Description of LP-PAN system

LP-PAN 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 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. This is largely due to the fact that a couple of the SDR apps are based on the open source FlexRadio Systems PowerSDR^TM  software.


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...

Refer to the LP-PAN Sound Card page for a discussion of sound cards, recommendations, and links to help setting up and configuring the recommended sound cards.


Installation and Operation of an SDR application...

There are several main apps which we recommend...

1. The newest entry and the one most people use is NaP3 by Pete, F5VNB. It is based onWU2X's version of the FlexRadio Systems PowerSDR^TM software, but includes some unique features developed by Pete. The feature set includes the best features of both of the above programs, plus a "fixed" mode. This allows the user to select a section of the band to display, then allows tuning both the VFO A and VFO B cursors over the display without the band segment changing. It also provides extremely high resolution when zoomed in, like TRX-Pan, which makes it quite usable for tuning digital modes like RTTY and PSK. Installation and operation details for NaP3 can be found on our NaP3 setup page.

2.The first really good SDR for panadapter use was Scott, WU2X's version of FlexRadio Systems PowerSDR^TM.  His version, 1.19.3.5, has been around for a number of years, but hasn't been updated in awhile. NaP3 is based largely on Scott's work, though. nstallation and operation details for PowerSDR/IF can be found on the PowerSDR/IF setup page.

3. Another program worth looking at is TRX-Pan from Laurent, F6DEX. It does not provide an audio output of the tuned signal, but has some very nice graphic display features for users of rigs like K3 and FTdx5000 who don't need audio output. Larry, N8LP is a software contributor to this program as well. It is less cluttered and easier to configure than the PowerSDR^TM based SDRs. TRX-Pan requires either TRX-Manager or LP-Bridge running as the rig interface. Installation and operation details for TRX-Pan can be found on our TRX-Pan setup page.

4. 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 one 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.

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)


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 the SDR app.
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 channels. 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	Increase audio buffer size to 2048 or 4096. 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 the SDR app's audio setup.
When I start PowerSDR, the audio “motorboats”.	Increase the latency setting in the SDR app's audio setup. Recommended settings are 2-10ms for ASIO driver, and 25ms or more for MME driver.
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 Check the "ground lift" jumpers in LP-PAN Check the ground lift jumpers on your sound card (they should both be in lift position for E-MU 0202/0204) 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 older Kenwood, for instance).
The signal's frequency in the display does not match the rig frequency.	Perform the IF Frequency offset adjustments in SDR app per the procedure in it's Calibration section. Make sure your settings match the pictures, except for the Global Offset which will vary from rig to rig. Adjust Global Offset to sync the display with your rig.
I don’t see my sound card listed under the available sound cards in the Audio Input / Output selector.	Check that your sound card is properly installed. You can do this in Device Manager. It is wise not to make your LP-PAN sound card the Windows default. Update your sound card’s driver to the latest available from the manufacturer’s website. If your sound card is USB, it is usually recommended to use a USB 2.0 port. Use of a USB router for a sound card is not recommended. Try all available drivers in the Drivers selection box for your SDR app. ASIO is the preferred driver if available, followed by MME.
E-MU Sound card will only work at 48 kHz.	Make sure your USB ports are 2.0. The E-MU 0202/0204 defaults to 48 kHz with USB 1.1 ports. Turn off E-MU and turn it back on. Use E-MU control panel to set a new sampling rate.
I can’t get the rig to go to VHF bands when connected to PowerSDR.	Go to IF Frequencies tab in your SDR's applicable Setup page and set Frequency Limits Max to the highest frequency you use.
I can’t connect to my rig.	Make sure that “SDR-1000” is selected as the radio model in the Setup>General>Hardware Config tab if you're using PowerSDR/IF. Make sure you have the correct rig type, com port and baud rate set in the Rig Connection tab for your SDR app. Make sure that the baud rate in the rig is set to match the baud rate set in the SDR app. Make sure that no other program is connected to your rig. Make sure that you didn’t accidentally set up the PowerSDR/IF CAT interface for the same com port as your rig if using PowerSDR/IF. If you're using a USB-to-serial adapter, make sure that Windows hasn't changed the port number. ALso, make sure you have the latest driver to match your OS. Make sure that the SDR app hasn't reverted to COM1 because your rig was off or LP-Bridge / LPB2 wasn't running when it was supposed to be.
Rig connection is erratic.	Make sure that polling isn't set too low. It should be in the 200-500ms range. If you are using a USB-to-serial adapter, make sure you have the correct driver. In general, adapters with FTDI chipsets are preferable to ones with Prolific chipsets.

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.