Skip to main content

HPSDR_FPGA_USB Board Update

Here is a picture of the FPGA_USB board after soldering most of the components:



Yet to be soldered is the FPGA, USB connector, and connection headers.

I soldered all of the components by hand. Soldering the 128 pin 0.5mm pitch Cypress FX2 microcontroller was much easier than I thought it would be. I need a little more magnification than the Bausch and Lomb 3.5x eye loupe has. I also have a Luxo magnifying fluorescent light that I use when soldering the other components. I am thinking about getting a 7x Bausch and Lomb loupe that clips onto glasses for soldering the 0.5mm pitch stuff. There is a seller on Ebay that sells stereo microscopes on a boom arm for about $260 that would be nice.

Basically I spread a lot of flux on the pads for the FX2 chip, tacked down the pins in the corners to keep the chip in place, and then proceeded to solder the pins using a drag technique with a conical tip on the Weller EC2001 soldering station. I then inspected each pin by lightly pushing sideways with a fine pointed tool to check for any pins that where not soldered down. I found 4 out of 128 and a light touch up with the soldering iron fixed those.

The other components were a piece of cake using the magnified swing-arm fluorescent light. I used 0.015" SN63PB37 Kester solder, SP-44 Kester Paste Flux, and a Weller ETU 0.01" x 0.4mm flat tip on the soldering station.

Next I will solder on the USB connector, apply power, connect to the PC, and see if the FX2 enumerates.

Comments

Anonymous said…
hi phil,

i was wondering wht do you think of solder reflowing (instead of hand soldering) for smaller pitch smt parts. (like the s3 xcs400 pq208)
7:10 PM
Post a Comment

Popular posts from this blog

History of HPSDR Mercury and Quick Silver

History of HPSDR Mercury and Quick Silver Philip Covington, N8VB Early HPSDR and XYLO In 2005 I started a High Performance SDR (HPSDR) project which was to consist of a motherboard carrying a FPGA/USB 2.0 interface and power supply with the provision for plug in modules through 40 pin headers. I had planned a narrow band high dynamic range module based on a QSD/DDS/PCM4202 audio ADC and a wide bandwidth module based on a high speed 16 bit ADC: http://www.philcovington.com/SDR/PICS/HPSDR_FPGA_USB_Board_top1_800600.jpg http://www.philcovington.com/SDR/PICS/HPSDR_FPGA_USB_Board_top4.jpg I soon selected the LTC2208 ADC from Linear Technology. A representative from Linear Technology came across my blog ( http://pcovington.blogspot.com/ ) and offered evaluation boards and samples to support the project. At about the same time my HPSDR project came about, Phil Harman, VK6APH and Bill Tracey, KD5TFD were interested developing a sound card replacement to be used with the SD...
1 comment
Read more

2323 Wilt

Post a Comment
Read more

RFFE1 Why you may (or may not) need it

RFFE stands for "Radio Frequency Front End" and the "1" stands for the first version (0-62.5 MHz coverage). When I was designing the QS1R board, I had to decide whether to include bandpass filtering and RF amplification on the board. In fact the initial prototypes "RevA" included RF amplification on the QS1R board. Unlike another DDC based direct sampling receiver "Perseus", QS1R was designed to be more than a SW receiver. In addition to a SW receiver, QS1R was meant to facilitate experimentation in the RF spectrum up to at least 300 MHz. I finally settled on a 55 MHz low pass filter (which can be bypassed) and no active components in front of the ADC on QS1R. Any active devices, bandpass filters, or attenuation would be added by a separate board such as the RFFE1. The antenna that I use for my QS1R is a center fed, non-resonant dipole at 50 feet. The total wire length is about 240 feet with only about 100 feet of that running horizontally...
Post a Comment
Read more