Transformer Ratio Meter

[SurreyNick]

Oh, Lawrence!
Now they would have been perfect and they will be a definite feature on some of my future designs. As you suspected though, there isn't enough room to accommodate them on this particular construction. I think it's going to have to be sticky labels or waterslide transfers for this one. But does anyone know a company/individual who can do a sheet cheaply? I can always do the artwork.
Nick

[pwdrive]

I think David (yorkie) will probably know.

Lawrence.

[SurreyNick]

Just in case anyone is considering making one of these little meters and wants to use identical voltmeters they can be bought here:
http://www.surplussales.com/Meters/MtrACVolts.html
They are item (MTR)33005 at $19.00 each (appx. £12.35). Shipping for a pair (First Class) to the UK is $23.50. That's appx £40.00 (forty quid) total for the two meters inclusive of shipping, which is quite a lot but it's the cheapest I could find.
Nick

[Radio Fixer]

It can be done:  here is a PYE 350C that I restored including the front panel.  The decals under many coats of lacquer, and skill is needed to do that,  didn't look like decals.  The only way you could / can tell is by looking at an angle against the light.  Applying the lacquer needs starting with mist coats, else the decals crinkle, and then building up.

   
   

But what you need is someone with an Alpes thermal printer and most of those are in the US.  You could try advertising on the AVR forum.  That's where I found my guy who used to print a sheet from supplied artwork for a few dollars + postage.  Alas, brilliant restorer that he was, he has now retired.

Gary

[Radio Fixer]

I guess the lesson there Nick is to think of the box construction first. You can cover up and get away with things inside but not out. Now if you had made the panel say grey or pale blue than black on clear decals, easy on most printers, would have done.

Here is the Forum I quoted: http://antiqueradios.com/forums/index.php

Another way would be to use those dry rub off transfers, in white, bought in art shops. But for me it hardly ever looks right, just not steady enough hands. Also, I think you would need to strip the front panel and have it flat to pull it off. My way out would be to buy (Crafty Computers) some of the letters on white decal paper (never tried this). Then the letters could be black, put a nice fancy black box line around the label and it should look OK.

http://www.craftycomputerpaper.co.uk/.In...er_151.htm

But on the + side, great drawings and build.

Gary

[SurreyNick]

Thanks Gary. In my younger days I used to get accused of spending too much time intellectualising "all brains and no action Nick". Ha, ha if only my old boss could see this. Oh, well...next time I'll think it through better.
I have emailed a couple of companies that do custom sheets of white typeface waterslide transfers. Just have to see what they charge. Failing that I'll follow up your line of enquiry.
Nick

[Nick]

...In my younger days I used to get accused of spending too much time intellectualising "all brains and no action Nick". Ha, ha  ...

Same here - it goes with the name

[SurreyNick]

If someone can spare a few seconds I’d like to just check ’ve done my calculations correctly

I could only get a 6v 60mA miniature filament bulb for the Ratio Meter, which means the 120 ohm resistor specified in the circuit is too high. The transformer drops the supply voltage to 9v and so I calculate I need a 51 ohm 1.4W resistor…

Voltage drop: 9v minus 6v = 3v
Resistor value: 3v divided by 0.06a = 50 ohm (round up to nearest standard value = 51 ohm)
Resistor power: 0.06a times 0.06a times 50 ohm = 0.18 watts

I haven’t done this enough times for it to become second nature, so just want to make sure I have done this right? I am assuming I don’t need to compensate for the fact the bulb is receiving an a.c. supply either. Is that right too?

Thanks

Nick

[pwdrive]

C'mon someone stick their neck out  

Looks ok to me, switch on and be damned (that's my technique)

Lawrence.

[Alan Douglas]

Looks correct. No difference whether AC or DC.