Premier Midget

[cathoderay57]

I've completed restoration of a Premier Midget 3-Band superhet set, referred to in another thread. The SenterCel RM2 rectifiers were shot so I replaced them with a 1N4007. The metal bracket that they were attached to was a useful anchoring point and thermal shield for the diode tag strip and 470 Ohm HT filter resistor that had original been left floating on its wires. The rest of the chassis refurb was relatively straightforward, replacing the usual leaky paper caps. The OPT had an open circuit primary but I managed to purchase from eBay a small enough replacement with approximately the right turns ratio while the original is being rewound. All the valves tested very good to excellent. The smallest value HT cap (8uF) was duff and so I replaced it with a 10uF. The 32+32uF tested OK. On applying power it did work but was rather deaf. I realigned it but the improvement was only marginal. I found by accident that, by lightly touching grid 1 of the IF valve (6K7GT) with my finger, the sensitivity improved significantly. Guessing that this was the effect of hand capacitance I slaved a 22pF capacitor between the top cap of the valve and chassis and an even better improvement resulted. So I opened up the first IF can and removed the capacitor (actually two 75pF micas in parallel) across the secondary coil and tested them on my Avo bridge. They showed OK at 170pF. I was puzzled because the secondary IF had appeared to peak. However, I then realised that it was peaking with the slug about dead centre of the coil and so for peak sensitivity it actually wanted a bit more inductance or capacitance. Replacing the caps with a single 200pF did the trick. In the late evening I managed to pick up R. Caroline on 648kHz which is a rare event here in Bristol. It was remarkably sensitive on SW too. The cabinet cleaned up very well with Greygate No. 5 and wax polish. Cheers, Jerry

[G6Tanuki]

Fascinating. I have seen quite a few of the Premier Midget radios but they have always been MW/LW TRFs, intriguing that they also did a superhet with SW coverage.

At least with SW coverage there will be something vaguely interesting to listen to.

Either way, it's good to hear of another one of these little radios being brought back to life.

[Kentode]

Well done, Jerry!

Could you post a clearer picture of the tuning dial, please?

I've got another Premier in the roundtuit pile and I'm not sure but it might be the same.

[cathoderay57]

Here you go

[Sideband]

Originally Posted by G6Tanuki

Fascinating. I have seen quite a few of the Premier Midget radios but they have always been MW/LW TRFs, intriguing that they also did a superhet with SW coverage.

I'm sure I saw an advert in (probably Radio Constructor) for both superhet and TRF versions.

I have a Barton's version which uses an identical cabinet. It's a 3 band superhet. The circuit for that one is on Paul's CD. It might be the same as the Premier superhet kit.

[Kentode]

Originally Posted by cathoderay57

Here you go

Cheers Jerry, I'll go and have a good root around in the store (box room!) today and compare...

[cathoderay57]

There are a few images of the 2-band TRF scale here for comparison https://www.vintage-radio.net/forum/showthread.php?t=8347. Cheers, Jerry