'Transformers'

[Harry Bloomfield]

I believe rotary convertors were a motor rotating the shaft of a dynamo. That is I am sure what was use to power the military 19 sets.

They were quite powerful devices, I was able to use a Wolf electric drill on the DC 200 Volt (?) HT supply from the rotary convertor.

Yes, it was mounted in a separate box which sat on the left of the 19 set, with a big red light on it and a massive multi-way plug linking the two. I remember someone mounting one in the engine compartment, used to power his electric razor whilst camping.

I've converted 19 sets and R1155's from Lancasters in an earlier life.

 

[ericmark]

OK fair enough not well put, but to get the 12 volt supply to around 200 volt there were two methods, one was a single unit, the other multi-unit, with same result.

If we compare the latter with today the 12 volt is still turned into AC but at a high frequancy which allows smaller transformer to be used, and less smoothing required when converting back to DC.

The same transforming down, still use a wire wound transformer but using a high frequancy it can be much smaller.

The diffrence is today the it is combined not seprate units.

 

[JohnW2]

I read Erics post .... to mean: the title we applied to a vibrator/transformer combination was a rotary converter. Even now I can't read it any other way or add any word(s) to make it read differently.

I agree.

Kind Regards, John

 

[Harry Bloomfield]

AH... but...

I had 2 different power packs for my 19 sets, the one you describe with the vibrator and the dual voltage dynamotor/rotary convertor but the other one had 2 dynamotors, one which ran continuously and the second which started for TX PA HT. Apart from the continuous whine it was a better system for RX/TX changeover as there was no HT dropout.

They would always remove the platinum (?) wire from the rotary ATU of those sets.

 

[SUNRAY]

They would always remove the platinum (?) wire from the rotary ATU of those sets.

IIRC they called them something like 'variometer' mine came with a broken shaft, I was able to drill some more holes in the outer sleeve and move all the inner gubbins forwards so the remains of the fibre shaft was enough to refix the knob. I remember the wire looking like tarnished silver so always assumed it was silver plated copper. But I now have no idea one way or the other.

 

[JohnD]

looking like tarnished silver

platinum does not tarnish

it is quite difficult to work.

I don't know when Platinum Points started to become popular, but they used to be kept in a safe.

 

[Harry Bloomfield]

IIRC they called them something like 'variometer' mine came with a broken shaft, I was able to drill some more holes in the outer sleeve and move all the inner gubbins forwards so the remains of the fibre shaft was enough to refix the knob. I remember the wire looking like tarnished silver so always assumed it was silver plated copper. But I now have no idea one way or the other.

It was basically a coil, wound onto a tubular fibre former. The former had a track/groove cut into its surface, from memory the former was around 2" dia x 6" long. A metal roller had a similar groove cut around its perimeter, mounted on a rod. As you operated the crank handle, the idea was that the metal roller would make it's way along the winding, varying the tapping point on the coil, to tune the antenna. What ever wire it was, had been removed for its scrap value, from all of the ATU's I came across, so my assumption was it was platinum as they were tropicalised sets.

 

[JohnD]

Until recently, the price of platinum was higher than gold, partly due to the difficulty in smelting and working it.

 

[SUNRAY]

It was basically a coil, wound onto a tubular fibre former. The former had a track/groove cut into its surface, from memory the former was around 2" dia x 6" long. A metal roller had a similar groove cut around its perimeter, mounted on a rod. As you operated the crank handle, the idea was that the metal roller would make it's way along the winding, varying the tapping point on the coil, to tune the antenna. What ever wire it was, had been removed for its scrap value, from all of the ATU's I came across, so my assumption was it was platinum as they were tropicalised sets.

Ah you're describing a roller coaster inductor, I'll say my limited experience of such things, ½dozen at most, some were tarnished and some were gleaming bling, as such I'll very happily offer that both types of wire have been used.

The WS19 used a different device which was a cylindrical enclosure

Sadly my memory from 1975 of making that repair doesn't give me total recall, however it basically consisted of a coil mounted on the spindle something like this:

And a big face capacitor. I'll assume there is a second, static, coil but any sort of detail eludes me. I want to say there are spring wires connecting the the coil (just like a meter movement) but again I'll not offer that as fact.

These were designed to be mounted directly under the aerial mount in tanks and an adapter bracket including a connexion to an aerial socket was made for use in Landrovers which fitted into keyhole slots on a modified WS19 case.

 

[JohnW2]

... As you operated the crank handle, the idea was that the metal roller would make it's way along the winding, varying the tapping point on the coil, to tune the antenna. What ever wire it was, had been removed for its scrap value, from all of the ATU's I came across, so my assumption was it was platinum as they were tropicalised sets.

In the distant past I've had, and used, ATUs containing those sort of things (and probably still have a few!), and I was always under the impression that the wire was silver-plated. That's certainly what it looked like and it did tarnish to some extent over time.

Kind Regards, John

 

[Harry Bloomfield]

In the distant past I've had, and used, ATUs containing those sort of things (and probably still have a few!), and I was always under the impression that the wire was silver-plated. That's certainly what it looked like and it did tarnish to some extent over time.

Near 60 years ago, so my memory is vague. The one I had, was in a square box, part of something else in the same box, perhaps a PSU - but seems unlikely to be the PSU so close to the antenna.

 

[SUNRAY]

Near 60 years ago, so my memory is vague. The one I had, was in a square box, part of something else in the same box, perhaps a PSU - but seems unlikely to be the PSU so close to the antenna.

And specifically for the WS19?
I've never been aware of any different arrangement for the set, but I'm not any authority on their history and that may very well be something new to me.

 

[Harry Bloomfield]

And specifically for the WS19?

It came with it when I bought it..

I've never been aware of any different arrangement for the set, but I'm not any authority on their history and that may very well be something new to me.

Nor I.

 

[Harry Bloomfield]

roller coaster inductor,

Yes, that was the name.

 

[davelx]

Near 60 years ago, so my memory is vague. The one I had, was in a square box, part of something else in the same box, perhaps a PSU - but seems unlikely to be the PSU so close to the antenna.

That might have been a version of the add-on linear amp to boost the RF transmitter power to about 25W- Made WS No.19 into a WS No.19 HP.