ZL1CVD

Fuchs S0 / 25


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Specifications Internal Layout
Cards Pinouts
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The FUCHS SO/25 is an HF Transceiver used by the South African military. Its also reffered to a B25 and a similar product is the French Thomson TRC-300. Several interconnecting modules are used to configure the transceiver for manpack, mobile or fixed station use.

I purchased the B25 faulty in 2005 but was not able to locate service / circuit data and ended up selling it in 2006.


 

Specifications

General
  • Frequency Range: 2.000MHz ~ 29.999MHz
  • Operation Modes: A2J (CW); A3H (AM); A3J (USB and LSB)
  • Frequency Step: 1 kHz
  • Frequency Stability: +/- 1X 10-6
  • Antenna: 2.315m whip or 7m longwire
  • Antenna Impedance: 50 Ohms direct + ATU support for whip & wire
  • Tempreature Range: -15 DegC ~ +55 DegC
  • Dimensions (HxWxD):  421mm x 212.5mm x 92.5mm
  • Weight: 7.5Kgs

Power

  • Battery: 14.4V (12x1.2V 4AH NiCAD) - built-in charger accepts 10~32V.
  • Battery life: 12 to 15 hours based on 1:9 transceiving / receiving ratio (speech)
  • KB/26 PSU module (pictured): 12~24V
  • Current: 0.45A RX, 3A TX Low, 4A TX High
RX
  • Sensitivity: >0.4uV(12dB(s+n)/n)
  • Image Rejection: -90dB
  • 1st IF Rejection: -80dB
  • CW Bandwith: 300Hz
  • AM Bandwith: 3kHz
  • SSB Bandwith: 2.7kHz @ 6dB
  • AF Power: 10mW into 300 Ohms, 20mW into 150 Ohms
  • AGC: AF level does not vary more than 3dB through an input range of 1uV to 100mV

TX

  • A2J Output Power: 10W (CW) into 50 Ohms
  • A3J Output Power: 6W PEP Low or 20W PEP High (USB or LSB) into 50 Ohms
  • Carrier & unwanted sidband rejection: >= 40dB in AJ3 mode.
  • Linearity: <25dB
  • Dynamic AF Range: 15dB
  • Harmonics: -40dB
  • Compression Time: appx. 1.5us
  • Output Protection: short and open circuits

Internal Layout

S0-25-BOTTOM.jpg (1017893 bytes) S0-25-TOP.jpg (743768 bytes)
S0-25-FRONT.jpg (647443 bytes) S0-25-FRONT-REAR.jpg (1358643 bytes)
S0-25-PA-REAR.jpg (474694 bytes) S0-25-PA-FRONT.jpg (757079 bytes)

Cards

Each card is colour coded and those that are a similar size are uniquly keyed to avoid the wrong card being plugged into the wrong slot.

Card/Module Top Card/Module Bottom
S0-25-28100888-TOP.jpg (611777 bytes) S0-25-28100888-BOTTOM.jpg (659732 bytes)
S0-25-28105688-TOP.jpg (877421 bytes) S0-25-28105688-BOTTOM.jpg (826679 bytes)
S0-25-28105908-TOP.jpg (823947 bytes) S0-25-28105908-BOTTOM.jpg (792950 bytes)
S0-25-15028212-TOP.jpg (903456 bytes) S0-25-15028212-BOTTOM.jpg (862020 bytes)
S0-25-15028214-TOP.jpg (892178 bytes) S0-25-15028214-BOTTOM.jpg (766115 bytes)
S0-25-15028215-TOP.jpg (956941 bytes) S0-25-15028215-BOTTOM.jpg (872076 bytes)
S0-25-28100872-FRONT.jpg (1370306 bytes) S0-25-28100872-BOTTOM.jpg (1301185 bytes)
S0-25-28103958-FRONT.jpg (426714 bytes) S0-25-28103958-BOTTOM.jpg (632304 bytes)
S0-25-15029937-TOP.jpg (833397 bytes) S0-25-15029937-BOTTOM.jpg (803640 bytes)
S0-25-28000962-BOTTOM.jpg (786379 bytes) S0-25-28000962-TOP.jpg (813028 bytes)
S0-25-28000962-END1.jpg (447744 bytes) S0-25-28000962-END-2.jpg (688511 bytes)

Pinouts

Handset_Pinouts.gif (33937 bytes) B25_ACC_Plug.jpg (27506 bytes)