notes: DDS_107

This contains the scottyspectrumanalyzer yahoo group backup
Post Reply
S. Cash Olsen
Posts: 323
Joined: Sat Apr 28, 2018 6:48 pm

Builders notes: DDS_107

Post by S. Cash Olsen » Thu Oct 02, 2008 4:24 pm

I am building a set of boards and have some notes about things I found

regarding the building of the boards.



Install all of the components (capacitors, resistor and diodes) that are

attached to the 12 pin connector, P1, but only solder the leads that will

not to be soldered to the connector pins. Don't solder the connector at this

time because it will keep the board from setting flat on the table.



Install C28 and C29 before soldering the XF1 in place because the crystal

filter will make the ground connection of these components more difficult.



The inductors, L1 and L2, will need a little scraping because I purchased

the smaller (0805) inductors. Scotty made provisions for both size parts and

mentions this in his notes. I purchased these inductors from Digikey, and

yes I have verified that they are in the right magnitude range, i.e.

microhenery not nanohenery or millihenry. The parts I measured and installed

in my DDS boards measured a little low, in the range of 5.1 to 5.4

microhenry.



As mentioned remove the solder mask in the area of the fence between the DDS

and the MCF filter.



Install the P1 connector on the "bottom side" (opposite of the component

side) of the pcb and solder a single pin, make sure it is perpendicular and

flat against the board, and then solder the remaining pins and the component

leads connected to them.



You might consider soldering the fence around the board before installing

the connector.



I have also built the Control board and will offer some note on it a little

later.



Cash Olsen KD5SSJ



Kits to build Scotty's Spectrum Analyzer http://www.zianet.com/erg

Scotty's Spectrum Analyzer website http://www.scottyspectrumanalyzer.com

Sam Wetterlin's website http://www.wetterlin.org/sam/

Yahoo Builders Group http://groups.yahoo.com/group/spectrumanalyzer/

Post Reply