Unknown radio or should that be wireless?
 

Some 7 years ago I ended up with a large job lot of radio, tv, components etc from a deceased collector, all purchased from the surving family for an agreed price. Anyway my question is does anyone recognise this set? Is it a commercial unit, was it a homebrew variety or could it be built from a kit? Another thought is could it be a reproduction from the last 20 years?

The ebonite top control panel was already damaged and it has been in my outbuilding since aquiring it. It is missing the valves but does have 2 plug in coils with it.

It would be good to know more about this mystery set and I am adding 8 pics to help in this task.

Thanks

Dave

Re: Unknown radio or should that be wireless.
 

Here are the remaining 3 pics.

Dave

Re: Unknown radio or should that be wireless.
 

It has all the hallmarks to me of a 1925ish homebrew, components all look consistent with the period and the overall design reminds me of projects included in a Boy's Wireless Annual I have from about then. There would be nothing to stop someone assembling something similar in the 21st century if they had a well-stocked box of vintage parts and a big sheet of ebonite, but I doubt many folk have gone to the trouble and if they did they would likely have taken more care of the set afterwards. It could possibly have been built in a little "cycle and wireless" type shop for local sale, but the jumbled look of the panel argues against any larger enterprise: and manufacturers no matter how small would usually leave their identity, a serial number and often a model name engraved on the panel.

Paul

Re: Unknown radio or should that be wireless.
 

Looks like a homebrew set of the early to mid 20s, commercial sets normally had engraved ebonite panels or some of the "cheaper" ones (sets were all quite expensive at the time) such as mid 20s Fellophones used transfers to mark the controls.

Re: Unknown radio or should that be wireless.
 

I recognise the GecoPhone tuning cap, wonderful bit of engineering. I do have one nos and boxed.

If commercial , I would have thought more dovetail joints on the case.

Re: Unknown radio or should that be wireless.
 

Based on an early Scott Taggert design perhaps?

Be interesting to get it going again, valves of the HL2 family may well be suitable

Ed

Re: Unknown radio or should that be wireless.
 

The first major problem is finding a way to repair the ebonite panel. It seems that there's not a lot of effective adhesives available for this. Mainly due to the ebonite actually being a type of hard rubber that contains a considerable amount of sulpher. My first thoughts were super glue or epoxy resin but my internet searching suggests that they are not suitable. I do have a possible third option that is called 'Stixall' but I've yet to check the manufacturers application/specification data. If no go it looks like making a replacement panel perhaps out of black acrylic, I don't know at this stage.

Dave

Re: Unknown radio or should that be wireless.
 

I wonder if the best way to 'repair' the Ebonite would be to do so in a way which makes no attempt to conceal the repair, rather accept it as part of the thing's history?

Kinda like the Japanese "Kintsukuroi" powdered-gold-ceramic infill used when repairing broken pottery?

Brass angle-strip underneath, countersunk Brass screws clearly visible on the top-side...

Re: Unknown radio or should that be wireless.
 

What I was going to do if |I find a suitable adhesive is clean the broken edges as best as I can and then put the joining adhesive along the exposed broken areas and then hold them together while the adhesive sets. Any excess adhesive will then be scraped off. This will leave the lines of the breaks still visible on the panel, at least thats what I would think. It's all early days yet as I still need to find something that will definately work. The Stixall comes in various colours including black, so that could be a possible contender. I'm not going to do that thing where the edges are chamferred and then back filled like you see on the BBC's Repair Shop.

I'll let you know how I get on in due course once I've had chance to check the adhesive specifications etc.

Dave

Re: Unknown radio or should that be wireless.
 

I had a friend in Germany who used to do just such a thing: build sets up from 1920s magazine designs using original components. Sadly he is no longer with us.

Re: Unknown radio or should that be wireless.
 

If at some point you did wish to create a new panel, black phenolic 'Tufnol' would I think be an acceptable substitute for Ebonite.

There's a family firm in Hull who supply an extensive range of plastics and make plastic fabrications for industry. The have an eBay should where they sell various thicknesses of phenolic Tufnol sheet in various sizes. No connection other than as a satisfied customer - I've used them several times over the years.

This is just an example - 200mm x 100mm of 8mm thick sheet:

https://www.ebay.co.uk/itm/360897586...8AAMXQjq5Q-9lI

If ever you did need any sheet, your best bet would be to either drop them a line specifying your requirements or give them a call to discuss:

GFG Plastic Fabrications Ltd,
Nigel John Gray,
Bridge works,
101 West Dock Street,
Hull.
East Riding of Yorkshire
HU3 4HH.
01482 610110.

https://gfgplastics.uk

Hope that might help.

