Half size picture showing PowerSDR, TRX-Manager, CW Skimmer and N1MM all connected to my K3 through LP-Bridge. Sound card is Infrasonic Quartet and feeds both PowerSDR and Skimmer at the same time. Serial connection is through microHam MK2. My PC is a 3-year old Dell WS360 with 2.8GHz P4, 1.5GB RAM and separate inexpensive video card. This PC has very low latency for its age, and I get no audio dropouts or slowdowns, but this system is just about maxed out. If you plan to run all these applications with LP-PAN, especially if you use a USB sound card, I recommend a dual core machine. Without CW Skimmer, the requirements are considerably relaxed. Also, the sub receiver adds about 10-15% load to the CPU when turned on.

     

             Top and rear views of first production unit.










Reviews:
 
 Visit eHam.net Product Review page for LP-PAN.

February 2009 QST Product Review of LP-PAN.
 
Reprinted with permission of ARRL.


Ordering:

Due to the huge number of orders placed at Dayton, there will be a delay of about a week for new kit orders, and 2 weeks for new assembled orders, placed after 5-18-09.

Important reading before ordering:
Hundreds of users are successfully using LP-PAN and its associated software, and they love it. BUT, this is one product where reading the manual is essential. We also recommend reading the Sound Card page. That page also has links to some of the recommended sound cards for specific installation and setup info. The PowerSDR software can be confusing unless you familiarize yourself with it first. Familiarity with installing and configuring software is highly desirable, especially if you run Vista. Installation of LP-Bridge is straightforward, even though it is a powerful application and provides a unique integration of rig, panadapter, loggers, etc. You can install and set up all the software before ordering if you are concerned about the complexity involved. Just use some audio source, like the output of the K3 or an iPod or something to check it out. The display will be limited to the spectrum of the sound source, but all other aspects of the software suite will work normally.

In general, setting up LP-PAN is similar in complexity to setting up a FlexRadio SDR-1000, much easier than building and setting up a SoftRock, but not nearly as easy as plugging in a DMU. On the other hand, the results are amazing and well worth the effort. Both email and phone support are available from TelePost, as well as the LP-PAN User Group.

Updates: Latest news about LP-PAN

Manuals:
Note: Older manuals should only be used for assembly of older kits. Once finished, the current manual should be used for setup and operation.

Manual for serial numbers 1-207

Manual for serial numbers 208 -308

Manual for serial numbers 309 - 513

Current manual for serial numbers 514 -

Current High Resolution schematic


Software downloads (free):

PowerSDR-IF Stage . PowerSDR-IF Stage provides the panadapter and computer control of frequency, band, mute, mode and more. The PowerSDR link takes you to the website of Scott, WU2X, who did the programming on the IF Stage sub-version of PowerSDR.

PowerSDR-IQ Beta Page. Under development. Adds a number of supported links between the K3 and PowerSDR, including VFO B, Split (sub-rcvr tuning), Preamp and CW Pitch.

LP-Bridge LP-Bridge web page. LP-Bridge provides the linking between PowerSDR-IF Stage and the K3 for mode, band, frequency, IF offset, mute and more. It also provides a way to easily share multiple applications, like loggers, CW Skimmer, PSK programs, etc. with the K3 and PowerSDR. All applications have access to the K3 independently and concurrently. LP-Bridge currently only supports the K3, but will support Kenwood and K2 in the near future. For other rigs, use HRD or N4PY as noted below.

Ham Radio Deluxe (HRD) provides limited linking (mode and frequency) between PowerSDR-IF Stage and rigs other than K3.

Refer to the latest LP-PAN manual for the latest installation and configuration information. Also, for those of you who currently use N4PY software with an Orion or other rig, Carl has expanded his software to provide linking to LP-Bridge. Carl's website is here. (N4PY software is not free.)


Useful Links:

LP-PAN FAQ Important reading to address just what the LP-PAN can and can't do.

LP-PAN User Group Join for latest news, feedback, support, etc. This is the preferred place to post questions and comments on LP-PAN. Please limit use of the Elecraft reflector for LP-PAN specific questions.

System Requirements Recommended minimum PC hardware configurations.

Sound Card Info Please read before deciding on a sound card.

K3 Buffer Mod Simple mod that improves noise floor of panadapter display by reducing loss in the K3 IF output. Not required, but some users have found it well worth the effort. The link takes you the Files section of the LP-PAN User Group.

Z10000 buffer kit from Clifton Laboratories (Jack, K8ZOA) to add an IF port to the K2 or Orion. You will find detailed K2 installation information in the Z10000 manual. In addition, VE7TK has posted this paper on Orion installation. HRD and N4PY software supports Orion and LP-PAN. K2 will be fully supported in LP-Bridge soon, but currently can be controlled using HRD.


General Information:

LP-PAN is a software defined IQ direct conversion receiver with integrated SDR application to provide a high quality panadapter to rigs with IF output jacks. The unit uses a combination of SMT and through-hole technology, a custom aluminum case with powder coated finish and silk-screening. Pricing for an assembled and tested unit is $225 plus shipping, and a kit is available for $175 with SMT parts pre-installed. The kit takes an average builder about 2 hours to complete, plus another few minutes to adjust the front end filter. LP-PAN is aimed at the Elecraft K3, but can also be used with many earlier Kenwoods with IF output jacks, as well as TenTec Orion and Elecraft K2 whe modified to bring out the IF signal.

Here is a list of current features...

