Click ti enlarge
Picture: Bill Frost
The
above SPR-4 belongs to me, Bill Frost, WD8DFP. Jean-Marie and Sindre
have been after me for years to send them pictures.
The
frequency read out is a "sample" of the DG-1 display.
The "samples" were brought to Miamisburg by Mario
DeLorenzi of Transradio, Bissone Switzerland, during one of his visits to the
R. L. Drake Company, many years ago. It was thought to be used in the
4-line products (I think this was during the C-line time period).
The
VFO hood and dial bluing/white are removed, as well as the VFO dials and gears.
The display PC board assembly mounts to the sub-panel as the VFO
hood was mounted. The pilot lamp and socket are removed and the filament
leads are used to power the display assembly. The coax input is
connected to the injection stage, I forget exactly how or to what.
The
unit works great and I was lucky enough to have my SPR-4 available as a
"test unit". The draw back that stopped the company from
pursuing the DG-1, was that it is basically a frequency counter and if there
is no input signal, it doesn't count and if it doesn't count, there is no
displayed frequency. It justs sits there with blinking zeros. So,
you can't tune the receiver, as you can't see any frequency unless
it is connected to a working antenna.
The
cabinet is a vinyl clad pressed wood enclosure that was also considered for
the SPR-4. Since it was all solid state, heat was not a factor.
However, it never went beyond the "sample" cabinets. I have
a T-4C reciter that I mate with the SPR-4 and it is also in a wood
enclosure. A fan keeps it cool.
73,
Bill