Yaesu FT-501 Instruction Manual

Introduction

The FT-501 is a high-performance SSB transceiver with advanced design, offering SSB (USB and LSB selectable) and CW modes. It features a digital frequency counter for accurate readings and operates at 500 Watts PEP for SSB and 380 Watts DC for CW on 80 through 15 meters, with slightly reduced input on 10 meters. The transceiver utilizes solid-state devices and two separate 9 MHz crystal filters for sideband generation. Built-in standard features include VOX, break-in CW with sidetone, a 100 KHz calibrator, noise blanker, clarifier, and 15 MHz WWV/JJY reception. An optional 600 Hz CW filter is available and automatically selected in CW mode.

The optional FP-501 matching AC Power Supply with a built-in speaker is also available.

Specifications

General

• Frequency Range: 3.5-4.0 / 7.0-7.5 / 14.0-14.5 / 21.0-21.5 / 28.0-28.5 / 28.5-29.0 / 29.0-29.5 / 29.5-30.0 MHz (optional frequencies indicated by %)
• Modes: A1 (CW), A3J (SSB - USB or LSB)
• Input Power: 500 Watts PEP (SSB), 400 Watts 50% duty cycle (CW) (slightly lower on 10 meters)
• Carrier Suppression: 40 dB minimum
• Sideband Suppression: 50 dB at 1000 Hz minimum
• Spurious Radiation: -40 dB minimum
• Frequency Response: 300 Hz - 2700 Hz ±3 dB
• Distortion Products: -30 dB minimum
• Antenna Impedance: 50 - 75 Ohm unbalanced
• Frequency Stability: Less than 100 Hz in any 30-minute period after warmup
• Sensitivity: 0.3 uV for 10 dB S/N
• Selectivity: 2.4 KHz at -6 dB (SSB, CW), 3.8 KHz at -60 dB; 600 Hz at -6 dB (CW, optional filter), 1.2 KHz at -60 dB
• Image Rejection: 50 dB minimum
• IF Rejection: 50 dB minimum
• Audio Output: 3 Watts @ 4 Ohm (10% distortion)
• Power Requirements: Receive 140 VA, Transmit 650 VA maximum
• Power Source: FP-501 AC supply
• Dimensions: 350(W) x 292(D) x 160(H) mm
• Weight: Approx. 10 Kg

Tubes & Semiconductors

Tubes: 2 x 6KD6, 1 x 6BZ6, 1 x 6GK6, 1 x 6U8, 1 x 6EJ7, 1 x 6CB6

Transistors: 7 x 2SC711D, 2 x 2SC710D, 5 x 2SC372Y, 1 x 2SC697, 3 x 2SC372Y, 1 x 2SA628A, 3 x 2SC373, 1 x 2SA628A, 3 x 2SC735, 1 x 2SA628A

F.E.T.: 3 x 2SK34E, 1 x 2SK19GR, 2 x MK10D

I.C.: 3 x CA3053, 1 x HA1306, 1 x TA7042M

Diodes: 18 x 1S1007, 1 x 1S334, 8 x 1S1555, 1 x 1S188 FM, 7 x 1S1941, 1 x 1S2110, 1 x 1S1943, 1 x WZ060, 1 x 1S145 (1S236)

Counter Section

• Nixie Tube: 6 x DG12M
• Transistors: 5 x 2SC373, 2 x 2SC735Y, 2 x 2SA628A, 1 x 2SK19
• I.C.: 10 x SN7490N, 2 x SN7486N, 6 x μPB249D, 1 x SN7472N, 4 x SN7475N, 1 x SN7404N, 2 x SN7400N, 1 x SN7403N
• Diodes: 44 x 1S188 FM

Installation

Carefully unpack the FT-501 Transceiver and FP-501 Power Supply, checking for any physical damage. Retain the original packaging for future use. Avoid placing the transceiver in excessively warm locations; ensure adequate space for free air circulation. Connect a good ground to the GND terminal on the rear panel. Avoid using gas or electrical conduit pipes for grounding. The ground lead should be as heavy and short as possible.

The FT-501 is designed for a 50 to 75 ohm load. If your antenna or feed line impedance deviates, use an antenna matching device.

CAUTION: NEVER TRANSMIT WITHOUT A PROPER ANTENNA OR DUMMY LOAD CONNECTED.

