National NC-183 / NC-183D
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| Frequency | RX: 0.54–31 MHz + 48–56 MHz (6 m) |
| Power | Receiver only |
| Modes | AM, CW |
| Weight | 29.4 kg (64.8 lb) |
| Connector | binding-posts |
| Year | 1947 |
| antenna | binding-posts |
Estimated (unverified): Weight ~29.4 kg (64.9 lb) is the spec-sheet figure for the NC-183D; the single-conversion NC-183 is similar. Antenna connection is via terminal/binding posts (era-typical).
National's premium post-war general-coverage receiver, a larger and more capable sibling of the NC-173. Sixteen tubes, two RF and two IF stages, a crystal filter, and push-pull 6V6GT 'Hi-Fi' audio, covering 0.54-31 MHz plus the 6-meter band (48-56 MHz) with calibrated bandspread on the ham bands. The NC-183 (1947) is single conversion; the NC-183D (1952) adds dual conversion for better image rejection on the higher bands.
It is a heavy boatanchor at roughly 65 lb and receives AM and CW only - single-sideband reception needs the aftermarket CQ 6J6 product-detector modification. National's amateur-receiver business declined through the 1950s, and factory parts support ended with the company.
The NC-183 was a high point of National's post-war engineering, with the extra RF and IF stages giving better weak-signal performance than the simpler NC-173. The dual-conversion NC-183D, often fitted with the popular 6J6 product-detector mod, makes a capable vintage single-sideband receiver. Both remain desirable classics.
The National NC-183 is a premium post-war communications receiver from 1947 - a larger, more capable sibling of the NC-173 aimed at the serious operator. It is a five-band, single-conversion superheterodyne with two RF stages and two IF stages for excellent sensitivity and selectivity, covering 540 kHz to 31 MHz plus the 6-meter band from 48 to 56 MHz, receiving AM and CW.
The extra RF and IF stages gave it noticeably better weak-signal performance and image rejection than the simpler NC-173, and it carried the smooth tuning, push-pull 6V6GT audio, and robust construction that made National receivers prized. The later NC-183D added dual conversion (a second IF at 1720 kHz on the upper bands) for improved image rejection; single-sideband reception on either model is usually handled by the popular aftermarket CQ 6J6 product-detector modification rather than a factory product detector.
As one of the better general-coverage receivers of the immediate post-war era, the NC-183 remains a desirable and rewarding vintage set. See the simpler NC-173 and the later NC-190.