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Table of Contents
Series V RangeMaster
Owner's Manual
Thank you for purchasing a HardWay RangeMaster V. Here are some things you
should know: There will be a test later.
The HardWay RangeMaster is a very accurate reproduction of the original legendary
Dallas Rangemaster Treble Booster of around 1967. A total of 8 Series V units were
built, numbered from RMV001 to RMV008. (RMV001 was the prototype). The serial
number is written on the bottom outside of the unit, and on the inside, on the cover.
Not very many original Dallas Rangemasters were built (nobody knows how many)
and they were hard to find, even in the 1960s, even in England, where they were
made. Moving ahead to the 21st century, I saw one on eBay the other day, listed for
$5,000. Seriously.
The Rangemaster was a very simple circuit, centered around a Germanium transistor
(usually a Mullard OC44 or NTK 275 or a Mullard OC 71). The original circuit consists
of 1 transistor, 3 resistors, 4 capacitors, a potentiometer, a switch, and a battery.
That's it.
The Welwyn preset pot was 10K Ohms. The boost knob was scratchy when adjusted,
due to the DC voltage present on the pot. This is the way the original was designed;
it is normal for this device.
The Series V HardWay RangeMaster has three PNP Germanium transistor modules,
selectable with a three-way rotary switch on the back of the unit. Each transistor
module consists of the transistor, the bias resistors and a 50 µF capacitor. The three
transistors included with the Series V RangeMaster are OC76, OC44, and AC125. The
gain of the transistors used in this series ranged from 82 to 112. (True gain, which is
apparent gain minus leakage.)
Series V also has a 3-way frequency cutoff selector switch on the back of the unit that
changes the boost frequency from "Stock" to "Wide" or "Full". The stock (middle)
setting is as the RangeMaster was designed in 1966, a true treble boost. The upper
"Wide" setting expands the boosted range to include more mid-range frequencies,
and the lower "Full" setting boosts the entire range of a normally tuned guitar.
April 2020
1
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Table of Contents
Summary of Contents for HardWay RangeMaster V Series
- Page 1 Series V RangeMaster Owner’s Manual Thank you for purchasing a HardWay RangeMaster V. Here are some things you should know: There will be a test later. The HardWay RangeMaster is a very accurate reproduction of the original legendary Dallas Rangemaster Treble Booster of around 1967. A total of 8 Series V units were built, numbered from RMV001 to RMV008.
- Page 2 Series V RangeMaster Owner’s Manual Series V units all use the Welwyn preset potentiometer as the boost control, as original. The pots are all 25K Ohms, unlike the original’s 10K Ohm pot. Unfortunately, I cannot find any 10K pots anywhere, they may be extinct. As a result, you may find that much of the range of the pot is unusable due to noise.
- Page 3 Series V RangeMaster Owner’s Manual CHECKING BIAS 1. Use a fresh battery, unplug both jacks, turn unit off, remove cover. 2. Set your DMM for DC Volts. 3. Attach the RED lead to a ground (the case, or the ground wire to the rotary selector switch).
- Page 4 This RangeMaster V is guaranteed to be free from manufacturing defects for a period of 6-months from the date of the original invoice. HardWay is not responsible for any unit that is abused, modified from the original circuit, or used in an abnormal application.
- Page 5 Series V RangeMaster Owner’s Manual SCHEMATICS Schematic of the RangeMaster Gen. V. There are three individual transistor modules, each with its own biasing resistors (Rb and Re); these resistors vary depending on the values required to bias each transistor into the middle of its range, and they are individually selectable via the 3-way rotary switch on the back of the unit.
- Page 6 Series V RangeMaster Owner’s Manual RangeMaster V Enclosure Layout RangeMaster Gen. V component position layout Biasing Module Transistor Bias Module schematic. April 2020...
- Page 7 Series V RangeMaster Owner’s Manual PRODUCT PHOTOS Rear panel of RangeMaster Gen. V (Left) Frequency cutoff selector. (Middle) Rotary switch transistor selector: OC76, OC44, AC125 Gen. V RangeMasters (Far right) Gen. III RangeMasters with large enclosure. RangeMaster Gen. V transistor modules (Left) Three individual biasing modules for the OC76, OC44, and AC125.
- Page 8 Series V RangeMaster Owner’s Manual April 2020...
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