On 7/7/2012 11:00 PM, Joe Subich, W4TV wrote:
>
> > First question. I have an Ameritron RCS-10 that doesn't seem to work
> > on all positions. Mine only works on 1-4 with no connection on the
> > other positions. What would cause that? It almost seems like 2 and 6
> > are hooked together and 1 and 5 too!
>
> RCS-10 uses a "binary tree" arrangement of relays. You will probably
> find the input relay has been arced so that both the normally open and
> the normally closed contacts are connected at the same time (all the
> time).
Using double pole relays in binary trees is normally considered a very
unreliable way to go in industry. Solid state logic is much more
reliable and only takes 4 lines to count to 10 (BCD) and is simple to
decode with one chip. I can't imagine why anyone would use relays in a
binary tree. I've never seen an RS10 so I can't verify the
construction, but I have used the more conventional RCS4 and 8 that use
the second set of contacts on each relay to prevent any other relays
being active other than the one selected.
73
Roger (K8RI)
>
> > Second question is about the need/benefit of grounding coax cables at
> > the bottom of a tower.
>
> It's called lightning protection. You want the shield of all cables
> connected at both the top and bottom of the towers so that a lightning
> strike can't cause a high voltage between the tower and cable shield
> which would "puncture" the insulation and put the high voltage on the
> chassis of any connected equipment. There is a lot more in the literature.
>
> 73,
>
> ... Joe, W4TV
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