His Master's Voice 1101 radio
His Master's Voice was not a very wide-spread radio brand in The Netherlands.
So it is special to have one in my collection.
The circuitry of this model looks like an American AC/DC model adapted for
European mains voltages.
Though it was impossible to find information on it, it was still quite easy to fix.
This is a bit of an unusual radio in the Netherlands.
His Master's Voice was only a small brand over here.
This one looks sober, modern and functional.
It has a plywood case, with fine veneer and
a cream painted wooden loudspeaker grille, venetian blinds style.
On the front, there are four controls: volume/on/off, tone,
band selection switch and tuning.
This model is marked “HMV1101”.
It is a modest radio with 3 bands, LW, MW and SW.
Judging by the Dutch and Belgian stations on the tuning dial,
this model must have been aimed at the Dutch and maybe Belgian market.
A look on the inside.
The circuit is rather common, a basic superhet.
The valves are all octal types from American manufacturers:
|12SA7 ||heptode as frequency changer,|
|12SK7||HF penthode as IF amplifier|
|12SQ7||triode and double diode as detector and AF preamp,|
|50L6GT||penthode as output stage,|
There is no tuning indicator.
This valve line-up is typical for an
"All American 5-tube AC/DC radio"
from the early forties.
However, my HMV1101 has a power transformer that delivers
36 and 50 V for the heaters and 250 V for the plate voltage,
and has primaries for 110-240 V.
The heaters are partly in parallel, partly in series.
The power transformer
has a somewhat awkward position on the side of the chassis, while the output
transformer is mounted on a triangular bracket, probably to get a
perpendicular orientation towards the power transformer to reduce hum.
The power transformer seems to have been added as an afterthought,
but it most definitely
looks like it has been fitted in the factory, not by some repairman.
This model may be a derivative from an American AC/DC radio, adapted for the
Apart from the choice of valves,
the radio is not constructed as an AC/DC radio, as
the chassis is not particularly well isolated
and the earth connection and gramophone input
do not have coupling capacitors to isolate them.
I got this radio through an advertisement on Internet.
The previous owner told me it dated from the fifties.
He told me it still worked, although it cracked badly.
He thought a defective valve was causing the cracking.
I tried to find information for this model, and I was happy when
I was offered some service documentation for a HMV1101 model.
But when received it, it turned out to be a different radio, an American
model from 1939, using different valves.
Front of chassis, taken out of the case.
View of the chassis from above.
Chassis taken out of the case.
I found a photograph of an identical HMV1101 on
Johan Catteau's radio pages
He could not tell what valves were in his radio, because they were missing.
My HMV1101's loudspeaker grille looks a lot like the one on a HMV914
I found somewhere else on the Web.
I found another collector who has a HMV920 that looks identical to my
But their owners could not find any documentation, neither on the HMV914 nor
on the HMV920. This is really confusing.
On Malcolm Bennett's site
I found some information on some HMV1101 model,
but he again dated it in 1938/39, and turned out
to have the same American documentation I received earlier.
Yet, my radio is real and looks original.
On the back of the case there is a type card with the "HMV1101"
brand, the type number and serial number.
The same type number and an HMV logo are rubberstamped on the back panel.
The dial is showing the HMV logo with "Nipper", the HMV dog
listening to a phonograph.
There is also a coloured decal with the HMV logo on the top of the case.
The serial number is rubberstamped on the chassis, the same serial that is
mentioned on the type card.
If you look at these pictures and say
“Hey, I recognise this radio”, please let me know.
The radio was quite easy to fix.
First I let the electrolytics reform.
During the process, I noticed the coupling capacitor to the output stage
was very leaky, so I replaced it.
There were a number of these flat, black capacitors branded
"Micamold", but the dielectric cannot possibly be mica,
because they are so leaky. I think they must be paper capacitors and
the "mica" in the "Micamold" brand must be a marketing thing.
After this, I turned the radio on and it worked.
Only, the strong stations were unduly loud and distorted.
I suspected that the AGC didn't work properly.
I measured detector output and AGC voltage (using a voltmeter with a
10 MΩ input) for different stations and
indeed, the AGC voltage seemed to be attenuated.
The bypass capacitor on the AGC was another of those Micamolds.
Replacing it restored due operation of the AGC circuit, as proven by a lower
voltage on the detector and a higher AGC voltage on the smoothing cap.
And of course, the sound became much better.
So now my HMV radio is working fine.
It looks really great on the bookshelves in my study.