Re: Unknown radio or should that be wireless.
 

Thanks David, I've just had a look at their ebay phenolic paper based sheet. The original sheet size in this radio is 620mm x 208mm x 4mm. I think 4mm is perhaps a little too thin for the weight that it has to support, so thought 5mm as a replacement, however the next thickness up seems to be 6mm. I will probably need to replace some of the fixing screws to accomodate the 6mm thickness. I'll sent them a message via ebay to see what they can do and take it from there.

The adhesive idea looks like a real pita to resolve, as non of the modern types that I've checked even mention ebonite as a material. Several specify that they can't be used on a sustrate that is leaching and I suspect that the sulpher content could be considered to leach out. It will need some specific questions to the various adhesive manufacturers to see what they think and if they can make any suggestions.

The panel will need a complete strip down to repair and also part of it is warped. I don't want to invest any expense for adhesives that will not work as well as all the time to strip, repair and rebuild if the panel is going to break again. Probably better to start with a thicker replacement panel.

Dave

Re: Unknown radio or should that be wireless.
 

Quick update, I've emailed GFG via their website. Hopefully they will reply sometime soon.

Dave

Re: Unknown radio or should that be wireless.
 

Araldite should work and you could glue some braces across the cracks underneath. Better than scrapping the original panel.

Re: Unknown radio or should that be wireless.
 

I'll have to do some research into this and am in no rush to start at present. I have too many other jobs at present to keep me occupied.

I did come across HDPE as a possible contender as a replacement panel material should I go in that direction. I've not decided on the best way forward as yet, just considering all the options.

I do feel that the set although appearing to be 1920's style is too clean internally to be original, but I could be wrong. The person whose collection it came from did have quite a lot of period parts, that came with all the other stuff that I aquired. This is why I wondered if it was a modern build to look old. I'll never know if that was the case as the original owner is long gone now. He also used to deal in valves but someone else obtained the those by way of the will.

Dave

Re: Unknown radio or should that be wireless.
 

I think it's usual for battery-powered 1920s sets to be clean as a whistle under the top panel, almost regardless of where they've been kept. With no ventilation requirement, dust and spiders are generally pretty well excluded.

Re: Unknown radio or should that be wireless.
 

Hello,

I think your set started life as a four valve set circa 1923-25 but appears to have been modified to a simpler three valve set probably in the late 1920s.

This makes me think it is an original set and not a replica as why would you build a replica and then rather crudely modify it?

The fact it has two intervalve transformers and the position of the swinging coil reaction unit suggest that it probably had a high frequency stage followed by a detector and two low frequency stages (1-v-2).

If you look at the set now. most of the wiring associated with the first valve stage has been removed. The GecoPhone tuning condenser is more modern than the other components so is a replacement and the metal clad intervalve transformer (Marconi?) is probably a replacement whilst the other transformer looks original.

All this suggests that the set has been converted to a simpler three valve set with a detector and two low frequency stages (0-v-2).

Please think very carefully before replacing the ebonite panel with a more modern material.

Yours, Richard

Re: Unknown radio or should that be wireless.
 

I agree.

If it were me I'd repair the original, even if it meant that the repair could be seen and even if it had to be reinforced with perhaps brass plates with small brass nuts and bolts - it's a 'historical' repair.

Re: Unknown radio or should that be wireless.
 

Before doing anything with the original ebonite panel in this set I think the best way forward will be to find some small bits of sacrificial ebonite and try the various adhesives to stick 2 bits together and then see which is the best after a week or two. Hopefully that way I'll be reasonably sure what to use for a lasting repair job. Just need to sort out some odd bits of ebonite, maybe even get a small sheet that could be broken and then stuck back together, perhaps this will be nearer to the radio panel problem.

Dave

Re: Unknown radio or should that be wireless.
 

Having not been able to source any ebonite bits and given the prices of sheet material, I've decided to try the superglue approach. There is a Loctite product by the number of 480 that contains rubber particles and is suitable for some types of rubber and phenolic materials. With having the rubber particles contained it can cope with a little filling of the joint, so hopefully it will do the job. As a bonus it's black in colour although whether it will cause any whitening around the joint I don't know.

I'll report back once I've received the adhesive and tried it.

Dave