Funny thing about bias current and radio-teletypewriter sets. If the bias supply
 is set too high, it can burn out the modulator of your set.
 F'rinstance, whether you're working with an AN/GRC-26D, an AN/VRC-
 29 or an AN/GRC-46, the bias current should measure 60 milliamperes.
 Since all sets use the TT-98 and the TT-76 teletypewriters, a couple' perti-
 nent paragraphs in appropriate TM's should straighten you right out-especially
 if radio repair is your specialty and
 Steletype work isn't.

 CHECK YOUR
 MANUALS FOR THE.
 ADJUSTING
 PROCEPURE5!





 Para 2-8c and fig 2-7 in TM 11-5815-
238-12 (Dec 65) on the TT-76 and
para 2-13 and fig 2-9 in TM 11-5815-
200-12 (Feb 66) on the TT-98 fill you
in on quick bias adjusts on the teletypes.
 It's a must to make the adjustments
at initial installation, when changing
from commercial power to another
source, or after any adjustment of the
power supply.
 In addition to the method in the
TM's, you can use a TS-352 multimeter
by placing the probes across the bias
terminals.
 Place the TS-352 setting in the 100
MA range, and adjust the bias of the
TT's to 60 MA.


I