Receiver R1224A
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I understand this battery
operated receiver was made by Ferguson and dates from circa 1942
(but its design looks much earlier). This example has the early
serial number "690" and needs a coat of paint. As the
metal panel is engraved the lettering should be restorable once
this has been done. It's missing a small variable capacitor in
the hole marked "Aerial Trimmer" but otherwise appears
complete and has not been modified.
A scan of the Internet revealed
this specific receiver was sold in December 2023 at Regent Auctions
in Blackpool for £24 plus fees or circa £30. I paid
£52 plus £8 postage so not too bad considering it
was offered originally for £153.
Below is the receiver pictured
in 2023 followed by some technical details and its circuit diagram.
Is it my imagination.. but why is there more blue paint on the
December picture? |
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Below are some pictures
of other examples of the receiver. The first is S/No 4403 and
the second 4448. |
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Here's some pictures of
the receiver having removed the chassis from its wooden box. |
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The number is 690 with
the "6" poorly punched.
On the left you can see all
the components appear to be original.
The chassis securing screws
fitted from under the wooden case were missing and the transformer
was unscrewed from the chassis. Was this being tested to see
if it was open circuit? That remains to be seen. If it was open
circuit it would explain the lack of evidence suggesting recent
(ie. post 1950s) use.
The power lead is original and
carries a pair of large croc clips no doubt used to connect to
a 2 volt accumulator. That probably dates the last use of the
receiver to the 1950s.
Note also the missing screws
at the three coil cans.
Although the receiver design
is pretty old, it's a superhet rather than a TRF design. The
knob marked "reaction" which would suggest a TRF design
is for bring the receiver into oscillation to receive CW signals.
This is a cheap alternative to fitting a BFO.
In the picture below you can
see the coils for the three wavebands are fitted with tunable
cores plus trimmer condensers making alignment a straightforward
job.
The valves look like a hotchpotch
of junk box examples I wonder if the filaments are intact because
it was too easy in this style of set to mess up battery connections? |
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This calibration chart
is on the underside of the wooden lid and shows the three wavebands
covered by the R1224A. Note the
biro markings re the valves.
I'm wondering how easy it would
be to change the coil settings and trimmers to cover the whole
of the medium waveband, plus top band, 80m and 40m amateur bands?
This may be impractical due to the capacitance swing of the tuning
condenser. |
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These are the valves.
When I unboxed the set I found that the output transformer had
become detached from the chassis and two of the valves had unplugged
from their sockets. I don't believe there was any resulting damage
and the valves were intact, however a resistance check at their
filament pins showed that the two ARP12s had open filaments.
The FC2A has "V2" marked on it relating to its position
on the chassis so will be original. The remainder are replacements
and are not true equivalents.
I refitted the transformer whose
resistance readings were hopeful and whose 4BA brass fixing screw
had sheared off.
The output valve on the right
(VR118) is marked "PM22" has a good filament but the
4th valve (VR21) has no visible markings and is defunct.
My junk box has plenty of ARP12s
and close equivalents to the VR21.. eg 210LF. If needed I also
have for the frequency changer an X21 (which might do?) and a
well used FC2A. |
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The first thing I'd like
to do is tidy up the receiver.. starting with the front panel.
Removing this from the chassis looks a bit tricky as all the
screws have varnish on the nuts and a previous painting has filled
the screw slots. However I successfully detached the panel with
the screws holding the jack sockets in place being the most difficult
to remove. The tuning dial pulled off after loosening one of
the two screws holding the connecting bush in place the second
had a broken slot.
I'd been wondering what the
original factory paint had been. The panel under the dial, as
you can see is a greener shade of blue meaning the dial hadn't
been detached before the dark blue paint had been applied (probably
the damaged screw explains the reason). But under the aerial
terminal (and the serial number plate) looks like an original
dark grey colour which I'm assuming is the factory colour. |
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Above is the front of
the chassis. I've already applied Jenolite rust remover which
has reduced the surface rust to a grey colour matching the original
chassis finish. Now the panel's detached I can finish the job.
Below, reassembled after a front
panel repaint. I used a brush-on dark grey hammerite but not
the hammer finish variety. Engravings were filled with a childrens'
white wax crayon. I fitted a temporary aerial trimmer as the
original was missing. |
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pending....
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