Collins 32S-1 — Serial Number & Production Guide
VK6ADA Technical Reference · Collins S-Line Vintage Amateur Equipment · March 2026 · Mike Peace VK6ADA
The Collins 32S-1 SSB Transmitter was the first of the S-Line transmitter series, introduced in 1959 alongside the companion 75S-1 receiver.[1] Produced at the Cedar Rapids, Iowa facility through approximately 1964, the 32S-1 established the S-Line station concept and remains a highly sought collector piece. This guide consolidates serial number ranges, emblem transitions, manual edition history, and known circuit variations to assist collectors and restorers in authenticating and dating their units.
Overview & Specifications
Manufacturer | Collins Radio Company — Cedar Rapids Division, Cedar Rapids, Iowa |
Model Number | 32S-1 (Collins type designation: SSB Transmitter) |
Production Period | 1959 – approximately 1963–1964 |
RF Power Output | 100 W PEP SSB / 100 W CW |
Frequency Coverage | 3.5–4.0 MHz (80m), 7.0–7.5 MHz (40m), 14.0–14.5 MHz (20m), 21.0–21.5 MHz (15m), 28.0–29.0 MHz (10m) |
PA Tubes | 2 × 6146 / 6146A / 6146B (parallel pair, pi-network output) |
Driver / Exciter | 6146 driver stage; PTO-based VFO with ALC system |
Modes | USB, LSB, CW |
Carrier Suppression | ≥ 50 dB below PEP output |
Unwanted Sideband Suppr. | ≥ 50 dB below PEP output |
Mains Supply | 115 V AC or 230 V AC, 60 Hz single-phase (primary wiring selectable) |
Companion Receiver | Collins 75S-1 |
Companion Amplifier | Collins 30L-1 Linear Amplifier |
Introduced | 1959 [10] |
Important Note on Serial Number Sequencing
Per CCA historical research and a direct account from a former Collins employee,[9] Art Collins decreed that S-Line serial numbers were to be issued in random (non-sequential) order — a deliberate policy to prevent price discrimination among model variants sharing the same chassis. A lower serial number does not necessarily indicate an earlier production date. Broad ranges do, however, correlate meaningfully with production eras, particularly when cross-referenced with front-panel emblem type and internal component date codes.
Collins Logo / Emblem Production Eras
Collins Radio used distinct front-panel badge emblems across the S-Line production life. The emblem is the most reliable single dating indicator. For the 32S-1, which reached end of production around 1963–1964, virtually all units carry the Winged Emblem — any Round Emblem 32S-1 would be an extreme rarity requiring careful authentication.[3]
| Emblem Type | Production Period | Approx. S/N Range | Physical Description | 32S-1 Applicability |
|---|---|---|---|---|
| Winged Emblem | 1959 – Fall 1969 [3] | ~101 – ~7,500 (est. upper boundary) | Classic silver-and-blue winged Collins insignia. Two mounting holes visible either side if badge replaced. | Standard / expected. The 32S-1 production ended before the emblem transition. All authentic 32S-1 units should bear this emblem. |
| Round Emblem Transition | Fall 1969 only [3] | N/A — post-production | Round “meatball” emblem plus two small grey screws plugging former wing-emblem holes. | Not applicable. 32S-1 production concluded before Fall 1969 emblem change. |
| Small Round Emblem | Fall 1969 – ~1975 [3] | N/A — post-production | Circular Collins emblem, approximately dime-sized (~18 mm). No flanking screw holes. | Not applicable. Emblem replaced after 32S-1 production ended. |
| Large Round Emblem | ~1974 – FY1976 [3] | N/A — post-production | Round Collins emblem, approximately nickel-sized (~21 mm). Slightly bolder typeface. | Not applicable. |
Note: S/N range boundaries are derived from the CCA S-Line Production Surveys by Rod Blocksome K0DAS[4] and community-documented sales. They are best-estimate ranges, not definitive cut-offs.
Serial Number Lookup Reference
Quick Era Identifier — Enter Your Serial Number
Documented Serial Number Data Points
| Serial Number | Emblem / Era | Notable Features | Source / Reference |
|---|---|---|---|
| ~1,xxx range | Winged | Early production; consistent with 1959–1960 manufacture. Original 6146 PA tubes reported in several low-S/N examples. | CCA 32S-1 survey data [4] |
| ~3,xxx range | Winged | Mid production; corresponds to peak 32S-1 output c.1961–1962. 6146A tubes standard. | CCA survey / community documentation [4] |
| ~6,xxx range | Winged | Late production; consistent with 1963–1964 manufacture. Verify component date codes for confirmation. | QRZ Forums / collector community [7] |
Manual Edition History
| Edition | Date | Collins Part Number | Notes |
|---|---|---|---|
| 1st Edition | 1959 | — | Original publication with initial production units. Archived at the Collins Radio Association (CRA).[1] |
| ~2nd–4th Editions | 1960–1963 | Various | Progressive service bulletin amendments incorporated. Available at worldradiohistory.com. |
| Final Edition | Post-1963 | — | Final revision incorporating all service letter amendments. CRA PDF archive recommended for reference.[2] |
Circuit Variations by Production Era
| Change Description | Component(s) Affected | Era Indicator |
|---|---|---|
| PA tube type progression | V (PA pair) | Early units shipped with 6146; mid and late production standardised on 6146A. 6146B is an approved modern substitute. |
| ALC circuit refinements | ALC loop components | Service bulletins addressed ALC stability with certain SSB audio sources. Incorporated from approximately mid-production. |
| Rectifier diode specification | HV rectifiers | Original selenium or early silicon types. Replacement with 1N4007 equivalents recommended for all eras. |
| Filter capacitor values | HV filter bank | Electrolytic capacitor specifications updated across service bulletin revisions. Reform or replace on any stored unit. |
Physical Identification Guide
Step 1 — Front Panel Emblem
All authentic 32S-1 units should carry the Winged Emblem. Any 32S-1 presented with a Round Emblem warrants close inspection of the serial number plate and internal date codes, as the emblem transition did not occur until Fall 1969 — well after 32S-1 production ceased.[3]
Step 2 — Serial Number Plate
Located on the rear panel. Plain integer format — no alphabetic prefix or suffix. Use the lookup tool above to cross-reference estimated era. Typical confirmed 32S-1 serial numbers fall within the ~101–7,500 range, though exact upper production boundary is subject to ongoing CCA survey refinement.
