|
Homebrew Equipment A place to show, design and discuss the weird and wonderful electronic creations from the hands of individual members. |
|
Thread Tools |
1st May 2021, 4:53 pm | #1 |
Heptode
Join Date: Jul 2020
Location: Larkhall, South Lanarkshire, Scotland.
Posts: 671
|
Signal tracer question(s)
Working on a homebrew signal tracer, The output of the LM741 Is fed to the input of the LM386 via a 0.5uf capacitor but i don't have one, What other values will suffice ? Also the input to the LM741 is via a 1uf NP Capacitor. I don't have one of those either. Would a 1uf electrolytic do the same job ?
See schematic below. Thanks Jay
__________________
Help!! I've been electrocuted by a glass thing that glows |
1st May 2021, 5:53 pm | #2 |
Hexode
Join Date: Mar 2020
Location: Rochdale, Greater Manchester, UK.
Posts: 439
|
Re: Signal tracer question(s)
Hi Jay,
0.47uF is the common preferred value, hard to find a new 0.5uF these days, and not really a critical value component in this circuit. The NP (non-polarised) input capacitor is specified because you won't know if the input signal has a positive or negative bias relative to that point in the circuit. It is possible to wire two capacitors in a reverse-parallel configuration to overcome this difficulty. Also watch the voltage rating if you intend to troubleshoot valve circuits with your signal tracer. If you still need these caps I would be happy to pop some in the post for you. Cheers Chris |
1st May 2021, 8:49 pm | #3 |
Hexode
Join Date: Mar 2020
Location: Rochdale, Greater Manchester, UK.
Posts: 439
|
Re: Signal tracer question(s)
Hi Jay,
these two guys should do the job for you. The orange one is Philips 0.47uF 100V and the other a 1uF 50V to couple the op-amps. Just let me have your address and they can go in Monday's post. I'm not bothered about the stamp, what goes around comes around mate. Cheers Chris |
1st May 2021, 8:57 pm | #4 | |
Heptode
Join Date: Jul 2020
Location: Larkhall, South Lanarkshire, Scotland.
Posts: 671
|
Re: Signal tracer question(s)
Quote:
Thanks Jay. Could a mod lock the thread please...
__________________
Help!! I've been electrocuted by a glass thing that glows |
|
25th May 2021, 2:43 pm | #5 |
Heptode
Join Date: Jul 2020
Location: Larkhall, South Lanarkshire, Scotland.
Posts: 671
|
Re: Signal tracer question(s)
Found a small glass Ge diode in the parts bin, Distortion now gone Happy man Never thought the detector diode would be so critical. Another thing learned,
Cheers all Thanks Jay
__________________
Help!! I've been electrocuted by a glass thing that glows |
25th May 2021, 2:59 pm | #6 |
Dekatron
Join Date: Apr 2011
Location: Cornwall, UK.
Posts: 13,454
|
Re: Signal tracer question(s)
So all workie ok so far
The clue for me was the diode type and the absence of a blocking capacitor to the diodes input. Lawrence. |