Emerson Keystone Figure 637, Service Manual

Page: 36 / 37

Field Service Bulletin #1 (cont*d)
R-06 and Pin #3 of 6wU damper tube*
5. For sets coded Triangle 1 and Triangle U, unground R-26, 3900 ohm,
1 watt and connect to red lead on nearby terminal board which
actually connects to U,000 ohm bleeder resistor.
NOTE: For 120110B and 120113B with no code changes perform change
#1 which is listed in the service note before doing above
revision.
Models 6lUB, 637B, 614iB,
6U7B
chassis 120110B and 120113B Triangle
Codes 6 and 7.
1. Replace 33,000 ohm, 1 watt with 10,000 ohm, 1 watt from Pin #6
of V-5 (6AU6 to lug on terminal board).
2. Remove connections from Pin #6 of V-5 but keep them connected.
Refer to #2 above0
3. Connect a jumper wire from pin #6 of V-5 to C-Ul square terminal
lug of electrolytic #925166.
U. Remove jumper wire from terminal board side of 10K, 1 watt resistor
as in #1 above and junction of U70K ohm resistor and green wire
from fuse on terminal board under horizontal blocking oscillator
transformer.
5. Put 16" jumper wire from terminal board 3ide of 10K resistor as in
#1 and junction of R-36 damper resistor and lead to Pin #3 of
6wU
damper tube.
6. Replace C-19, .0U7 mf. with a .01 m f . condenser U00 volt.
NOTE: Materials needed for above revisions: One 10K watt resistor,
one .01 mf. condenser and l6H of jumper wire.
Additions to Addendum Sheet for Models 6ll*, 637, 6U±, 6U7 chassis
12011OC and 120113C.
All 120110B or 120113B chassis with Triangle 6 or over using the auto
transformer without the 6
k
6 vertical output have an electrolytic
#925166 instead of #925161 for C-39, C-Ul, C-7U so note this on parts
list for these chassis.
All 120110C andl20113C chassis use the #925166 electrolytic condenser,
therefore, correct the addendum part list for these chassis.
Very truly yours,
EMERSON RADIO
&
PHONOGRAPH CORPORATION
George Cohen
General Manager of parts
GC:VA Sales
&.
Service Division
Scanned by mbear2k - Jan 20121/17