HMV 442 back

[Phil G4SPZ]

I am seeking an image of the rear of an HMV 442, in order to replicate a missing back panel. Any information would be welcome.

[Panrock]

Phil, here's a snap of a Marconiphone 296 I have on file, taken pre-restoration. This is a Marconi equivalent and should be similar.

Maybe this will help?

Steve

[Phil G4SPZ]

That's brilliant, thank you very much, Steve.

My question has been very promptly answered, Mods, so this thread can now be closed.

[stevehertz]

Out of interest Phil, how will you replicate that back?

[Phil G4SPZ]

I was thinking the same thing, Steve... Slots and rectangles are relatively easy to make, using hardboard and a router. The design and layout of this back are simple, but whilst I own several diamond drills, they make round holes! Some compromise may be necessary. As the radio will sit on a shelf in a museum, it's not a major issue.

[Phil G4SPZ]

After further thought, I may have the answer - a hardboard panel with large ventilation holes, onto which is glued a thick paper or thin card into which the diamond-shaped holes can be cut using a sharp blade or chisel. A couple of coats of dark brown oil-based matt paint will complete the illusion.

[mark_in_manc]

That sounds good...though...if you were keen, you might form the end of a piece of thin-wall steel tube into a diamond shape over a former filed up from a lump of steel bar (the perimeter would I guess need to be similar!) - ending up with a kind of wad punch. Then see if, when sharpened a little, it would cut through hardboard onto something soft. Don't know how often you'd need to sharpen it for all those holes!

[Phil G4SPZ]

I'd considered doing something like that, Mark. However, my experience with using purpose-made hole punches to cut materials like leather and even cardboard led me to dismiss the idea of a punch. Hardboard is surprisingly strong in compression and I just don't think I could make a cutter strong enough to punch through it.

I might just try cutting diamond-shaped holes with a sharp chisel.

[stevehertz]

All good ideas.

WRT your 'stick on' idea, what about using some cardboard the same as is used on the back of A4 pads? it's a bit thicker and of the correct texture. And here's a whacky idea, use the same cardboard sheet at the front and back of the hardboard, then fill in the gaps with silicone or something? In truth that's quite a big project, if it were me I'd probably settle for a nice looking hardboard back painted the correct colour and with large holes, but anyway, all interesting stuff.

[Phil G4SPZ]

Hi Steve,

The cardboard's a good idea. I plan to browse the local stationers and craft shops to look for something suitable with the right textured surface, as hardboard itself is just a little too smooth to be the real thing. However I think I'll just apply the card facing to the outside of the hardboard, otherwise the whole thing could end up a bit too thick!

[stevehertz]

Yes, I did think that myself to be honest.

[Panrock]

I was once sought to achieve a similar effect and ended up using the rough side of hardboard, but smoothed somewhat and painted. See 7 pictures up from the bottom here:

http://www.radiocraft.co.uk/606.htm

Steve

[stevehertz]

Steve, Steve Rowley here, I couldn't help read the rest of that (TV) restoration, lovely job! Hope you're keeping busy.

[Panrock]

Steve Rowley... now there's a name to conjure with from the remote past!

I am following this thread with interest. Backs are often hard to do well, with their odd hole shapes. In the instance above I was thrown on my own resources but normally I would try to either find another off a scrap set or approach someone who specialises in making backs.

Steve






















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[stevehertz]

Repro backs are like the one missing piece in the jigsaw. Lots of people make other repro parts; knobs, dials, logo badges, but not backs. In fairness I know that people have had backs made for high profile sets such as Round Ekcos and stuff, but as far as I know there's not someone specialising in the game. Perhaps a small business opp for someone as an aside to the VW/VTV hobby? It would be a great start if we could find a source of the proper back material? Anyone know a producer/manufacturer?

[Phil G4SPZ]

The first replacement back that I made was for a round Ekco! The second was for a pre-war Ferranti. They both had slots rather than diamond-shaped holes.

Steve (Panrock), that does look a fabulous restoration. You describe using hardboard to make the extended box over the TV tube neck, and I like the idea of sanding down the rough side, but your material looks rather thinner than the stuff readily available in DIY stores - where did you find it? I use regular 3mm hardboard (smooth one side) and I've measured the thickness of several original vintage radio backs - they are between 2mm and 3mm. Earlier backs such as the one on my Philips 634A are rigid and more like modern hardboard, but most set backs are more flexible. I believe the material was known as "fibreboard" but I've no idea if there is a present-day source.

Phil

[Panrock]

Originally Posted by Phil G4SPZ

Steve (Panrock), that does look a fabulous restoration. You describe using hardboard to make the extended box over the TV tube neck, and I like the idea of sanding down the rough side, but your material looks rather thinner than the stuff readily available in DIY stores - where did you find it?

Leaning against the wall in the workshop! Beyond that I haven't a clue (sorry). So much stuff seemed to mysteriously materialise there over the years. Probably something to do with my 'magpie' tendency.

By the way, it looks like you are no mean restorer yourself!

Steve

[Phil G4SPZ]

Thanks to everyone for their interest, and especially to Steve for your generous and kind comments above! I am perhaps a "mean" restorer because like most of us, I rarely throw away any material that could perhaps come in useful at a later date. As a result, we magpies live amidst clutter but it really comes in useful at times. A lovely although off-topic example was a few weeks ago when we were on holiday in our caravan, I managed to repair a lady's mobility scooter using a small tubular piece of plastic rod that just happened to be lurking in my spares box 'just in case'.

Back to backs. I'm going to try hardboard but the other way round, as Steve did. I still haven't cracked the diamond holes but I'm thinking about it.

[stevehertz]

Originally Posted by Phil G4SPZ

I still haven't cracked the diamond holes but I'm thinking about it.

Get hold of someone with CNC machining capabilities, it'd be a doddle to them. You may have to sandwich the hardboard between two sheets of metal though to ensure a clean cut.