Your house will have better lightning protection with a ground around the
perimeter with ground
rods (10 foot) driven at each corner and every 10 feet around the house. The
idea is to make
the entire house at the same potential. The problem is when lightning strikes
and the grounds are
not equalized, there is a voltage gradient that could be several KV's. That is
when radios turn
black inside and no longer work since the smoke escaped. Be sure to use the
largest bare
copper you can afford for this. 4/0 is about the smallest I would use but it's
cost is high.
73 and good luck
Clayton N4EV
On Wednesday, May 14, 2014 9:23 PM, denton sprague <denton@oregontrail.net>
wrote:
Nice going Bob…as you might recall, I put out a query on qrz and a couple of
other places about the xyl and I having a new double wide installed on our
qth….and me running twin lead underneath the floor and out the back for a multi
band horizontal loop…we will be having a concrete pad with presumably
contruction cloth for reinforcement poured.
That got shot down pretty nicely, so will go to plan B…making a porthole in the
side of the new house for balanced feeders plus a couple of coaxial lines for
other stuff…and installing a ground rod via ICE type glitch arrestors and
static drains.
Trouble is…the station is on the north side of the house and the electrical
panel with attendant ground rod will be on the south side of the house.
NEC says run a really thick cable and a bunch of ground rods around the
perimeter of the house to connect the station ground to electrical ground.
Question..can I run the ground line from the twin lead ground rod to the
electrical input ground rod underneath the house? I will be making provisions
to have the contractor install portholes in the foundation perimeter to run
coaxial feed lines from the station room's porthole to the back of the new
house.
From what I have seen…no can do….gotta run around the perimeter of the house.
Antenna is a multi band horizonal loop up about 30 feet, fed with an LL
(balanced Pi) tuner fer 10 thru 160 meters with an ICE type glitch arrester and
450 ohm (?) modified twin lead.
when I was kid I had a crystal radio….I think I miss it a lot….
BTW…I did have the forethought to have the construction people run a dedicated
20 amp 120 vac line just for the station.
If this don't make much sense, blame the nice whiskey I am imbibing!
On May 14, 2014, at 4:38 PM, "Bob McGraw - K4TAX" <RMcGraw@Blomand.net> wrote:
> Why? I bring mine all the way to the tuner sitting on the shelf above the
> radio. If the line is operating anywhere near a balanced condition there
> will be little to no radiation from the feed line.
>
> Ground? Someone said use one for lightning protection. Why? All lightning
> protection should be OUTSIDE of the house and never inside. I operate from
> the 2nd floor of the house. No ground from the station to the outside is
> ever needed.
>
> I still question why connect the data audio into the mike input. The signal
> to the radio from the computer needs to be 20 to 30 db higher which will
> improve the signal to noise ratio. Thus the level of RF will be effectively
> reduced 20 to 30 db. There is no magic here, just math.
>
> Yes, one can change the feedline length which will move the voltage point,
> perhaps further from the radio. Still, that is not perceived to be the best
> solution.
>
>
> 73
> Bob, K4TAX
>
>
>
>
>
> ----- Original Message ----- From: "Mike Schatzberg"
> <cherokeehillfarm@earthlink.net>
> To: "Discussion of Ten-Tec Equipment" <tentec@contesting.com>
> Sent: Wednesday, May 14, 2014 6:16 PM
> Subject: Re: [TenTec] Eagle problem?
>
>
>> Hello Carter,
>>
>> Why not eliminate the balanced line near the house?
>>
>> Install a 4:1 current balun on the balanced line well away from the house,
>> and connect from the balun to your tuner with 50 ohm coax. Bring it thru the
>> wall and have nothing radiating in the shack.
>>
>> A line isolator can also be installed right before the Eagle.
>>
>> I sit under a fan dipole and have no issues with 100 watts portable.
>>
>> Naturally, a good single point ground with a short low impedance ground
>> connection is desirable, but I operate at the beach from the second floor
>> without it.
>>
>> Leave the RF outside.
>>
>> 73,
>>
>> Mike
>> W2AJI
>>
>> Sent from my iPhone
>>
>>> On May 14, 2014, at 6:43 PM, "Rick - DJ0IP / NJ0IP" <Rick@DJ0IP.de> wrote:
>>>
>>> Actually James hit on an important point here: feedline length.
>>>
>>> Actually it has nothing to do with impedance matching but everything to do
>>> with the behavior of common mode current on the feedline.
>>> Unlike the transmitted RF current which is the same for the entirelength of
>>> the feedline, common mode current is not the same at all places along the
>>> feedline. It varies constantly.
>>> It is worst a half wavelength away from the feedpoint and minimum a quarter
>>> wavelength away from the feedpoint.
>>> You must consider the vf of the feedline (but not its transmission line vf,
>>> rather the vf of the individual wires - which is probably about .97 our
>>> .98).
>>>
>>> G3TXQ reports measured data on this on his web site at the bottom of his
>>> page on RF chokes:
>>> http://www.karinya.net/g3txq/chokes/
>>>
>>> You didn't specify which band(s) the problem is on.
>>> A quick try would be to insert 1/8 wavelength of additional feedline between
>>> the existing feedline and the JV Matchbox.
>>> Of course it you are on 80m, this is not going to be an option.
>>>
>>> I still suggest the dual RF choke as per my previous email.
>>>
>>> 73 - Rick, DJ0IP
>>> (Nr. Frankfurt am Main)
>>>
>>>
>>> -----Original Message-----
>>> From: TenTec [mailto:tentec-bounces@contesting.com] On Behalf Of TTMaven
>>>
>>> Have you tried different lengths of feed line - window line and coax,
>>> respectively? I won't recite all the reasons here, but you know how various
>>> lengths of feed line matter to impedance matching, etc.
>>>
>>> _______________________________________________
>>> TenTec mailing list
>>> TenTec@contesting.com
>>> http://lists.contesting.com/mailman/listinfo/tentec
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