Heathkit SB-104 - VFO Filter Circuit Board

VFO/Filter Circuit Board
TROUBLESHOOTING CHART
SYMPTOM
Premix signal low on 10
meters.
Premix signal low
all bands
(VFO missing).
X-RAY VIEW
POSSIBLE CAUSE
1.
D1254thru D1255.
2. Q1251.
1. L1251, L1252.
2. C1254, C1255, C1256.
-
DIODES
D1251-Dl254
Dl255
(Shown from component side)
NOTE: Heam part numbers that correspond to the circuit
component numbers will be found in the Parts List starting
on Page
91 of this Manual.
TRANSISTOR
Q1251 1 MPSA20
I
417-801
QUAN-
TITY
4
1
TYPE
IN4149
1 N458
HEATH
PART NO.
56-56
56-24