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Technical Profile: Pride "Amatuer" Dual-Tube Amplifier

1. Unit Identification

Manufacturer: Pride Electronics (California).
Model: Likely a DX-3000 or a high-power variant of the KW-ONE.
Production Era: Late 1970s.
Defining Characteristics:
- “AMATUER AMPLIFIER” typo on the brushed metal faceplate.
- Red rocker switches for Power/Meter functions, riveted directly into the faceplate.
- Rectangular chassis wider than the standard DX-300/KW-1 “cube” design.
- Evidence of a missing adhesive-backed nameplate on the lower front panel.

Vacuum Tubes: Two (2) 4CX250B (or similar) ceramic power tetrodes mounted in parallel.
Cooling: Centrifugal squirrel-cage blower designed for a pressurized plenum.
Power Supply: * Massive high-voltage plate transformer showing surface oxidation.
- Separate filament/control transformer.
RF Deck: * Large ceramic multi-tap tank coil for band switching (80M through 10M).
- Dual variable capacitors for PLATE and ANT LOAD tuning.
- Parasitic suppressors (resistor/inductor combos) connected to the tube anodes.

The unit reportedly operates but is limited to 100 Watts output. Potential “Cold Test” targets include:

Component	Symptom	Suspected Issue
Parasitic Suppressors	Darkened/Cooked appearance	Resistor failed open; choking RF output path.
Input Swamp Bank	Resistor cluster near input	Drifting high or incorrect bypass “hack” limiting grid drive.
Mode/Tune Logic	Stuck in “Tune” or “AM-1”	Internal relay or rocker switch failing to engage high-bias state.
Tube Health	Visual debris in cooling fins	Tubes may have “gone soft” due to overheating.
Transformers	Surface rust on laminations	Potential insulation breakdown from moisture.

Objective 1: Use LCR meter to verify parasitic suppressor resistors (target ~$47-100 Ohm).
Objective 2: Check input attenuator resistors for value drift.
Objective 3: Inject low-level RF via signal generator to trace signal loss through the band switch and grid drive circuit.
Objective 4: Manually inspect blower rotation and clear debris from tube cooling fins.