* Crystal controlled local oscillator for low phase noise.
* Up to 192 kHz display on PC, sound card dependent
* Switching quadrature detector for high dynamic range
* Strong buffer amp with very high LO isolation to protect K3.
* Ground isolated inputs / outputs with mil spec audio output xfmrs
* Fully balanced architecture with balanced and unbalanced outputs
* Jumperable ground lift on RF input and audio outputs
* Point and click frequency control with PowerSDR / IF Stage and LP-Bridge or HRD . In addition, LP-Bridge allows sharing of K3/LP-PAN with almost any logger, PSK program, CW-Skimmer, etc.
* Useable with many other SDR programs.
* Powder coated aluminum enclosure with silk screened graphics.
* Hardware or software mute
* Available for the following IF frequencies...
    8.215 MHz (Elecraft K3)
    8.83 MHz (most older Kenwoods)
    9.00 MHz (TenTec Orion)
    4.915 MHz (Elecraft K2)
    10.7 MHz (IC-R8500/9500 and others)

Orion & K2 require hardware modification to add an IF output port. IC-R8500/9500 require the addition of a blocking cap in the RF cable to LP-PAN.

Here are current specifications (sound card dependent). Note: Measurements represent the composite results of K3 / LP-PAN. Standalone LP-PAN performance is better.

*  Approx. -125dBm MDS with K3 preamp on (about 8dB better with K3 buffer mod installed).
* +2dBm maximum input with K3 attenuator on
* ~105 to 115dBm dynamic range, depending on sound card
* >100dB image rejection with PowerSDR-IQ, ~60dB image rejection with PowerSDR-IF
* Greater than +20dBm IP3 @ -15dBm, 2kHz to 20kHz spacing (composite value for K3/LP-PAN combo)
* ~90dB IMD DR @ -35dBm, 2kHz to 20kHz spacing (composite value for K3/LP-PAN combo)
* THD ~ 0.005%
* 600 ohm output Z, balanced or unbalanced.
* +2dBV (1.27 Vrms, 3.6V p-p)  nominal output level at recommended maximum RF input
* Adjustable gain to interface almost any sound card
* 6 kHz L.O. offset to allow use with older sound cards
* 11-16 VDC @ 55 mA

Note: Specifications dependent on sound card, and subject to change. Cited values were taken with an E-MU 0202 USB sound card. All measurements also apply to M-Audio Audiophile 2496 PCI or FW cards (limited only by 96 kHz display width), the Infrasonic Quartet and E-MU 1212m PCI sound card. Measurement details are included in the Performance section below. PowerSDR^TM  is an open source application for use with IQ based software defined radios, and is a trademark of FlexRadio Systems.


Hardware:

LP-PAN consists of a multipole bandpass filter, followed by a strong buffer amplifier with high isolation, followed by a balanced switching mixer. The output of the mixer is fed to two pairs of balanced low noise op-amps with ultra wideband 600 ohm output transformers for flexibility in sound card interfacing.  I have also tried to maximize interfacing flexibility with the sound card, to minimize hum and noise issues there. The devil is in the details, and that is where I have concentrated my efforts to make LP-PAN the best integrated panadapter solution for use with K3.


Software:

LP-PAN can be used with most SDR decoding applications, like PowerSDR^TM, Rocky, SpectraVue, Spectrum Lab, etc. With PowerSDR^TM and LP-Bridge, point and click frequency tuning is available, thanks to Scott, WU2X's customized version of PowerSDR called PowerSDR/IF Stage (http://www.wu2x.com/sdr.html#powersdr). LP-PAN will also work with other programs which will decode an audio IQ signal, like the nifty CW Skimmer from Alex, VE3NEA. The pictures in the performance section below are taken from PowerSDR^TM.


LP-PAN allows you to use your PC / sound card as a second receiver with lots of nice features if you use the PowerSDR^TM app. Shown above is split operation using the main and sub receivers in PowerSDR. VFO A (green) from the K3 is linked to the main receiver in PowerSDR, and VFO B (blue) is linked to the sub receiver. The K3 doesn't need the KRX3 2nd receiver option. PowerSDR provides both receivers. PowerSDR^TM has lots of flexibility in terms of modes, bandwidths, interference reduction tools, etc. I find listening to SW broadcasts with the synchronous AM detector very nice.

Performance:

Note: All test results were obtained using an E-MU 0202 USB sound card. Similar results can also be obtained with the E-MU 1212m or 1616m PCI cards, or the Infrasonic Quartet PCI card. At up to 96 kHz, the M-Audio Firewire Audiophile card (discontinued but available on eBay) or E-MU 2496 PCI card will also produce similar results. Except for the 1616m, these cards are all priced in the $90-150 range.

Performance is a composite of LP-PAN / K3 system unless otherwise noted.

Usable Dynamic Range:

When connected to the K3, LP-PAN provides up to 115dB dynamic range between noise floor and clipping, depending on sound card. Below is an example of LP-PAN working with PowerSDR^TM. There is no higher order distortion visible at a level of -20dBm (~ S9 + 53dB) from my HP-8640B signal generator at this bandwidth setting. 2nd harmonic, not shown, is about 80dB down. Increasing the level to -10 dBm (~ S9 + 63dB), about 5 dB before clipping, a couple small distortion products appear about 10-15 dB above the noise floor. The average noise floor is about -120 dBm (~0.2uV for 10dB S/N) in this setup. This test was run with the K3 preamp OFF. Noise floor with the preamp ON is about 10dB better. The smaller blip is the image, which is 70dB down.

