November 15, 1945. The day that amateurs had waited for, ever since December 7, 1941. Finally, after three years and 11 months of wartime radio silence, amateurs were allowed back on the air! Granted, we didn't have everything back yet. The initial authorization allowed amateur operations on 10 meters (28-29.7 Mc), five meters (56-60 Mc), and the new two meter band at 144-148 Mc. And there were restrictions on these limited frequencies. Our old pre-war five meter allocation was temporary. The new post-war band was shifted to six meters (50- 54 Mc), but the actual transition would not take place until March 1, 1946. So, we were back on the 56-60 Mc segment for only 3-1/2 months.
On the new two meter band, the frequencies 146.5-148 Mc were unavailable within a 50 mile radius of Washington, DC and Seattle, Washington. The military was still using these frequencies, as well as our 160, 80, 40, and 20 meter HF bands. The military also occupied our new UHF and microwave allocations. It would be months, maybe a year or more, before the Armed Forces would fully vacate our bands and return them to us.
But amateurs didn't care. Unlike 1919, when there was open hostility to us by the military and the threat of our elimination, the post WW II Armed Forces, as well as the FCC, were fully aware of the tremendous assistance that amateurs had given throughout the war and they were eager to give us back our frequencies. The ARRL was working closely with the FCC and the military to get our bands back.
One band, however, was apparently not coming back. Our 160 meter band, the birthplace of our post 1912 operations, was fully occupied by the military with it's new LORAN Radio Navigation System. The Armed Services and the FCC made it clear that this segment was to remain for the use of LORAN. Over the years, the ARRL obtained small concessions -- a 25 kc segment here and there, 25 watt power limitations, day and night restrictions; but from the 1940s right up to the early 80s, our 160 meter band sounded like a huge broadbanded buzzsaw as LORAN completely dominated it.
But this was a minor blot on the landscape as amateurs rushed to get back on the air. Ten meters was the band they went to first and the 28-29.7 Mc range became crowded with those making up for lost time. Two meters was next; hams modified their old 2 1/2 meter equipment to operate on the new band, and soon the rushing sounds of the superregenerative receiver were everywhere. The more adventurous were trying out something called FM. Five meters was quiet. Since the band was available for only 105 days, many hams spent that time converting their rigs to the new six meter band.
On March 1, 1946, our old five meter band died and the new 50-54 Mc segment was born. Also on that date, to compensate amateurs for the loss of 29.7-30 Mc, we were given an 11 meter band at 27 mc. That's right, the present day CB band was once an amateur allocation.
By May 1946, we had our 80/75 meter allocation back. We also had a temporary allocation from 235-240 Mc, which would soon be shifted down to 220-225 Mc. On November 2, 1946, the FCC finally released our 40 and 20 meter bands. By the end of 1946, we had our full HF spectrum back, 80/75, 40 meters (which was CW only), 20, 11 and 10 meters. Note that there was no 15 meter allocation then. Our 15 meter band did not appear until 1952. The military restrictions on our two meter band were lifted in June 1947, and, except for 160 meters, the military was off of our bands.
By 1947, every amateur band from 80 thru two meters was full of stations. But there was trouble brewing. Amateurs weren't the only ones taking to the airwaves. Television was growing by leaps and bounds. In 1946, there were only 7,000 TV sets. In 1947, the number jumped to 180,000, and by 1948, there were over 1 million TVs in use. Amateurs, who were used to harmonically related bands and an empty VHF spectrum, were not prepared for the TVI their neighbors were experiencing. A typical unshielded amateur transmitter, operating on 14, 28 or 50 Mc, could wipe out all the TVs in the neighborhood. QST ran a series of articles on proper shielding and filtering of stations and hams gradually learned to eliminate harmonics from their transmitters. But there was one band where shielding and good design didn't seem to help -- six meters. Our 50-54 Mc segment was sandwiched right between TV channel 1 (44-50 Mc) and channel 2 (54-60 Mc). At that time, only channel 2 was actually being used for TV. The channel 1 range was still part of the old pre-war FM Band (42-50 Mc) which was being phased out in favor of the new 88-108 Mc allocation. We were causing interference to WCBS and the other handful of stations on channel 2. And the problem would only get worse when channel 1 became available. Tests were run and an interesting solution was proposed. Because a television video signal is amplitude modulated, operates with a wide bandwidth and uses the lower portion of the TV channel, it was determined that channel 2 was twice as susceptible to interference from a 6 meter station than channel 1 was. The ARRL's proposal to the FCC? Eliminate channel 2, keep channel 1. But this idea didn't sit well with the stations already on channel 2, nor did it win the approval of Major Armstrong, who was still fighting the grand battle to keep FM Broadcast in the 42-50 Mc range. And so, in August 1947, the FCC withdrew channel 1 from the TV allocations. By the end of 1947, all the pre-war FM broadcast stations had disappeared from the 42-50 Mc range, which was then turned over to Public Service. Amateurs learned to operate in the lower portions of 6 meters to avoid TVI to channel 2.
In our next installment, we are going to look at a major upheaval that began 30 years ago and pitted amateur against amateur, and (according to some) the ARRL against hams. I'm talking about incentive licensing, and how it changed the entire licensing structure.
Copyright 1996, 2001, 2005 by William Continelli, W2XOY
All rights reserved.
These columns were originally written for the Schenectady Museum Amateur Radio Club.