Connect the FT-501 to the FP-501 power supply using the supplied power cable. Ensure the accessory plug is installed correctly. Before connecting the power supply to an AC source, inspect for damage. Verify that all tubes and crystals are properly seated and that all controls rotate freely. Confirm the AC supply voltage matches the voltage marked on the power supply chassis. If not, refer to the Power Supply Section for rewiring instructions.

CAUTION: IMPROPER AC SUPPLY VOLTAGE WILL CAUSE PERMANENT DAMAGE.

Controls & Switches

The FT-501 is designed for ease of operation with factory-preset adjustments. Familiarize yourself with each control before operation.

Front Panel

• (1) MAIN TUNING DIAL: VFO tuning knob for frequency selection in conjunction with the BAND switch. Features a zero-backlash tuning mechanism providing a 16 KHz frequency change per revolution.
• (2)(3) BAND: Selects the operating band. Green indicators denote the use of the green scale on the VFO dial. The 28 MHz range is selected with knob (3) when knob (2) is fully clockwise.
• (4) CLARIFIER: Receiver off-set tuning control. Provides ±5 KHz receiver tuning variation when the CLARIFIER switch (12) is depressed. When the CLARIFIER switch is OFF, receiving and transmitting frequencies are coincident.
• (5) RF GAIN/AF GAIN: RF GAIN controls receiver sensitivity; AF GAIN controls audio output level.
• (6) MIC: Microphone jack for a standard 1/4", 3-contact, T.R.S. plug. Supports high impedance microphones.
• (7) PHONE: Headphone jack for low impedance, 4-ohm headphones.
• (8) CALIB: Calibrates the frequency readout against the 100 KHz marker signal. With the 100 KHz calibrator ON, adjust the main tuning knob for zero beat and set CALIB for an exact 100 KHz digital readout.
• (9) CARRIER: Adjusts carrier level for CW and MIC GAIN for SSB operation (early models adjust only CW carrier level).
• (10) MODE SWITCH:
  • POWER: Connects AC power to the supply.
  • N/R (Normal/Reverse): Selects sideband mode. N: LSB on 3.5/7 MHz, USB on 14/21/28 MHz. R: USB on 3.5/7 MHz, LSB on 14/21/28 MHz.
  • TUNE: Places the transmitter in tune-up mode.
  • CW: Selects CW mode.
• (11)(12) FUNCTION SWITCH:
  • PO/IC/ALC: Selects meter function for transmitter metering.
  • NB: Activates the noise blanker.
  • CLAR: Activates the clarifier.
  • MOX: Activates the transmitter manually.
  • PTT: Activates the microphone Push-to-Talk switch.
  • VOX: Activates the Voice Operated eXchange (VOX) function.
  • AGC: Selects AGC decay time-constant (depressed for longer constant).
  • 100 KHz: Activates the calibrator for 100 KHz markers.
• (13) PRESELECTOR: Controls RF tuning of the receiver and drive tuning of the transmitter.
• (14) LOAD/PLATE: Adjusts PA plate tuning and loading.
• (15) DIAL: Digital frequency counter readout.

Rear Panel

• (1) ANT: Coaxial connector for antenna connection.
• (2) RF OUT: Low-level output for optional equipment (e.g., FTV-650 transverter) or an optional receiver.
• (3) KEY: Jack for connecting a key for CW operation.
• (4) GND: Ground connection.
• (5) ACC: Accessory socket with various pin connections for power, ALC, and relay control.
• (6) EXT VFO: Socket for external VFO connection.
• (7) EXT SP: Jack for a 4-ohm external speaker.
• (8) PHONE PATCH: Input jack for phone patch connection (5 K ohms impedance).
• (9) POWER: Power input connector.

Internal Controls

• DELAY: Adjusts VOX relay "hold on" or delay time.
• ANTITRIP: Adjusts VOX antitrip level.
• VOX: Adjusts VOX sensitivity.
• RELAY: Adjusts VOX relay operating level.
• BIAS: Adjusts bias on PA tubes.
• MIC: Adjusts Mic Gain (early FT-501 models only).

Operation

Ensure all cable connections are correct and a suitable antenna is connected before powering on. The AC power plug should only be connected after all preliminary checks are complete. The "Aux" plug should be in the accessory socket.

