WS19 mains converter
 

I am wanting to use my ws19 set as a home based unit. Could someone kindly recommend a suitable 240v ac to 12v dc converter please.
Any help or advice would be much appreciated. Thank you.
Kev.

Re: WS19 mains converter
 

Just a thought, If it is just a 12volt supply you need to drive an existing converter a redundant computer power supply will fit the bill usually with amps to spare but you need to watch the turn-on current for those valve heaters...otherwise a float charged car battery takes some beating!

Orakle42

Re: WS19 mains converter
 

Dell server PSUs have a lot of Amps at 12 Volts available but if (why?!?) you plan to use the rotary converter you'll need to do something about the startup current, as mentioned above. Surely better to build a mains-driven supply of 12V, 275V and 550V.
Graham

Re: WS19 mains converter
 

The 19set powe unit uses a rotary converter aka 'dynamotor', a sort of combined motor and two generators. There are three commutators and sets of brushes. It takes a surge of well over 30 amps on starting and runs about 10 amps before you start transmitting.

This is far far beyond the capabilities of any 12v section of a computer power supply. 30A 13.8v psus fpr amateur radio 100W rigs hit current limiting and fold back when trying to run these things. There are two real cures. A battery with a suitable charger will run a 19 set, but the noise of the motor generator spinning, while not noticeable in a running tank is very objectionable in a domestic environment. The other solution is to build an alternative to the 19 set power unit, a box with a mains transformer to power heaters plus 275v HT for the low power and receiver stages, and 500v HT for the 807 power amp. This is a lot more efficient than going down to 12v and back up, and it's silent.

Running the dynamotor supply is interesting to demonstrate to people, but it's tiring for any time longer.

David

Re: WS19 mains converter
 

A 10 amp 13.2v common or garden mains PSU with a 7 Ah SLAB across the terminals works for my WS19. But as has been said the dynamotor is noisy and you have to let it spin up before you start talking. Using a complete mains PSU also helps preserve your dynamotor by not using it!

Re: WS19 mains converter
 

I can't really recall reading about anyone using a Dynamotor in a domestic setting after the war Norman as they were designed to aid mobilty in an Aircraft or [as in this case] a Tank. Very noisy unless it was a Radio Amateur "Field Day". Perhaps you may want to demonstrate in that way? Even so you need a PSU at home I would think. Do you actually plan to Transmit which clearly bumps up the power requirement? Have you any photos of your installation? Personally I was never impressed with these machines :shrug:but the B set was interesting. There are comments re this on other threads with doubts about their actual efficiency in "action". There are many people who would disagree though. I bought a chassis in the sixties [minus valves]. It was 5/- or maybe 2/6pence:thumbsup:

Dave

Re: WS19 mains converter
 

That is exactly right.

In fact even a vibrator supply (which is much quieter than a dynamotor) is such that while you can get away with one in a car/radio environment, if the radio is on your desk in a quiet domestic setting it is annoying. For my military radios like the ZC1 I use solid state replacements for that reason.

Also, as we all know even a fan in a computer/supply or some test bench apparatus can be very annoying while trying to listen to a radio or quiet sounds. The broadband audio noise tends to mask quiet sounds.

You could always use headphones with the WS19 set and get away with the dynamotor, but that is always more fatiguing than listening to a speaker. So the advice to build a silent suitable HV and LV supply is good.

Re: WS19 mains converter
 

If you are not licenced then you don't need the 500v supply which makes a mains PSU easier. Another non transmitting option is the Canadian PSU which runs off a vibrator for receiving only. And as Argus25 has said, fitted with a solid state vibrator they are totally silent.

Re: WS19 mains converter
 

Why is everybody trying to put the OP off using the dynamotor power supply, rather than helping to answer his question?
Yes, the dynamotor is noisy, but it is what it is.
In my view the whole point of owning and restoring vintage equipment is to appreciate the technology of its day, 'warts and all'.

Having said that, I do have to agree with the sentiment in post no. 5, the dynamotor is a mechanical device with brushes, commutators and bearings so does have a limited life unless replacements for worn parts can be sourced.

Andy

Re: WS19 mains converter
 

After all the remarks about the tiring noise, there is nothing more impressing then a dynamotor starting as you turn a set on.....

I run a BC191F and a BC348R as a set both on their dynamotors.

The BD-77-D puts out a staggering 1000 V at 1 Amp peak ( 0.5 Amp nominal ).

I power that thing with a ex ICT server power supply but as the filament heaters are also on the same power supply you need a large unit. A 1000 watt unit is hardly capable of delivering the starting current, a 1470 Watt Dell unit ( 121 amps output ) should do the trick.

The power consumption of a WS19 set is much lower so a moderate server power supply delivering 400 to 600 watt should do. Do not use a too small supply, they are NOT designed for high starting currents.

