Description
of LP-PAN system
LP-PAN 2 is a fixed frequency Software Defined Radio. It is tuned to
the
IF frequency of your radio, and is capable of receiving signals within
about +/- 100kHz of the frequency that your rig is tuned to. LP-PAN 2
is
basically a wideband direct conversion receiver which converts the IF
output of the radio to two wideband audio signals which differ only in
that there is a 90 degree phase difference between the channels at all
frequencies. These signals are interfaced to the SDR application using
a high quality sound card. Almost all of the functionality is provided
by the software application, with the outputs being the screen display
and sound card speakers (headphones).
The
various software packages provide a spectrum display, waterfall display
and often the ability
to demodulate signals using the standard modes of AM, FM, SSB, CW, etc.
The software usually provides DSP filters, noise blankers, noise
reduction and notch filtering. It also provides linking to some of the
rig's controls, like VFOs, mode and filter width. For modern radios
like the K3 and FTdx5000, the user may choose only to use the visual
aspects of the SDR app, since the rig already has extensive DSP
capability. For users with radios like older Kenwoods or FT-950, the
user may want to take advantage of the DSP controls in the SDR, which
rival any DSP based radio.
For this tutorial, we will assume that
the user is using the following popular components...
LP-PAN or LP-PAN 2
K3 or FTdx3000/5000
Asus Xonar U7 USB sound card
NaP3 v4.0 software
Most of the info provided can be applied to other hardware or software,
although the cabling and the software entry screens may be somewhat
different.
Connecting LP-PAN to your rig and PC...
Basic interconnection information can be found on the LP-PAN Hardware Installation page.
Installing a sound card...
Asus U7 sound card installation info can be found here, Asus U7 Installation. Refer
to the LP-PAN Sound Card page
for a discussion sound card recommendations and test results.
Installation and Operation of NaP3...
There are several main apps which we recommend...
The
best SDR application is NaP3, developed by Pete Connors, F5VNB. It is
based on WU2X's version of the FlexRadio Systems PowerSDRTM software, but includes some unique
features developed by Pete, and can even display telnet spots in the
pan window from popular web clusters or from CW Skimmer. Here is the link to our NaP3 installation
page.
What are LP-Bridge and LPB2, and when
should I use them?
LP-Bridge and LPB2 are special programs which provide several important
functions. They provide a method of sharing rig coms with an SDR app
and up to five other programs at the same time, like loggers, PSK apps,
CW Skimmer, etc. They also provide buffering of the coms to reduce rig
traffic and eliminate packet collisions from multiple simultaneous
polling requests. Additionally, they provide frequency data for
hardware such as SteppIR controllers and amplifiers, and serve as a
control center for all the applications that need to talk to the rig.
LP-Bridge is designed for K3, while LPB2 works with K2, K3, Kenwood and
recent Yaesu radios (starting with FT-2000). LP-Bridge has slightly
more capability, but for most users the two perform similar functions.
Here are links to the setup and installation web pages for the two
programs...
LP-Bridge
Installation, Setup and Operation
(for sharing of K3 with multiple
apps)
LPB2
Installation, Setup and Operation
(for sharing of K2, K3, Yaesu,
Kenwood with multiple apps)
CW Skimmer...
Another SDR based
application that
many users run with LP-PAN is CW Skimmer from Alex, VE3NEA. This
program can be run at the same time as NaP3 or separately. of the
above SDR apps using
LP-Bridge or LPB2 to tie things together. Installation and operation
details can be found on Alex's website. For configuration tips for sharing CW
Skimmer with another SDR, go to our CW Skimmer
configuration page.
Basic Troubleshooting
Problem
|
Suggested solution
|
Display shows noise but no signals
|
Check audio and RF cabling.
Make sure the correct
sound card and driver are selected in NaP3.
|
There are two sets of signals that move in
opposite directions as I tune, ie. there is no image rejection.
|
Check that you are getting audio from both
I & Q channel.
Check sound card settings
Check cabling
Read the section titled Eliminating
Images for a more detailed explanation of
the causes and cures of images.
|
The audio in the SDR app drops out
frequently,
or "motorboats"
|
Read the excellent paper Vista
Tuning for LP-PAN.pdf written by
Dave, W8FGU. It is useful for all Windows versions.
Increase the latency setting in NaP3's audio setup.
|
The sidebands are reversed when I listen
to NaP3 output.
|
Check your audio cabling. If you are using
color coded audio cables, the red cable should connect to the Left (I)
input of LP-PAN, and white to the Right (Q) input. You can also reverse
sidebands by clicking the "Swap IQ" checkbox on the Input tab in NaP3.
|
There is a “hump” or “hole” in the noise
floor near the center of the display.
|
Check your cabling for a loose connection
Check the Bal/Unbal switch on the back of LP-PAN, or the BAL-UNBAL
jumpers on LP-PAN 2.
Check for power supply ground differences between radio and LP-PAN.
Could be the result of using non recommended sound card
Could be an anomaly of the rig's IF output (poor filter matching in
an older Kenwood, for instance).
|
The signal's frequency in the display does
not match the rig frequency.
|
Perform the IF Frequency offset
adjustments for your rig as shown on the NaP3 Help page. Make sure your
settings match the pictures, except for the Global
Offset which will vary slightly from rig to rig. Adjust Global Offset
to sync
the display with your rig in AM mode if necessary.