Image Rejection:

The one parameter that is difficult to maintain over a wide bandwidth (2.5% in the case of the K3) is image rejection. There are a number of reasons for this, and greatly improving it would be beyond the scope (and cost) of this project, I think. Some SDR apps, like PowerSDR-IQ from SV1EIA, Rocky and M0KGK's KGKSDR, provide automatic gain/phase balance tracking... but this is not the case with PowerSDR-IF,  which only allows for manually optimizing of the balance at one frequency. Scott is looking into adding automatic image nulling to his version of PowerSDR-IF. This would be a welcome development, but even without it, image rejection is excellent with LP-PAN, especially over a 96 kHz display..

The above display shows typical image rejection, and this level can be expected over most of the 180 kHz+ display. Here is a summary of measured image rejection...

PowerSDR-IF, varies from 55-70dB over 192kHz, >60dB over 96 kHz span.
Rocky, 90-100dB over 96kHz span
PowerSDR-IQ, >100dB at all frequencies

Image rejection is partly affected by the input impedance flatness of the sound card used.

Rocky doesn't support 192kHz sampling. Image rejection is somewhat dependent on the input impedance of the sound card, which is why the output impedance of LP-PAN was intentionally kept low (600 ohms). I have added a load balance pot to optimize image rejection with different sound cards. Here is a picture of the gain/phase balance measurement screen in Rocky over a 96kHz bandwidth. This shows LP-PAN has ~ 0.5 degree phase variation, and ~ 0.5% gain variation over the entire display bandwidth. This accounts for the excellent image rejection numbers I'm getting.


These image rejection numbers indicate that an S9+20-30 dB signal will have no visible image on the display. In practice, tuning around the bands, I don't see any images on anything but very strong SW BC stations. In fact, the strongest signal I have seen so far is less than -20dBm (S9 + 53dB) on 40m at night. Most strong signals are in the range of -40dBm (S9 + 33dB). 

I am working with Christos, SV1EIA to fullt integrate LP-Bridge with PowerSDR-IQ, which will completely eliminate image rejection as an issue with LP-PAN.


Blocking Dynamic range (BDR):


I wanted to make sure that the K3 was the limiting factor when used with LP-PAN, at least up to the maximum signal level of LP-PAN, which is +2dBm (S9+75dB). Above that level, the combination of the K3 roofing filters and hardware AGC add another 30dB of dynamic range under most conditions, making it the best rig on the market in that regard. Luckily, the user will likely never see a signal that large, and the +2dBm maximum signal handling of LP-PAN will not be taxed unless you are in a multi-multi contest station or in Europe next to a large broadcasting station.

To test the BDR performance of the LP-PAN / PowerSDR^TM combo, I set up the following test...

I fed a strong signal (S9+50dB) to the K3 using a homebrew xtal oscillator which has very low phase noise. 2kHz away I mixed in a 3uV signal from my HP-8640B signal generator using a hybrid combiner. The widening of the base of the signal from the xtal oscillator is due to the phase noise of the K3. I purposely used a xtal local oscillator for LP-PAN to minimize phase noise degradation. The 3uV signal in this case has about 10dB SNR, more than enough for solid copy. In practice, this situation would never occur since most transmitters are far noisier than my xtal generator, and the transmitter noise would bury any weak signal 2 kHz away. Receiver design has clearly advanced to the point where it far exceeds transmitter design.


IMD Dynamic Range:

Here is a comparison of IMD DR with the standalone LP-PAN, and through the K3. The setup is the same as the one for the BDR test above, except that both the xtal oscillator and the HP-8640B are set to the same level. Signal levels are -33dBm (S9 + 40dB), and signal spacing is an amazing 500Hz! The slightly wider signal on the left is the HP, but it's still excellent phase noise performance compared to today's synthesized generators, and stands up well against the xtal oscillator. As you can see in the top picture for the standalone LP-PAN, IMD DR is >90dB, with no extraneous distortion products. Quite amazing for this bandwidth.

The bottom picture was taken with the K3 in line, with the K3 preamp Off. You can readily see the effect of the K3 phase noise by comparison. Reciprocal mixing with the K3 synthesizer noise sidebands produces a noise hump around the signals. This is actually excellent performance for a synthesizer, but clearly degrades close-in dynamic range. We have also picked up some minor blips.

         
L.O. leakage / isolation:

Because LP-PAN connects to an unprotected IF port on the radio, it is important that any LO leakage in the rig's passband be very low. This is something I spent a lot of time on in design and testing. As a result, the measured LO signal at the input of LP-PAN is -135dBm (~0.05uV).  Adding in an estimated 20dB+ isolation for the buffer in the K3, this should be a more than adequate amount of isolation to prevent any issues with the K3. In my initial testing, I have not been able to detect LP-PAN's LO in my K3, confirming that the leakage is below the noise floor of the K3. For comparison, the LO leakage of a couple SoftRock receivers that Jack, K8ZOA and I checked, measured about -40dBm (S9+33dB)... almost 100dB higher than the buffered LP-PAN.

I also added more filtering to the input of LP-PAN to filter out the numerous spurious signals I found in the K3 IF output once I got my rig. These signals include LO leakage from the K3, plus harmonics and mixing products of them. The picture on the left shows the K3 IF output with one signal in the passband with about an 80 MHz span. The second picture shows the same conditions with my filter installed. In practice, I see a number of products sliding through the panadapter display as I tune without the filter, but none with it.

Here is the response of a breadboarded version of the filter. I could probably reduce the bandwidth, but at the expense of loss and ease of tuning.The K3 already has more loss than I would like from antenna jack to IF output, and I am being careful not to add to it.  I think this filter is appropriate for the application, and is more tolerant of component variations. I use variable caps and 2% precision SMD coils in the filter, and tuning  is just a simple matter of peaking the two variable caps.

