Testing the TK Tar Baby

[picowatt]

Scoping both xmtr and rcvr simultaneously presents no problems at all. There is no discernible effect on hooking up the scope grounds... wait... yes, the phases are of course locked, and I believe this is true whether or not the scope grounds are connected, but it does seem that the "supernova" mode is _more_ stable with the scope grounds connecting the two units. Hardly fair, that.

I don't have a diff voltage probe here, nor a scope with  isolated grounds like the Fluke0Scope.

Both traces indicate nearly the same voltage, too. There is only a couple volts drop (from 50 or so p-p at the tx) across the usual 3 inches I'm using as a "standard" distance.

TK,

With both RCV and XMT simultaneously observed on the 'scope, what are the differences between the waveforms when sliding in and out from "supernova" to normal?  Trigger off the xmtr so you can watch rcvr phase.

PW

[TinselKoala]

TK,

With both RCV and XMT simultaneously observed on the 'scope, what are the differences between the waveforms when sliding in and out from "supernova" to normal?  Trigger off the xmtr so you can watch rcvr phase.

PW

Verrry interesting, thanks for the suggestion.

As I move the RX loop closer to the TX loop, the frequency of both units decreases... but the RX freq tries to decrease a little faster. This results in an increasing phase shift between the two sinusoids... but only about 10 or 12 degrees, then there is a little "jump" and the two freqs synch again ... lather rinse repeat, with a little phase-lock jump every few mm as the loops approach. It's like a little stick-slip ratchet process.

ETA: Sorry, forgot to specify it's the RX that makes the little "jumps"; the TX freq decreases smoothly with increasing closeness.

[picowatt]

Verrry interesting, thanks for the suggestion.

As I move the RX loop closer to the TX loop, the frequency of both units decreases... but the RX freq tries to decrease a little faster. This results in an increasing phase shift between the two sinusoids... but only about 10 or 12 degrees, then there is a little "jump" and the two freqs synch again ... lather rinse repeat, with a little phase-lock jump every few mm as the loops approach. It's like a little stick-slip ratchet process.

ETA: Sorry, forgot to specify it's the RX that makes the little "jumps"; the TX freq decreases smoothly with increasing closeness.

TK,

If you are triggering off xmtr, it is likely the xmtr is doing all the changing in response to the rcvr.

Are you seeing solid phase lock-up?

Do you stay phaselocked all the time or just in supernova?

Can you position rcvr distance/paralellism accurately enough to find a true null whe doing the "ratchet" thing (which I assume is during supernova)?

What is the main observed diff betwee supernova ad normal?

PW

[TinselKoala]

If the tuning is close to begin with the "supernova transition" is just a small twitch, but if the tuning is less close, then the transition is marked, by a sudden definite change in brightness and a snap to a lower frequency and greater amplitude on the scope traces.

[TinselKoala]

I'll just make a video illustrating the scope changes. It will take a while though, I might need to take a nap, it's been a long day.

Thanks for your interest... I'm just really weary right now. I'll make a scope trace video after a while.