Dr Ronald Stiffler SEC technology

[Slider2732]

Nick - Yep, nowadays I know about AC coupling, but the idea in the vid was to show that no DC voltage was coming through the wall adapter. Simply had no idea to differentiate the 2 sources for knowledgeable folks. It looks odd now I can quite agree.

Gyula - Many thanks again for the comprehensive breakdown !
Willy-nilly is something i'm learning to avoid lol, though it is present in many of my videos.
The 27MHz crystal is the only working one here. But that thing is suspect. Direct connections to it with the scope and no coils around still shows the 9MHz.
Yes, it's a distorted sine 
The 33MHz has a big dent in the top. It was tried and the input LED comes on without blowing, but there's no signal output. I'd imagine the crystal itself is in tiny pieces, but the supporting circuitry is still ok.
The sniffer coil is just a copy of something seen on someone elses video years ago. It does work well for giving the correct frequency. The wave shape can be somewhat distorted and of course, the amplitude increases with proximity toward the source. The person in the video called it a sniffer, so sniffer it got named. 
Good point about individually tuning the coils...which will be done.

[AlienGrey]

Nick - Yep, nowadays I know about AC coupling, but the idea in the vid was to show that no DC voltage was coming through the wall adapter. Simply had no idea to differentiate the 2 sources for knowledgeable folks. It looks odd now I can quite agree.

Gyula - Many thanks again for the comprehensive breakdown !
Willy-nilly is something i'm learning to avoid lol, though it is present in many of my videos.
The 27MHz crystal is the only working one here. But that thing is suspect. Direct connections to it with the scope and no coils around still shows the 9MHz.
Yes, it's a distorted sine 
The 33MHz has a big dent in the top. It was tried and the input LED comes on without blowing, but there's no signal output. I'd imagine the crystal itself is in tiny pieces, but the supporting circuitry is still ok.
The sniffer coil is just a copy of something seen on someone elses video years ago. It does work well for giving the correct frequency. The wave shape can be somewhat distorted and of course, the amplitude increases with proximity toward the source. The person in the video called it a sniffer, so sniffer it got named. 
Good point about individually tuning the coils...which will be done.

Some crystals are low power for battery applications like in 32678khz series you don't drive them the same way as brute force. The 27khz isn't it a 1/3 over tone for 9mhz if you want 27mhz you might need a tank coil (in some cases) ?

How I did it if you use a CD4093  Scmitt trigger (most of them will run at 15mhz easy 10 -12 will do it) , normally the gate output goes through a 2k2 to the 1Meg across the crystal back into the gate input as per normal with tuning caps to 0 volts to trim, if that doesn't work properly yo need to get rid of some of the power just use 2 red leds 1.2v type back to
back in parallel with a 0.1 cap in one of the leads to 0 volts that always works for me.
AG

[gyulasun]

Hi Slider,

The sniffer coil designation is okay with me, as I know it is used in the jargon to refer to probing, detecting EM field and pick it up.

I agree with AlienGray on the possible 3rd overtone operation, the internal crystal is able to oscillate at 9 MHz too and the output pin may need an LC tank tuned to 27 MHz. The tank should be connected between its output pin and its positive supply pin (or, albeit unlikely, between the output pin and the negative supply pin).

The best would be if you could connect first say a 1 kOhm resistor between the output pin and the positive supply. If it is an open collector, then you might see a nicer sine wave across the resistor,  probably still at 9 MHZ, riding on a certain DC level, the scope would show that. And if you see improvement in the wave shape and it remains at 9MHz, then a 27 MHz LC tank would help to suppress the 9 MHz and enhance the 27 MHz output.

A tank circuit for 27 MHz involves less than 1 uH coil (0.74 uH) if the parallel capacitor is say 47 pF (consider scope probe self capacitance is around 15 pF already when checking the tank waveform).  If there is a label printed on top of the oscillator body and it includes type number of manufacturer then it may be worth to do a google search on it.

Notice on crystal oscillators: if you or someone else have motherboards from old personal computers or laptops put aside or just collecting dust in a junk box, they usually have some onboard crystals and/or crystal oscillators that might be close to 13.5 or could be divided down. Just by pure luck, that is...

Gyula

[TinselKoala]

27 MHz is of course quite close to the ten-meter amateur radio band (28 MHz - 29.7 MHz) and also is straddled by the CB radio band (26.9650 MHz to 27.4050 MHz).
Experimenters in the USA especially should beware of putting too much power into their little radio transmitters. You just might get a visit from the FCC ! (I can attest that those folks are serious about what they do.) SO if you see an unmarked white van with a few antennas on the roof cruising your neighborhood...

[NickZ]

   What about ordering the right crystal 13.4MHz, or as close to it as possible.
   I agree with TK that you might be tuning into Radio Moscow, instead, @27MHz. Doc said that is not the right frequency...  Or not?

   I think that getting the same led bulbs, is critical. Otherwise zilch, on AC bulbs, unless you use the same type, like the Doc is showing. Makeshift don't cut it, here. Got to have the metal backing,  or low voltage (24v) input apacitance will not light the AC bulbs. Nor it looks like, most any other led boards, without adding a ground line in there. But, the Doc's circuit needs no ground line, nor having to touch the bulbs, for them to light up.   There lies the difference.
  Gyula, I think that this type of tests are very very critically frequency dependent, to see any positive OU results. Otherwise capacitance is just another way to light some LEDs.