[Boatanchors] Old ARRL Handbooks

[W4AWM at aol.com]

In a message dated 9/29/2006 15:56:11 PM Eastern Daylight Time, 
robert at isquare.com writes:

> Hallicrafters SR-75 transceiver (!) A combination S-38B and 10-watt 
> transmitter

Hi Bob,

I actually have one of these.  It was a terrible design for operation on more 
than one frequency and band.  To change bands or frequencies, the interlocked 
rear cover must be removed.  The crystal and coil are each located behind 
tubes which will most probably be hot unless frequencuy and band excursions are 
made before operation is begun.  A pair of D-cells are required for the keying 
relay. These are located on top of the chassis. Transmitter tuning controls 
were located on the rear apron of the chassis. The only appearence difference on 
the front panel between the SR-75 and a standard S-38B is the nomenclature 
and the labeling of the Receive/Transmit switch.  This is a CW only rig and 
boasts 10 watts input to the 50L6 final/audio output tube. All in all, this AC/DC 
set is a "do it to yourself" home electricution unit and should absolutely not 
be operated without an isolation transformer!

In visiting a slightly better design, the Hammarlund HQ-105TR is slightly 
better, although operation is restricted to 10 and Lord Forbid, 11 meter 
transmit. In case some of you young pups don't recall, 11 meters used to be a ham 
band. In any event, the crystal socket on this transceiver is accessed through a 
cutout in the rear of the cabinet and rocks were instantly interchangable. A 
passive switch, dubbed the CB-8, was offered as an accessory. This allowed 8 
crystals to be installed and instantly selected by means of push buttons. The 
switch was mountable to the unit by means of special clips which fit into the 
ventilation holes on the top or sides of the cabinet and the unit was connected 
by means of a pigtail which plugged into the crystal socket on the main 
chassis.  There was a stick on escutheon label which mounted to the front panel 
around the bandspread knob which indicated the CB channels.  Since this unit was 
basically designed as a CB  transmitter/receiver, the AM phone input is limited 
to 5 watts. Conversion from CB to 10 meter operation requires retuning of a 
coil and transformer for which adjustment, the cabinet must be removed. Cautions 
are printed in the instruction manual stating that CB adjstments be done only 
by the holder of a Second Class Radiotelephone license or higher and that 10 
meter adjustments be preformed by the holder of a General Class ham ticket or 
higher. There is no prevision for CW operation, but PTT is available for 
phone. The receiver portion was general coverage from the broadcast band through 
30MHz with a ham band calibrated bandspread. It also boasted a power transformer 
and clock.

I am basically a Hallicrafters collector, but I have an affinity for a 
transmiter that happens to be installed in a receiver, so there is one of these rigs 
in my collectioon, also.

73,

John,  W4AWM