Some people like to lock the windings and the leads in place with a heavy layer of encapsulant. This works better if you put the part to encapsulated under vacuum before you pour on the encapsulant.
I've never seen it done, but I've heard about it. It's apparently very messy.
Wet stuff is messy, really nasty in production. In the case of a txline transformer made with a few turns of coax, there's no reason to pot it.
We just spin a few turns on a bobbin and clamp it into the pot core. If it got sloppy, a tie-wrap would secure things.
Some people like the idea of potting things. Weird.
John Larkin Highland Tech Glen Canyon Design Center Lunatic Fringe Electronics
I've designed passive bandpass filters with adjustable pot cores. There are times when they make sense.
John Larkin Highland Tech Glen Canyon Design Center Lunatic Fringe Electronics
Last year we did a TDR that had to survive being pounded into hardpan with a slide hammer (>20k gees). Potting was the right answer there!
We put in small bits of foam sticky tape to keep the epoxy from trashing the pulse shapes. If we did it again, we'd probably go to a six-layer board and use stripline to avoid the problem (mostly).
Cheers
Phil Hobbs
Hard-cure epoxy can crush and destroy parts too. And, I've heard, wreck opamp offsets.
JLC does cheap 6-layers.
John Larkin Highland Tech Glen Canyon Design Center Lunatic Fringe Electronics
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