Another Pilot Little Maestro.

[FERNSEH]

Following the Ultra EU4052 another small radio receiver needs attention.
This time it is a series 2 Pilot Little Maestro. This is the model with the line cord mains dropper. That horrible thing had to go and it has been replaced by a 4uF motor run capacitor. It's fitted in the same manner as the other Little Maestro I restored last year. A bracket for the large capacitor has been made and is fitted on the speaker magnet.
Like the Ultra EU4052 the mains neutral is switched so that has been attended to and now it is the live side of the mains that is switched.
The HT 16 + 16mfd smoothing was found to be useless and has been replaced.
Now all that work has been done it's time to try out the set. The variac will be used for the initial tests.

DFWB.

[Herald1360]

That looks like the set that sat on a high shelf (out of reach of little fingers) running 16/7 by the kitchen/dining room doorway in my parents' house in the '50s/'60s.


I never got my hands on it- I think it got scrapped when we moved in 1966. It was probably disgusting by then anyway- kitchen grease and two smokers would have seen to that!

[FERNSEH]

After the variac was turned up to full output the set soon began to receive stations, but the sound output is very low. All voltages are correct. Then, I noticed a type of capacitor that has given me problems before. C20 the tone correct capacitor has the appearance of a mica type, perhaps it is, but it is leaky. Two years ago I serviced a Derwent radio set which had this type of capacitor in it and all were faulty.
Mains filter capacitor C21 will also be replaced.

DFWB.

[FERNSEH]

The faulty tone correction capacitor.
Micamold Brooklyn.

DFWB.

[David G4EBT]

Because they’re called ‘Micamold’ it’s reasonable to assume that they’re mica, but that isn’t necessarily so. Higher values were often paper and no more reliable than any other paper caps. The company simply use the same encapsulation for both mica and paper. It’s a topic that crops up on the US Antique Radio forum:

https://www.antiqueradios.com/forums...c.php?t=112157

It might be interesting to crack it open in a vice, if only out of curiosity?

[Nuvistor]

Recent discussion about these capacitors.
https://www.vintage-radio.net/forum/....php?p=1186506

GMB in post #7 notes an advert he as seen, I have seen a similar one but like GMB can’t find it now.
Found one from August 1944.

Full magazine link.
https://americanradiohistory.com/Arc...es-1944-08.pdf

[PJL]

My BC348 was full of them and many were a near short. Apply some power and the wax inside violently escapes out of the ends by the leads.

[Neil Purling]

Fernseh: as a matter of interest: How is the Series 2 different from Series 1?
I have the earliest version: Line-Cord, field-coil speaker, dial has 'Deutsch'sender' on LW at around 1500M. Sadly the chassis has been 'got-at' (cut) & the speaker was knackered. I am sure it was American??

[FERNSEH]

Hi Neil,
I've never come across the model 1 Little Maestro. According to the Volume II Molloy and Poole Radio and Television servicing book it would appear that apart from the cabinet presentation models 1 and 2 are very similar except for the following differences. Frequency changer valve in model 1 is the pentagrid 6A7G, 6K8 triode-hexode in model 2. The HT rectifier in model 1 is the 25Z6, 25Z4 in model 2. The other valves are: 6K7, 6Q7 and 25A6. Both sets use a line cord. Model 1 has one with tappings for the HT rectifier and dial lights. Line cord in model 2 simply functions as heater chain dropper resistor.
Model 1 has an energised loudspeaker, PM 'speaker in model 2 and resistor capacity HT smoothing.
From the valvepage: https://www.thevalvepage.com/radios/...o/lilmstro.htm
From the Radiomuseum:
https://www.radiomuseum.org/r/pilot_little_maestro.html

Models 3,6 and 8 employ a 6.3volt heater transformer. Valves: 6K8, 6K7, 6Q7, 6V6 and 6X5.
Models 4, 5 and 7 employ 0.15amp valves: 12K8, 12K7, 12Q7, 35L6 and 35Z4. Line cords?
Except for model 7 all these sets have the on-off switch in the mains neutral.
Double pole mains switches in later models 8, 9 and 10.

