Radios, then and now

vintage craft rc radioI bought my first radio control system in 1977. It was a Kraft KP-4A, the best I could afford as a 7th grader. If I’d had more money I’d have bough a real Kraft radio or maybe a Proline. If I’d had less, I’d have been stuck with a Cirrus (Hobby Lobby) or Tower Hobbies system. But I had my Kraft radio, even if it wasn’t compatible with the upscale Kraft radios. It cost $204.00 plus shipping. Keep that price in mind later…

A Full House radio control system…

One of the big attractions (besides being a Kraft) was that it came as a full house system. That means it included 4 servos and NiCad batteries for both the transmitter and receiver. It also had open gimbals (plastic, not metal like the “real” Kraft radios). In those days, cheaper radios often used AA disposable batteries instead of NiCads, only included 2 servos, had closed gimbals, etc. The day I got it was one of the happiest days of my childhood.

A heavy radio control system…

As much as I loved my KP-4A, it was heavy. The battery (550 mAH) weighed a whopping 6 ounces. The servos (KP-14) were 1.6 ounces each, and the 4 channel receiver was 1.7 ounces. Add another half ounce for the switch/power harness and a 2 channel flight pack was almost 3/4 of a pound. Besides the weight, everything was BIG. It barely fit into my Airtronics Q-Tee and it was definitely too heavy for the Q-Tee.

In spite of the size and weight, I managed to get it stuffed into my Q-Tee and it actually flew successfully. After 4 or 5 flights the cabane struts broke and I couldn’t figure out a way to fix them without adding more weight to an airplane that was already too heavy. I put the Q-Tee on a shelf and built a Midwest Little Stick. The KP-4A was moving to a new home, a real Full House (4 channel) ship. Unfortunately it was also on the heavy side for the Little Stick, which never flew very good.

After the Little Stick, I went back to 2 channels and put the radio into a Bridi Soar Birdy glider. In spite of the heavy radio, the Soar Birdy actually flew really good. I wish I still had it, but I sold it many years ago when I lost interest in RC for awhile…

Kraft KP-4A vs today’s radios…

My KP-4A came with a full flight pack – receiver, 4 servos, NiCad batteries, and switch harness. It even came with a few molded plastic servo trays and a battery charger. It worked in the 72 MHz radio band, and there were only a few frequencies available. Frequency control was a big issue at RC flying sites. If someone turned on a transmitter on the same channel as yours while you were flying, you could probably say goodbye to your airplane. All of that cost $204 in 1977, which is about equal to $830 in today’s dollars. I recentl bought a new radio for $215, which would have cost about $53 in 1977 dollars…

Of course, all is not equal between the two. My Taranis radio only included the transmitter (Tx), receiver (Rx), and Tx battery. No Rx battery, no switch harness, no servos, and no battery charger. There is actually a really good reason it doesn’t include them, but I’ll add the cost of those items to make the comparison fair. I paid $22 for 2 batteries, $45 for a battery charger, $30 for 4 servos, and $15 for an electronic speed controller/BEC. Total money spent: $327, or about $80 in 1977 dollars.

For my “$80” I got a 9 channel radio that’s expandable to 16 channels. It operates on the 2.4 GHz band using some magic called SSFH (spread spectrum frequency hopping). Sounds fancy but all it means is that interference from other transmitters isn’t an issue.

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