MAILBAG
Feedback on
radio kits
Enclosed is payment for the
renewal of my subscription for
another year. Keep up the good work.
I wish to bring to your attention a
problem I have observed in the PCB
artwork for the mini stereo transmitter published in the October 1988
issue of SILICON CHIP. If one end is not
cut off correctly, the antenna output
is shorted. It's always the simple
things in life that make life frustrating, to misquote the Kelloggs ad.
The transmitter sounds quite good
and it's amazing that the whole thing
runs on only 1. 5 volts.
Another very good kit of yours is
the AM Stereo Radio. The whole thing
went together so easily, and it worked
first go. However, it sounded even
better after I aligned it. It's a pity that
the radio stations in Sydney can't improve the music they transmit!
The sensitivity of this radio is also
something fantastic. It will pick up
stations in Wollongong and Gosford
during the day.
Mark Allen,
Gore Hill, NSW.
Specialty chips
are difficult to get
These days, more and more project
designs are including specialty chips
not carried by our turnover conscious
electronics stores. Consequently, construction of such projects is made
more difficult, as the specialty supplier ring around begins.
The problem raised itself recently
when l was trying to source a
"doorbell" chip. I remembered your
UHF doorbell of August 1988, and
eventually dug up the relevant article. It uses the SAB0602, yet doesn't
mention any more about that particular IC. I realised that it was a
Siemens chip from the similarity to
the dreadful SAB0600. One wonders
what went through the minds of the
Comeng engineers when they decided
to put this horrific sounding creature
inside the NSW Railway's Tangaras.
I'm still sure it was a joke that went
wrong!
Might I suggest that when presen-
ting projects using non-standard components, a "shoparound" column
should be included. Better still, why
not a feature article on ·semiconductors, their labelling, identification,
and supply? Accompanying the article could be a table of suppliers for
each of the state capitals. I for one
would benefit from a further
understanding of IC labelling in particular and I'm sure many other
readers are in a similar position.
Thanks for the magazine. Keep it
up!
Greig Sheridan,
Ashfield, NSW.
The story of
electrical energy
Congratulations on the Bryan
Maher series describing electrical
energy. The man is not only clever but
thoroughly readable and informative.
The conclusion of his mammoth series
on electric railways left, for me, a
large hole in SILICON CHIP. This series
had captured my interest from the
jump and was always the first article
to which I'd turn upon receiving each
issue. Thankfully, that hole is now filled by a writer I enjoy on a subject in
which I have much interest.
By starting this new series, you
have given me yet another reason to
be glad that I subscribe to SILICON
CHIP.
Julie Kentwell, VKZXBR,
Springwood, NSW.
Listing for
computer clubs
The secretaries of user groups and
computer clubs who read your
magazine will be interested to know
that it is now possible for them to arrange, through Telecom Business Offices, an entry in the Yellow Pages
under the new classification: "Clubs
- Computer".
A charge is made for a white pages
entry; eg, the secretary's private
number and address preceded by the
name of the group/club and this is a
pre-requisite for the free Yellow
Pages entry as above.
We in Canberra, with its rather
mobile population, have been conscious of the need for this for some
SILICON CHIP,
PO Box 139,
Collaroy Beach 2097.
years and we think that others will
want to take advantage of it too. We
are informed that the first cab off the
rank will be the 1991 Sydney Directory, entries for which will close in a
few months time.
K. W. Shands, Secretary,
Commodore User Group,
Curtin, ACT.
How about a reprint
of earlier issues?
I am one of the many readers who
would like a copy of the November
1987, December 1987 and January
1988 issues of SILICON CHIP but they
are sold out. Why don't you see how
many people are interested in a copy?
It may be economically viable to print
another edition.
Jason Semple,
Preston, Vic
Extended guarantee on
boards with VLSI chips
In the July issue of SILICON CHIP,
Mr R. Hobson of Glenreagh, NSW
wrote about the boards supplied by
Electronic Solutions which have surface mounted VLSI chips.
I would like to answer his concerns
as follows. First, he says that if the
boards had chip carriers to hold the
VLSI chips, this would solve the
"repairability" of the boards. The
reason that manufacturers are moving away from chip carriers is that
because of the large number of connections (and this number is increasing as larger scale integration is being achieved), the chip carriers
themselves are unreliable and are
tending to fail after a period of time.
Second, special tools are required
to remove and replace VLSI chips.
Third, VLSI chips are extremely
reliable. This makes products that
have a small chip count due to the use
of VLSI chips very reliable as well.
Therefore, as Mr Hobson has
brought this to our notice, from July
1990, all boards with VLSI chips that
are supplied by Electronics Solutions
will carry a full 12 months parts and ·
labour warranty.
Ian Hardwick, Managing Director,
Electronic Solutions,
Lane Cove, NSW.
SEPTEMBER 1990
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