The Ultra Probe Demodulator – Amplifier

Posted by: @larry_n7luf

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I just printed my very first PCB for the “The Ultra Probe Demodulator – Amplifier”

I have question for this board, I had only one pad lift of after soaking in the water. Only half of the pad was left and what is the way to fix it before I etch this board.

Also this calls for double sided board for a ground plain, what do I do to protect the back of the board?
I hope this okay to ask here in the forum.

I am excited after all these years for my first board and it was truly easy and now to do more.

I normally use nail Polish it works really well hope it helps.

Another update on my project.
I was sure surprize on some flaws I did not see, but it is okay.

Now to started adding some parts.

Today I finished “The Ultra Probe Demodulator – Amplifier“.

I have to tell you I was afraid to turn it on with all the work I put into this unit.

Yet to my surprise it worked and now is finished.

The only thing I wish I had done better was the lettering and did not notice I did not cut all of the cut line off and really showed up after the clear coat.

Well here it is and thank you Mr. Paul Carlson for his support and encouragement on Patreon.

@larry_n7luf Fantastic looking unit you’ve got there Larry. Tnx. for sharing and Congrats. So, now your next step is building the probe head itself I suppose. Good Luck and eagerly waiting to see some pictures with the end results… 😉

@ovi4 Thank you, and I made up the PCB when I did the other board.
I just need to trim it down to fit the tube, then I can start putting the parts on to the PCB.
Not sure to add here on this thread or start a new one, what do you think as they do go together?

@larry_n7luf In my opinion it should be added here as as is obviously part of the very same project and on the other hand it greatly help keeping the forum less cluttered. Keeping the number of topics organized by topics (that are part of the same project) makes more sense and is easier to follow. 😉

@ovi4 Not showing the circuit side of the board, how do I get this to fit inside of this tube?

Off to the sanding belt to take the size down to fit.

After awhile I was able to shave it down to fit and I have to tell you it is very close fit.

Not time to start adding the parts.

@larry_n7luf Nice job. However: keep in mind that you don’t want to be “too precise” since you still need to be able to “somewhat” screw the metallic aluminum end caps without too much “side/lateral” friction to avoid twisting the already small and “somewhat” fragile PCB. If after soldering the components and 1 cap to the PCB + soldering all the necessary cables to it you conclude that this is the case, you might then have to manually further sand off some more width. It was the case when I’ve built the “Superprobe”. My PCB was also a very close fit and thought was ok (at that very moment) but soon after soldering the components and cable + the one end cap to the PCB I had a “hard time” screwing the tube fully because the friction was obviously too high. So I took a bit of sandpaper and gradually sanded off just a “touch more” on both “long sides” and perhaps I even lightly “lubed” the interior of the tube body and the caps “thread” with some silicone based Vaseline for a “good measure” and all of the sudden the friction has “magically” disappeared.

@ovi4 Well today I got all the resistors except two 20M SMD that I do not have and had to order.

Also for the 50 ohm resistor, I only have 51 ohm resistors, so I had to order.

I guess the 51 ohm would have worked.

Now to add the caps and saving the IC for last.

@larry_n7luf I wonder if Mr Carlson has thought about providing some STL’s so people could 3d print the enclosures for some of his projects?

I don’t think I have ever heard Mr C mention 3D printing. Not sure if he has one. 

@gbfreeman123 Sorry it has taking me so long to get back to you.
The probe shell acts as a shield for the PCB, but their has been some that has 3D printed the “The Ultra Probe Demodulator – Amplifier” case.
Believe me I would have 3D printed the probe.
I already had the box for the amplifier.

@ovi4 Just to give you an update, I soldered the PCB to the end cap today.
I used two tri square tool along the barrel with some tape and had the PCB inside the barrel with part of the PCB sticking out.

Fired up the soldering gun and did the soldering, and when cooled, it just screwed right in no problems.

Now I am just waiting for some parts to come in and found out I did not have any BC817.

@larry_n7luf Well, I’m glad that it worked and did not give you any “grief” as mine did (a little) … 😉 Looking forward to see the completion… 👍