On 8/17/2010 10:18 PM, Jim Brown wrote:
> On Tue, 17 Aug 2010 20:46:05 -0400, Roger (K8RI) wrote:
>
>> I'm just using a common rotator cable in this case, so it's unshielded,
>> 8 conductor..
> Shielding is NOT important, but a twisted pair for each control line
> would be a big plus.
>
>> I need to add a grounding lug for the box which is ungrounded.
> Is there anything in it besides LEDs and switches? If not, it's not
> likely to matter, other than for safety.
It's a very simple system. So simple they needed an extra port in which
to run the DC supply. The two control heads are just aluminum boxes
with two rotary switches that provide power to the relays out at the
tower AND to the LEDs through dropping resistors. That's it. Only one
relay is used per path from input to output. The relays (DPDT) are
interlocked so the same line can not be selected for both inputs. Simple
and effective. It could be designed for more isolation, but it's more
than sufficient for my SO2R operation even when both stations are
active. It'd work with CAT5e or CAT6, but I don't like using wires
that fragile, but they are twisted pair and would allow enough room to
slip in the two DC lines without any drilling of holes. That and I have
LOTS of both CAT5 and CAT6 cables of different colors in "pull boxes".
I'm just not very enthusiastic about pulling out the two lines to the
shop and two lines to the den and pulling in replacement CAT5 or 6
lines. All I'd have to do is tie the new lines on the ends of the old
ones and use those as pull lines. It takes about 5 minutes to hook up
each end. The whole replacement operation could likely be done in well
less than an hour by myself, but maybe get my wife to watch the pull
boxes so the lines don't get kinked.
OTOH it works and I have a LOT of antenna work left to get done in just
a few weeks. Maybe, I'll put the "glowing LEd problem" off until I have
more time to devote to it using twisted pair and maybe bypass caps along
with grounding the switch/light enclosures.
73
Roger (K8RI)
>
>
> 73, Jim K9YC
>
>
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