Amateurs had been operating radiotelephone on the 80-meter band between 3,500 and 3,600 kHz since it had first been permitted in late 1925.¹ To do so they had to return their licenses to their local radio supervisor for endorsement. On the 150-meter band, phone already dominated operation. And as the broadcasting boom continued, phone’s popularity grew as a specialized pursuit for some amateurs on both bands. For others it was a source of QRM since every phone allocation shared space with CW in its various forms, particularly on 80 meters, and there was not yet a band plan to keep them separated.

Whether from proponents or detractors, the heightened interest in phone operation caused QST Technical Editor Robert Kruse to call for articles about it. Long before he joined the ARRL staff, Kruse, with his background at the Bureau of Standards, had been a vocal proponent of clean signals, especially on phone, calling for honest signal reports, observing that horrible signals were being met with reports of “FB OM.” But his viewpoint had softened considerably since 1921 when he had referred to phone as an “obnoxious perversion of the CW set.” Six years later, though he considered phone worthwhile, hams still had a long way to go to get decent signals on the bands. So he called for QST articles not with a main editorial or a technical article introducing the problems in detail, but with all of two-sentences as a Strays entry in the June 1927 issue of QST:²

QST could find space for a few good articles on amateur phone operation. Anybody got anything they’d be good enough to write up for the information of the gang?

There was no title, nothing to draw attention to it—the third and last item in this Strays column. But it was situated at the bottom of the same page as ARRL Secretary Kenneth Warner’s correspondence with the Federal Radio Commission about the fate of the 150-meter band, something nearly all readers paid close attention to. No one missed seeing those two little sentences in Strays. The volume of reaction, which ranged widely between opposite viewpoints, probably surprised Kruse and was large enough to prompt him to elaborate in QST later that summer—taking a half-page this time.³

His disdain for the current state of phone operation was palpable. Most of what he heard on the air was awful, though not hopeless, and he believed that to get it right the proper construction and adjustment of a station for phone operation required far more care than for CW. So he asked readers to send material describing “actual high grade radiotelephone stations” and technical details about common challenges such as purity of power supply, modulation systems, and speech amplifiers.

If such material can be obtained—if any reader knows where to get it—then it seems entitled to be considered with QST’s other material and to be allowed space in the magazine in case it is able to stand the test of comparison with other contributions. If it cannot stand that test it does not belong in the magazine, just as the phone itself will deserve more space in the ether only if it can prove itself the equal of c.w. in effectiveness without an undue creation of undesirable situations.

He plainly had reservations beyond concern for column space in QST.

At the same time, a single letter to QST touched off its own thread of discussion, indicating the high level of reader sensitivity to the subject. 8MX and 8CBM, of the US Army’s amateur station 8BMW in Detroit, wrote that 80 meters was “too small and too important to be monopolized by phone,” and suggested that the band be returned to CW-only operation and that 150 to 175 meters should be a phone-only band where, they said, “the very few credible phones on 80 would be super-quality” (meaning that if a station had achieved good quality at 80 meters, it would sound even better on 150 since quality signals were easier to produce there). This would also help firmly establish amateur use of that band and open the possibility of 175 to 200 meters being offered in appeasement to the broadcasters if and when they again pushed for expansion.⁴ Several reactions followed, the unusually large number of which probably indicating a lively behind-the-scenes collection of viewpoints from which the editors had selected a few to publish:

8RD, also of Detroit, came to 80-meter phone’s defense saying he’d had success working several hundred miles on the band at night.⁵ Phone was a bit harder than on 175 meters but the distance was much greater. Besides receiving complimentary audio reports in QSOs, his evidence of good modulation was that his call sign was almost never copied incorrectly. (Phonetics were not yet widely used.) He also took note of a growing phone listenership, claiming that a fifteen-minute QSO would typically result in his receiving eight QSL cards.

7OX of Yakima, Washington, had been in radio since 1920 on all modes, worked DX, experimented with everything, but had grown tired of CW and with short, non-conversational QSOs that were meant only to produce a card. He now wanted to do something “that has a kick to it” by comparing his phone signals to CW on the same band, as did many others.⁶ Why keep phone in the 150 meter band? He wanted to hear more opinions on both sides of the issue, adding, “Why not turn our energy to making amateur phone something to be proud of? We have heard amateur phones that were superior to some of the broadcasting stations…”

A newly licensed amateur, 9AUH in Louisville, was drawn into amateur radio from being a broadcast listener hearing amateur phone operators and reading QST.⁷ He did not understand the 8BMW crew’s claim that 80 meters was being “monopolized” by phone operation when the bulk of traffic was now handled on 40 and 20. “I understand that phones are permitted only from 170 to 180 meters and 83.28 to 85.66 meters while our honorable brass pounding brothers have six, count ‘em, bands in which to pursue their feverish struggle for a W.A.C. certificate,” he wrote, adding “More power to ‘em!” But QST should be representing the phone enthusiasts too since they were “far more numerous than is supposed.”

