Testing TMOS FETs
 

International Rectifier has an entire section on their website for the
testing methodology for MOSFET's --
their were also several FET tester circuits in "Ham Radio" magazine -- one
of the great bargains is to have the collection on CD-ROM. Do you have a
FAX --email me privately and I'll send a copy.

Jack

"JGBOYLES" wrote in message
...
Hi,
Anybody got a cheap and dirty way of testing mrf150's out of circuit?
My
homebrew amp using 8 150's died, and some or all of the fets failed. At
$50 a
pop I don't want to throw away any that have life left in them. I did the
usual static ohmic checks in circuit, and only identified one that looked
bad.
Also on application of dc bias, all 8 began to turn on. At very low power
levels all 8 seemed to amplify, but with normal drive levels, no rf
output.
These are 4 push-pull sections with 2 fets per section.
73 Gary N4AST

International Rectifier has an entire section on their website for the
testing methodology for MOSFET's --
their were also several FET tester circuits in "Ham Radio" magazine -- one
of the great bargains is to have the collection on CD-ROM. Do you have a
FAX --email me privately and I'll send a copy.

Jack

"JGBOYLES" wrote in message
...
Hi,
Anybody got a cheap and dirty way of testing mrf150's out of circuit?
My
homebrew amp using 8 150's died, and some or all of the fets failed. At
$50 a
pop I don't want to throw away any that have life left in them. I did the
usual static ohmic checks in circuit, and only identified one that looked
bad.
Also on application of dc bias, all 8 began to turn on. At very low power
levels all 8 seemed to amplify, but with normal drive levels, no rf
output.
These are 4 push-pull sections with 2 fets per section.
73 Gary N4AST