Is a Direct TV / satellite receiver involved? I have experienced RF
getting into the Direct TV / satellite receiver causing it to change
channels, turn on and off, and reset. It is the fact you are radiating
RF which is the desired intention and this RF is getting into the
"plastic box" of the receiver. Plus many of these receivers use RF
Remote control as opposed to IR Remote control.
If it is just the TV that is turning on and off, I suggest putting
common mode chokes on the AC power cord at the TV and also on any other
inputs or outputs at the TV. This also could be an issue where the TV
Remote control is a RF Remote as opposed to a IR remote. I've found
these RF Remote receivers have basically no selectivity and any RF close
by will or can cause issues.
Your roof mounted mast should have a ground positioned as close as
practical. A driven rod is required. Use #6 copper from the roof
mast to the ground rod with suitable clamps. Straight runs preferred
with large radius bends if and where needed, otherwise no sharp bends.
Also some form of lightning protection is needed at the point or
before the feed line(s) enters the house. This can be attached to the
same ground system.
Now here's the kick in the pants..........this ground rod must be bonded
back to the AC Mains ground and this needs to occur outside of the house
even if it means running 50 ft or more of copper between the two
grounds. This is per NEC. I trenched mine in about 6" deep around the
foundation.
All of my feed lines and rotor control lines enter the house at an eve
vent, traverse across the attic and drop down through the ceiling to the
operating position. My lightning protection is at the point the feed
lines exit the tower adjacent to the house. I do not have any ground
from the station operating position to the outside world. I only use
3rd pin safety ground. Use dedicated jumpers between each piece of
equipment to the common power supply ground terminal. Do not daisy
chain pieces of equipment. I make my ground jumpers using #10 auto
primary wire with suitable crimp lugs attached on each end.
You may also need to place a common mode choke on the feed line near or
at the radio. This can be the coax jumper between the radio ANT and the
SWR/Pwr meter or input to the external ATU.
Running only 100 watts, I'd think the #8 ga power feed from the breaker
panel is way over-kill. I's spend my money on copper in other places.
Just run a dedicated 20 amp service. If you install a ground rod
outside of the shack, this rod must be bonded outside of the house back
to the main AC Mains driven ground as well.
Finding the problem and applying the proper solution is the challenge.
Throwing random solutions around likely cost money and won't produce
results. Just remember that grounding is a defined system and done
correctly will protect not only the structure but the equipment. Yet
grounding not properly done can be extremely dangerous.
73
Bob, K4TAX
K3S s/n 10,163
On 9/26/2015 12:41 PM, [email protected] wrote:
On 40m my TV turns off and on by itself when I transmit. I'm thinking that
it's related to grounding because I've not figured that out yet. I have a
roof mounted mast that holds my dipole. The coax comes down through the
roof, routes through the attic down inside the wall to the station. I've
been told I need to ground the feedline BEFORE it enters the house but I'm
not sure how to get a ground correctly up to the roof. No matter how I run
the ground a lightning strike would likely ignite my house inside the attic
if I run it inside the house. I have a low pass filter installed just
before/after the Rig.
The plan I'm thinking of so far.
1. Run an 8 gauge dedicated power feeder from my main panel (on the
opposite side of the house) to the shack with a 20A breaker. The 8Ga is to
lower ground losses.
2. Install a ground rod outside my shack and run a heavy gauge to the
shack to bond with the dedicated power line ground.
3. Ground all gear in the shack to the dedicated power ground.
4. ?? maybe do a run of 14-2 romex with all three leads bonded together up
to the mast, install a mast antenna switch and ground it with the 14-2.
Thoughts /comments?
Running only 100w into a Buckmaster 7 Band OCF dipole at 35' per the
instructions. The dipole is broadside to 45 degrees for EU coverage.
Thanks in advance. I've read A LOT on grounding but haven't seen this
scenario covered.
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