Frequency Hopping Radios
DH4PY

Click picture to enlarge

 

 

 

 
  SEM-70
      SEM-90

 

 

 

 

 

 

  SEM-70

is a modern backpack. It can only be used portably, there are no additions, e.g mountings for mobile use. Frequencies are set by

  • "Handwahl (HW)" hand, using fixed frequencies ; or by
  • "automatischer Kanalwahl (AKW)" , scanning frequency bundles.

    AKW is no real "Frequency Hopping".Since the radio scans preset frequencies, I also list it in this category.
     
    Parts of the radio:( see pictures )

    Main block , consisting in

  • Main block A/VHF and
  • "automatischer Kanalwähler FSP 70" the automatic frequency changer.
    FSP 70 has 10 memories, each serving 16 channel bundles.
    The main block cannot be used without the additional set.

    The additional set for portable use, consists in:

  • Battery case BB 70
  • Antenna matcher AT 70.
  • Handset H-155
  • Cable NF 10-NF 10 for H-155.
  • Pouch TT 70 , with built- in counterpoise. A smaller pouch may be taken off. It contains handset, cable, and spare battery.
  • Long antenna : Antenna with bendable foot.
  • Short antenna : only antenna.

    Relais - addition RSZ 70: By using RSZ 70, two SEM-70 can form a relais. The RSZ 70 does NOT belong to the main block or the additional set.

    Freqency range:
    30.000 ... 79.975 MHz

     

    Technical data:
    HF output:
    low: 0.4 Watt
    high: 4.0 Watt
    Powered by:
    Lithium battery 16.8 V 8 Ah
    Channel spacing:
    25 kHz
    Modulation:
    Frequencies set by hand: FM
    Automatic frequency setting : digital, delta modulation
    Data transmission:
    up to 16 kBit
    Antenna lengh:
    short antenna: 42 cm
    long antenna: 103 cm
    Range:
    short antenna / small power: 2 km; / big power: 3,5 km
    long antenna / small power: 3 km; / big power: 5 km
    Size and weight:
    ready for use in Pouch:
    416 x 275 x 180 mm, ca 8 kg.