[Elecraft] Re: no PolyPhaser?

Tue May 20 15:57:01 2003

On Tue, 20 May 2003, Vic Rosenthal wrote:

> Something important to keep in mind (which I'm sure Steve has done but 
> didn't mention) is that in addition to the antenna leads which go 
> through the lightning suppressors at the entrance plate to the house, 
> you should also pass ALL of the AC, telephone, rotor, etc. lines for the 
> shack through the entrance plate with appropriate suppressors.  That way 
> there shouldn't be any large differences in potential between circuits 
> inside the shack if there us a nearby strike.

The house layout dictates that I can't (or it would be VERY hard) to bring
in AC, Telco, CATV, RF and Rotor/Switch cables via a single entry point or
even within several feet of each other so, as it stands, the AC, Telco and
CATV leads come in via one entrance at one side of the basement and the
RF, Rotor/Switch cables come in on the other side about 15ft away.

I have implemented a DITEK "whole house" surge arresting system now.  It
consists of the following:

On the AC power, I have installed the following at the service panel:
Model: DTK-120/240 CM
Connection Method:  Hard wired, parallel 
Response Time:  <5 nSec installed, <1 nSec component level 
Operating Frequency:  0 - 400 Hz 
AC Protection Modes:  L - L, L - G 
Service Voltage:  120/240VAC10 
Max Surge Current:  25,000 Amps per Mode 
Max Energy Dissipation:  420 Joules 
MCOV (L-G):  130VAC 

On the telco circuits, I have installed the following at the DEMARC:
Model: DTK-2LVLP-SCP-RUV
Class:  Low voltage line protection 
Connection Method:  Screw terminals, 22 - 14 awg wire 
Continuous Current:  <150 mAmps 
Response Time:  <5 nSec 
MCOV:  175VDC 
Max Surge Current:  9000A per pair 
Max Energy Dissipation:  76 Joules per pair 
Typical Let Through Voltage:  130VRMS 
Protection Modes:  L-G (All lines protected) 

On the CATV, I have installed the following at the DEMARC:
Model: DTK-VSP-A
Class:  Coaxial Cable Protector 
Installation Point:  CATV Entry 
Connection Method:  Female IN/OUT 
Response Time:  <5nSec  
MCOV:  75VDC (center pin-shield), 38 VDC (shield-ground) 
Impedance:  75 Ohms 
Standing Wave Ratio:  1.2:1 
Band Pass:  0-1.5 GHz 

Does anyone have anything good/bad/indifferent to say about the DITEK
products?

For the RF lines and rotor/switch lines, I am redesigning the system.  The
antennas are down and the gear is either in repair or being prepared to be
sent to repair after the lightning hit.  The hit did NOT come in the RF or
the rotor/switch lines but, this still gives me the opportunity to build a
better grounding/arresting system.

I am looking for a source of copper plate currently.  Something that I can
then mount the polyphasers, knife-switches, ICE equipment to and then
connect to my copper strap that goes to the ground rods.  I know that
polyphaser sells one but, @$70.00 for a piece of copper plate seems to be
a bit extreme.  Surely there is some other source.

Alternately, I suppose that I could use some other metal plate but, my
thinking is that copper will be the best bet.  Does anyone have any
suggestions on sources and comments on copper vs some other metal plate?

Also, I'm getting mixed messages trying to do research on how to properly
set up the ground system.  Some people say DON'T connect it to the
electrical ground, some people say DO connect it to the electrical
ground.  Which is right?

Also, I've been told to keep the ground as short as possible.  Does this
mean the ground strap from my bus point to my ground rods or the
overall length of the grounding system?  I ask this because the run from
the "bus" to my ground rod is about 12ft.  It will be another 25-30ft
from that ground rod to the electrical service entrance if I want to bond
the two.

This page: http://www.k9wk.com/litenin.html has something similar to what
I'm trying to achieve.  He is using the $70.00 polyphaser copper plate
though.

Any ideas, suggestions, etc would be nice.

Now, for my ARRL rant: It would be %^*&# nice if they were actually had
this information on their website vs requiring you to buy a book from
them!  Jeesh!

73, John - K4WTF
...used to have the station pictured at http://www.k4wtf.com/