Field Strength Meter
IM-84/URM-50
used with external antenna or handheld RF sniffer to tune & monitor transmitters
Comprises
IM-84/URM-50 FSM
accessory case w/ remote meter and RF sniffer coil
mast-mounted antenna
schematic - download 0.3 MB pdf
NAVSHIPS 91946 -
download 28 MB pdf
accessory case
OCT-3 (rack mount)
Frequency Shift Monitor
two OCT-3 new in crate -
better photos coming soon
comprises CHZ-60170 receiver
Senses RF in transmitter room or uses external antenna
- see pp 172-173 of "RTTY from A to Z"
OCT-2 (cabinet) and OCT-3 (rack mount) are a 1947 contract. There was an earlier OCT with a different design before this model. It was used to monitor FSK shift in RTTY transmitters. It is basically a superhet receiver with two limiters and a discriminator whose output is supplied to a VTVM which indicates the amount of frequency shift. The audio output (phones) comes from the discriminator to aid in tuning, so it is essentially an FM receiver, not useful for AM or CW.
NAVSHIPS 91131