SuperPro Performance

With a 21st century perspective......

Keep in mind that we are talking about a radio that ended its seven year production run more than 70 years ago. My Super-Pro 210 has not been restored and completely re-capped -- only repaired to maintain operation.

Frequency Readout and Stability

The main tuning scales are marked every 100 KHz between 5 and 20 MHz, every 50 KHz between 2.5 and 5 MHz, every 5 KHz between 0.2 and 0.4 MHz, and every 2 KHz between 0.1 and 0.2 MHz. It's not difficult to find WWV at 2.5, 5.0, 10 or 15 MHz, even if things don't line up exactly where they should. The bandspread dial is calibrated from 0-100, not directly in frequency. Even so, when tuned to 10 MHz WWV on the main dial, my SP-210's bandspread tracks frequency directly down to 9.4 MHz very linearly, ie. 67.5 on bandspread corresponds to 9.675 MHz within a couple of KHz. Makes it very easy to find shortwave broadcast stations. Other bands don't line up so nicely, but it's still easy to tune to a known "powerhouse" broadcaster at the top of the band and use the bandspread to find the one you really want.

The SP-200 will drift in frequency until it is fully warmed up. After 30 minutes or so you really don't notice it while listening to AM stations. If you operate CW, the drift is more noticable but still very managable with either the bandspread tuning or variable BFO. Drift on the LF bands is negligible. Frequency readout and stability is one area in which boatanchors will never beat the modern frequency synthesized receivers.

Sensitivity and Selectivity

The SP-200, with its 1 microvolt sensitivity, will hear most AM and CW signals as well as the modern competition. The selectivity options are good, especially on AM signals. The combination of crystal filter and variable IF bandwidth is very effective. The narrowest crystal selectivity can create problems on CW signals if you haven't let the receiver warm up -- signals will drift out of the passband in just a couple of minutes if you don't pay attention! It doesn't have the steep skirt selectivity of radios with mechanical or multipole crystal filters, but does have some measure of heterodyne rejection with the crystal phasing. This is very effective on the shortwave broadcast bands where stations are separated by only 5 KHz.


This is one area where the SP-200 series outperform more modern radios. Typical "serious" communications receivers and modern solid state gear have audio outputs of only 200 *millwatts* to 1 watt, and are often bandwidth limited to frequencies less than 3000 Hz. The SP-200 has high fidelity output from 40 to 8000 Hz at a power level of 14 watts. Distortion is very low up to 2 or 3 watts out, still enough to drive typical HI-FI/stereo speakers to impressive volume levels. This radio really sounds great!

User maintenance

This is another area where this radio and other "boatanchors" shine. Tubes and most discrete components in this radio can be easily checked and replaced by competent "old-school" technicians. The alignment and troubleshooting procedures require only basic test equipment.


There's something special about listening to a 50+ year old radio that you've repaired, aligned, and spiffed up.... the yellow-orange glow of the main and bandspread tuning dials and S-meter.... the additional warmth in the shack (important in New England winters). The SP-200, and all its Super-Pro kin, are something special.