Skip I understand you frustration with the Orion.
My frustration with SDR's began with the purchase of the Jupiter about 3
years ago.
I know you probably don't want to hear this, but, these rigs are very
susceptible to RFI. If there is any...and I mean any, stray RF in your shack
the
Orion or the Jupiter will find it.
First off, the Orion, like the Jupiter, is nothing more than a computer in
an RF environment inside a transceiver case.
Special RF Grounding and Power Supply precautions must be taken in order for
the Orion or Jupiter to perform without incident. I know what your going to
say, "hey, I never had any problems with my other rigs". Well, your other
rigs were not SDR's.
A lot of hams have jumped into the SDR arena without thinking, like myself,
about what they were getting themselves into. SDR's are the next step in the
evolution of ham radio transceivers. By the peak of the next solar cycle you
will see one of the other leading manufacturers of ham radio transceivers
come out with an SDR. It could be Icom, they are in the early stages with the
introduction of the IC-7800.
All of the top rigs out today, TS-870, TS-950SDX, FT9000DX, IC-7800 and so
on will be referred to as "Boat Anchors", just like we refer to the tube type
rigs of yesterday as "Boat Anchors". I know all of these rigs work great, but
there is a time when a product must evolve to the next step. And, SDR's are
the next evolutionary step in Amateur Radio. Whether you, I, or anyone else
likes it or not......its coming.
If your dead set on getting rid of the Orion, don't waste your time reading
any further. However, if your willing to give it one more shot......keep
reading.
Firstly, when you hear or read about an Orion owner praising the operation
of their rig, they are not trying to blow smoke up your butt. It's true, the
Orion is a great rig, and in my opinion, the best rig on the market today in
any price range.
So, here we go! Please follow these instruction exactly.
1. If your running a balanced antenna, purchase a 1:1 50ohm Bal to 50ohm
Unbal current balun from Radio Works (B1-2K) and install it at the antenna
feed
point. This balun will prevent antenna currents from coming down the shield
of the coax and entering you station and at the same time allow for a graceful
transition from a balanced system to an unbalanced system.
2. If your running an unbalanced antenna, purchase an RF Balun kit from
Polomar-Engineering and install it at the antenna feed point. For reasons
above.
3. Purchase from Radio Works a T-4 Line Isolator. This isolator will install
right at the back of the coax connector/s on the Orion. This is a must do.
4. The power for your Orion, I assume, is coming from a DC Power Supply that
is plugged into a 115vac circuit. This circuit should be a dedicated circuit
and not shared with other appliances in your home. Appliances in your home,
depending on their load impedance's are dumping reactive currents onto your
service neutrals and grounds. The currents are in the milliamp range and could
create havoc in your power supply depending on how well your power supply is
capable of filtering the incoming AC.
5. What I do is, the DC power cable going from the power supply to the Orion
is wrapped around a 2-1/2" toriod donut, 6 turns one direction and 6 turns
the opposite and other direction.
6. One of the biggest culprits is the Orion amplifier keying line. This line
should be wrapped around one of those 3/4" x 3/4" x 1-1/4" toriod cubes as
many times as possible. RS sells them.
7. Now heres a subject that you may or may not have a problem with: RF
Grounding.
Some hams get a little confused when talking about Grounding for RF and
Grounding for Lightning protection. They are not the same and should be
addressed
separately. Grounding for Lightning protection will do very little for RF
grounding. But Grounding for RF will help with Lightning protection.
Most ham radio books illustrate a typical station grounding system, where
you have this big copper plate or bar behind your station and every piece of
your equipment is supposed to be grounded to this bar and then a wire runs from
this bar outdoors to a grounding rod. This illustration is 100% totally wrong
and does result in the biggest ground loop in the history of Amateur Radio.
See Part 2 for continuation.
73
John / N0KHQ / St. Louis
Always on 18.130
Antennas:
You can build 'em better than you can buy 'em
Please visit the sites below:
_http://www.hamuniverse.com/antennas.html_ (http://www.hamuniverse.com/)
_http://www.cebik.com/n0khq.html_ (http://cebik.com/nokhq/html)
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