I’ve been asked to repair a transmitter used by a local Unitarian Universalist church to provide services to the hearing-impaired. It’s used for regular sunday services, music concerts, weddings, etc.
The base unit is a Telex SoundMate ST-200 and the telescoping antenna has snapped off. The unit is in a rolling rack which makes it pretty certain that if I just replace it with exactly the same antenna, it’ll get snapped off again in six months. So I’d like to replace it with a rubber duckie type antenna with the same characteristics. But I can’t find one online… my antenna-fu is weak, my ham license expired in the 1980s, so it’s hard for me to tell what will work.
The original antenna is a 1/4 wave telescoping chromed tube, 41 and 5/8 inches in length (the transmitter is claimed to use 72-76 Mhz, so that makes sense if speed of light equals frequency times wavelength). It was mounted on an old-fashioned fat threaded male UHF connector (PL259 style) which in turn was mounted on a right-angle adapter. I still have the right-angle adapter, and most of the antenna.
Does anyone know of a good rubber-duckie style antenna I can use to replace this one? Failing that, does anyone have any tips on making one? I read the American Radio Relay League’s .PDF guide, but it’s for a different frequency and it calls for expensive tools I don’t have (I have a multimeter, and I can tell what 120VAC 60Hz feels like with my fingertips). The other online references I’ve found (so far) also seem to assume I have tools and knowledge I lack.
Any and all advice gratefully accepted!