Initial Settings:

• POWER: Off
• SSB: N (Normal)
• RF GAIN: Fully clockwise
• AF GAIN: Desired listening level
• CLAR: 12 o'clock position
• BAND: Desired band
• MOX/VOX/100 KHz: Open position
• PTT/AGC: Depressed position
• PO/ALC/NB/CLAR: Open position
• IC: Depressed position
• PRESELECTOR: 12 o'clock position
• CARRIER: Fully counter-clockwise
• CALIB: 12 o'clock position

Turn on the transceiver. Panel lamps should illuminate, and the counter should display the operating frequency. Adjust AF GAIN for speaker output. Peak the PRESELECTOR for maximum S-meter reading and tune for a desired signal.

Initial Adjustment - Dial Calibration

• SSB: Depress the CALIB switch. Tune the main tuning knob to the nearest 100 KHz point where an audio note is heard. Slowly rotate the knob to decrease the audio frequency until zero beat is achieved. Read the frequency on the counter window and adjust the CALIB knob for an exact 100 KHz readout. Ensure the CLARIFIER switch is OFF.
• CW: A 8999.3 KHz crystal is used for TUNE and CW transmission, and a 9000 KHz crystal for CW reception, producing a 700 Hz beat tone. The counter reads 700 Hz higher than the actual transmitted frequency on 14, 21, and 28 MHz bands, and 700 Hz lower on 3.5 and 7 MHz bands.

Transmitter Tuning:

Tune into a 50-ohm dummy load or a clear antenna frequency. Ensure the transmitter frequency is within the band limits.

CAUTION: DO NOT OPERATE THE TRANSMITTER WITHOUT A LOAD.

• Set controls: TUNE (depressed), CARRIER (fully counter-clockwise), PLATE (desired band marking), LOADING (9 o'clock), METER (IC position).
• PRETUNING:
  1. Peak PRESELECTOR for maximum receiver speaker noise.
  2. Depress MOX.
  3. Advance CARRIER clockwise until the meter reads slightly above idle current (50 mA).
  4. Peak PRESELECTOR for maximum meter reading. If the reading exceeds 0.2 Amp, reduce CARRIER.
  5. Rotate PLATE for minimum meter reading (plate dip).
  6. Release MOX by repressing the PTT switch.

Final Tuning:

CAUTION: EXCEEDING TIME LIMITS DURING FINAL TUNING CAN DAMAGE FINAL OUTPUT TUBES.

1. Depress IC, TUNE, and PTT switches.
2. Momentarily depress MOX and increase CARRIER until the meter indicates 300 mA. Adjust PRESELECTOR for maximum meter reading. Depress PTT. Maximum MOX switch time is 10 seconds. Allow a 20-second interval between attempts if the procedure is not completed within 10 seconds.
3. Rotate CARRIER fully clockwise. Depress PO switch. Momentarily depress MOX (max 10 seconds) and adjust LOADING slightly for maximum meter reading. Depress PTT.
4. Momentarily depress MOX, adjust PLATE for maximum meter reading with the meter switch in the PO position.
5. Repeat steps 3 and 4 until maximum meter reading is achieved.

Operate at 80% of "off resonance" plate current. To establish this, depress the IC switch, momentarily depress MOX, detune PLATE momentarily, observe maximum IC reading, then tune PLATE for minimum plate current (dip). The dip current should be 20% less than the maximum off-resonance current. If not, repeat steps 3 and 4, adjusting LOAD to achieve this condition.

The final tubes' screen grid voltage is reduced by a series resistor for protection during tuning. The transmitter is now peaked. Return CARRIER to zero and set MODE to desired position.

SSB Operation:

After tuning, depress MODE for N or R operation. Depress ALC and MOX switches. Adjust CARRIER/MIC GAIN so the meter drops to mid-scale (green area) when speaking normally into the microphone. For VOX operation, depress the VOX switch and adjust VOX gain until your voice actuates the transmitter. Set ANTITRIP to the minimum level required to prevent speaker output from tripping the VOX. Adjust DELAY for suitable release time.

For VOX troubleshooting:

1. Depress VOX switch. Set VOX gain, ANTITRIP, RELAY, and DELAY controls fully counter-clockwise.
2. Slowly advance RELAY control clockwise until the relay trips the transceiver into transmit.
3. Slowly rotate RELAY control counter-clockwise to a point slightly beyond where the receiver recovers. This is the proper relay sensitivity setting.
4. Follow the VOX adjustment procedure described above.

