[MRCA] GRA-39 Ops from standard 9 volt battery

[B. Smith]

                        I was curious last night about powering the set 
with a smaller standard 9 volt battery and was wondering about the 
telephone line audio voltage levels.  I guess I could go to the Dollar 
Store and pickup a bunch of BA-30s (D cells) (6 cells required for each 
unit) but for short military rally operations perhaps just using a 
smaller single 9 volt battery would suffice. So we ran some tests and 
used just the smaller 9 volt battery.  BTW I picked up my GRA-39 set at 
Gilbert several years ago in the Saturday morning flea market. Ten bucks 
for for the pair  2328 and 29.


Z


Here are my notes


Both units can work off of a smaller standard 9 volt battery and for 
short operations this might be an advantage.*Note Ringer workseven if 
unit is turned off in order to alert the  operator. *TEL only works in 
TEL positionotherwisecan not hear anything

"Remote Control Unit 2328.GRA-39

GRA-39  2328 Current draw info using _9 volt power supply_. Full vol 
squelch open 30 ma.

Reduced vol squelch open about 20 ma.

Transmit draws 30 Ma

RAD mode 10 ma

TEL mode 10 ma

Unit functionsTrans and Receive down to about 5 volts and continues to 
receive

below 5 volts.

*NOTE: GRA-39 2328 makes an excellent aux audio amplifier and looks neat.*

GRA-39 O Scope telephone line measurements

O Scope on line 3 volt PP when hooked up to the "Local Control" unit at 
the transceiver. 6 volts ppwhen not on line.

Transmit Voice peaks 10-15 volts PP no load and this is super imposed 
over tone.

Transmit Voice is 8 volts PP when operating on line and under load.

Receive test using Transworld TW-100 with Transworld vol positioned at 
1/2 the line voltage about 2 volts PP

"Local Control Unit 2329GRA-39

Current draw info using 9 volt battery.

Receive mode 5 ma or lower.

Transmit draws 23 ma when activated byRemote unit

RAD mode nil on receiver

RAD mode 12 ma on transmit

TELE draws 4 ma