GE Rangr conversion to 6 meters lowband VHF Amateur / Ham Radio April 2006 - Jason Buchanan - N1SU

This page is not intended to replace the documented procedure written by Gary NZ5V (see link below). I felt like there needed to be a little more presence and discussion about converting the GE Rangr low band high split radio for use on the ham bands. Buck K4ABT has a nice PDF (see link below) for conversion as well and both are excellent reading. I recommend that you read both before taking the top cover off of your Rangr.

The purpose of this page is to clear up a few questions that others might run into. There's a few things to keep in mind:

• The procedure is not difficult
• Some Rangr units need less (some need more) stretching or expansion of the low pass coils on the PA board
• You need a dummy load to do this right
• When you finish you should have a radio that will not get hot with a 60 second key-down at 90 watts

VCO Board

PA Board

The photo above is of an unmodified Rangr, purchased from eBay seller mastrii - I highly recommend this seller.

Modified coils appearance:

Notice that the coils are stretched only enough to slide a piece of paper between each turn. Your mileage will vary - some radios need more, some need less. I do not know why. The goal of stretching the coils is to reduce the wasted power created when the coils are not tuned to the frequency used during transmit. The large ferrite transformer and power transistors will get very hot if the coils are not adjusted. The thermistor will prevent them from melting through the chassis but over time their life expectancy will diminish rapidly. The maximum output when unmodified will be somewhere around 70 watts, maybe higher if the radio is in mint condition.

You will have completed the adjustment when there is no difference in output power between your highest and lowest transmit frequency. Any difference in output power represents heat build-up in the PA components. For operation of FM voice using repeaters you should be able to adjust the coils so that you have equal output power at 52 and 53 MHz.

Close-up photo of L8 coil:

The large ferrite transformer should not get hot after 60 seconds keydown at 90 watts. The ceramic tops of the power transistors should not get so hot that you can't hold your finger on them for 3 seconds after the same keydown.

Locate the red mica cap on the large ferrite transformer and cut it off. It is removed in the photo above.

Helpful Links

• Gary NZ5V conversion of GE Rangr LowBand Radio to Amateur Use - where I got the idea for this
• Buck K4ABT conversion of GE Rangr for 6m FM use
• GEMOTO - New England area ham club that converts commercial gear to ham operation