Defiant valve portable battery radio Model BPSH 247.

[Barbel18]

hi.

Please help.I have obtained a beautiful green Defiant portable valve radio.
I believe these were marketed by the COOP. But I am not sure who actually manufactured them.
It needs the usual 1.5V LT and 90V HT from an ever ready B103 battery pack.
It has 5 valves of the DK and DAF series.
It is in incredible condition.
Problem is I cannot find a schematic anywhere for this radio.
It has 4 control knobs on the front, tuning, volume, LW,MW, and "normal,economy"
I would appreciate any help you can give.

Martin

[Gabe001]

Hi Martin

Is it the green one from the large defiant collection on eBay in Stanley?

They were made by plessey and the service information is almost impossible to come by. I have circuit diagrams for the M234 AC and AC/DC models which I submitted to the bvws and which will be included in the next iteration of the CD. They won't help with this particular model though. If you've picked up others from the same collection, I have spotted a few of them that seem to use the same chassis.

Gabriel

[paulsherwin]

Some photos would help.

Are you sure it has 5 valves? While not impossible, this would be unusual. Most 50s battery portables used very similar 4 valve designs - DK9x, DF9x, DAF9x, DL9x.

[Cobaltblue]

Yes this one has push pull ( I assume) DL92's

I is a nice set unusual looking.

Cheers

Mike T

[Gabe001]

Originally Posted by paulsherwin

Some photos would help.

Are you sure it has 5 valves? While not impossible, this would be unusual. Most 50s battery portables used very similar 4 valve designs - DK9x, DF9x, DAF9x, DL9x.

It's probably this one
https://www.ebay.co.uk/itm/Defiant-V...-127635-2958-0

[paulsherwin]

Originally Posted by Cobaltblue

Yes this one has push pull ( I assume) DL92's

In that case we can guess what the economy setting does

I think there were a few other battery sets with a similar arrangement.

[Techman]

The first thing to check is the continuity of the output (speaker) transformer primary winding, as if it's open circuit (which it often is on battery valve portables) it can be a total show stopper, unless you want to throw some money at it.

Unusual for me to say this, but repair of the rest of the radio usually just involves replacement of the old paper capacitors. There's often very few of them in battery portables and I've found that all of them seem to be critical to the performance of the set, so will need replacement. The HT decoupling electrolytic capacitor in these sets is nearly always found to be faulty with leakage dragging the HT down and flattening the battery and also having a distinct lack of capacitance causing 'motorboating'. So what I'm saying is that with care you should be able to repair this radio without any service information - it may just take a little longer, using the valve data for each valve.

[HamishBoxer]

I mentioned all this yesterday in an email I received from Martin in my role as BVWS archivist.

Great minds think alike!

"A quick look and I certainly do not see a circuit anywhere, though on a simple set like that should not really be needed.

If it has DK 91 /96 types valves in, it will need 1.5V heaters and 90V HT.

The heater voltage is critical and a D cell ideal, anymore than 1.5V and they are gone.

Are wanting to overhaul this set and do have any technical know how I need to ask?

It should not take much for it to speak again, I am assuming it does not at present of course?

If the valves are ok, then a few capacitors and check resistors for way out of tolerance will no doubt sort it. Plus worth checking output transformer is not open circuit.

I am guessing it is full of wax or the dreaded Hunts capacitors."

[Barbel18]

Yes it is from Stanley near Durham. Very nice man. Yes it is 5 valve.
initial test with the LT at 1.5 V is 343mA with the knob in the Normal position.
2 x DL92 in push pull.Just spent £20 on 9v pps batteries to make up the HT. Just about to try it.
Great looking radio. Only criticism, these 1.5v valves don,t seem to glow. I would love to attatch photos but cannot figure out how to do it on this forum!

[McMurdo]

no you won't see them glow

[Cobaltblue]

Graham did a Sticky on posting pictures you can find it here:

https://www.vintage-radio.net/forum/...ad.php?t=77650

Cheers

Mike T

[Gabe001]

Originally Posted by Barbel18

Yes it is from Stanley near Durham. Very nice man. Yes it is 5 valve.
initial test with the LT at 1.5 V is 343mA with the knob in the Normal position.
2 x DL92 in push pull.Just spent £20 on 9v pps batteries to make up the HT. Just about to try it.
Great looking radio. Only criticism, these 1.5v valves don,t seem to glow. I would love to attatch photos but cannot figure out how to do it on this forum!

The sets in that collection seem to have been really well cared for. Your set has the battery connectors for pp3 and 1.5v batteries already in situ, in a nice reproduction box of an original Eveready battery. Someone has clearly put in a bit of effort already and if be surprised it requires anything substantial doing to it

Did you pick up anything else from that lot?

Gabriel

[Barbel18]

No, but I wish I had.

Martin

[steve102]

I bought an HMV 1200 motor tuned radio from the Stanley collection. Great guy to deal with. The radio has been recapped and the speaker wires replaced with white PVC multicore cable. Not the neatest of jobs but it works. I was tempted by the Defiant MSH 938 but it went for a tidy sum.

[paulsherwin]

No further discussion of the eBay sale please.

[Tractorfan]

Hi,
As an aside.
Does the 'economy' setting just take one valve out of circuit, or does it re-jig the output as a single ended amp?
Cheers, Pete.

[Techman]

Originally Posted by Barbel18

Just spent £20 on 9v pps batteries to make up the HT. Just about to try it.
Great looking radio. Only criticism, these 1.5v valves don,t seem to glow. I would love to attatch photos but cannot figure out how to do it on this forum!

That's expensive at £20!

Normally 5 packs of 2 at £1 each at Poundland do the job!

It sounds to me like you bought expensive Alkaline types, which personally I wouldn't recommend. Two reasons...there's too much current available, which could be dangerous if there was an accidental short circuit within the case and secondly, they have more of a tendency to leak and blow their ends out, particularly if they're of a certain make other than the pound shop Kodak types, which I think most of us find are very good - and they're also only £1 each. However, even though it seems that this set has an extra output valve I'd still stick to a zinc carbon type, which is what the original one would have been. If it wasn't for the fact that it looks like you've already got all the PP3 connectors there, I would have considered using AA cells, which are £1 for a pack of 10 at Poundland and are good quality Kodak branded types. The last pack that I bought had 4 extra free in the pack making it 14 for £1, so a very cheap option...I'd go for the big soldering iron and solder the whole lot together in series and pack them without holders, but you'd need to take care not to get any shorts!

Seeing as more is now known about the set it looks like it probably won't need any work after all and would seem to have already had the known likely faulty components replaced. As has been said, full instructions for posting pictures is available on the forum and then it can be confirmed what has been done within if you take some close ups.

[Chris55000]

Hi!

I'd like to mention a small point – 1.4V battery valves do exhibit a filament glow – obviously they have to in order to emit – you CAN see it in a completely darkened room as a very thin dark red line running into the middle of the electrode assembly, but it takes at least three or four minutes for the eyes to dark adapt enough to see it – I can confirm I have seen the dark red glow from a correctly supplied 1.4V filament!

It is quite correct that it's impossible to pick it out in normal daylight tho' – if you're ever unsure, a valve battery set should come to life within two seconds of switching on the h.t. and l.t. batteries – any more than this indicates a run–down l.t. battery or damaged valves, most likely from over–running their filaments!

Chris Williams