From the mid-1930’s until World War II, amateur radio’s #1 mode of voice operation was AM, a.k.a. double-side band with a carrier. After the war, single-side band voice mode became popular for a number of reasons including 3 kc of bandwidth versus 6 kc of bandwidth in an AM signal and, because of the narrower bandwidth, more power could be “concentrated” on the narrower SSB conversation meaning a longer range to the signal. Amateur/ham AM radio prevailed for about 20 years, but technological advances caused it fade out in favor of SSB.
A Collins KWS-1, an early SSB transmitter that was installed in B-47’s and B-52’s flown by Actor and Air Force General Jimmy Stewart and 4-star General Curtis LeMay, who masterminded the WW2 “fire bombing” of Tokyo and the atomic bombing of Hiroshima & Nagasaki. Click on the photo to enlarge.
It’s apparent that the same thing that happened to AM radios is happening now to not only SSB, but also VHF & UHF analog FM radios. Digital modes are quickly taking over from the analog SSB & FM modes.
SSB is in competition with numerous digital modes on the 160M to 10M HF + VHF, UHF and more bands! Fortunately, we have devices like the Tigertronics SignaLink™ USB Digital Communications Interface that will help us use digital modes on HF and, to a certain extent, VHF & UHF. The SignaLink™ will give your radios RTTY, SSTV, CW, PSK31, WSPR, WINMOR, Winlink 2000, FLDIGI, MT-63, AMTOR, PACTOR, G-TOR and more.
The SignaLink™ as yet will not give your fairly-soon-to-be-antique analog FM radio access to proprietary digital modes such as C4FM (Yaesu only), D-Star (Icom and FlexRadio Systems only), DMR (available from several vendors), etc.
Digital modes are coming on quickly! So, don’t forget about a digitally enabled radio when you make your next radio purchase. Please remember that only the C4FM form of digital modes from Yaesu is what would be compatible with our club’s four repeaters.
Your analog radios will continue to work as we move into 2017, 2018 . . . but, analog radios are not able to communicate with digital radios. BARC, like everyone else, plans to move toward digital modes including possibly an Internet linking technology such as D-Star.
BARC has four (4) Yaesu C4FM/analog repeaters, but when our 444.1 and our 145.23 receive a D-STAR signal, they automatically switch to D-STAR. D-STAR is the king of digital modes in Georgia, especially Georgia ARES®, which is why two of our four repeaters are D-STAR capable.
de John MacDonald, K4BR