Most common parts in this receiver may be replaced with their off-the-shelf
equivalents: resistors, capacitors, transistors, diodes, and so forth. The only parts
for which TEN.TEC is the sole source is the pre-programmed U2 microprocesser IC
and the fabricated steel, aluminum or plastic parts 0f the enclosure. All parts used in
the receiver may be ordered by TEN-TEC part number as specified in the Parts List or
Component Index. Minimum order charges may be applicable.
T-KIT Technical Assistance may be contacted at (865) 453-7172, Monday through
Friday, during normal business hours.
1254 Troubleshooting Chart
No Speaker Audio
Make sure that the headphone jack cable is plugged into J6
and that the headphone jack is wired correctly.
E xternal s peaker with 1/8”
mono plug does not work
Front panel jack is wired for stereo. Change the speaker
plug to stereo, or change jack wiring per page 21.
Only one side of stereo phones
or stereo speakers is working.
Front panel jack is wired for mono. Change the jack wiring
to stereo per page 21.
Signals seem very weak
compared to other receivers
1. Make sure coils T6,. T9, L10, L11 and T7 have been
peaked for maximum signal strength.
2. C onnect a 0.1μF capacitor directly from the antenna to
the 1st Mixer input (cathode of PIN diodes D13 or D14). If
this results in a significant increase in signal strength, there
is an error in the shield bandpass filter section.
Erratic or blank display
Perform Microprocessor Reset
Stored frequencies not in
memory when receiver is
turned back on.
1. Memory backup battery bad or not installed.
2. Check battery snap connector.
Signals seem somewhat off
frequency compared to other
receivers.
1. Make sure C2 is adjusted to WWV (Assembly, p. 69).
2. Be sure you understand function of Clarifier control.
Numerous heterodyne or
“birdie” s ignals when us ing
indoor or active antenna
Antenna is too close to receiver and may be picking up
display multiplexing harmonics. We recommend at least 15
feet away with coax feed.
Very strong signal at 455 kHz
This is normal: the 455 kHz product detector oscillator (Y2)
is being picked up at the RF input.
1254
–
Reference - 37
Содержание SSB-CW-AM
Страница 25: ...1254 Assembly 4...
Страница 34: ...Phase 2 0 Assembly begins on page 14 1254 Assembly 13 This space is for your notes...
Страница 35: ...1254 Assembly 14 Phase 2 0 Schematic Diagram Details...
Страница 46: ...This space is for your notes Phase 3 0 Assembly begins on page 26 1254 Assembly 25...
Страница 47: ...1254 Assembly 26 Phase 3 0 Schematic Details...
Страница 57: ...1254 Assembly 36 Phase 4 0 Schematic Details...
Страница 68: ...1254 Assembly 47 This space is for your notes...
Страница 69: ...Phase 5 0 Schematic Details 1254 Assembly 48...
Страница 77: ...Phase 6 0 Schematic Details 1254 Assembly 56...
Страница 93: ...1254 Assembly 72 This space is for your notes...
Страница 101: ...Figure 3R Model 1254 Block Diagram 1254 Reference 8...