28360Re: Troubleshooting Softrock lite RX - FIXED!!
- Dec 3, 2008Hi Tony
Checka all capacitor and rseitance values this afternoon and all
seemed OK. Despite having inspected everything under 10X
magnifcation and found no problems, I decided before yanking
components to flux everything around the mixer and op amps and touch
up every joint with a hot iron and it came to life - must have been a
joint that was OK for DC but not AC as all voltages were OK.
It's sitting on the bench putting out about 1.6V of I and Q from
about 40mV RF in.
Anyway - thanks again for all the help.
Any news on when I'm likely to get the Si570 for my V9 kit? Ordered
on October 8
--- In email@example.com, "Tony Parks" <kb9yig@...> wrote:
> Hi Norman,
> With DC gain of each op-amp about right, it seems that R9 has a
larger resistance than 10 ohms, or C14 has more capacitance than 220
pF, or there is an AC load on the pin 1 output of U5. (Also still
the possibility there is a problem with U5.) I would suggest
removing C16 first to see if the AC voltage at pin 1 of U5 increases
with the RF test signal input you are using. Next, remove C14.
> Tony KB9YIG
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