Good comments from everyone.
FETs are interesting. But as luck would have it and strange as this is I had
the tube.
Working quite well now
On Sun, May 2, 2010 at 11:07 PM, Burt I. Weiner b...@att.net wrote:
For what it may be worth, I've swapped Nuvistors out with FETS. I see from
the
: [time-nuts] Nuvistors and FETs...
Interesting idea. In fact, the later versions of the loop used FETs in
place of Nuvistors. I've not compared the circuits.
Because the thing is only 60 KHz, the change in grid/gate capacitance may
not matter much. There may be some mounting and stability
Bob wrote:
Last time I went down that road, finding a FET with *low* enough Gm
to match the tube was the issue.
You can always lower the gm of a FET by adding source resistance. To
replace pentodes, you can use cascoded FETs (you may or may not be
able to use the existing screen supply for
as well.
Don
- Original Message - From: J. Forster j...@quik.com
To: Discussion of precise time and frequency measurement
time-nuts@febo.com
Sent: Sunday, May 02, 2010 9:23 PM
Subject: Re: [time-nuts] Nuvistors and FETs...
Interesting idea. In fact, the later versions of the loop
Interesting idea. In fact, the later versions of the loop used FETs in
place of Nuvistors. I've not compared the circuits.
Because the thing is only 60 KHz, the change in grid/gate capacitance may
not matter much. There may be some mounting and stability issues though
because the plate caps were
You can also look up the gm of the nuvistors and get a reasonable match to a
fet as well.
Don
- Original Message -
From: J. Forster j...@quik.com
To: Discussion of precise time and frequency measurement
time-nuts@febo.com
Sent: Sunday, May 02, 2010 9:23 PM
Subject: Re: [time-nuts
