John, I finished the 150xt yesterday.
The enclosure is the nice part--it's just a plastic cassette case which I spray
painted black. It's very easy to modify, drill and cut. I used hot glue to keep a
thin piece of rubber under the circuit board, then hot glued the circuit board onto
the rubber. The two coils are 5mm "Unicoils" from Coilcraft. The violet is 7½ turns
and is 156nH with the core removed. The green is 5½ turns and is 99nH with the core
removed. The crystal is a common 16MHz with a 20pF load capacitance. It was ordered
from overseas at a great discount on eBay. The final frequency tunes at
A small hole was punched for the antenna wire. A power switch was added and its hole
carefully cut with an Exacto knife. 4x AAA rechargeable NiMH provide 4.8 volts. The
battery holder still fits inside the slim cassette box.
The design may be simple, but the results are sturdy and professional. Clear audio. A
good range. And inexpensive and easy to build. The design is flexible and allows
using substitute and junk-box parts. Some of small capacitors values were changed to
my nearest available value... i.e. 22pF to 27pF, etc. I'm making a few more of