The tuning scale has cleaned up nicely and an authentic pencil-strip has been fitted.
The dubious AF/RF gain control knob has been changed for a genuine one and all the
missing labels are now in place. One thing that I have noticed on this receiver is
that the band-change knob is permanently slightly out by more than one tooth on the
bevel gears. This implies that the hole that has been drilled through the shaft,
that holds the pin for aligning the knob, is lightly out. A quaint peculiarity maybe?
I still don’t have the pillars and metal strap for securing the Jones connectors,
but that really isn’t an issue. Alignment and testing was largely straightforward
and uneventful. The radio worked first time ... The moment it was switched on! When
I stripped the coil-box and released the cores in the many inductors, I made a note
of where the end of the core was in relation to the rear wall of the coil-box. Then
when I refitted the core, I was able to screw it back in to (almost) the same position.
The only unexpected problem that arose was that the two ceramic trimmers that adjust
the high end of bands 1 and 2 had seized. These were replaced with the same two trimmers
from the salvaged coil-box. Apart from that, alignment went as per the book with
minimal adjustment required. The R1155 was never intended for resolving SSB. On my
AD8882B, I have the BFO set for resolving LSB on 3.5MHz and 7MHz. However, on this
R1155A, I found that very strong LSB signals on 7MHz were ‘impossible’ to resolve,
whilst moderate SSB signals on both 7MHz and 14MHz were resolvable for the same BFO
setting. This had me scratching my head to the point that I carefully measured the
LO frequency to ensure that I had not tuned it to the ‘image’ (RF - IF as opposed
to RF + IF). The Local Oscillator was indeed set correctly on both bands. The BFO
was working fine but I was getting the impression that I was not able to bring the
actual 280KHz (IF/2) signal low enough in frequency even when the tuning capacitor
was fully meshed ... And when I attempted to adjust the inductor in the BFO, the
top of the ferrite core came away! I compensated for this by paralleling a small
Silvered Mica capacitor (39pF) across the tuning capacitor. This enabled me to bring
the frequency lower but I still had problems with very strong LSB signals on 7MHz.
However, you have to bear in mind that the R1155 is NOT a modern top of the line
contest-winning HF receiver with narrow brick-wall IF filters. There was an HF contest
on at the time and it’s at times like these that folk tend to turn the ‘wick’ right
up on their PAs, so that would explain the proliferation of very strong signals.
I also found that with very careful tuning, I could in fact resolve these strong
stations. I also noticed that the fine control on the Type-35 tuning mechanism is
actually coarser than the older Type-13 mechanism that my AD8882B has and I am accustomed
to, and this was probably why I was finding it difficult to resolve the signals.
There is also a small amount of back-lash on the Type 35 mechanisms, and that didn’t
help either. All-in-all, I am very happy with this restoration. Another R1155 has
been brought back to life complete with fully functional Direction Finding circuitry
... Next on the list ... The accompanying T1154!