for a piece of 40-year-old electronics!
The preference of tubes vs.
transistors is highly personal, there's
no clear "right" choice for everyone,
and each has its advantages. Tubes
are often cited as being prone to
failure. Yet a well-known tube amp
designer has stated that a properly
designed tube amp can be every bit
as reliable as a solid-state device.
While solid-state products have
controlled the market for years, there
have been more tube devices
manufactured lately than at any time
in the last 25 years. Who'd have
guessed that would happen?
La Grange Park, IL
the diode does and recommend a
replacement. It is quite certain that it
was not used as a rectifier in the high
voltage circuit. Using a diode as a
fuse would not be reliable because
the failure mode is almost always as
shorted. Using a diode as a switch is
a common application. If the broken
diode is a small glass type, a 1N34A
will no doubt replace it.
Starting with calendar year
2004, we are archiving a
years’ worth of issues on a
CD that can be searched,
printed, and easily stored.
[#05054 - May 2005]
I need an inexpensive I/O card
that has about 12 digital input/
outputs and six analog input
points. It needs to fit into a
standard slot in a PC.
#2 That is probally a Tunnel Diode
made from germanium. They can
switch in less than a nanosecond but
the voltage range is about 0.1 to 0.5
volts and are usually followed by
amplification. Your best bet is to find
a Tek website and try to get a
replacement from a similiar model
scope. Or at least the same part
number. TDs are no longer made and
if so, are very rare.
You can purchase said disk
from us for your own
personal use and dispose of
your old paper copies that
are collecting dust in the
garage. (Your spouse will love
you for it!)
We will also be archiving
earlier years as well, so stay
tuned for their availability.
Omega.com sells a board for
Have you considered using a
microcontroller such as Atmel's
ATMega8, connected to your PC's
RS-232 port? This MCU has
enough onboard I/O to meet your
requirements and the RS232 interface
is easy to program. I can help you
with this if you are interested.
[#06054 - June 2005]
There is an Internet provider in
Calypso, NC which provides
broadband Internet service with
We need someone to put
something like this in our
community, as the phone company
will not install DSL lines because
there is not enough revenue to pay
for new fiber optic cables.
NUTS & VOLTS
[#05055 - May 2005]
I was troubleshooting a
Tektronix scope's high voltage
circuit and I broke a germanium
diode. It looks like it functions as a
switch in this application. Why
would a germanium diode be used
in any circuit other than a crystal
radio? Are they sometimes used as
fusing devices because of their
lower current rating?
Will any germanium diode
#1 If you gave the scope model,
someone could tell you exactly what
#1 I know Curt WB4WAA
personally, and am in the exact same
situation. The local phone provider
here is Sprint, and the cable company
is also Adelphia.
Neither wants to invest the
resources to make high speed
Internet available here in much of
Eastern North Carolina.
In a nutshell, in many cases, the
economic feasibility is not there for an
individual or many ISPs to see any
kind of return on investment.
So, looking for a solution, I
approached a local ISP (NCISP) and
they agreed to try a cost sharing