I’m trying to find service
information or help for a BSR
MCD8090 AM/FM Stereo Receiver.
This unit was called a "Thunder
Thrower" and was purchased from
DAK Industries. The FM section is not
Any help would be appreciated.
I got the amp working, but I can
not get the vibrato to work. The
oscillator is very weak. It looks like
someone worked on it before me and
rewired the vibrato circuit.
I cannot find a schematic for it.
Does anyone have one or know how it
is wired? The output of the oscillator
goes to the grids of the two 6V6s.
#2053 Jon Garee
I need to purchase a good,
reliable, and low cost schematic
capture/board layout program.
I recently purchased a 48 VDC to
12 VDC switching power supply from
a surplus place. What are the general
rules of thumb for getting this thing to
I know switchers need a load, but
on which output? It has + 3 V, + 5 V,
- 12 V, and + 12 V outputs. I am only
interested in the + 12 @ 10 A output.
This supply has a couple of sensing
circuits; what do they usually tie to?
The supply house doesn't
acknowledge any tech questions —
they just sell the stuff. The factory
made these on a special run and
doesn't want to admit that they made
the thing. Now, I'm out in left field
trying to get it to work.
#2052 Bob Sheetz
I'm working on an old Epiphone
Electar Zephyr guitar amp. It looks
like it’s from the 30s or 40s.
I have a bunch of unmarked
LEDs. Is there any way to determine
the specs (forward voltage) of an LED
if you don't already know it?
#2055 Jeff Rocchio
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How can I restrict outgoing calls
on my land line from one phone?
#2056 Bill Gregory
I am looking for a wiring diagram
to help me build a cable tester. The
cables have between six and 12 wires.
#2057 Nestor Quiroga
What circuitry could I use to
determine the winner of a Pine Box
Derby race? These little cars cross the
finish line at very fast speeds and are
usually only milliseconds apart. I
would like to use infrared or laser
beams to be broken by the cars as the
trigger for the circuit to determine the
NUTS & VOLTS
[10045 - October 2004]
I got a new computer with
Windows XP on it. (My old
computer had Windows 98.) I use a