Ten-Tec SSB-CW-AM Instruction Manual page 21

H. Model 1254 SWL Receiver
Kit Assembly OVERVIEW
You will build the Display Board first and then occasionally plug it into
the Main Board for further testing. To get a good fit of the LED's and 3-
digit displays, you'll be handling the front panel and display lens - be
VERY careful not to touch these with your soldering iron!
After finishing PHASE 2.0 (Logic and DC Power Input sections), the
powered-up Display Board plugged to the Main Board (via P1, P2) can
now simulate all receiver functions or features described in the Operating
Instructions in the Reference section, though not executing them.
Finishing PHASE 3.0 requires VCO coil adjustments done with a simple
voltmeter measurement at "VCO TP." Individual board drawings are
provided as a help for correct assembly of the two shielded VCO sections.
Completing Phase 4.0 lets you verify that the audio amplifier, product
detector and Second IF amplifier work properly. This Phase also includes
the AGC and uses the largest number of parts of any of the assembly
sections.
Phase 5.0: Finishing this section results in a non-tuneable receiver with
full sensitivity capable of receiving a 45 MHz test signal, with the Clarifier
control operational. Mixing the 45 MHz 1st output with the 44.545 2nd LO
produces the 455 kHz signal detected and amplified in the Phase 4.0
circuitry. The receiver is designed to generate its own 45 MHz test signal.
Phases 6.0 and 7:0: (RF Input and First Mixer sections, Final
Assembly): You're ALMOST ready to start using your receiver, so
don't rush these building phases! This work brings in the antenna
signals through the shielded Bandpass Filter circuitry to the First Mixer
(also shielded), where received signals are mixed with the tuneable 45-75
MHz LO signal from the VCO's. This mixing results in a 45 MHz 1st IF
signal fed to the input of the circuitry you built in Phase 5.0. Very simple
alignment is done in Phase 7,0 with the receiver mostly assembled. The
result is a frequency-synthesized dual-conversion receiver rivaling radio
sets costing much more.
See following foldout page for details on the major
mechanical parts used to finish your receiver in Phase 7.0.
1254 Getting Started 20