Rear panel shown with optional dual coupler board installed.

A truly unique and innovative design. We didn't just stick a digital display on an old fashioned design. Compare to any meter at any price! There is nothing else like the LP-100A on the market. Please take the time to read this entire page (and links, including the extensive manual) for a summary of features and performance data of this station monitoring and antenna measurement system.

We think you'll agree... the LP-100A is in a class by itself. Available as a fun to build kit, or assembled & calibrated with NIST traceable reference. Free calibration also available to kit builders (you pay only for shipping).

Couplers:

Standard coupler is LPC1, 3KW PEP/CW**, 1.8 to 54 MHz.

Optional couplers for ham use include...

LPC2 0.10W to 5KW CCS*, 1.8 to 30 MHz
LPC4 0.10W to 5KW PEP/CW**, 1.8 to 54 MHz
LPC5 0.20W to 10KW PEP/CW**, 1.8 to 30 MHz

* CCS refers to continuous duty (key down).
** PEP/CW refers to 50% duty cycle typical of most ham modes.

Note: Allow up to a week delay for orders with optional couplers.

Pricing & Ordering:

7-13-09: Current status -

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Plot

Here are some comments on the Plot program since its release...

Great work on your Plot software.  Another reason that the purchase of the LP-100 is a 'no brainer"!

I have been using LP-100 Plot, and it is an exciting software that mates perfectly with my Mark V Field. Now all my antennas have their SWR plots stored!

Did a plot on my 6m 5L in about 30 seconds after connection.

I really like the plot program. I have phased verticals for twenty meters and it showed me I should tune them for a little higher in the band.

Works great so far. I plotted my antenna in its old location, and will do it in the new one when I get my radials put down.

This plotting facility is absolutely fantastic. I am using an ICOM 756 Pro III so I connect plotter via HRD.

I did some plots on some of my antennas. A super program. Thanks much. I love the LP-100.

Below are reduced size screen grabs from alpha version 0.97 of the Plot program. This version has a nicer graphing component, than the earlier version I reported on. The Plot program can scan any frequencies, with sample spacings of 10, 25, 50, 100, 250 or 500 kHz. It displays...

R+jX
Z magnitude and phase
SWR
reflection coefficient
Return Loss
Smith chart
Power (dBm) (not released yet, but shown on the Plot samples page)

I still plan a lot of new functionality for the Smith Chart, like display of constant SWR circles, and adding beginning and ending frequency tags. Eventually I also want to add the ability to transform impedance, measure transmission lines for distance to fault, etc.

Plot uses a variety of methods to control the transmitter. Direct control of Kenwood and Elecraft K2 are provided, as well as transparent linking to three popular rig control / logging programs... TRX-Manager, Ham Radio Deluxe (HRD) and DXLabs' Commander C-IV. Also, Simon HB9DRV is planning a similar application for HRD to provide yet another control option. These programs are either free or inexpensive. I expect to provide direct control of Icom rigs as well, but the big advantage of linking to existing programs is that almost any radio that has a CAT interface can be controlled.

Version 0.96 offers smooth Spline interpolation and a two-pass automatic sign detection for Reactance and phase angle of Z. The sign detection algorithm uses a combination of Z and Phase slopes to determine proper phase sign, but it breaks down a little when the Z is broad and flat. To address it, I have included the ability to edit the curves. After a plot, it is pretty obvious from looking at the Phase curve where a mistake has been made. The plot can be fixed by clicking on a bad point... it will automatically reverse sign. Once the curve is fixed, you can save and/or print the corrected curve. Editing is allowed on all plots which involve sign, including R+jX, Z/Phase and the Smith Chart. Editing any of these corrects the source table so that the result ripples across the screens.


Click here for more screen grabs of Plots. Included are antenna plots of R+jX, SWR, RL, Smith and the newly added Power display. Also included are comparisons of Plot to my HP VNA with a 2-30 MHz sweep of a reactive load I use for calibrating the LP-100As, and with a pi-net filter. The filter demonstrates the versatility of the LP-100A and Plot program. It shows the power response of a homebrew low pass filter, as well as the input impedance when terminated with a 50 ohm load.

The new Power display is an important addition to the Plot program. This is a capability that no antenna analyzer has to my knowledge. Since they are all 1-port devices, they only allow reflection measurements. The LP-100A / Plot combo also allows transmission measurements, like a VNA. This allows placing a DUT (device under test) between the transmitter and LP-100A coupler, allowing power response measurements of filters and other frequency sensitive devices. Click here for more screen grabs of Plots.

Click for LP-100_Plot Help file.


PolarPlot


PolarPlot is a freeware program written by Bob Freeth, G4HFQ. It is designed mainly to create polar antenna plots from power samples, but it can also produce histograms of power over time. I have added support for PolarPlot in VCP ver. 1.0.7, and Bob has provided an input selection for LP-100 in PolarPlot. Combined with the nifty high-sensitivity calibrated Field Strength feature of the LP-100 / LP-100A, PolarPlot provides a slick way to plot beam patterns, calculate gain, etc.

For more information on using PolarPlot with your LP-100 / LP-100A, see the Software section of the latest manual.

TRX Slave