excerpts of comments on the subject -
--------------------------------------------
I am quite sure that you cannot easily manufacture the required
grounding blocs yourself????
----------------
Affraid if you are not going to set-up a production line, you even wont
find the different elements needed in small qnt.
( And if.......At what price ?....)
-------------------------------------------------------
I was surprised to see the range of comments and particularly to two above
regarding the problem of lightning protection for rotor control cables.
Clearly
they must be protected, and there are at least two commercial sources
manufacturing packages that handle up to 8 conductors. But there are
alternative
solutions that permit some customization as well.
My problem for rotator control was protecting the 9 lines for DC power and
direction indication. Using 110volt selsyns for direction indication was a
problem for the standard commercial products as they are limited to the lower
voltage of most rotators - I think the peak voltage was less then 80volts.
Okay
for 24 vac sources, but not higher voltage.
The first thing to do is find out what the commercial guys use to make their
devices. Disassembly of one revealed low inductance ground strip foil, and
short leaded devices looking like disc capacitors. These turned out to be
radial lead Varistors. Checking one of the components sources (Jameco) a
whole
series of varistors is listed with various voltage ratings and peak current
ratings. The cost is nominal less then $0.60 each in packs of 10. They can be
mixed allowing me to make 5 terminals for 110v and 4 for 24volts. The housing
may take a little creativity depending on the the requirements (indoor or
outdoor). These devices can be added at both ends of the cable which might be
useful in protecting the intermal circuitry of the rotor itself.
There usually is no "magic" in these types of electronic products, but there
are some rules. low inductance common ground termination for each device, and
short leads to the "hot" terminals. Good mechanical connections first, then
secure with solder. Of course the package has to be connected to a low
inductance ground system as well. In my case it is the SPG entry to the shack.
Jameco also carrys a line of diecast boxes that work well for this
application. www.jameco.com
Regards,
Norm W4QN
_______________________________________________
See: http://www.mscomputer.com for "Self Supporting Towers", "Wireless Weather
Stations", and lot's more. Call Toll Free, 1-800-333-9041 with any questions
and ask for Sherman, W2FLA.
_______________________________________________
TowerTalk mailing list
TowerTalk@contesting.com
http://lists.contesting.com/mailman/listinfo/towertalk
|