From Lincoln, Nebraska, 9ANZ’s view was that, although amateur radio was usually said to exist for operator training and development of radio technology, we were, in fact, all in it for fun.⁸ He got more fun out of tinkering with the technology than even operating, and had started using phone on 85 meters within days of its authorization. “Short-wave radio telephony is about due for development,” he judged. It was not true that phone operators were poor CW operators; many were experts such as he was, being a “95%” CW operator. Some also took advantage of the brief period of regulatory uncertainty to operate on 40 and 20 meters with very encouraging results (even as he deemed such operation “foolish or inconsiderate”). He therefore advocated the expansion of phone privileges in the lower (wavelength) fifth of each band, the way it was on 80 meters. He realistically did not expect phone to compare with CW for DX work but nonetheless considered it valuable for communicating over long distances under good conditions.

After several months of taking this all in, Kruse had his own say, in detail, about the central problem in amateur radiotelephone.⁹ Taking aim at a popular misconception that phone signals were no wider than CW, he built his case step by step: With no key or microphone attached and a pure DC supply, CW theoretically has a single frequency component. Adding an AC plate supply one would also get two sidebands each 60 Hz away. If the station were using 500-cycle power, as did NAA, the sidebands would be separated enough that one could tune in to three distinct signal peaks. With voice modulation, those two sidebands would extend out, say, 3,000 Hz each if that were the range produced by the modulation system.

In this pure-carrier picture, one ought to be able to get very close to the edge of a phone station and not hear any interference. But that was hardly the practical case for phone or CW. “Now you know perfectly well that not one phone in a hundred is as sharp as that—nor one telegraph station in a dozen,” he reminded readers, asserting that “The sideband business utterly and entirely fails to explain the practical broadness of transmitters.” There were much bigger problems with the current practice of radio that overwhelmed theoretical bandwidth, things that made carriers impure.

If, as had been demonstrated, one could produce a cleanly modulated signal (what he called “sharp” carrying over a term from the earlier spark vs. CW discussions) even with sidebands, then one must look to something else as the cause of all the problems: a thing he called “wabbulation.” By this he meant inadvertent modulation of the carrier frequency. In a well-designed oscillator, lifting the key should simply cause the carrier to die out. But in a poor one, the frequency first would “swoop” across the spectrum far beyond 3 kHz. If you took an oscillator like that and used an AC plate supply (a common practice), it would be swooping 120 times per second! Besides causing QRM, a broadened signal was wasteful since at the receiver the extra breadth is not converted to sound. An unstable oscillator could also be shifted by a changing load, as when modulating an amplifier stage. One way to stabilize a transmitter was to use a crystal-controlled oscillator, but crystals were not yet widely available, at least not at a price affordable to most hams.

As an example of a good phone signal, Kruse cited the dramatically cleaned-up one coming from the WBZ transmitter, which now had a rock-stable carrier and sharp signal even when modulated and even though they were now transmitting with much higher power. Strong and clean were not mutually exclusive qualities of a radiotelephone signal. Amateurs had a lot of work to do. They’d soon be forced into action—innovation yet again—less than two years hence.

On 28 October 1927, the FRC expanded the phone allocation to include 150 to 190 meters (1,580 to 2000 kHz), and the top quarter (lower frequencies: 14,000 to 14,500 kHz) of the 20-meter band and the entire 5-meter band, but eliminated the phone band on 80 meters.¹⁰ The upper part (longest wavelength) of the 150-meter band was kept free of phone, not to protect CW operation, though that was also an effect, but as a “guard band” to keep amateur signals away from the broadcast wavelengths above. Some hams considered the loss of phone on 80 a good thing since many were complaining of QRM problems to both phone and CW stations and that the mixture on that band may have been a mistake. Nevertheless, later deciding it had overreacted by eliminating phone completely, the government restored phone privileges to the band.

Coincident with phone expansion, the final chapter was written for spark. While no spark transmitters had been heard on the air for quite some time, the FRC issued, for the first time, a federal regulation banning its use on all amateur bands.

de W2PA