Fairchild 627 from scratch

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DaveP

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Nov 8, 2005
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2,855
Location
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It has been a while since the last post as I had to solve an alignment problem with the pot extensions.



I cut the rods in half and joined them with a tight fitting spring glued on; this allows a nice smooth movement.

I roughened the surface of the front panel and applied two coats of aluminium primer.



The next step is to apply some matte black before the lettering.

The lettering font is a very close match to Arial and the letters and numbers appear to be about 4mm high.

From the photos I saw, I could not make out if the low roll was showing 60 or 80 before the 100. So I plotted the angle of the letters on the pot against frequency and got a nice curve with 60, but 80 was completely wrong.

The next job is to spray it matte black then to fix the lettering, then the whole lot will be sprayed with varnish.

best
DaveP
 

DaveP

Well-known member
Joined
Nov 8, 2005
Messages
2,855
Location
France
The front panel after the matte coat.


I had to calculate all the angles for the lettering and I have reproduced them below:-

Low Freq High Freq

20Hz 60o 4k 45o

30 150 5k 120

40 210 6k 180

60 260 8k 260

100 300 10k 315



Low Boost High Boost

0 30o 0 30o

2 85 2 90

4 125 4 130

6 150 6 160

8 170 8 180

10 200 10 215

12 245 12 255

14 290 14 300

16 330 16 330



The High roll is marked at 30o intervals and the low roll is marked to suit your 5-way switch. I have used Ohmite Dials for the input and output.



The lettering was positioned using masking tape and the numbers from pre-drawn discs of paper.

I have attached the lettering as two pdf's if anyone is interested.

Finished front panel



It would have been nice to finish it in the original black crackle finish, it was available to buy in the 1960’s but I seem to remember that some of the chemicals in it were carcinogenic and so it was withdrawn.

Best

DaveP
 

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Stevie342000

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Jan 4, 2014
Messages
19
Stove topping Crackle finish is something you can do in a domestic oven. Not sure where I came across it possibly Radio Constructer or on of the other older magazines or on line. I have seen it, its an application of the base material and then a crackle finish which I am sure you knew already.
 

DaveP

Well-known member
Joined
Nov 8, 2005
Messages
2,855
Location
France
I'm sure your right, but if the paint didn't kill me, then my partner would for using her oven!
 

scott2000

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Feb 21, 2015
Messages
3,182
Location
Sunny...Sometimes Florida- USA
Looking great.... I've been pretty impressed with some matte (or universal flat it might be called) clear spray as well for extra protection on a couple of things. The finish has been very consistent and seals over thin labeling nicely too.
 

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