QUESTIONS & ANSWERS
shot triggered by the first and has a
pot to vary the pulse time. You can
MAILBAG
Dear Russell,
In your Q&A column about transformer design, get a copy of COYNE
TELEVISION and RADIO HANDBOOK.
This old book has some good
information on transformer design and
has copper wire tables. I have seen this
book on eBay for about $10 and will
make transformer building easy.
— Edwin Fitzpatrick, W8MFS
get close to 100% duty cycle, but if
you exceed it, the duty cycle
lazy. A full circle draws easily but
partially dashed would be time
consuming. I don’t have a library of
tubes and do not plan to have one.
Dear Russell,
I just got my September issue of
Nuts & Volts. Your circuit in Figure 1
on page 24 is very interesting.
But, Mouser has no 762-LH2540T
part. Datasheetarchives has no
becomes 50% because it is triggered
every other pulse.. NV
762-LH2540T nor do they have a
LH2540T. So, what is the correct part
# for the solid-state relay, in Figure 1?
— Paul Bergsman, N3PSO
I got my Nuts & Volts today and I see
your problem. The 762-LH1540T is a
solid-state relay, 350 VAC, 120 mA rating in a six pin DIP package, apparently
no longer stocked by Mouser. An equal
substitute is: 849-LCB110S, $2.71 ea.
Thanks for the info, Ed, I will have to
check it out.
Dear Russell,
On page 29 of the August issue,
you answered a question about
building a vacuum tube version of a
solid-state audio amplifier. The tubes
were drawn wrong. When I was just
getting into electronics almost everything was tubes. At that time, when
a dual tube was used, both sides of
the tube had the same V designation,
and the symbols had partially dashed
or sometimes open enclosures. Has
this practice been abandoned, or is it
now personal preference? Thanks for
listening to my rant!
— Paul Baxter
You are absolutely right, I was just
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