Letters To The Editor
All letters will be carefully considered; those of general interest will be used. Send to Model Aviation, 1810 Samuel Morse Dr., Reston, VA 22090.
Electric Power Control
It's been called to my attention that in many instances a particular characteristic of my Electric Speed Control, which was published in the June 1983 issue of Model Aviation, can cause a potential safety hazard. It seems that, in some cases, loss of signal from the receiver may cause the electric motor to advance to full throttle. Obviously, with no control, this could cause serious harm to person and property.
The fix is fairly simple and straightforward. All that is required is to change the value of C3 to 0.2 or 0.22 microfarads and to add a 10-megohm resistor in parallel to C3. This 10-megohm resistor will bleed off any excess input bias current coming from B1 which may be causing the problem.
If anyone who has purchased a Speed Control from me (Jomar Products) feels that this mod is beyond his or her ability, simply return the Speed Control to Jomar and the upgrade will be put on and the Speed Control returned free of charge. It is essential that we do all that is possible to make our flying as safe and problem-free as possible.
Joe Utasi Cincinnati, OH
Bravo, Model Aviation
In the past few years it would seem that there has been a resurgence of interest in Control Line. At a time when several of the major manufacturers have found it unprofitable to continue to produce Control Line kits, it has been reassuring that Model Aviation has done such an excellent job of keeping our interest keen.
The idea of printing Ted Fancher and Al Rabe side-by-side in the June issue was exciting and made the differences in approach remarkably clear. I was particularly grateful to see Al Rabe print again after his prolonged absence. As a newcomer thirsty for knowledge and concerned about disagreement between two pilots, I was happy to see both views in print and hope Mr. Rabe will be able to contribute his knowledge again in the near future.
Richard Kaye New Rochelle, NY
U.S. Patent Office
I read with great interest the April 1985 issue of Model Aviation article by Jan P. Koniarek about the U.S. Patent & Trademark Office.
Dave Willough San Diego Aero Space Museum
I get a thrill every time I visit the museum. I'm just writing to add a little information concerning the article. The museum also houses a second-floor library which contains a large collection of three-views, photographs, plans and books on the aviation aspect. The museum can be of great help to anyone doing research. Just let the gate attendant know you want to use the library; there is no charge.
Regarding the U.S. Patent Office, some MA readers may be interested to know there are over 50 Patent Depository Libraries (PDLs) across the country that have copies of some patents on file at the Patent Office. Some PDLs are city or county public libraries; others are libraries on university campuses. For a room list, phone the Patent Office, Washington, D.C., (202) 557-3158 — ask General Information. A letter to the Commissioner of Patents & Trademarks will bring a pamphlet of general information.
The Los Angeles Public Library's Patents Room claims to have the only complete file of patents west of St. Louis. There is even a PDL at the San Diego Public Library, which I was unaware of until I received the pamphlet.
Thanks to Mr. Koniarek's article, we may be able to add a new dimension to our modeling experience — and we may not have to travel to Washington, DC to do it.
Robert Womak La Mesa, CA
Luther's Mailbag
Can you help me? I received a letter from a reader about aerial photos. It did not have a SASE enclosed, so I set it aside to answer later. When an envelope is enclosed, I usually answer on the back of the writer's letter and mail it right away. Perhaps this letter was thrown away with the Christmas cleanup. The answer I wanted to give is as follows:
Dear aspiring photographer: You said you were puzzled about how to take aerial photos using an RC model. I assume you can figure out how to use an extra servo to trip the camera, so I will also assume your intended question was about aiming the camera to ensure you will get the wanted subject. With a simple forward-looking camera arrangement, you cannot know where the camera is pointed, so you use a reference line such as the wings and shoot every which way you can in the general direction. Instead, if you aim the camera out the side of the model in the direction of the left wingtip, you can circle the area and trip the camera shutter at every level and angle required to be sure you have the correct photo among the exposures. With practice, you can obtain many usable photos on each flight. The most important thing is to fly the model smoothly.
You wanted to photograph your house in the winter, but I can tell you that most wintertime pictures are very dismal in appearance. Also, I hope you are on an isolated farm, as you should not fly over your neighbors' homes. Don't fly in populated areas!
For further references on what can be done with aerial photography from models (besides the Space Shuttle photo you already have seen), please refer to the June 1979 and June 1980 issues of Model Aviation.
Luther Hux Annandale, VA
USAF Museum
As many of your readers are interested in the U.S. Air Force Museum's Research Center, we thought that they should be made aware of our new policy regarding use of our research facilities. We would appreciate it if you would run the following announcement in your publication.
Due to the steadily increasing workload and limited manpower to support research requests at the U.S. Air Force Museum's Research Center, access by the general public to the museum's reference files is by appointment only. This policy went into effect in January 1985. It will provide patrons better service and will allow museum personnel to maintain the files more efficiently. Also, any written requests to the Research Center from the public for data will be honored except under unusual circumstances. Appointments for access to these files may be made by letter or phone: (513) 255-4644. The Research Center is open 9:00–4:00 Monday through Friday except federal holidays.
Charles G. Worman Chief, Research Division U.S. Air Force Museum Wright-Patterson AFB, OH 45433
Transcribed from original scans by AI. Minor OCR errors may remain.
