Vertical VHF D-MOSFET used at HF

My guess is that there is a misprint in the last two S parameters at 10 MHz. If you move the three last values right by one column, the results seem much more believable. It would not be the first datasheet with such errors.

That looks likely, yes. But I had my eye on the rising s21 phase shifts.

Yes, I'm sure it's possible. I was looking for some insight into *how* to get a stable amp using those s-params. Any advice to offer?

The pictures that Lasse linked show VHFTV modules (single and dual) like the ones I have.

They're linear-ish (class AB) and work pretty well at 144MHz with no retuning, despite being designed for 225MHz. As JL suggested.

Clifford Heath

Here's a pic of a nice 300W amplifier made with that transistor.

From Broadcast Concepts, I think. They talk about repairing BLF278 FM300-108 pallet amplifiers from Richardson Electronics, so maybe that's the source. TV band stuff.

That looks like a wideband (untuned) part. The higher-frequency dmos RF parts are sometimes wirebond tuned for a specific band.

looks like theses have version from .5-110MHz