NOTE: When the meter is set to IC, voice modulation peaks indicate 250-300 mA (actual peak current is approximately double this value).

CW Operation:

Connect a key to the rear apron jack. Set the transceiver as described in transmitter tuning, adjusting CARRIER for desired power output. After final tuning, insert the key and depress the CW and MOX switches for manual CW operation. Depress the PTT switch for receive after transmission. For break-in operation, depress the VOX switch and adjust VOX gain and DELAY controls.

The CW sidetone level can be adjusted via VR302 on the main printed circuit board.

Block Diagram and Circuit Description

The FT-501 utilizes a single-conversion receiver and an exciter transmitter. Many sections are shared between the receiver and transmitter.

Receiver Section:

The antenna signal passes through the antenna relay to the RF amplifier (6BZ6, V3), then to the receiver mixer (6U8, V2). The local oscillator signal is coupled to the mixer's cathode. The IF output from the mixer plate is amplified by the first IF amplifier (2SC711D, Q110) and fed to a 9 MHz crystal filter. SSB filters are automatically selected by a diode switch based on the mode setting. The IF signal is further amplified by two stages (CA3053, Q102 and Q103). The output from the third IF amplifier (Q102) is fed to a ring demodulator (IS1007, D1-D4) for SSB and CW reception, with the carrier signal from Q101. The demodulated audio is amplified by Q312 and Q311, delivering 3 Watts to a 4-ohm load. A noise amplifier (Q114) and pulse amplifier (Q112, Q113) feed noise pulses to the noise blanker driver (Q111). A gate diode (D117) grounds the first IF amplifier output during noise pulses. AGC voltage is generated by rectifying the IF output (D114, D115), amplified by Q107, Q108, and controls the gain of the second IF amplifier (Q103) and RF amplifier (V3). AGC voltage also feeds amplifiers Q107 and Q108 to provide meter deflection proportional to signal strength (S9 ≈ 50 microvolts). A crystal-controlled oscillator (Q309) provides a 100 KHz marker signal for dial calibration, amplified by Q310 and coupled to the receiver RF amplifier. Trimmer capacitor TC301 calibrates the 100 KHz crystal frequency.

Transmitter Section:

The speech signal from the microphone is amplified by Q313 and Q314, controlled by the MIC GAIN control, and fed to a ring modulator (D101-D104) via a change-over relay. The crystal-controlled carrier oscillator (Q101) generates a 9 MHz carrier signal for the balanced ring modulator. Carrier balance is achieved via VR101 and TC102. The double sideband, suppressed carrier output is amplified by the first transmitter IF amplifier (Q104) and fed to an SSB crystal filter. The output is then amplified by the second transmitter IF amplifier (Q105). For CW, the CW carrier oscillator (Q106) generates an 8,999.3 KHz signal, amplified through the CARRIER control (VR8). The amplified IF signal is mixed with the local oscillator signal in the transmitter mixer (6EJ7, V4) to produce the transmitted frequency. The signal drives the transmitter driver (6GK6, V5) and then the final linear amplifier (6KD6 x 2, V6, V7). Neutralization is achieved via TC3. Output power is fed through a pi-network to the antenna. A portion of the RF output is rectified by D4 for power output indication (PO meter position). ALC voltage (D2, D3) controls IF amplifier gain to prevent overdrive. The VOX circuit amplifies the microphone signal via VR2, feeds it to a VOX amplifier (Q306), and then to VOX relay control transistors (Q307, Q308) to actuate the VOX relay (RL1). The antitrip circuit uses a threshold voltage from speaker output via VR3 to prevent false VOX activation. The tone oscillator (Q304) operates in CW mode, producing an 800 Hz tone amplified by Q305 and coupled to the receiver audio amplifier for sidetone monitoring. The output also feeds the VOX amplifier (Q306) for break-in CW. A voltage regulator circuit (Q301-Q303) provides a stable 9 Volt DC supply. The CLARIFIER control (VR9) uses this voltage to offset receiver tuning by ±5 KHz. VR11 allows adjustment for coincident receive and transmit frequencies when CLARIFIER is OFF.

