I´ve been given an old long range cordless telephone. The base station
takes two antennas (transmit and receive) but only came with the RX
antenna. I can make a homebrew TX antenna but need to know the
transmission frequency in order to do so.

Naturally the unit came with no manual, no specs, and no schematic. No
manufacturer´s name appears outside or inside the equipment, not even on
the PCBs. There are no FCC or UL numbers to look up. I do have a clue,
however: The base unit´s reception antenna is clearly labled ¨RX: 70
MHz¨. And inside the handheld unit there is a component stamped ¨70.365
H.ELE. CH23 1J¨. So 70.365 MHz seems to be the base unit´s RX frequency.
Also inside the handheld are two apparently identical commponents stamped
39.040 and 10.245 respectively. So perhaps one of these is the base
unit´s TX frequency in MHz?

To test my idea I looked inside the base unit. There are four apparently
identical components, stamped 59.665, 10.245, 49.740, and ¨10M 15A¨,
respectively. So is it safe to conclude that 10.245 MHz is the base
unit´s TX frequency and that I should make the antenna for that frequency?

--
Warren Post
Santa Rosa de Copán, Honduras
http://srcopan.vze.com/