Audio Interfacing:

To minimize installation problems, I added transformer coupling of the IF port and mil spec audio xfmrs, all with "ground lift" jumpers to minimize hum and noise in the audio interface. Audio output is 600 ohms to allow driving any sound card, and one channel has an adjustable load to balance out any termination variations in the sound card / cabling. This level of detail is required to acheive the image rejection that I am able to get, which rivals a superhet with xtal filtering when carefully adjusted. The outputs can also be used in either balanced or unbalanced mode for further isolation when a professional sound card with balanced inputs is available. As the PowerSDR screen shots show, there are no spurious hum or noise signals from the audio interface in my installation... even at the 0 Hz center frequency.


Using LP-PAN as a spectrum analyzer:

One of the more useful pieces of test equipment for ham use, but also one of the more expensive, is a spectrum analyzer. An example of a good use of LP-PAN in this regard is a project I worked on recently. I was asked by the FDIM organizers to build and test their 2008 Buildathon project, a 10W QRP amplifier for CW/SSB. I have a Tektronix 7L13 spectrum analyzer, and normally use this for testing spurious emissions like harmonic suppression and IMD. The Tek works great for checking harmonics, and IMD with fairly wide tone spacing, but is not so good at displaying IMD with 1200 Hz tone spacing as is commonly used to check SSB amplifiers.

Below are displays from the Tek with tones spaced 20 kHz, and LP-PAN with tones spaced 1200 Hz. You can see where the resolution bandwidth of LP-PAN/PowerSDR is quite welcome. The same would hold true for other decoding applications like SpectrumLab or SpectraVue. The panadapter display could actually be zoomed in much more if needed These pictures were not taken under the same conditions of drive level, so cannot be compared directly, but you can see the similarities. Looking at 20 kHz spaced tones on LP-PAN results in traces that are thin vertical lines because of the enhanced resolution bandwidth.


If the transmitter output is attenuated to about -20dBm, the distortion of the K3 and LP-PAN can essentially be ignored, as it will be below the noise floor. This guarantees that the testing hardware will not color the results. It still leaves at least 80dB of measuring range, which is comparable to a professional spectrum analyzer.

Note: All test results were obtained using an E-MU 0202 USB sound card. Similar results can also be obtained with the M-Audio  Firewire Audiophile card (96 kHz sampling) and E-MU 1212m PCI sound card (192 kHz sampling). Other cards are being tested.

Pricing and ordering...
Note: LP-PAN kits and assembled products are in stock for K3. For other rigs, please contact us to order.

Note: All prices in $USD. Standard US shipping charge is $10 for Fedex Ground or USPS Priority Mail - 2 to 4 days.

INTERNATIONAL:

A 1% currency exchange fee will be added to overseas orders, but PayPal generally provides a very good exchange rate. For overseas orders, custom orders or items not shown below, use the following guidelines,or email us for quote. Proper documentation is provided, including correct harmonized code to avoid duties where applicable. Customs documents require an accurate value, and usually copies of the invoice. Please don't ask us to falsify these documents!

Note to European users: For PowerSDR-IF Stage to work properly in most countries, you have to set the Regional and Language Settings in Windows so that they use US English numbering format (use of commas and periods in numbers reversed from normal European format). Most programs will use whatever format is selected, so hopefully this will not be a problem with other programs you have installed.

Canada, Mexico:
LP-PAN kit = $176.75USD
LP-PAN assembled = $227.25USD
USPS Priority Mail, 6-10 days, insured, trackable online... $19USD
USPS Express Mail, 5 days, insured, trackable online... $24USD

Europe:
LP-PAN kit = $176.75USD
LP-PAN assembled = $227.25USD
USPS Priority Mail, 6-10 days, insured, trackable online... $28USD
USPS Express Mail, 5 days, insured, trackable online... $36USD

Australia, New Zealand, Japan, Singapore, Hong Kong:
LP-PAN kit = $176.75USD
LP-PAN assembled = $227.25USD
USPS Priority Mail, 6-10 days, insured, trackable online... $29USD
USPS Express Mail, 5 days, insured, trackable online... $32USD

APO:
USPS Priority Mail. Use US Order buttons below (and thanks for your service).

Others: email us for quote.

In general, I recommend Express Mail. I have sent hundreds of LP-100s overseas using Express Mail and have never had a problem. Payment can be made at www.paypal.com. For PayPal address, credit card or other payment methods, email us.

NOTE: Before ordering, it is recommended that you read the manual and the FAQ. A working knowledge of computers is very desireable. Most users have had no unusual problems setting up the software, but PowerSDR can be a little tricky on some systems, especially for overseas users. Installing the latest drivers for your chosen sound card and your OS is essential to smooth operation. Studying the Sound Card page is recommended, as well as the Setup & Configuration page for your selected sound card. Reading the mail on the LP-PAN User Group can also be quite useful. With hundreds of LP-PAN systems in the field, there are plenty of users who can help if you run into problems. It is also possible to install and check out all the software before even ordering LP-PAN. Just use an audio source such as the output of the K3. The display will only show the center 3kHz of spectrum, and there will be no image rejection, but everything should work properly otherwise. Set the Global Offset adjustment in PowerSDR to zero for this test.


Price List for US Orders Only:
For orders outside US, please read above international ordering section.

For overseas orders, please see above international ordering section.
 
