Section 6.9 Other Problems - Henry Radio 3K Classic Mark II Operating And Maintenance Manual

The 5F': Classic filaments
are in series and the voltage should read about
15.6 VAC.
becaf the voltage varies more than 5% from these figures, the
taps on the filament transformer should be changed.
HIGH VOLTAGE
TRANSFORMER - The 3F, Classic Mark II domestic amplifier is
supplied with the ECA 1120A. The primary tap connections are listed below:
ECA 11 2UA
23C+ VAG--------------- T'ap 1
:-----Tap 3
:------Tap 5
213r? VAC--- -------Tap 7
The 31C Classic X and 5K Classic are supplied with one of the following high
voltage transformers:
ECA 1171 or ECA 1*214A
i= ^,mm,^n------^-----------Tap 1
'.,Uo-2n1 r) VAiJ---------- Tap i
'210-234 VAL:-..-------.---Tap 3
::30-12"40 VAC-.----------Tap 4
The
high voltage transformers are located on the bottom plate of the power
supply section.
SECTION 6.9 OTHER PROBLEMS
AMPLIFIEF? WILL NOT TURN ON The most likely cause is the circuit breaker.
Check
the continuity of the circuit breaker with an ohmmeter if the unit
will not turn on or off.
Another possible cause is the improper instal-
lation of the power plug on the power cable. If the high voltage turns on,
but the pilot lights, blower, and relay supply do not come on the 3 AG fuse
has blown.
ALC CIRCUIT SHORTED
A defect in the ALE circuit will prevent the tubes
from being driven properly.
FILAMENT
VOLTAGE FAILURE With a ceramic tube it is not easy to make sure
that the filaments are lighting. If the filaments are lighting correctly,
the air flow from the amplifier should feel warm. If the filaments are not
lighting,
the amplifier will not draw any resting plate current when it is
keyed. The filament voltage passes through a 4 pin Jones plug into the RF
chassis, so you have no filament first check that the plug is properly con-
nected.
After that you would have to check the filament transformer, the
filament
choke on the bottom of the RF chassis, or a problem at the tube
socket. Check the filament voltage at the pin jacks on the rear panel of
the RF deck. It should be 7.8 VAC for the 3K and 15.6 VAC for the 5K.
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