Monday, November 16, 2009

Upgrading My LP-100

I own 2 of these meters. They are the LP-100 Digital vector wattmeters by N8LP. I was an early adopter, having built my first meter in 2006 when they first came out. My serial number is in the low 100's. I was so happy with this meter I bought a second one a few months later, as I routinely run 2 "stations" simultaneously, one for ragchewing and one so that I can chase DX while I am ragchewing. That means 2 amps and 2 sets of antennas so I wanted 2 meters in the line.

These meters are calibrated with a know traceable NIST source and are accurate to within about 2% or better across the range from 50 mW to 3000W They also measure phase and resistance as well as SWR and can be used as a highly accurate field strength meter.

These meters have performed flawlessly for that past 3 years, EXCEPT they had a PLED display and PLED displays have a problem, they wear out if you leave them on. Larry N8LP solved this by upgrading the LP_100 to the LP-100A. Most manufacturers would just let you eat the obsolescence. You would get the "sorry we don't carry that part anymore" routine. Larry OTOH designed a conversion kit to renew the LP-100 and convert it to a fully functional LP-100A. This is the delight of software defined products that you can easily extend their lives to match current production products

The upgrade consisted of installing a daughter card which contains the original micro-controller a driver for the new display and the new display

There are several options of assembly from a kit format to sending the unit back to Larry for factory intallation. I chose the kit route. Assembly and installation was trivial. I installed the new components and uploaded the firmware and I was back on the air with a pretty new robin's egg blue display!!

The latest version of this meter includes a dual coupler option which allows 2 signal paths to be displayed on one meter Larry has a vast array of accessories for various ham radio products as well as his spiffy watt meters. The watt meter is a virtual transmitting VNA capable of sweeping antennas for SWR and impedance information using a radio like the F5K which can become a software controlled freq generator. It also can be used to plot antenna pattern information using a radio like the F5K Check out the LP-100 and Larry's other brainy creations at