DFWB.

[usradcoll1]

Originally Posted by Neil Purling

Fernseh: as a matter of interest: How is the Series 2 different from Series 1?
I have the earliest version: Line-Cord, field-coil speaker, dial has 'Deutsch'sender' on LW at around 1500M. Sadly the chassis has been 'got-at' (cut) & the speaker was knackered. I am sure it was American??

I looked at the schematics on the US websites and it seems that there is a lot of US influence in their design. I'm not quite sure that it was a US concern or a British one. All the valve types are US types.
Another US practice was the switching of just the neutral line, using a single pole switch. There never was that big of a concern because of our lower mains voltage.
Dave, USadcoll1, as always!

[FERNSEH]

From my first post: "This time it is a series 2 Pilot Little Maestro. This is the model with the line cord mains dropper. That horrible thing had to go and it has been replaced by a 4uF motor run capacitor."

Not forgetting of course to wire in a 470Kohm 2watt discharge resistor across the capacitor.

DFWB.

[G6Tanuki]

Originally Posted by usradcoll1

Another US practice was the switching of just the neutral line, using a single pole switch. There never was that big of a concern because of our lower mains voltage.

Given that in the timescale of these radios in the UK many would have been run from 'adapters' fitted into bayonet-lightbulb-sockets, or from 5-amp 2-pin socket outlets - neither of which have any concept of polarisation - the position of the on/off switch with respect to the 'polarity' [or absence thereof] of the supply isn't really relevant. Enforced polarisation of mains "live" and "neutral" is still distinctly optional in the majority of the wired world !

Also, there were still DC power-supplies in some parts of the UK well into the 1960s: coupled with a 'reversible' mains-plug this would give a 50% probability that a radio wouldn't work when plugged-in so you had to take the plug out and turn it 180 Degrees.

[FERNSEH]

In 1951 the Little Maestro was completely redesigned. The AC mains version uses five miniature valves. 6BE6 FC. 6BA6 IF. 6AT6 detector and AF amplifier. 6AQ5 output. 6X4 rectifier.

DFWB.

[FERNSEH]

The last model in the Pilot Little Maestro series was the T105.
As with all later UK made Pilot products the American valves were replaced by ones supplied by Mullard.
In the T105: UCH81. UBF80, UCL83 and UY85.

DFWB.

[David G4EBT]

The basic cabinet of the T105 was brown Bakelite, which by 1956 was probably going out of fashion, so one version was in a bright turquoise blue colour with gold edging along the front edge. I bought one as a 'basket case' and assumed that the colour was probably a DIY paint job, but discovered that was how they left the factory. As found, it was dirty and faded but when I cleaned up part of the top, the original colour became evident and I was able to match the colour in an aerosol exactly.

I resprayed the cabinet and re-did the gold lining around the front edge and I find the set quite appealing. Works very well too after restoring the electronics.

The dials on all Little Maestros are excellent and very durable.

[rojosuiza]

the blue wonder - daring

[Neil Purling]

Mine had the remnants of the line-cord when I got it. I cannot understand how on earth so many flower petals could have got inside, unless the set had been inside a greenhouse.
I do have the original valve set. The ones depicted here are: ECH35, 6K7, 6Q7 PL36 and PY33. That case must be unusual. The backboard has got rather baked and the dial bulb is useless. All it does is to illuminate the 'Little Maestro' figure.
So: I assume mine is a Mk1.

[Nuvistor]

Re post #15.
The bright colour looks good, the 1950’s when colour in decorating and household goods moved away from the drab dark brown and greens of the 1940’s.
My parents started to have much more colour in the house in the 50’s, my mother was fed up with the drab colours only available in the 40’s.

[Neil Purling]

The bakelite cases copied from the Little Maestro were sprayed to meet the new taste for something brighter.
The kit radios look like LM's but the knob spacing/positioning is different. I know I offered my chassis into a kit radio case.

[FERNSEH]

So that's what the Series 1 Little Maestro looks like. This was the pre-war model which used the 6A8G as the frequency changer. All the other models with octal valves used the 6K8 or 12K8.

DFWB.