Payment can also be made by credit card at 734-455-3716, or regular mail at:

TelePost Inc.
49100 Pine Hill Dr.
Plymouth, MI 48170

NOTE: PayPal orders are processed immediately, even if shipment is a few weeks away. Credit card orders placed by phone won't be processed until shipment is imminent. 



Frequently Asked Questions

1. What is LP-PAN?

A direct conversion receiver with quadrature detector to provide I and Q audio signals for connection to a sound card. It is designed to receive a range of frequencies centered on ~8.215 MHz, the IF frequency of the K3. By using quadrature detection, a total bandwidth almost equal to the sampling rate is obtained, ie. 192 kHz sampling will give almost +/- 96 kHz tuning range, etc.


2. Does LP-PAN require a PC?

Yes. A PC and sound card are required to use LP-PAN. Suggested PC configurations are given above in the General Information section. They are similar to what would be required with any SDR type radio application. The software application does the IQ decoding and provides a spectrum display, second receiver, etc.. Other applications, like CW Skimmer provide other functionality. See Software section above.


3. Will LP-PAN work with a Mac or Linux?

LP-PAN depends on the use of an SDR application. There are a number of these around. The most popular is probably PowerSDR from FlexRadio, which is an open source application, but a quick search doesn't reveal a version for Mac. I don't know what options there are for a CAT interface / logging program using platforms other than Windows. You might consider Wine or Parallels or VMware, or using a dual boot configuration. Make sure your sound card is supported though, especially if it's Firewire based.


4. How does LP-PAN interface to the K3?

It connects to the IF output. You will need the KXV3 option for the K3. The K3 also needs to connect to a PC serial port to provide frequency data to the SDR application if you want the display to show actual tuned frequency. LP-Bridge will allow interfacing the K3 to LP-PAN and several other programs at the same time for full bi-directional serial control from all applications, without adverse interactions, and with very easy configuration in one simple program.


5. Can LP-PAN be used without a serial interface?

Yes. The program can be set up to display relative frequency referenced to an arbitrary center frequency, like 0kHz or 8.215 MHz. To use point and click tuning, or to display actual receive frequency, a serial port connection is required.


6. What software is required for point-and-click tuning with the K3?

This is available using the PowerSDR-IF Stage sub-version that Scott WU2X has written along with LP-Bridge or HRD (see discussion earlier on this web page in the Software section). LP-Bridge provides more features and linked parameters, but only works with the K3. Support for K2, Kenwood and FT-2000 will be provided shortly. HRD can be used or other rigs, with fewer supported features, but still provide frequency and mode linking.


7. Is LP-PAN sold as a kit or as an assembled unit?

LP-PAN is available both as a partial kit (with pre-installed SMD parts) or fully assembled unit. Kit builders will need to adjust the input bandpass filter, but I have designed the filters to allow this to be easily done. The resulting adjustment should provide a passband flatness of about 1dB. If the builder wants it better than that, he should buy the assembled unit, which is adjusted for maximum flatness using my HP VNA. I haven't seen any obvious advantage to factory tuning, but it could affect image rejection slightly I suppose.


8. What is required to connect LP-PAN to my K3 and PC?

A 50 ohm coax cable with BNC connectors to connect LP-PAN to the K3 IF output. For audio, a pair of balanced or unbalanced cables with 1/8" mono/stereo phone plugs on the LP-PAN end, and appropriate connector(s) / adapters on the sound card end is required, depending on the sound card. Also, a source of 11-16VDC @ 45mA. LP-PAN is supplied with a power cord with 2.5mm DC connector on one end and tinned leads on the other. It can easily be powered by the accessory 12VDC output of the K3. An RCA "PTT" type jack is provided for muting PowerSDR during transmit. This is only needed if you find that the software muting provided by LP-Bridge isn't fast enough for the modes you use. The Mute input requires a short to ground to mute, and no more than ~ 7VDC when not muted. For safety, an isolated relay or open source transistor driver is recommended.


9. What features does LP-PAN offer besides a spectrum display?

Spectrum/panadapter display is only one feature that can be used with LP-PAN. Features are application dependent, and vary from program to program. I have played mostly with Rocky and WU2X's IF version of PowerSDR so far. In addition to the panadapter display, I have used LP-PAN as a second receiver for SWL'ing. PowerSDR has a nifty synchronous AM detector that makes SW listening a pleasure. It can also decode digital voice modes and a host of other things. As a receiver, it performs very well. See the performance section above. I have also played a bit with VE3NEA's very clever CW Skimmer program, which allows you to see dozens of decoded CW signals at a time for a section of the band, and it displays callsigns and RST reports for all the stations, plus a decoded message section for the signal you are listening to.


10. Can LP-PAN share a sound card with other applications?

This can be done with the low cost VAC (Virtual Audio Cable) program, but there are a couple problems with this approach. One has to accept resampling of the audio signal and resultant artifacts. Another is that you may want to feed the K3's audio to the other applications instead of LP-PAN's audio. I recommend a dedicated new card for LP-PAN to get maximum bandwidth, resolution and overall performance. All of the recommended sound cards will allow feeding multiple applications with the same sound... for instance CW Skimmer at the same time as PowerSDR.

