10 Silicon chip Australia’s electronics magazine siliconchip.com.au
brought back plenty of memories. The first and heaviest
was one and a half Byer/Rola 66 II, reel-to-reel tape re-
corder. The half is a transport deck, without the amplifier.
These machines were the FJ Holdens of broadcast qual-
ity tape recorders.
I then came across two more tape recorders made by EMI.
I’m not sure of their exact model number, either L1 or L2.
These came to me from a Melbourne station about 1970.
These were an early portable machine, battery operat-
ed, enclosed in a wooden case (like the Rola machines),
with a 4-inch tape and I presume it ran at 7½ IPS (inches
per second).
I also found two 16-inch Australian-made Byer turnta-
bles. I believe these were something of an industry stand-
ard to play long programs on large 16-inch discs at 33RPM,
before tape became the standard for distribution of nation-
ally distributed program material.
I then came across two National 12-inch turntables
that I purchased around 1963. They were well built from
pressed steel, and rather pleasing to the eye, with a stand-
ard engineering rubber drive wheel to the inside rim of
the turntable.
They had an innovative speed variation control, built
like a disc brake system. On the bottom of the stepped
capstan drive for the fixed speeds was a steel disc 70-
mm in diameter.
The speed variation was simply a magnet that would
swing over the disc exerting drag, and depending on how
far you extended the magnet, it slowed accordingly.
I also found, in a cupboard in the shed, two Reslo rib-
bon mics. One is working; the other needs a new ribbon.
The ribbon is mounted within a frame, like a tiny picture
frame, and then the frame is placed securely so that the
ribbon is in the magnetic field.
Ribbon mics have faded out of use in radio broadcast-
ing but they have been well replaced by low impedance,
dynamic uni-directional equipment. Then I found some
J. S. (Jørgen Schou), type 0.32, No. 251 audio transform-
ers which sell for $500-2000 on various sites.
That just about covers the first wave of sorting all the big
and obvious things. There will be more smaller treasures
such as a BA tap with nuts and bolts and some 1/8-inch
Whitworth, which I can’t use with aluminium because
they are brass. There’s also a 5/8-inch tap and die, brass
thread, for making extra microphone stands from extruded
aluminium or electrical conduit.
The three and a half tape recorders (as mentioned ear-
lier) are free to a good home; anything with commercial
value, I’ll try to sell. The rest of my treasures I will hap-
pily give away to a young person who has shown an in-
terest in all things electronic.
I started reading “Radio, TV and Hobbies” magazine
back in the 1960s. I paid two shillings and six pence for
each copy! I still remember Neville William’s article on
how CD players worked. Later electronics magazines, up
to and including Silicon chip, have kept me informed
and challenged.
Over the years I have made lots of preamps, power am-
plifiers, various mixers and distribution amps. There is
still a buzz for me when having built a small amp and
connected it up, a clean sound comes out!
Ken Ewers-Verge
Albany, WA.Serviceman’s lawnmower modifications could be dangerous
I just read Dave Thompson’s Serviceman’s Log column
on poor designs, in the February 2019 issue. I would like
to comment about him adding 10mm of washers to low-
er the cutting disc of his lawnmower. It may well have
worked for him, but before anybody else attempts this,
they should consider whether the manufacturer recessed
the cutting disc as a safety measure.
Also, keep in mind that this change could affect the
balance and vibration of the mechanism, which if upset,
could lead to fatigue and possibly disastrous failure. If the
disc comes loose because of the added washers, I would
hate to think of the consequences.
As for the sandwich maker which needed to be disman-
tled for cleaning, we had the same problem in my last
place of work. I also refused to use it because everybody
was too busy to wipe it over after each use. They just used
it and left it with crumbs and filling on the plates. I often
saw flies sitting on it.
Geoffrey Hansen,
Littlehampton, SA.
Cleaning out the shed before it’s too late
I am only a few years from obtaining my OBE (Over
Bloody Eighty)! Recently, I received a few directives to
“clean out your shed; otherwise, your children will have
to do it”. That scared me, because the children are com-
plete philistines when it comes to electronics. The thought
of my prized possessions being thrown indiscriminately
into a skip bin was enough to spur me on!
As I went through my collection, some of the older items
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