Heathkit SB-200 Complete modern parts list

SB-200 Complete modern parts list

 1. High-Voltage Power Supply Components

Component Original Spec Modern Replacement Spec Mouser Part Number DigiKey Part Number Notes

Filter Capacitors (C1–C6) 125 µF / 450 V 220–330 µF / 450 V, 105°C, Snap-in 598-331A450M2PH (Cornell Dubilier, 330µF) 493-15716-ND (Nichicon, 330µF) Upgrade to 330µF requires Soft-Start mod.

Bleeder Resistors (R1–R6) 30 kΩ / 10 W 82 kΩ / 3 W or 2x 220 kΩ / 1 W 283-82K-RC (Ohmite, 3W) 82KQT-ND (2x 220k in parallel) Reduces heat from 26W to <1W total.

Rectifier Diodes (D1–D16) Silicon Rectifier 1N4007 (1000V/1A) or BY225 (1300V/3A) 512-1N4007 (Vishay) 1N4007FSCT-ND (Diodes Inc.) Use 10x in series for safety margin.

Bias Filter Capacitor ~100 µF / 6.3 V 100 µF / 16 V Aluminum Electrolytic 667-ECA-1CM101 (Panasonic) P1235-ND (Panasonic) Low voltage rating is sufficient. 

HV Fuse N/A (Add-on) 2 A / 10 kV Ceramic High-Speed 504-50200 (Littelfuse) F10200-ND Essential for tube flashover protection.

Inrush Thermistor N/A (Add-on) CL-90 or MS32 10002 (10Ω, 5A) 527-CL90 (Ametherm) 2156-CL90-ND Limits transformer/cap inrush current.

Glitch Resistor N/A (Add-on) 15 Ω / 10 W Wirewound (Non-inductive) 290-15-RC (Ohmite OX series) 15F10-ND Absorbs energy during catastrophic failure. 

Heathkit SB-200 power supply capacitor kit

2. RF Deck & Tube Circuit Components

Component Original Spec Modern Replacement Spec Mouser Part Number DigiKey Part Number Notes

Plate Resistors (Suppressor) 47 Ω / 2 W Comp 56 Ω / 2 W Carbon Composition (Non-inductive) 290-56-RC (Ohmite OX series) 56F2-ND (Ohmite) Critical: Must be Carbon Comp, not film. 

Suppressor Wire Bare Copper 12-14 AWG Teflon Insulated Stranded 566-1240-ND (Belden, 14 AWG) AE1014-ND Cut 115mm length for hairpin loop. 

Grid Resistors (R21, R22) 33 Ω / 2 W 33 Ω / 2 W Carbon Composition 290-33-RC (Ohmite) 33F2-ND Match pair within 1% if possible.

Grid Capacitors (C14, C15) 200 pF / 500 V 200 pF / 500 V Silver Mica (5% tol) 594-CD15FD201JO3 (Cornell Dubilier) CD15FD201JO3-ND Keep leads <6mm.  Some use 510pF.

Filament Choke (RFC2) ~10 µH 20–25 µH RF Choke (High Current) 546-190-253J15 (Miller) M8660-ND Ensure current rating > 3A.

Filament Bypass (C12) 0.02 µF 0.022 µF / 630 V Film (Polypropylene) 667-ECQ-U2223KL (Panasonic) EF1126CT-ND Non-inductive film type preferred.

Plate Choke (RFC3) ~50–100 µH 60 µH / 500 mA RF Choke (J-W type) 436-1025-ND (J.W. Miller) M4563-ND Verify DC resistance is low (<10Ω). 

Anode Blocking Cap 500 pF / 5 kV 500 pF / 7.5 kV Ceramic Doorknob 80-C941U501KZS (Cornell Dubilier) 399-11455-ND High voltage rating is critical. 

Tube Sockets Ceramic 4-Pin Ceramic 4-Pin (572B/811A compatible) 520-1423 (Amphenol) AE1023-ND Replace if original is plastic/cracked. 

Tubes (V1, V2) 572B 572B (Shuguang/Taylor) N/A (RF Parts Co.) N/A (RF Parts Co.) Not typically stocked by Mouser/DigiKey. 

Heathkit SB-200 parasitic suppressor assembly

3. Input Network & Metering Components

Component Original Spec Modern Replacement Spec Mouser Part Number DigiKey Part Number Notes

Input Caps (80m) ~510–910 pF 560 pF / 1 kV Silver Mica 594-CD15FD561JO3 CD15FD561JO3-ND Values vary; verify with analyzer. 

Input Caps (40m) ~360–510 pF 390 pF / 1 kV Silver Mica 594-CD15FD391JO3 CD15FD391JO3-ND

Input Caps (20m) ~200–360 pF 220 pF / 1 kV Silver Mica 594-CD15FD221JO3 CD15FD221JO3-ND

Input Caps (15/10m) ~47–68 pF 56 pF / 1 kV Silver Mica 594-CD15FD560JO3 CD15FD560JO3-ND

HV Divider Resistors 4.7 MΩ (x3) 1.5 MΩ / 1 kV Metal Film (x10) 299-1.5M-RC (Vishay) 1.5MQBK-ND Series chain totals 15 MΩ.

Meter Protection Diodes N/A 1N5408 (1000V/3A) or 1N4148 512-1N5408 1N5408FSCT-ND Install inverse-parallel across meter. 

Meter Shunt ~1 Ω 1 Ω / 5 W Wirewound (Precision) 283-1.0-RC (Ohmite) 1.0QT-ND Ensure low temperature coefficient.

Meter Lamp 6.3 V Incandescent 6.3 V LED with 1kΩ Resistor 512-LED63V (If avail) or Generic LED5MM-ND + 299-1K-RC Reduces heat inside cabinet.

4. Relays, Connectors, and Mechanical

Component Original Spec Modern Replacement Spec Mouser Part Number DigiKey Part Number Notes

Antenna Relay (K1) DPDT 120VAC Vacuum Relay or High Power RF Relay 546-JEN1212 (Jennings) JEN1212-ND Lower loss on 10m/6m than original.

Input/Output Connector Proprietary SO-239 (UHF) or BNC Bulkhead 523-142-0201-202 (Amphenol) ARF1055-ND Use Teflon insulated (RG-142) coax. 

Cooling Fan Blower Motor 4" (120mm) 115/230V AC Muffin Fan 527-109P0412 (Sanyo Denki) 109P0412-ND Ensure ≥20 CFM airflow.

Line Cord 2-Wire Hardwired 3-Wire Grounded Cord + Strain Relief 536-701960000 (Schurter) WK2030-ND Mandatory for safety grounding.

Wire (Internal) Cloth Covered 22/18/12 AWG Teflon (Silver Plated) 566-1420-ND (Belden 1420) AE1020-ND High temp, low loss dielectric.

Coax (Internal) RG-58 RG-142 (Silver/Teflon) or RG-316 566-1421-ND (Belden 1421) AE1021-ND Same OD as RG-58, higher temp rating. 

Implementation Notes

Resistor Types: For parasitic suppressors, carbon composition is mandatory.  Metal film or wirewound resistors will act as inductors at VHF and fail to suppress oscillations.

Capacitor Voltage: Always exceed the working voltage by at least 20%. For the input network, 1 kV rating is recommended despite lower operating voltages to handle SWR spikes.

Sourcing Tubes: 572B tubes are not typically stocked by general distributors like Mouser/DigiKey. Purchase from specialized RF suppliers like RF Parts Company or Tube Depot. 

Soft-Start Requirement: If upgrading filter capacitors above 220 µF, the inrush thermistor (CL-90) is mandatory to prevent tripping breakers and damaging the transformer.