My line 4 Drake
Upgrades on my R-4C
- Modification FCN PRO first mixer.
- Modification FCN PRO second mixer.
- Modification FCN PRO product detector.
- Install 1 FCN PRO filter on the 1st FI (BW 6 Khz) (Replaces the original BW 8 Khz).
- Install 1 FCN PRO filter on the 2nd FI SSB (BW 2.1 Khz) (Replaces the original BW 2.3 Khz).
- Install 1 FCN PRO filter on the 2nd FI AM (BW 6 Khz) (Replaces the original 2 W resistor).
- Change the 240 VAC 60 Hz power supply transformer for another 230 VAC 50 Hz transformer to avoid excessive heating.
- Install a 6.3 V and 3 A switched and stabilized direct current power supply to power the valve filaments.
- Install a silent turbine to cool the 230 VAC 50 Hz power supply transformer.
- Install 3 voltage stabilizers of 14 VDC, 11 VDC and 10 VDC +/- 1mV to power the VFO, the crystal oscillators and the product detector.
- Install a 150 VDC voltage stabilizer to power the plate and grid circuits of the valves.
- Install AF circuit of 4 Ω and 5 W.
- Install DDS IN and MUTE input connectors to connect the VFO DDS R-4C.
- Clean switch contacts and valve sockets.
- Change electrolytic capacitors and resistors with altered value.
- Adjust all RX parameters and calibrate oscillators.
- Mechanical gear adjustment and analog dial knob.
- Cosmetic restoration (Change screws for identical stainless steel ones, polish buttons and legs, put new rubber stops on the legs, paint the white stripes on the controls, change dial and smeter lamps, change filters dial and smeter window blues, etc).
Upgrades on my T-4XC
- Cosmetic restoration (Change screws for identical stainless steel ones, polish buttons and legs, put new rubber bumpers on the legs, paint the white stripes on the controls, change dial and smeter lamps for LEDs, change blue dial and smeter window filters, etc).
- Install silent turbine to cool the final step.
- Install a 13 VDC + - 1 mV voltage stabilizer to power the carrier and band oscillators.
- Change electrolytic capacitors and resistors with altered value.
Upgrades on my AC-4
- Replace all components including the power transformer with new inputs of 220, 225, 230, 235 VAC 50 Hz.
- The transformer is installed on four rubber supports so that the source is completely silent without buzzing or vibration.
Current line 4 + DDS VFO
- Frequency coverage: 1.5 to 30 Mhz in a running band.
- Sensitivity: 0.1 uV for 10 dB SINAD in all bands.
- Frequency resolution: 1 Hz.
- Frequency steps: 1, 10, 100 Hz, 1, 10, 100, 500 Khz and 1 Mhz.
- Frequency stability with the new DDS version 10.0 with built-in 10 Mhz GPS external reference: +/- 0.01 Hz , so you don't need any further calibration.
- Functions: DDS level, Dial lock, Tx time, Memory write, Memory read, VFO A=B , B=A, A, B, Split, Rit, Band, -Fun, Fun+, -Key, Key+.
- My R-4C VFO DDS controls both the R-4C and the T-4XC. The equipment is left with a totally original look, like from the factory!