Modern Era Handy Portables
DH4PY

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      SEM-52A
 SEM 52-E 1/2
 SEM 52-N
      SEM -52 S

 

 

 

 

 

 

   SEM 52-N and
   SEM 52-E 1/2

are most likely prototypes, developed as replacement for SEM-52A - they also use the same housing.

They have 12 crystal controlled channels ; for each channel one module is inserted into the channel switch. The number of modules provided still is unknown. (I could not find any other technical details except the chart below).

SEM-52-E 1/2 was produced by SEL. All known specimen have low production numbers; it seems that only few were produced.

SEM-52N was built in or for Norway (Mottaker = receiver). The interesting part is the BW- sign and the BW Serial number. It shows that the radio was given free for BW- use. But no one knows anything about it.

In spite of the development of these (crystal controlled) prototypes with 12 channels the successor became the (synthesized) SEM-52S with 6 channels.

Technical data in comparison:

Technical specification
SEM 52A
SEM 52N
SEM 52-E1 / 2-4
Frequency range 47 - 57 mHz 70 - 78 mHz 2) 39 - 48 mHz
3) 47 - 62 mHz
4) 60 - 80 m
Channel spacing 25 kHz 25 kHz 25 kHz
Number of RF channels 6 out of 400
crystal oscillator		 12 out of 320
crystal oscillator		 12 out of 360, 600 or 800;
crystal oscillator
MTBF (calculated) 4000 hrs 4000 hrs 2000 hrs
RF output 0.3 Watts 0.3 Watts 0.3 Watts
Sensitivity @ 20dB 0.4 µV 0.4 µV 0.7 µV
Power supply 6.6 - 9 V 6.6 - 9 V 6.6 - 9 V
Power consumption standby / receive 5 / 35 mA 7 / 45 mA 11 / 38 mA
Power consumption on transmit 225 mA 230 mA 210 mA
Battery life 15 hrs 15 hrs 15 hrs
Range 3 - 5 km 3 - 5 km 3 - 5 km
H x W x D 180 x 85 x 36 mm 180 x 85 x 36 mm 180 x 85 x 36 mm
Weight excluding batteries 600 g 600 g 600 g
Manufacturer SEL ? SEL