"Officially, I broke the rules. BUT, I do it anyway because it helps" Some of them can be bent. Others can be broken. Hans "Morpheus" Summers

#problem #qcxmini #40m #opamp

To add to HA3HZ's comment, the methods "some" use to remove a part seem a bit scary to me... I'm not saying they don't work, but certainly not the methods I would use with these tiny parts. I'm sure I

#problem #qcxmini #40m #opamp

Donald, thanks for the link. Neat stuff!

#problem #qcxmini #40m #opamp

There are also low melting point solders which are used to lower the melting point of existing solder to ease part removal, one is ChipQuik: https://www.chipquik.com/store/index.php?cPath=200 Another

#problem #qcxmini #40m #opamp

The trouble I have here, is that the most junior lab tech has this habit, when visiting QRP Labs HQ R&D division laboratory, of reaching up and turning the knob on my soldering iron to the max. Which

#problem #qcxmini #40m #opamp

Hi Scott, just a small comment about soldering. If you use a temperature-controlled soldering iron, it's a good idea to experiment with a small panel that is not in use to see what the highest tempera

#problem #qcxmini #40m #opamp

Hi Scott It can be quite tricky, understanding what goes where on the diagram. My PCB layouts are all only 2-layer - however quite compact and complex, all the traces are placed by hand by me - auto-r

#problem #qcxmini #40m #opamp

Hans Thank you for taking to the time to jump in. Sorry if I created confusion with my terminology; I was uncertain of the correct (hence the quotes). When the IC9 pads 1 & 7 came off, I had expected,

#problem #qcxmini #40m #opamp

Hello Scott Glad to hear it is all working! I'm not sure what you mean by "true in board traces". The QCX-mini (and other QRP Labs boards) are all two-sided boards having a top copper layer and a bott

#problem #qcxmini #40m #opamp

I would like to publicly thank Mont (KM6WT) for talking me off the proverbial ledge. His encouragement and advice over the last couple days allowed me to get my mini back from the grave. For those cur

#problem #qcxmini #40m #opamp

I just sent you a private email. 73 km6wt

#problem #qcxmini #40m #opamp

But there's a much closer component it also connects to. IC9 pin 7 AND pin 6. So just attach pin 6 & 7 together... ( the bottom line in this pic goes off to the left to C20 ) km6wt

#problem #qcxmini #40m #opamp

If I send you the shipping costs will you send it to me? 73 Andy

#problem #qcxmini #40m #opamp

Well, we can close this thread. This mini is going in the bin. After connecting IC9 pin 7 to C20 underneath the IC voltage measured off on all pins except 8. Then when replacing the IC with yet anothe

#problem #qcxmini #40m #opamp

Thanks for the quick response. I had thought this possible, albeit challenging, as C20 (to which IC9's pin 7 connects by the manual) is on the underside of the board. I had simply felt it odd that I c

#problem #qcxmini #40m #opamp

Not at all... Look at the Schematics (black and white Hi-Res Schematics Click Here) and find the component that pin connects to. Then solder a small wire from IC9 pin to the component that the missing

#problem #qcxmini #40m #opamp

Sadly IC9 in my QCX-mini failed for a 2nd time. Even more sadly, while replacing the opamp a 3rd time, the pcb pad for pin 7 came off. I cannot see any visible trace to even attempt connection (jewele

#problem #qcxmini #40m #opamp

Because of it's usage as part of the QSD in the QCX, only replace with a genuine 4562 chip. You can substitute the OPA227's with the 5532's with the only problem being increased current usage. I have

#opamp #qcx40

Try this DigiKey number: 296-43962-5-ND

#opamp #qcx40

Hi https://www.digikey.co.uk/products/en/integrated-circuits-ics/linear-amplifiers-instrumentation-op-amps-buffer-amps/687?k=LM4562&k=&pkeyword=LM4562&sv=0&pv69=411897&pv1291=294755&sf=0&FV=-8%7C687&q

#opamp #qcx40