Hello All,
One more time:
I realize that some Orion and Jupiter owners are not having RFI problems.
Good!
For those of you out there that are, I would like to recommend the following:
1. Purchase a T-4 Line Isolator from Radio Works. The Isolator connects
inline with the
coax coming out of the back of the rig. Cost, approx. $39
2. Install a 0.01uf cap across the audio pin to the ground pin on the mic
connector.
This application may have to be applied to the CW key pin and PTT pin.
3. Contrary to popular consensus, I recommend that the grounding inside the
rig/s be
reinforced. I have applied this procedure to my Jupiter and have spoken
with Ten Tec
about this issue. I don't want to mention any names, my Jupiter just
returned from TT
with the grounding reinforcement still installed, I was insured that the
installation could
only help and in no way would damage the rig. I can tell you this, if
they didn't like it
they would have removed it.
4. Your station should incorporate what is called a single point ground
source. In my case
the last piece of equipment in my chain is the antenna tuner. From the
antenna tuner
grounding lug. From the grounding lug there is a small length of 14ga
wire running to a
TT 1251 RF Counterpoise Tuner. From the tuner to outdoors there is a
length of 14ga wire
running to what is called a common tie point for .15 wavelength pieces of
14ga wire for
every band that I operate on. These pieces of wire are buried 1" below
the grass level. At
the ends of each wire is soldered a 2' piece of 1/2" copper pipe that is
driven into the
ground below grass level. When tuning up the TT 1251 is adjusted for
maximum current
as shown on the TT 1251 Tuner meter. This type of installation will not
only rid you
station of any RF but when adjusted properly will add 3DB to 6DB of gain
to the antenna
you are presently running. (ref. ON4UN "Low Band DXing) It works!!
5. If you can measure any resistance from the grounding lug on the rear of
the rig to the
ground pin on the mic jack you have a path for RF to sneak in.
Some hams have returned their rigs back to TT because they couldn't get rid
of the RFI, that was a big mistake on their part.
The Orion and Jupiter rigs are "Computers in an RF Environment". Proper
grounding is key
to trouble free operation.
Happy Holidays
73
John / N0KHQ / St. Louis
Always on 17M
Antennas:
You can build 'em better than you can buy 'em.
Visit: http://www.hamuniverse.com/antennas.html
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