1967 Heathkit Model GR-54 "Deluxe SWL Receiver"
This is a Heathkit Model GR-54 radio. This is the first of many
Heathkits that I have built. The radio has 6 tubes and 5 bands covering:
Band A: 180 to 420 kc
Band B: 550 to 1550 kc
Band C: 2 to 5 Mc
Band D: 5 to 12.5 Mc
Band E: 12.5 to 30 Mc
The radio has a bandspread and a BFO to receive CW and SSB. An RF gain control and
Automatic Noise Limiter is also included. It also has a relative signal strength
meter, but I added an external Lafayette Model 99-2512 "S"-meter unit that can be seen on the top
of the radio. The IF for this radio is an unusual 1682 kc with the IF bandwidth set
by a crystal lattice filter that provides excellent selectivity. The radio has a antenna
tuning control to improve antenna matching. There is also a standby switch.
I was an avid shortwave listener back then and I have several QSL cards
from several foreign stations.
See the QSL card page to see these cards.
I have seen discussions regarding hum in the audio of this radio. My radio was
no exception and this radio had hum right after I built it, the loudness of which would vary with the
audio gain control when the radio was placed in standby with the standby switch.
I eventually solved the hum problem. Heathkit assumed the ground
connection from the main circuit board to the ground of the volume control is adequately
made through the chassis. It turns out this assumption is not valid. To
minimize the hum, I soldered a wire from the ground plane of the main board to the
ground lug of the volume control potentiometer. At first glance, this may appear
redundant but this solved the problem and the radio is quiet as far
as hum is concerned.
I used this same approach to minimize hum in one of my Heathkit SB-610 monitor
scopes. That scope had a slight hum it its trace, and I minimized the hum by
running a wire from the chassis ground on a tube, to the ground lug of
the vertical gain potentiometer. Thus using the chassis as a ground between a gain
control and its amplifier is not good design practice.
||BFO & Prod Det
||Rider's Manual Page #
||2 x 6BA6
Below are details on this receiver as advertised in the 1966 Heathkit Catalog.
Page 90 of 1966 Heathkit Catalog Showing the GR-54 Shortwave Receiver
Below is the cover of the 1966 Heathkit catalog. Note that the GR-54 shortwave receiver is
featured on the upper right corner of the cover.
1966 Heathkit Catalog Cover