The Shark
SEVERAL YEARS AGO I designed a conversion of the Top Flite Nobler to radio control, featuring coupled flaps and elevator. At that time, it seemed to me that the Jetco Shark 45, designed as a control-line stunter by Lew McFarland, would make an even better subject. It is a larger model, thus a bit more suited to larger engines. It also offered the advantage of being able to accept slightly larger radio equipment. Surprisingly, the Shark 45 is about the same size as a Kwik-Fli. In my opinion, it is a much prettier model than the old Nobler I have enjoyed so much.
The Finishing Touch
OVER THE PAST 30 years of model building, there have been many materials introduced for covering and finishing models. The most popular and easiest to finish at the time I became an active modeler was Silkspan (like tea-bag paper). For larger models, one used silk. Dope was the only finish used then. The period was 1948. Up to that time, nitrate dope sufficed because models used either gasoline ignition or diesel engines, or were rubber powered. When Ray Arden introduced the glow plug engine in the late 1940's, the now familiar glow fuel containing alcohol and nitromethane came into being. Nitrate dope was no longer suitable so we began to use butyrate dope. Butyrate dope is used on full scale fabric-covered aircraft because it is fire resistant while nitrate dope is not. It has the virtue of being hot "fuel proof," or more appropriately, hot fuel resistant.
Low-voltage Detector/Indicators
FOR MANY YEARS, the modern RC system traditionally has had a meter that indicated RF output by bleeding off a tiny bit of the RF from the final amplifier, rectifying it via a diode and using the rectified output to drive a sensitive micro or millimeter. Most have afforded a rough indication of RF output that one could really only use as an indication if there were a significant change, e.g., "50 percent of normal." One simply estimated safe flying time for airborne battery pack, e.g., six 15-minute flights. Eventually, some improvement was afforded with the introduction of battery test units such as the Super Cycle and several others that discharge the pack through a calibrated load and indicate the discharge time. At least this provides one with a better estimate of capacity and helps spot bad cells.
