I was happy to finish out my normal duties last night (training, practice my lute, etc.) and move the MMM to a more permanent perfboard. In the case of this mounting, I did my best to preserve the layout of the schematic if at all possible. I checked continuity after mounting each component, etc. Everything seemed to be going great. But I couldn't get any signal at 3.579 MHz. Damn. Truly, I didn't beat myself up about it. Instead, i headed back upstairs after the youngest went to bed and did some reading.
I have the circuit another look on a short work break. Tested I connected the battery and heard the slightest amount of oscillation. Hey! And I noticed significant shifts in oscillation when I fooled with the L1/L2 coils.
Troubleshooting: I'm not sure why this would occur. I understand that touching the coil would change the inductance. Ought I need to fix this before moving forward? Exactly how would I do this?
This feedback from Bill Maera:
Yes, or you could go with a toroidal coil Aside from the value in uH you have to pay attention to the tap -- and make sure that you are tapping from the correct side (usually X number of turns up from the bottom). Try it.
If it doesn't work, take a look at the coil and the tap.
You are mentioned on the SS blog. With a link to your site.<--the real cool part
I then put the MMM on a scope shown below.
- Better understand the coil issue.
- Build a low pass filter (LPF) to pass frequencies below 4 MHz.