HRO power supplyHRO power supply
HRO 5T with coil packs before restorationThe HRO receiver started in production
at the end of 1934 and appears in various guises and until a few
weeks ago I knew nothing about them but having recently repaired
my brother in law's set, for which exercise I read the handbook
and examined the circuit diagram, I discovered a bit of information
and a quick look around the Internet gave me some background.
In 50 years I've probably only laid my hands on two. It was very
odd then, that before the re-invigorated model left my workbench,
a second should join it out of the blue when a customer offered
me one for sale. After examining the first model (an ex-military
R106 version) I found my purchase to be marked in tiny letters
"5T". This must be a later model than the basic version
because it has a range of octal valves rather than the older "UX"
based set. I need to do some research.
The picture shows a few problems for the restorer. A slow motion
dial connected to an Eddystone 40pF tuning condenser (in series
with a 30pf beehive trimmer) has been fitted to provide a measure
of fine tuning. That will need a hole filling up. The original
crackle finish has been thickly repainted with a soft crackle
paint and this is in poor condition. The main problem though is
the case. I haven't had a good look yet to see why, but the receiver
has been fitted with a wrap-round enclosure having a coarse aluminium
mesh let into the top. This doesn't look original and was probably
fitted because the original case was lost or for some reason was
never fitted. A cursory look at the front panel doesn't indicate
it to be a rack mount version. The power supply has a "matching"
outer case and may conceal an original box underneath (I haven't
looked yet). Oh and the original S-meter's been swapped.
I read the other day that an original HRO cost as much as the
van it was delivered in ie. between 350 and 400 dollars.
All nine of the standard coils seem to be present with my new
acquisition although I heard once that a set of amateur band coils
were once supplied. I quite fancy trying the thing out but restoration
will have to wait for a lot of inspiration.