Step 3 — Internal Component Date Codes
Electrolytic capacitors carry date codes in format YY WW (year / week). The latest date code on original components establishes the earliest possible ship date. Replacement components post-date original production and should not be used for dating.
Step 4 — Manual Edition Check
Examine the copyright page of any original accompanying instruction book. Earlier copyright dates (1959–1961 only) indicate an early-production unit or a replacement manual from that era.
Step 5 — Distinguishing 32S-1 from 32S-3
The 32S-3 (1964–1980) is visually similar. Key identifiers: the model number is clearly stamped on the front panel and rear serial plate. The 32S-3 introduced a reconfigured front panel layout and different final-amplifier screen regulation. Cross-check the manual edition — 32S-1 manuals reference different service bulletin numbers to those of the 32S-3.[1]
Typical Restoration Considerations
| Component | Recommended Action | Notes |
|---|---|---|
| HV Filter Capacitors | Reform or replace as first priority | Original electrolytics are 60+ years old. Reform carefully; replace if any signs of leakage or ESR failure. |
| HV Rectifiers | Replace with 1N4007 or equivalent | Original selenium rectifiers must be replaced without exception. Early silicon types should also be replaced. |
| PA Tubes (6146 pair) | Test and match; 6146B recommended | Matched pair essential for balanced output. 6146B is directly substitutable. Re-peak all tuning after tube replacement. |
| ALC Calibration | Verify per manual procedure | ALC threshold may drift after decades of storage. Follow manual calibration procedure with calibrated power meter. |
| PTO (VFO) | Verify alignment and stability | The permeability-tuned oscillator is a precision Collins mechanical assembly. Do not adjust unless drift is confirmed out of specification. |
| Mechanical Filters | Test insertion loss; seldom fail | Collins mechanical filters are extremely reliable. Failure is rare but verify with signal generator if audio sounds distorted or narrow. |
This guide consolidates publicly available CCA survey data, community restoration reports, and documented sale records. Serial number range estimates should be treated as approximations. Contributions and corrections are welcome via vk6ada.com.au or through the Collins community at r-390a.net.
References, Citations & Credits
- Collins Radio Company. 32S-1 Transmitter Instruction Book. Cedar Rapids Division, Cedar Rapids, Iowa. Various editions 1959–1964. Archived by the Collins Radio Association (CRA): collinsradio.org — Technical Archives
- Collins Radio Company. 32S-1 Transmitter Instruction Book, final edition. Cedar Rapids Division. Post-1963. CRA PDF archive: collinsradio.org
- Blocksome, Rod K0DAS. “The Collins S-Line Logo and Emblem Transition History.” Collins Collectors Association (CCA) Historical Archives. 2013–2016. Documents Winged Emblem (1959–Fall 1969), Round Emblem Transition (Fall 1969), Small Round Emblem (~1969–1975), and Large Round Emblem (~1974–FY1976) chronology. collinsradio.org — Historical Archives
- Blocksome, Rod K0DAS. Collins S-Line Transmitter Production Surveys. Collins Collectors Association (CCA) Technical Archives. Various years. Survey of serial number data, production quantities, and design change chronology for the S-Line transmitter series. collinsradio.org — Blocksome Surveys
- Collins Radio Association. Collins Radio Technical Archives — Manuals, Service Bulletins, and Historical Articles. collinsradio.org — Technical Archives
- WA3KEY Virtual Collins Radio Museum. Collins 32S-1 Reference Pages. Comprehensive community reference including circuit documentation and collector resources. wa3key.com. Accessed 2026.
- QRZ Forums — multiple threads documenting Collins 32S-1 serial numbers, restoration notes, and production eras. forums.qrz.com. Accessed 2026.
- Collins Collectors Association FAQ — Credits and biographical notes on Collins Radio engineers, including Gene Senti W0ROW (KWM-2, 30L-1, KWS-1 designer) and Dennis Day (75S-3 series). Hosted by WA3KEY: wa3key.com/ccafaq.html. Accessed 2026.
- Anonymous (attributed to a former Collins employee; reported by Roger KB4THL). “[Collins] Winged versus Round Emblems” — QTH.net Collins Reflector, July 2005. Documents Art Collins’ decree of random S-Line serial number issuance. qth.net/pipermail/collins — July 2005
- QST Magazine — Collins Radio advertisement, 32S-1 SSB Transmitter, American Radio Relay League (ARRL), 1959. QST archive: worldradiohistory.com — QST Archive
- Peace, Mike VK6ADA (Administrator). r-390a.net — R-390A/URR FAQ and Collins Community Knowledge Base. r-390a.net. Administered 2010–present.
- Peace, Mike VK6ADA. vk6ada.com.au — Collins S-Line Reference and Vintage Radio Documentation. vk6ada.com.au/collins-collection/. 2025–2026.