[Drake] TR4 TR4C

[Gary Poland]

Dennis,
   There isn't a whole lot of difference electrically between the two. The
TR-4C had two PTO dials instead of one. The second one reading out in KHz as
opposed to markings on the dial skirt for the TR-4. Some later TR-4's had
the neon pointer over the dial to match the B-Line. It also told you which
PTO was in use when using the RV-4. The C used a lamp/red lens in the upper
right corner. The knobs on the TR-4 were originally the fluted TR-3 knob,
then the B-Line knob, then finally the C Line style knob for the TR-4C.
   Also the C used 8 pole SSB filters as opposed to 4 pole in the earlier
TR-4's. The TR-4 itself went through a few changes over the years. Early
TR-4's did not have an additional transistor audio stage which gave the
later TR-4's and TR-4C's more audio. The C also had a socket installed for
the optional noise blanker where as the TR-4 had it hard wired or no
provision for it at all. The PA cage originally did not have a cover on the
early TR-4's and the VOX controls and mic and head set jacks were on the
sides. The TR-4's also had an additional knob between the PLATE and LOAD
controls for reading relative output on the plate meter. TR-4C's used a
switch in conjunction with the LOAD control.
   The only TR-4's to have CW filters were the TR-4CW and TR-4CW/RIT.

This all I can think of right now Hi Hi !

73, Gary