lf group
After many recent direct requests for decca 5501 mods for 73
Khz see following info.
This info is a general guide.
High band units need to be modified to Low band specification
for convenience to get on 73 Khz
Main coil inductance needs to be 126.75 uH which in
conjunction with existing Capacitor board of 37.5 nF will resonate on 73
Khz.
Guard cct will consist of 9 turn overlapping main coil winding
and in conjunction with C1/330nF plus C2/470nF in parallel will achieve the
object, see cct diagram of 5501 unit.
Low band unit 5F will need only slight adjustments, 6F will
need some more turns added to main coil, guard coil should be within tolerance
possibly.
73 and gl
de mal/g3kev
