Ever Ready Model T

[Techman]

This radio takes me back to my childhood in some ways, as I had both a Sky Queen and a Sky King and this set uses the same chassis, it even has the cut out in the metalwork to fit round the speaker as fitted in the other models. The Sky Queen was the first ‘proper’ radio I had and I think I paid thirty bob (£1.50) for it from my hard saved pocket money and I seem to remember that the battery I had to buy was something like two thirds of what the radio had cost me! The Sky King was either given to me, or I got it from a local jumble sale a while after buying the Sky Queen. It’s funny, but I remember the chassis in these sets were in absolutely mint condition, so it seems strange all these years later to be working on one covered in filth, rust and full of leaking capacitors. Actually, this radio wasn’t as mucky inside as a lot I’ve worked on and due to the weather being so wet lately I hadn’t done my usual practice of taking the radio outside and blowing all the muck out with the air blower, so I’ve been working on it dirty. Those two radios I had as a child are now long gone, thrown away during a house move by my parents when I wasn’t looking, I seem to remember!

I applied LT and HT to see what would ‘give’, if anything, and as I wound the HT up to try to get it to 90 volts there was some crackling from the speaker and the trace of a station as I wound the tuning gang (the drive cord was broken). This was very short lived and the HT started to be very heavily loaded and was dropping away faster than I could adjust it. My immediate suspicion was the 8uf HT decoupler, and in fact it was leaking badly electrically and getting worse. Having lifted one end, the load on the HT was reduced and stations could be received, although not at all well and without this capacitor in line, the set was not far off oscillating. Having replaced that capacitor, things calmed down, but performance was still extremely poor with nothing on long wave.

I’m using the BRTR service data sheet R106 which covers the Sky King, Queen and Prince. As far as I can see the circuit is virtually identical to the ‘T’ (and the prince set looks very similar), with the possible exception of the first stage aerial circuitry – it also has a different valve line up and I think the IF frequency is lower on the ‘T’, but otherwise it’s the same, certainly component wise, so it’ll do for what I need. I didn’t have to look particularly hard to spot a couple of mistakes in this service sheet and I suspect others that have worked on this range of sets have probably noticed the same, although they’re not serious mistakes.

The coupling capacitor to the output valve control grid is a disc ceramic in this set so shouldn’t need changing, and indeed all checked out good on the ‘g1’ pin of the DL94. The three 0.1uf decoupling capacitors are what I would describe as being in significantly critical positions, such that any leakage is very likely to cause problems to the operation of the set. These were replaced one at a time in the order of C20, C25, C28 (I think) with the sets performance improving all the time. I did also replace the 0.05uf on the AGC line and it was in a particularly awkward place and it was the only capacitor that didn’t make any actual difference that I could tell, although it’s not a bad idea to avoid leakage in AGC circuits.

During all this, the switch gear etc. was cleaned with Servisol 10. The wave change/on-off switch rotates all the way round on this set, with no stop position and repeats of all the positions in order as it’s rotated – is this normal on this model?

There was one more capacitor likely to cause trouble, and that’s the 0.001uf across the output transformer primary. While I was thinking about it, the sound started to intermittently go on and off, and then it was more off than on. Measurements showed that it was this capacitor that was breaking down putting a short across the output transformer primary. For a moment I thought it was the transformer starting to go open circuit as the symptoms were very similar, until I measured HT on both sides of the primary with the fault in progress. Snipping one side of this capacitor restored normal sound, and also a noticeable increase in treble response. However, I’ve fitted a disc ceramic of similar value it its place and the set is sounding good. I’m not one to replace original components unless absolutely necessary, but on this occasion this is the most capacitors I’ve had to replace in a single set to get it working properly in a very long time. I haven’t checked all the resistors and the odd one I did check was slightly high, but within working tolerance. I probably ought to do a few more voltage checks around the valves before putting it back together, although judging by the sets performance I don’t think there’s much wrong, so probably no need to bother.

One thing that threw me for a moment when working on this set was that I had measured a virtual short circuit across C25, and which was still there after replacement of the capacitor. Having wondered about anything strange going on with the valve base, I removed the valve and the short cleared. It wasn’t until I checked the valve data for the IR5/DK91, that I noted that there was an internal connection between pin 5 and pin 1 of the valve.

The drive cord has been replaced and the RF trimmers adjusted and the set is performing very well. The chassis is still out of the cabinet as it’ll need taking outside for a good ‘blow out’ before it’s all put back together. It was left running all evening and well into the early hours of the morning with no problems whatsoever. I could really do with finding a socket for that battery plug (B4 base socket) to make an adaptor for proper connections rather than removing the plug altogether to fit different connectors.

[Paul_RK]

Takes me back, this model - I bought one on my first ever visit to Swafham auction in 1968 or 9, seven bob. Still with me though it had suffered a bit in its early years, tuning window was missing and pointer had just its stumps remaining. It was something of a favourite even so, which I expect means it made quite a good fist of receiving AFN. They must have seen you coming when you bought that Sky Queen, mine around the same time was 2/- at auction, then 18/- for the battery - "obtainable everywhere", as the print inside the back had it - and a two mile walk home with them both.

Originally Posted by Techman

The wave change/on-off switch rotates all the way round on this set, with no stop position and repeats of all the positions in order as it’s rotated – is this normal on this model?

No, it shouldn't be like that - knob points upwards for 'off' and turns to one side or the other for LW and MW just as on the Sky Queen. I suppose that large knob makes it easy for anyone that way inclined to give it a destructive tweak. Good to hear the set's healthy again, though, and I hope I'll sooner or later awaken mine from, oh, probably at least 30 years of slumber.

Paul

[Techman]

Originally Posted by Paul_RK

No, it shouldn't be like that - knob points upwards for 'off' and turns to one side or the other for LW and MW just as on the Sky Queen.

That's what I thought, but wondered whether it was a strange quirk of just this particular model. You may notice that one of the knobs is non-original.

You're right, The Sky Queen was quite expensive for the time, but it was probably the early 60s and the radio would be only around ten years old at that time. It was bought from a second hand shop not far from London.

[Paul_RK]

Originally Posted by Techman

You may notice that one of the knobs is non-original...

I think two of them are. As far as I know the original outer knobs, in walnut bakelite of course, are much more like the centre one in design than your volume knob is, with more than its eight ribs.

https://www.radiomuseum.org/images/r...2a_1322587.jpg

shows them tolerably well.