And yes, dynos make a lot of noise, but hey, this old equipment as it was used back then already required headphones ( tank/aircraft noise ) and now they still do.

Re: WS19 mains converter
 

Something to remember about the 19 set, designed for use in tanks and armoured vehicles, is that it wasn't operated on a battery on charge. The practice in such vehicles back then was to have two sets of batteries, one powering the radio and another being charged. These were then switched over as necessary. So the radio is designed to operate on 12 volts, not 13.8 or 14 volts.

Andy

Re: WS19 mains converter
 

I think it was because the OP asked :

"I am wanting to use my ws19 set as a home based unit".

So the idea of operating it in a quiet home environment was considered by the responders and those of us who have operated dynamotor, vibrator and rotary converter supplies know what it can be like. It is fun of course to have the original equipment working albeit noisy.

Re: WS19 mains converter
 

Exactly as Argus says. That's why I mentioned the post war situation 8-\
The OP can certainly run it up if he can cope with the noise and Transmit if he's licensed but overall it's speculation based on what he's told us already.
It's not that clear what the motivation is really???

Dave

Re: WS19 mains converter
 

Thank you all for your detailed and informative replies - much appreciated.

I can see the advantage in David's idea of building an alternative PSU - the dynamotor is noisy - unfortunately this is well beyond my ability at the moment but certainly something to bear in mind for the future. I think that the simplest option for me at the moment is to continue with batteries.

I would add that the set is a mk2 with both English and Russian writting on it. It is for receive only, I dont have a licence.

Motivation was mentioned - I have several WW2 battery chargers which I exhibit at various shows, an obvious addition to this was a period radio hence the iconic ws19. Batteries are ideal for the show ground but I was looking for a simple alternative for home use. I use my set up at shows to show(educate?) the general public on the vital contribution that these pieces of equipment made to the war effort - that might, and probably does, sound a bit silly, but if it's not done this information will be lost/forgotten. As an example at a recent show a person spent a long time reading my information boards and looking at my exhibits and then thanked me saying that he had never before appreciated how vital batteries were to the war effort - made my day! Sorry to digress.

All the best, Kev.

Re: WS19 mains converter
 

That's great, Kev.

You do need the dynamotor running for the full effect for your demonstrations. It's a part of the whole thing that people can sense directly.

A mains PSU may be beyond your current abilities, but abilities grow with time. Something for the future.

It's fairly easy to get an amateur licence and numerous clubs would like to help you. Then you could really show the 19 set doing its job.

There's lots of help available on here if you want to go a bit further.

Most people aren't aware that wifi and cellphones are radios. Education is very important.

David

Re: WS19 mains converter
 

Thanks for that clarification Kev. The Public Information aspect of your activities does, indeed, seem invaluable. Unless I've got it wrong, you were simply wanting a mains borne 12 volt supply to replace the batteries for home use [not a dedicated HT/LT unit to replace the Dynamotor altogether].

I think I misunderstood that aspect:dunce: so we got side-tracked on to just the issues re running the Dynamotor "at home"! I would have thought you might simply need a heavy duty commercial type car Battery Charger to do that but others can advise you I'm sure. What sort of events do you exhibit your equipment at by the way?

Dave

Re: WS19 mains converter
 

Kev,

If you haven't aleady found them, I'd recommend joining the WS-19 group on:

https://groups.io/g/wireless-set-no19

Cheers

Roger

Re: WS19 mains converter
 

Thank you for your encouraging comments.

David - As I understand it to transmit on military radios - even vintage ones - I would need either an intermediate or a full licence - it would be good to get one though for the reason you mentioned - something to think about doing during the winter.

Dave - I exhibit/show at various vintage rallies during the summer months.

Roger - Thank you for that link I will look into that site.
All the best,
Kev.

Re: WS19 mains converter
 

Yes, you'd need an intermediate or full licence. The levels are rather basic and once you get to intermediate and full, you start learning things that can help you do radio better so it's not effort just spent on the licence, you get to keep some useful knowledge :-)

Your best approach is to find a local club that runs courses and the exams and contact them. Lists of clubs are on the RSGB website.

If you run into anything that seems difficult, drop me a PM on this site and I'll talk you through it. Once you know a few background facts, even the licence conditions start to make sense. If you've been doing a bit of radio for a while and have been picking up the lingo, you have a flying start.

With 2-8MHz coverage, the 19 set can operate on the 80m and 40m amateur bands which are going to be where most of the activity is for the next several years as we go into a sunspot minimum part of the cycle.

David

Re: WS19 mains converter
 

If you want to use your WS19, remember that it's now something like 70 years old and there are a number of components that will not have aged well: Wax-capacitors, rubber insulation for a start - then there are the resistors, many of which will have drifted significantly from their original values.

A WS19 properly and sympathetically re-componented can - despite its low power-output - still be useful on the HF bands. OTOH a neglected example can lead you to nothing more than frustration and despair!