Heterodyne Oscillator Section:

The FT-501 uses a "premix heterodyne system." The VFO module board contains the VFO (Q401) and buffers (Q402, Q601), generating a 5000-5500 KHz signal. A pass-band filter at the buffer output is tuned to this range. A varicap diode (D401) enables receiver offset tuning. The VFO output is fed to the local oscillator mixer (6CB6, V1). Crystal oscillators generate signals for different bands: 11 MHz for 40m, 35.5 MHz for 15m, 42.5 MHz for 10A, 43.0 MHz for 10B, 43.5 MHz for 10C, and 44.0 MHz for 10D. The mixer combines the VFO signal with these crystal signals to produce heterodyne frequencies (e.g., 16-16.5 MHz for 40m) which are then mixed with the incoming signal in the receiver mixer (V2) to produce a 9 MHz IF signal, and in the transmitter mixer to produce the transmitted signal.

Band and Heterodyne Frequency Chart:

Frequency Counter:

The frequency counter uses a 1 MHz crystal-controlled oscillator (IC-521-4, IC-521-6) as a clock. The 1 MHz signal is divided by a chain of dividers (IC-520 through IC-515). The output from IC-515 is delayed and applied to a one-shot multivibrator (IC-514-4, IC-521-2) producing memory and reset pulses. The VFO signal is converted by mixer Q507 for direct frequency readout. For 7.0 and 14.0 MHz bands, Q503 generates a 12 MHz signal, and for 3.5, 21.0, and 28.0 MHz bands, Q501 generates an 11.25 MHz signal that is doubled to 22.5 MHz by Q502. These signals are mixed with the VFO signal to produce intermediate frequencies that are amplified and fed to the counter chain (IC-513, IC-503, IC-506, IC-509, IC-512). The counter counts pulses over a given time period. Binary-coded decimal outputs are converted to decimal numbers and displayed on indicator tubes. Mega-Hertz indicators (V505, V506) are controlled by Q509, Q510, and IC-526. Additional ICs (IC-522-3, IC-522-4, IC-523-4, IC-525) add 500 KHz to the reading for specific bands. Blanking pulses flicker the indicator tubes if the VFO frequency is outside its range.

Alignment

WARNING: DANGEROUS VOLTAGES ARE PRESENT. EXTREME CARE IS ESSENTIAL. DISCONNECT POWER BEFORE WORKING INSIDE. DISCHARGE HIGH VOLTAGE CAPACITORS.

The transceiver is factory aligned. Alignment may be necessary after component replacement. This should only be attempted by qualified personnel with proper test equipment.

Test Equipment Required:

Stable signal generator, VTVM with RF probe, general coverage communication receiver, 300 Watts dummy load.

Voltage & Resistance Measurement:

Refer to the tube and transistor socket voltage and resistance tables. Measure voltages with a VTVM when tubes are installed. Discharge filter capacitors before taking resistance measurements.

Measure the regulated voltage at Pin 15 of the printed board; it should be 9 Volts. Adjust VR301 on the printed circuit board if necessary. If 9 Volts cannot be achieved, check for faulty components or low supply voltage.

VFO Alignment:

The VFO generates a 5,000 to 5,500 KHz signal. For alignment, turn off the crystal heterodyne oscillator by setting the BAND switch to 3.5 MHz and CLARIFIER to OFF. Use a frequency counter or the 100 KHz calibrator for alignment.

Coarse alignment is done with TC-401. TC-402 (split-stator trimmer) is for temperature compensation; readjust TC-401 after adjusting TC-402. Precise dial linearity adjustment may require bending rotor plates of VC401.

Premixer Output Coil Alignment:

Connect VTVM RF probe to the cathode of V1 (6CB6). Set BAND to 80m. Align L601 and L602 for specified band-pass characteristics.

Heterodyne Crystal Oscillator Alignment:

Disconnect the VFO plug. Connect VTVM RF probe to the cathode of V1 (6CB6). Set BAND to 40m and TC201 to half capacitance. Align L202 for 0.7 Volt VTVM reading. Set BAND to 21 MHz and adjust TC202 for 0.7 Volt. Set BAND to 28.5 MHz and adjust TC204 for 0.4 Volt. Adjust TC203 (28.0 MHz), TC205 (29.0 MHz), and TC206 (29.5 MHz) for 0.4 Volt injection voltage. Reinstall VFO plug.

