Jump to content


  • Content Count

  • Joined

  • Last visited

  • Days Won


Eland last won the day on November 18 2018

Eland had the most liked content!

About Eland

  • Rank

Recent Profile Visitors

The recent visitors block is disabled and is not being shown to other users.

  1. Thank you for all the commendation and thank you very much for your analysis @guidovelasquez ! What kind of editing would you recomand? At the moment I simply use the "narrow" filtering from watch-o-scope. I did not completely understand your last post. What do you mean by 50 hz network? I will try to pad the stand more efficiently! I life close to a very busy road and sometimes the whole table vibrates if a truck passes by. Maybe thats an extra factor apart from HD or Fan noises.
  2. So I uploaded 30s of recording with audacity and here is the pic of the scope mode. https://mega.nz/#!ymwkgSBK!mKWtU5Fb1pkmGIfhzpKqZ8SXCfBZnMbnUjjwrhA7PxM I also made some little improvements to my telegrapher stand like using a shielded cable for the short part between the piezo and the 3,5mm jack. Alos I added a copper plate to the back for addition shilling.
  3. So I managed to get everything together and got my first readings using a standard stereo pre amp I bought for a turntable several years ago. Sadly i still didn't manage to get my diy microphone preamplifer kit to work (the one i mentiont in one of my earlier posts). At the moment I think about ordering a already built preamplifier board but I do not have the qualifications to judge with would do the job (or at least would lead to better results then with my current solution. That's why I am again counting on your help. There are some pretty cheap options but I don't know how to judge the all over amplification from the specifications given. My current preamp has the following technical specifications: Input Impedance 100kOhm, 5mV, Output Impedance 100kOhm, 250 mV, S/N-Ratio: >50 db, 12V DC, 100mA The options I'm most into at the moment is something like that cause its cheap and and may be an improvement (however I'm not sure about that) https://www.ebay.de/itm/TDA2030A-Audio-Power-Amplifier-Board-15W-AC-DC-12V-Assembled/292336674126?hash=item44109fa54e:g:nUAAAOSwKrhVZbo1:rk:28:pf:0 or even simpler: https://www.ebay.de/itm/TDA2030A-Audio-Power-Amplifier-Board-15W-AC-DC-12V-Assembled/292336674126?hash=item44109fa54e:g:nUAAAOSwKrhVZbo1:rk:28:pf:0 There are more fancy options like https://www.gearbest.com/other-accessories/pp_009478010615.html?wid=1433363 or https://www.gearbest.com/other-accessories/pp_009478010615.html?wid=1433363 but I have absolutely no clue if they would be suitable for the task at hand. The thing is that (as you surely have noticed by now) do not know the first thing about electronic. But I'm eager to learn, I just don't know where to start. So thank you for your time cleaning my mess. On the bright site as I said, I managed to get my first signals and I'd link to share some pics of that: This is my set up at the moment and some readouts from two of my watches (I hope it's okay to post the watch-o-scope screenshots). Today I broke the piezo trying to replace the cabels between it and the jack with shilded ones and now I have to get some more piezos to get my DIY-timegrapher running again. Let me know what you think and thank you very much!
  4. I wanted to post a quick update on my timegrapher. All together I encountered a lot more difficulties then i thought. I screwed up the amplifier assembly kit by using blunt wire cutter and thereby accidentally ripping the conducting layer of the board as i tried to clip the wire of a resistance. I also have the hardest time soldering the brass pin onto the piezo element. I broke several piezos by applying to much heat an bringing the ceramic layer to crack . I'll visit a good friend of mine in January who is a electrical engineer and we'll try to get it done together (using his professional equipment). Until then I wanted to ask @24h if you have any special techniques u used to establish the connection between the pin and the piezo and also if you could elaborate why you used a rubber casting around the pin. I thought it might rather weaken the vibrations and therefore the signal. at least I am making a little progress with my timegrapher stand. Here is a picture of my first built (which is not functional because there is no piezo on the end of the pin):
  5. wait, i personally came to a different conclusion. My train of thought was that i would need R6 and C1 reverse since the piezo like a capacitor microphone does not have a separate power source an therefore I would need to pick up the power from the amp.
  6. Here is the link to the operations manual as a pdf. It's only available in German but it contains all schematics. It says that if you use a capacitive microphone you need to solder resistor R6 onto the circuit board an the electrolytic capacitor C1 needs to be in reverse voltage direction. I also studied the manual in the meantime. To that specific issue it says that you need to make that modification if you want to use a microphone without separate power supply like e.g. a capacitor microphone. What kind of pre amp did you order. Since I only soldered together some audio cables and have absolutely no clue at all about the principles of electrical engineering it is very likely the I will need one of them as well . Really hope your package didn't get lost though!
  7. I slowly get together all the parts I need and I also decided to built my own amplifier. Since etching my own circuit board seemed like to much of a challenge for me I decided to go with an assembly kit I found at a local electronic dealer for a mono microphone pre amp which offers a 1500 fold amplification. There are different options on how to assemble the kit depending on whether it is used with a dynamic or a capacitor microphone. From what I understand, the way a piezo element works resembles more the way a capacitor microphone works and so I'm going to solder the kit accordingly. What do you guys think?
  8. Wow, that was fast. Sadly I am based in Europe so your kind offer may not be a very cost-effective option. However I now have a point to stat from and I'll think I may find a solution. Would stainless steel be an option? it should not be able to become magnetized and I would be able to use something like this or that.
  9. Hi 24h, i'm trying to rebuilt your design at the moment. But I can't find a pin with 2 insertions for the e-rings anywhere. Did you built it yourself? @24h
  • Create New...