NimbleSig III
Mounted in a DieCast Aluminum Enclosure


    I decided I would like to try mounting a NimbleSig III board in an off-the-shelf diacast aluminum enclosure manufactured by Bud. This enclosue used here is a Bud CU-124, Digikey 377-1108-ND with a measurement specification of  4.37" X 2.37" X 1.21" inches outside dimensions. This box is oversized and you may be able to find a smaller box in which the NS3 board will fit. I plan to install a shield plate over the NS3 board and stack an application board on the top. I also plan to install a 5V linear regulator and hope to find room to build in an RS-232 interface. I plan to add text and photos to this page from time-to-time.

20090402 UpDate:
    Although NS3 runs OK in this die cast aluminum box version initial tests indicate the performance is not as good as in the relatively RF tight enclosure design described in my QEX article. The generator outputs are not as clean and the power detector noise floor is quite a bit higher. I think most of the noise being picked up by the power level meter is probably RF hash from the built in RS232 converter but further tests are needed to confirm that. However this method of construction may still be OK for many applications. There is probably several ways to improve the performance of this version and I am interested in hearing feedback from others on how to do this.

73 de
Tom, VA7TA


BudBox View with Connectors and Hdwr

Photo 1 : Top View of Bud Enclosure with  Connectors and PC Bourd Mounting Hardware

Bottom View of Bud Enclosure with NS3 Hdwr

Photo 2 : Bottom View of Bud Enclosure with  Connectors and PC Bourd Mounting Hardware

View of Bud Enclosure from Directly Above

Photo 3 : Aerial View of Bud Enclosure with  Connectors and PC Bourd Mounting Hardware

Bud Box PCB Mounting Hdwr

Photo 4 : PCB Rear Support Mounting Hardware

NS3 PCB Preparation

Photo 5: Preparation of PCB for Mounting

Connector and FeedThrough CloseUps

Photo 6: CloseUp View of   LockWasher Spacer used with FeedThrough Capacitor

View of PCB Mounted In Bud Enclosure

Photo 7: PCB Mounted in Bud Enclosure

CloseUp View of Connector PCB Interface

Photo 8: CloseUp View of the Connector PCB Interface.

NS3_BudBox_PopulatedPCB.jpg

Photo 9: View of the Populated PCB.

BudBox_PCB_Installed.jpg
Photo10: View of the Populated PCB Now Mounted. Note the ground bonding to the connectors and the wirewrap wire used for the external LED drive and the Reset/Load Switches. A 7805 provides 5V from an unregulated 9V DC supply.

BudBox_PCB_Installed2.jpg
Photo11: The feedthrough capacitor will provide +5V DC for an external active probe.

BudBox_ShieldPlate_Installed2.jpg
Photo12: The shield plate is intened to isolate noise from the RS232 converter and provide isolation for a possible future superhetrodyne 12 KHz BW tracking detector in the future.

BudBox_RS232_Installed2.jpg
Photo13: The RS232 converter fits with room to spare over top of the shield plate.

BudBoxEnclosed.jpg
Photo14: Finally the case is closed. This NS3 is calibrated and working.

BudBox_RearApronSwithes.jpg
Photo15: Since the NS3 PC board is burried externally accessable Load and Reset switches are needed to accomodate firmware updates.


73 & Enjoy!
Tom, VA7TA