Premixer Output Coil Alignment (Continued):

Connect VTVM RF probe to the cathode of receiver mixer tube V2 (6U8). Set BAND to 7.0 MHz and VFO to 7,000 KHz. Temporarily solder a 470 ohm resistor across the secondary winding of L5. Adjust the primary core of L5 for maximum VTVM reading (approx. 0.05 Volt). Remove the resistor. Solder a 100 ohm resistor across the primary coil and peak the secondary core of L5 for maximum VTVM reading (approx. 0.3 Volt). Remove the resistor. Set BAND to 21 MHz and VFO to 21.0 MHz. Peak the primary core of L4. Set VFO to 21.5 MHz and peak the secondary core of L4. Alternate adjustments of primary and secondary cores for unity output (approx. 0.3 Volt or more) across the VFO range.

Set BAND to 28.5 MHz. Remove the 43.0 MHz heterodyne crystal. Connect a signal generator to V1 (6CB6) cathode, set to 38 MHz, and adjust output for 0.5-0.6 Volt VTVM reading. Solder a 500 ohm resistor across L3 secondary and peak L3 primary. Remove resistor from secondary, solder across primary, and peak L3 secondary for maximum VTVM reading. Remove resistor. Check band-pass characteristics from 37 MHz to 39 MHz.

Disconnect signal generator. Reinstall 43.0 MHz crystal. VTVM should show 0.4 Volt output. Disconnect VTVM.

Band and Injection Voltage Chart:

Local Injection at Mixers

Final Amplifier Neutralization:

When replacing final tubes, readjust bias for correct idle current and check neutralization. Use only Yaesu Musen selected tubes.

CAUTION: HIGH VOLTAGES ARE PRESENT. EXTREME CAUTION IS REQUIRED.

1. Connect a 50 ohm dummy load. Depress the IC meter switch.
2. Locate TC4 (neutralization capacitor) on the underside of the chassis.
3. Check final amplifier idle current in SSB mode and adjust BIAS potentiometer (VR10) for 60 mA idle current.
4. Tune up at 29 MHz (28.999 KHz counter reading). With MODE in TUNE and FUNCTION in MOX, advance CARRIER until meter reads 100 mA (IC position).
5. Rotate PLATE TUNING for a dip on the meter. If the dip is not prominent, reduce loading slightly with the LOAD control. The meter should rise equally on either side of the dip.
6. Observe which side of the dip rises abruptly. Set PLATE control slightly to this side and maintain 100 mA meter reading.
7. Using a nonmetallic tuning wand, slightly rotate the neutralization capacitor (TC4) to reduce meter current. Repeat steps 6 and 7 until the meter indicates a smooth, equal rise on either side of the maximum dip.

The final compartment cover must be in place for RF shielding during neutralization.

Transmitter Mixer/Driver & Receiver Front End Alignment:

Set final amplifier idle current to 60 mA. Use internal signals for transmitter mixer/driver alignment and a standard signal generator for receiver front end alignment.

1. Connect a 50 ohm dummy load. Tune up at 29 MHz (28,999 KHz): Set BAND to 10B, VFO to upper end (28,999 KHz), PRESELECTOR to 12 o'clock, FUNCTION to MOX. Advance CARRIER and tune final amplifier, maintaining 100 mA plate current (IC). Peak cores of L8 and L13 for maximum output. Reduce output to zero with CARRIER.
2. Set to receive (PTT depressed). Adjust RF GAIN to maximum, AF GAIN to normal listening level, CLARIFIER and NOISE BLANKER to OFF. Do not change VFO/PRESELECTOR settings. Remove dummy load, connect signal generator (SSG) to antenna connector. Tune SSG to 28,999 MHz for a 1000 Hz beat note. Use minimal SSG output (approx. 1 micro Volt) to avoid AGC. Peak L29 for maximum audio output. Reconnect dummy load.
3. Set BAND to 3.5 MHz, PRESELECTOR to 2 o'clock, VFO to 3,500 KHz, FUNCTION to MOX. Advance CARRIER and tune final amplifier, maintaining 100 mA plate current (IC). Peak cores of L7 and L16 for maximum output. Reduce output to zero with CARRIER.
4. Set to receive (PTT depressed). Connect SSG to antenna, tune to 3,500 KHz for 1000 Hz beat note. Peak core of L28 for maximum audio output.
5. Set BAND to 21 MHz, PRESELECTOR to 12 o'clock, VFO to 21,250 KHz. Use L9 and L14 for transmitting power output and L30 for receiver front end alignment.
6. Set BAND to 14 MHz, PRESELECTOR to 12 o'clock, VFO to 14,250 KHz. Use L10 and L15 for transmitting power output and L31 for receiver front end alignment.
7. Set BAND to 7.0 MHz, PRESELECTOR to 1 o'clock, VFO to 7,000 KHz. Connect dummy load. Peak cores of L11 and L16 for maximum output. Set to receive (PTT depressed), peak TC2 for maximum background noise. Depress MOX. Adjust PRESELECTOR for maximum output. Adjust CARRIER for 50 Watts output. Check for maximum transmitter output at the same PRESELECTOR setting as maximum background noise in receive mode. If not, set PRESELECTOR for maximum output (1 o'clock) in transmit, and adjust TC1 and TC2 for maximum background noise in receive.

