More specifically, the CD4066 has higher resistance and slower switching speed. You would not have as good a S/N ratio with this as you would with the 74HC part in the same application, but you might not be able to tell the difference anyway. As Francis pointed out, the CD4016 may not switch fast enough to give you any sensitivity beyond a MHz or two. The CD4016's that RCA cranked out when the series was first manufactured (way back in the '70's), the parts I used switched way faster than the minimum specifications. Why not give it a try anyway?
The 74LS74 could work in place of the 74HC74, but you might need to add pull-up resistors to the outputs (perhaps 470 Ohms) to assure that the outputs swing quickly and cleanly through the threshold of the CD4016 (or whichever transmission gate you end up choosing. Take extra care in the decouling of the power supply since TTL, even LSTTL, generates a larger crossover spike when the output state changes than CMOS does. --- In [email protected], FRANCIS CARCIA <[EMAIL PROTECTED]> wrote: > > Mike the CD4066 is a slower part look it up on the web The LS is a bit slower and does not have as muck output drive. They will work if you are connecting the interface to a radio IF like 455 KHz. The 4066 may have different pinouts than the 74hc part I don't remember. You can go to TI or fairchild site and download the spec sheets for these parts. gfz > > miketa_us <[EMAIL PROTECTED]> wrote: Hello to the group, > > I am a beginner to SDR and have gotten my feet wet by building YU1LM's > DR2 I/Q Receiver. I chose this particular project mainly for two > reasons, I was experimenting with a new homebrew pcb image transfer > technique and had most of the through hole components in my junk box. > > How critical is the component selection for these SDR radios, > can I substitute a CD4066 for a 74HC4066 or a 74LS74 for a 74HC74? > > Has any else built the DR2 and got it working? > > Thanks in advance, > Mike > > > > > > > SPONSORED LINKS > Ham radio Craft hobby Hobby and craft supply Icom ham radio Yaesu ham radio > > --------------------------------- > YAHOO! GROUPS LINKS > > > Visit your group "soft_radio" on the web. > > To unsubscribe from this group, send an email to: > [EMAIL PROTECTED] > > Your use of Yahoo! Groups is subject to the Yahoo! Terms of Service. > > > --------------------------------- > Yahoo! Groups Links <*> To visit your group on the web, go to: http://groups.yahoo.com/group/soft_radio/ <*> To unsubscribe from this group, send an email to: [EMAIL PROTECTED] <*> Your use of Yahoo! Groups is subject to: http://docs.yahoo.com/info/terms/
