DRAKE TR-4CW - TR-4 CW Supplementary Instruction Sheet

TR-4C w_ SUPPLEMENTARY INSTRUCTION SHEET
The TR-4Cw incorporates all of the features contained in the TR-4C plus a 500 Hz
bandwidth crystal filter to improve CW selectivity.
This instruction sheet deals only in differences and additions that this feature
will add to the instruction manual supplied.
SPECIFICATIONS
Receiver Selectivity: 6 dB=500 Hz, 60 dB=2.0 kHz with Sideband Switch in 500 Hz
position.
OPERATION
The Sideband Switch selects between upper, lower, and 500 Hz filters. The side-
band being utilized is indicated by the upper/lower lights. When the sideband
switch is in the 500 Hz position, the same light will light as when the switch is
in the "X" position.
Tune Up is identical to that of the TR-4C.
Operation on CW is accomplished in the same manner as the TR-4C except that
the sideband switch can be placed on the 500 Hz position to more easily sepa-
rate stations under crowded band conditions.
It will be noted that when transmitting with the 500 Hz filter switched in, the
XMTR Gain Control will have to be advanced slightly further clockwise to ob-
tain the same plate current as obtained when either upper or lower filters are
used.
The center frequency of the CW filter is such that when a signal is tuned for
maximum S~meter reading, an audio beat note of approximately 800 Hz will be
produced. Therefore, when tuning in CW signals with the filter switch in the
"X" position, signals should be tuned for this audio frequency so they will
still be tuned in when switching to the 500 Hz filter.
SSB Operation is not recommended with the 500 Hz filter switched in since it
will narrow the bandwidth of both transmitted and received audio sufficiently
to make it virtually unintelligible.
MAINTENANCE
Alignment is accomplished in exactly the same manner as the TR-4C. No
special tuning of T6 or T13 is required.
Access to circuitry hidden by the 500 Hz filter is obtained by loosening the
two nuts holding the 500 Hz filter bracket to the upper/lower filter bracket
and lifting the filter and bracket as a unit off the transceiver.