Last time the subject of Nuvistor replacement with JFETs came up I
searched the Supertex page for the depletion mode MOSFETs they make
and did not find anything. I see now though that they are still in
production and available although you sure would not know that from
Supertex.
I think the LND150 will have too small a current rating and the next
larger device they make has too much capacitance.
On Wed, 02 Jan 2013 17:30:51 -0000, "Jamie" <jamietyson@...>
wrote:
Dunno if it'll be helpful or not but I'd had good results with LND150 depletion mode mosfets in various lower frequency tube circuits. They act a lot like a pentode in-circuit, with no screen connection, of course. Good to 450 volts.
Jamie
--- In TekScopes@..., David <davidwhess@...> wrote:
I have a mostly functional Tektronix 184 Time-Mark Generator that I am
restoring. It has six 7587 nuvistor tetrodes and they all appear to
work except for maybe the pair in the 500 MHz multiplier.
You can still pick up used but probably good and NOS 7587 nuvistors
for reasonable prices but how feasible would it be to replace them
with say JFETs with cascodes?
I will probably try it no matter what is said here just for the fun of
it but any advice would be appreciated.
David Hess