NOTE: If an SSG is unavailable, peak the receiver antenna coil for maximum background noise.

CAUTION: DO NOT TRANSMIT INTO THE SIGNAL GENERATOR.

IF Amplifier Alignment:

Set transceiver to SSB receive. Connect SSG to V2 (6U8) pentode control grid. Set frequency to 9 MHz, then precisely to the SSB filter frequency. Peak T107, T108, T109, T105, T104, T103, and T102 for maximum S-meter reading. Use minimal SSG output to avoid saturation.

Noise Blanker T110 Alignment:

Connect VTVM positive lead to test point, negative to chassis. Receive a 7100 KHz marker signal and detune the main tuning dial until the beat tone is not heard. Adjust T110 for maximum VTVM reading.

Carrier Oscillator Alignment:

Connect VTVM RF probe to test point. Set T101 for 80% of maximum VTVM reading (approx. 0.6 Volt). Adjust TC101 so the receiver noise pitch is the same when switching between Normal and Reverse SSB.

Transmitter IF T106 Alignment:

Adjust T106 for maximum power output.

CW Carrier Oscillator Alignment:

Connect VTVM RF probe to the center arm of CARRIER control potentiometer (VR8). Adjust T111 for approx. 0.5 Volt VTVM indication with CARRIER control fully clockwise. Adjust TC103 to 8999.3 KHz.

Trap Coil Alignment:

Set BAND to 7 MHz and PRESELECTOR fully clockwise. Connect SSG to antenna terminal. Set SSG output to 1 milli Volt at 9 MHz. Adjust trap coils L1 and L2 for minimum audio output.

S-Meter Alignment:

• Set transceiver to SSB Normal, RF GAIN fully clockwise (receive). Disconnect antenna. Adjust VR107 for zero S-meter set.
• Rotate RF GAIN fully counter-clockwise. Adjust VR106 for full scale S-meter indication.

AGC Threshold Alignment:

Connect VTVM positive lead to V3 (6BZ6) control grid, negative lead to chassis. Observe VTVM reading while rotating AGC THRESHOLD control (VR104). Rotate clockwise until VTVM shows +0.3 Volt.

ALC Meter Set:

Set transceiver to SSB transmit. Depress ALC meter switch and adjust ALC potentiometer (VR102) for full scale indication without modulation.

CW Sidetone Level:

Adjust VR302 for a normal sidetone monitoring level in CW mode.

Clarifier Alignment:

Turn on CALIB. Tune transceiver to a 14.1 MHz marker signal. Depress CLARIFIER switch and set CLAR control to zero (12 o'clock). Adjust VR11 (50 K ohm potentiometer behind CLAR control) for zero beat.

FP-501 AC Power Supply with Speaker

The FP-501 AC Power Supply is designed for the FT-501 Transceiver and includes a dynamic speaker.

Specifications:

• Supply Voltage: 100 / 110 / 117 / 200 / 220 or 234 Volts AC 50 / 60 Hz.
• Speaker: 3 Watts input power
• Semiconductors: 3 x Transistor, 15 x Diode
• Dimensions: 210(W) x 292(D) x 160(H) mm
• Weight: Approx. 10 Kg

The primary winding is split for multi-voltage operation. Refer to the power transformer connection diagrams for voltage selection.

Voltage Chart

NOTE: (1) DC voltage unless noted. (2) *DC voltage measured with VTVM. (3) AC voltage. (4) Band Switch set to 80 meter and Mode Switch to SSB Normal position.

Tube Voltages:

IF Unit (PB-1142) Voltages:

IF Amp, Unit (PB-1395) Voltages:

AF Unit (PB-1193) Voltages: