On Fri, 2 May 1997 K7LXC@aol.com wrote:
> > Aren't these DCU-1 control boxes kind of expensive for what you get? Do
> > you guys really feel like it is worth the extra money? Just curious.
> In defense of the DCU-1, it has some really NIFTY features! It has 6
> presets, dial selectable heading, automatic brake and rotation operation and
> computer compatibility and some more.
> Is it worth it? If I was putting together a more automated contest
> station - YES! Is it worth the money - probably. Besides, what else is
> there that'll do the job (forget the Prosearch unit)?
It may depend on the degree of automation required. Between leaning on
the buttons until the rotator reaches its heading and having presets,
there is an intermediate level of automation in which the operator simply
dials the desired heading and the beams automatically stops when the
heading is reached. This can be done with a couple of voltage comparators
and a couple of relays with transistor drivers, and perhaps a few other
paerts for brake delays, etc. Back in the 80s, I updated an earlier
design for the CDE rotators and then also did a version for the now
defunct Alliance HD-73. The latter unit is now nearly 10 years old and
operates with no difference from the first day of use. A more complex
version of the system recently appeared in QST, but the simpler systems
work fine for setting a precalibrated pot to a direction and letting the
system shut itself off when the heading is reached. Several of these
units (according to old correspondence) have been successfully built by
friends for blind operators using raised lettering/braille around the pot.
I do not think either unit cost me more than $20 in parts, including case
and power supply. Moreover, each unit requires only one entry into the
current CDE or Alliance control box with a single line (pair) brought out
for overall control. So it is an easy modification. The other
connections are made to the terminals on the back of the control box.
I am sure folks could update these designs for current parts and add
feature or two without much trouble. (W6ZZB just added an audio tone
generator to assist the blind--see Feb, 97 73.) No, they are not digital
precise, but at 50-60 degree beamwidths, neither are ham beams for the
Unfortunately, both the 73 CDE article and the CQ HD-73 article have
errors in the schematics (and the tradition has not stopped, since the Feb
73 article also has errors introduced by the editors).
I have also seen adds for control units that go inside the control case,
but do not know their internal workings. However, they appear to do the
same job of beam aiming.
So it all depends on what level of automation you need. It appears that
the price of automation increases geometrically as the desired automation
functions increase arithmetically.
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