11. What sound cards give the best performance?

I have only found four good 192kHz cards, with a fourth promising card awaiting testing. The three are the Creative Labs E-MU 0202 external USB sound card, Infrasonic Quartet, E-MU 1212m PCI card pair and it's cousin the 1616m which uses one PCI card and an external interface. All provide 24-bit depth. The 0202 is under $100, the Quartet and 1212m are in the $140 range and the 1616m is quite a bit more expensive. All other cards I saw that claimed to be 192 kHz had problems, or only used that sampling rate for output (playing music, etc.). LP-PAN requires a card that also can "record" at 192 kHz. If you can be happy with a 90 kHz wide display, there are some good 24-bit/96kHz cards around. The M-Audio Audiophile 2496 PCI card works extremely well, and the popular Delta44 is good with one caveat. See the Sound Card Info page for more details. For Firewire interfaces, I have found two acceptable cards. The M-Audio Firewire Audiophile is excellent up to 96 kHz, and the Edirol FA-66 works well up to 192 kHz sampling, but usable display bandwidth is about 150 kHz. There is another caveat as well, and you can read about it on the Sound Card Info page as well.


12. Do I need to be a computer expert to get this all working?

No, but it helps! LP-Bridge is very easy to install and use, but PowerSDR is fairly complex, and then there is the issue of installing the sound card drivers, etc. It really helps to thoroughly read the manual in advance of ordering. It would also be a good idea to join the LP-PAN User Group and see what issues people are having getting their systems going. Most problems are Windows or driver related, but everyone seems to get through them with the help of user group members. Many users have no trouble at all.


13. Can LP-PAN be used with rigs other than K3?

I can provide an LP-PAN for 9MHz (Ten-Tec) or 8.83 MHz (Kenwood). The standard 8.215 MHz LP-PAN could work with some Yaesu rigs, but this would depend on the following conditions being met: From an RF standpoint, LP-PAN can be used with any rig that has an IF output port with a signal pick off point before any narrow band filtering. The IF also has to be in the HF range, generally 10 MHz or lower. For these reasons, rigs which use an upconverting design with a VHF 1st IF are generally not usable, even if an IF output port is added. Most of these designs have a 20-40 kHz wide "roofing" filter at the 1st IF, which limits the bandwidth available at later, lower IF frequencies. If your rig doesn't have these limitations, but requires the addition of an IF port, Jack Smith, K8ZOA makes a low cost buffer amp PCB available to facilitate this. His website is www.cliftonlaboratories.com.

From a control standpoint, you can control most rigs with a combination of Ham Radio Deluxe and PowerSDR-IF Stage. This will not allow multiple applications to control the K3 simultaneously as you can with LP-Bridge, however, or currently support all linked parameters. Currently, LP-Bridge only works with the K3... with K2, Kenwood (and possibly FT-2000) to come, but there are plans to support other rigs eventually. NEW: Carl, N4PY has modified his software to work with LP-Bridge to allow full support of all LP-Bridge functionality with TenTec Orion and Orion II.

14. Can I use LP-PAN / PowerSDR in countries other than US?

Yes, but you need to set your Regional Language settings so that US English style number format is used, ie reverse the function of commas and periods in numbers. This is easy to do in the Control Panel, but it could affect other programs running on your PC. This is a consequence of the version of PowerSDR on which IF Stage v0.92 is based. LP-Bridge is internationally aware in terms of number formats.


Email me for more info.

73,
Larry N8LP



Updates:

(02-22-09)
Run 6 kits and assembled units are now shipping.

(01-23-09)
Check out the QST review of LP-PAN. You can find a link to it near the top of this web page. Due to the increased demand created by the review, run 5 will likely sell out early. Run 6 is in the pipleline and will hopefully be ready within a week of run 5 selling out.

(12-17-08)
We are caught up on the backlog we had experienced due to the demand for LP-PAN, but the current production run is almost sold out. As of this writing we had only 1 kit and 3 assembled units left. Run 5 is at the SMT assembly house, and is scheduled to be in house Christmas week. We expect to start shipping run 5 kits the week after Christmas, and assembled units about a week later.

(11-16-08)
Run 4 has been shipping for over a week now, and I am finally getting close to caught up ;-) I expect to have all current orders shipped within a week. I currently have about 30 units left to sell from this run, and parts for the next run have been ordered.

(10-30-08)
Run 4 is ready to ship, and will start shipping this week. It will take about 10-14 days to catch up on the backlog, so in 2 weeks time I should be able to ship LP-PAN from stock. Run 4 is almost half sold out at this time. I expect to have units available for Christmas, either from run 4 or run 5.

(10-10-08)
Run 3 is sold out. All shipments of run 3 should be complete by tomorrow. Run 4 is ordered, and we expect to smoothly transition from run 3 into run 4. Response to Larry's presentation at the W9DXCC Convention in Chicago a couple weeks ago was very positive.

(9-15-08)
Run 3 is almost sold out. We have been shipping steadily, and should have all run 3 units shipped within the next two weeks. Run 4 is ordered, and I expect to smoothly transition from run3 into run 4. No changes are contemplated. A new version of the manual has been posted, with much more detail. I have also started posting sound card setup pages (linked from the Sound Card page). The first two posted are E-MU 1212m and Infrasonic Quartet. I also posted a new version of LP-Bridge (v0.9.8.1), which eliminated a couple bugs. There is a version history at the bottom of the LP-Bridge web page. We will be in Chicago this weekend for the W9DXCC Convention. I will be giving a talk on LP-PAN / LP-Bridge, and hopefully have a demo set up there.

(8-30-08)
Run three started shipping last week, and I expect to be caught up in a couple weeks. I have about 30 units left from run 3, and have ordered some of the parts for run 4. I tested the Infrasonic Quartet sound card and added it to the list of recommended sound cards.

(8-15-08)
The first two production runs of LP-PAN are sold out and have all been shipped. All new orders will be filled from the third run. We have almost all the parts for the third run, including the PCBs with pre-assembled SMT parts. We expect to start shipping third run kits about August 20, with assembled units to start about a week later.