Also, make sure I and Q are not swapped.
|
I get a big red X in the pan display
window.
|
This is generally caused by a bug in NaP3
v4.0. In Setup, in the Display tab under "Band Plan", make sure that
the IARU region is set to Region 1 (even if you're not in region 1).
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Many
of the problems associated with the software have to do with wrong or
corrupt entries in the database files for PowerSDR/IF or NaP3. To
understand how to address problems and correct them, it helps to know
what files are created when the programs are installed, and where they
are
stored.
NaP3
The main installation
folder can be found
in this folder…
C:\Program
Files\NaP3
The files in the folder include the
program (NaP3.exe), a help file and supporting files. Because of the
UAC user
account rules in Vista / Windows 7, NaP3 does not save the
database files for preferences and settings in this folder, but rather
in one of the following AppData (or Application Data) folders…
The
folder contains a preferences file, called NaP3.xml. This file contains
all the settings
from the SETUP section of the program, and other parameters such as
WBIR seed values, band stack data, etc. Another file called wisdom is
also stored here. This file is created when you first start NaP3 and it
calculates the forward and reverse FFTs.
The
files can be found in the following paths
based on your OS, substituting
your user name for the name Larry ...
XP
C:\Documents and
Settings\Larry\Application Data\NaP3\NaP3.xml
Vista & Win7
C:\Users\Larry\AppData\Roaming\NaP3\NaP3.xml
With Vista and
Windows 7 you can also
enter the following shorthand
in Windows
Explorer, %username%\AppData\Roaming\NaP3
to quickly navigate to the file. This shortcut should be entered
exactly as typed here.
It is probably
smart to create a
shortcut to the appropriate folder for your OS, so that you can easily
navigate to these folders in the event that your settings become
damaged. It also makes sense to save a backup of the two database files
to another folder somewhere.
If it becomes
necessary to start
over, here is the procedure I would use to uninstall / reinstall NaP3…
Uninstall all
versions of NaP3
on your computer using “Add / Remove Programs” or “Programs and
Features” in the Control Panels folder. The one to use depends on your
OS. I would also delete the NaP3 installation folders in Program
Files after uninstalling, and remove the NaP3 folder in the
AppData folder. This removes the database files where NaP3
stores your user preferences and settings. The exact path will depend
on your OS and whether you chose "Just Me" or "Everyone" when
installing NaP3. If you chose "Everyone", and log in with more
than one username, you will have to delete the AppData database files
for each user, or for "All Users". We recommend using the "Just Me"
option.
You
will need to substitute your
username for "Larry" in the examples. Once you have removed all the
NaP3 remnants, NaP3 should install as though it was on a
virgin computer. You will need to re-enter all your settings unless you
have previously saved a backup of the files.
PowerSDR/IF
The
main installation folder can be found in this folder…
C:\Program Files\PowerSDR-IF Stage
v1.19.3.5
The files in the folder include the
program (PowerSDR.exe) and supporting files. Because of the UAC user
account rules in Vista / Windows 7, PowerSDR-IF does not save the
database files for preferences and settings in this folder, but rather
in one of the following AppData (or Application Data) folders…
XP
C:\Documents and
Settings\Larry\Application Data\PowerSDR IF-Stage v1.19.3
Vista & Win7
C:\Users\Larry\AppData\Roaming\PowerSDR
IF-Stage v1.19.3
(substitute your username for “Larry”)
The main files are called
database.xml and databaseIF.xml. These files contain all the settings
from the SETUP and SETUP IF sections of the proogram, respectively.
It is probably smart to create a
shortcut to the appropriate folder for your OS, so that you can easily
navigate to these folders in the event that your settings become
damaged. It also makes sense to save a backup of the two database files
to another folder somewhere.
If it becomes necessary to start
over, here is the procedure I would use to uninstall / reinstall
PowerSDR-IF…
Uninstall all versions of PowerSDR-IF
on your computer using “Add / Remove Programs” or “Programs and
Features” in the Control Panels folder. The one to use depends on your
OS. I would also delete the PowerSDR-IF installation folders in Program
Files after uninstalling, and remove the PowerSDR-IF folder in the
AppData folder. This removes the database files where PowerSDR-IF
stores your user preferences and settings. The exact path will depend
on your OS and whether you chose "Just Me" or "Everyone" when
installing PowerSDR-IF. If you chose "Everyone", and log in with more
than one username, you will have to delete the AppData database files
for each user.
You will need to substitute your
username for "Larry" in the examples. Once you have removed all the
PowerSDR-IF remnants, PowerSDR-IF should install as though it was on a
virgin computer. You will need to re-enter all your settings unless you
have previously saved backups of the database.xml and databaseIF.xml
files.
Support is
also available directly from TelePost through at n8lp@telepostinc.com
anytime or telephone at 734-455-3716 during normal business hours.
There is also a Yahoo User Group at
http://groups.yahoo.com/group/LP-PAN/ with a large number of helpful
users.