Solid State Radios of the 80's and 90's
These are solid state semiconductor powered radios.
Bought new April 1986
Combination digital clock and digitally tuned radio receiver.
gets dirty quickly, making keys inoperative. Long term fix: disassemble
keypad, clean contacts, then place a plastic sheet (cut from a zip-lock bag)
between the metal keytops and the black foam holding the plastic keytops in place.
Did this 3 years ago, keyboard still works fine. This set does have a
Uniden Bearcat BC140 Scanner, looks a bit like the GE above.
To make it a 16 channel
scanner, clip the diode crossing over
(component side) the biggest chip on the
main board, IC8.
A stereo digital time and tuned clock FM radio
Digital clock radios, analog tuned
This one with florescent display
A modern Philco:
mid 90's, from Radio Shack
Remove wires from "mono" switch leading to filter "CF1" to
make tuner more selective in AM stereo mode. Less interference from
nearby stations on the dial.
Tuning becomes more critical, though.
DX440 switchable chuff mod:
On some bands the "chuffing" of the mute
circuit can be annoying. But sometimes you want to have the mute function
on other bands and conditions. I modified my DX440 to have switchable
I gave up "frequency lock" to use that switch for this mod.
Proceed at your own risk!
Remove the radio's back, and locate an 8 wire ribbon cable.
This cable runs from the center of the radio to a board that
lives mostly behind the speaker. On the
board where this ribbon connects to a connector, disconnect the second
(from the left, the tuning knob is on the left here) wire of the
ribbon from the connector, and insert a separate AWG 22 wire in place
of it. Wire should be about 5 inches long. Solder another 5 inch
piece of wire to the disconnected 2nd wire of the ribbon cable, and
heat shrink this solder joint. Find the back of the "Lock" switch,
and cut the two traces leading to it on that board. Solder jumper
those cut traces together where there are solder joints next together
a few inches away from the switch on the board. And solder the above
two new wires to the switch, left and center switch posts. Such that
"Lock in" = muting in" and "Lock out" = muting disabled.
The ghetto blaster on the right is probably the only one presented on an
antique radio web site!
This one crystal locked
tuned to 99.7 KFRC. And I have another on KITS 105.3 MHz.
And there is an AM version, TFT8020, which is crystal set to 610 KFRC. And I have another set to 960 KABL.
Single channel receivers such as these can be tuned up or down one or maybe two channels by adjusting the IF frequency. This can be done by adjusting the IF transformer slugs, or even adding a few picofarad
caps to the resonant circuit portion of the IF transformers
and then adjusting the slugs.
This will work only if there are no fixed frequency filters
in the IF strip, though. Be careful that your new IF frequency
doesn't cause the radio to pick up a strong station on the image