Soft Rock - V7 Beta

Soft Rock 7 Beta

This data is from my Soft Rock V7 beta board built using an OPA2228 op amp. I also changed the phase shift capacitor (C9) to 8pf to get good IQ phase relationship - this is probably due to added stray capacitance from the .100 header I've mounted to allow me to easily change the phase shift cap..

MDS was measured as -109 dbm with an Extigy and -112 dbm with a Delta 44 sound card. . The specturm display does show some minor spurs, particularly with the Extigy which shows a hump at 0, and +/- 5khz

Some other measrements:

Input current: 29 ma@ 13.8 V supply
Max input signal without distortion on IQ output: -16 dbm (measured for an input signal @ 28.064 MHz)
Oscillator Frequency: 28.052 MHz

Panadapter view, -54 dbm @ 28.064 MHz - Extigy

Panadapter view, -54 dbm @ 28.064 MHz - Delta 44

Some pictures of the board

Top Side

Bottom Side

Comments to: Bill Tracey (

Last Updated 1 Arpil 2006

Copyright © 1 April 2006