LP-Bridge software is progresing nicely. I have gotten many reports saying that the latest release is stable and working seamlessly. I have posted an experimental version which adds a couple output ports for feeding antenna tuners, amplifiers and SteppIR controllers in passive listen mode. I have also started to add another two virtual ports.

Scott has been on vacation, but we expect to release PowerSDR-IF Stage v0.93 beta in the next couple weeks, which will add support for VFOB to use for split and sub-receiver. 

(8-01-08)
Run 2 is finished. Most of the parts are here for run 3, and I should have SMT populated PCBs in about a week. Run 3 is about half sold out at this point. I have released the LP-Bridge beta, and after a couple bugs, folks seem to be having no real difficulties with it. Scott also released version 0.92 of his PowerSDR - IF Stage program. We have added some nifty features with the combination, with more to come. For links to the beta programs, check the top of this page. Also, Scott and Lee, WW2DX, created a nifty little video demonstrating a couple of the more interesting features of LP-PAN / LP-Bridge / PowerSDR-IF Stage. Go here to see it on YouTube... http://www.youtube.com/user/ww2dx

(7-25-08)
Run 2 should be completely shipped by this coming Wednesday (7-30). There will be about a 2 week delay before run 3 starts shipping. The LP-Bridge beta is almost ready for release. Scott and I are just working out a couple minor issues with PowerSDR before we do a dual release. It has been in beta for a week or so. Only one issue has arisen, with a conflict with a USB to serial adapter, but nobody else is having that. We'll just have to see if that is a problem once the software is released. Here are comments from one of the beta testers...

I now have LP_Bridge, CWSkimmer, PowerSDR, MixW2.18, DXView and Outlook Express all running and working at the same time.  I've got three sound cards running at the same time.  E-MU 0202, Audiophile 2496 and the motherboard sound card.  I'm feeding a "Y" output from LP_PAN for PowerSDR and CWSkimmer.  The motherboard audio has it's input I/O from the K3 Line-In and Line-Out jacks and is being used by MixW.  All programs receive their CAT connection via LP_Bridge.  It's freaking koooool !!! Total processor load with all programs running is bouncing between 21% and 35%. 

He's using a PC with E6700 Core 2 Duo processor and dual monitors. Sounds like a good setup. I am running a 3 year old Dell WS360, 2.8GHz Pentium 4 / 1.5GB. My sound card currently is a E-MU 1212m. With PowerSDR, LP-Bridge, CW Skimmer, TRX-Manager and Logic8 all running (as well as Firefox) I am seeing about 65% CPU usage, with no clicks and few dropouts. The mixer in the 1212m is very flexible, and I am able to route sound to all my apps from the one card. The latency of my system is about 75 using Thesycon's DPC latency checker discovered by Roger, WA7BOC. It can be found at http://www.thesycon.de/deu/latency_check.shtml

The LP-Bridge beta currently supports 3 virtual com ports. The "virtual K3" which makes possible multiple connections currently supports the most important 26 K3 commands. Things like LCD screen reads and flash programming of the firmware are not supported yet. Nor are any of the developer commands. Also not yet supported are the new 2nd receiver commands, but I don't think any applications support that yet anyway. Because of the architecture, I can provide almost any number of virtual ports, and will probably add a couple more shortly, as well as at least one real serial port connectio on the output side for connecting to external devices such as SteppIR controllers, amplifiers or automatic antenna tuners.

LP-Bridge has been tested with the following apps... CW Skimmer, DXLabs' Suite, N1MM, TRX-Manager, Logic8, MixW, Logger32, Wintest and HRD. The only issue so far is that HRD uses a couple unsupported screen read commands, but I hope to add them shortly.

(7-09-08)
Half of run 2 has shipped, and I expect to get caught up in the next 2-3 weeks. Run 3 has already been ordered, and we will seamlessly transition into it at the end of run 2 shipments. Current orders will be filled from run 3. Work on LP-Bridge and Power SDR-IF Stage v0.92 continue. We are currently working on adding plug'n'play support for IF offsets from the K3, so that PowerSDR and the K3 will always be tuned to the exact same center frequency.

(6-28-08)
Run 2 is sold out, and run 3 is underway. I shipped 25 units from run 2 this week. Run 3 will have a couple minor changes. The LO has been shifted by 6 kHz to help make the unit more usable with existing internal sound cards by moving 0 Hz response errors of the sound card out of the passband. I am also trying to finish up LP-Bridge. I have added automatic collection of all available K3 IF offset data part of the program, which will eventually allow for plug'n'play operation as far as offsets go. This will make configuring the software MUCH wasier and less confusing. There are some pics of the latest LP-Bridge software in the Software section of this webpage.

(6-24-08)
Run 2 shipments began this week with the first dozen units shipping today. Work is continuing on LP-Bridge, but Scott is still working on a bug in ver. 0.92 of PowerSDR-IF Stage. I am planning on a change in run 3 to add a small offset to the LP-PAN L.O. to help users with internal sound cards which may have issues with response at 0Hz.

(6-19-08)
All LP-PANs from the 1st run have been shipped. I have only a few left to sell from the 2nd run, and have already ordered parts for the third run. I am still running a few weeks behind orders for shipping, but I'm closing the gap ;-) Scott has sent me an alpha of IF Stage v0.92, and I plan to post an LP-Bridge beta this weekend.

(6-14-08)
All kits ordered before May 4 will have been shipped by Monday, June 16, and all assembled units ordered by May 4 will be shipped by Wednesday, June 18. This will complete the first run of 100 units. I received the enclosures for run 2 this week, and will seamlessly move into run 2 after Wednesday. I have about 15 units left to sell from run 2 as of this posting.

On the software front, Scott is working out a final bug in the next release of PowerSDR-IF Stage, and as soon as he does I will test it with LP-Bridge and release a beta.

Please be patient. In addition to LP-PAN, I have had about 60 orders for LP-100A since just before Dayton, and have to find time to work on the software for LP-PAN as well as other products. I expect to be all caught up on everything in the next month or so.

(6-13-08)
 LP-PAN is featured in "What's New at Dayton 2008?" on page 51 of the July 2008 QST. Here's a scan of the article.

(5-12-08) Above are pictures of the final LP-PAN. I received the enclosures Friday, and the pre-assembled PCBs today as expected. I built two units for testing and they appear fine. I will package as many kits and assembled units to deliver to Dayton as time permits. If I run out of time, I will give priority to overseas orders. I will ship packages off to the assemblers tomorrow to do the assembled units, and should be able to ship a good percentage of the first run orders next week, both kit and assembled varieties. I expect to ship all first run units within a two week period. I should have a manual ready sometime next week as well.

(5-06-08) I have all the parts for the first run on hand now, and expect both the pre-assembled PCBs and enclosures by Friday. Since I have other things to get ready for Dayton, I will only be able to prepare a few LP-PANs for delivery at Dayton, with the balance to ship starting Monday 5-19. I expect to ship all ordered kits that week, and assembled units starting the following Friday.

(4-30-08) The first production run is almost sold out. I will be doing another run right after Dayton. I ordered the PCBs for the first run on 4-28, and expect to receive them on 5-5. I also expect to receive the enclosures sometime next week. I expect to receive the populated PCBs on about 5-12, just a few days before Dayton. I plan to bring enough kits to Dayton to deliver to everyone who asked about picking up a prepaid unit there. Hopefully I will be able to bring enough assembled units as well. I will give priority to overseas orders if I can't assemble enough before the show to meet all requests for pickup at the show.

(4-18-08) I have added an ordering section to this page today. I contemplate shipments of LP-PAN to start in 2-3 weeks, barring any unforeseen parts availability issues. Enclosures are in production this week and next, and I should hopefully have pictures of a completed LP-PAN at the end of next week. Two versions of LP-PAN are available... partial kit and assembled. The partial kit has all SMD parts installed, and the estimated assembly time is 2-3 hours. Calibration requires peaking of two trimmer caps while monitoring the PC display. 

(4-09-08) I shipped two more beta boards today. I also sent a test version of LP-Bridge to Scott for testing with the next revision of his PowerSDR-IF Stage program. 

(4-01-08) I shipped five beta boards today. I will ship another couple after I replenish my parts bin of a few parts. I hope to have some feedback this weekend, and will work on getting a version of LP-Bridge out early next week.

(3-29-08) I have built five beta boards now and tested them. I plan to ship them early next week. Here is a picture of a finished board...



(3-22-08) Above I have added a picture of the completed beta board installed in the prototype enclosure. I have fine tuned a couple of circuits and fixed a couple incorrect traces on the PCB. I have also added a hardware mute input. I have updated some of the screen captures in the performance sectio to reflect improvements in performance. I think I have solved the problem of tuning for kit builders by reworking the filter design a little bit. Tuning would require a noise generator, like the Elecraft NGEN. I may also add a noise generator to the PCB and jumpers to enable it, but this won't be in the current run.

(3-19-08) I now have LP-Bridge communicating with PowerSDR over the DDE interface, and should have a working program for beta testers some time next week, with most of the planned functionality in place. I still need to add the filtering and collision prevention for the virtual ports, but all the basic pieces are working now.

(3-18-08) I have received the prototype enclosure from TenTec (pictured above), and will have the revised PCB tomorrow. I should be able to ship the revised boards to the beta testers this week. Barring any unforeseen difficulties, I should be able to take orders next week and place the order for the first production run at the same time. Deliveries would begin a few weeks later.

(3-12-08) I have the parts on hand for the five beta boards, and should have the revised PCBs in a week. LP-Bridge is coming along fine, with three working virtual com ports now. I took some time off to build a project for the FDIM Buildathon, and test it for them. See the new section about using LP-PAN as a spectrum analyzer.

(3-6-08) I have approved the blueprints from TenTec on the enclosure, and expect to have a prototype in a couple weeks. Production enclosures should be ready 4-6 weeks after that, but I may go ahead and start shipments of LP-PAN before the enclosures are ready, with the enclosures being sent as a follow-up for those who are eager to play with LP-PAN.

I have added the "final" changes to the PCB layout, and ordered parts for five beta units. I changed the audio outputs to a pair of outputs which can be switched from unbalanced to balanced, along with ground lift jumpers for both outputs. This should provide plenty of options to find a minimum hum/noise audio interface to most sound cards, either consumer or professional level.

I should be ready in about a week for beta testing. I now have LP-Bridge working with three virtual ports, and may add more after I get beta site feedback. I am now working on the PowerSDR link from LP-Bridge.

(2-20-08) I have updated the image rejection and IMDR3 specs after making some changes. Image rejection is now 50-70 dB with PowerSDR, and 90-100dB with Rocky across the entire 192 kHz bandpass... even better for 96 kHz bandpass. Even with PowerSDR, now, images for most strong signals are at or near the noise floor. By further improving the QSD lowpass filter, and maybe adding variable loads for the output transformers, I think I can get another 10dB or so for programs with fixed image rejection asjustments like PowerSDR.