CM
maandag 1 juli 2019
Filenaam: Lunasix reparatie CM
Gossen Lunasix 3 (S) notes, repair, CLA
Thanks to Marek Lewandowski for is artikel to recalibrate the Lunasix (link to URL)
190 g
180 g
170 g
CM
maandag 1 juli 2019
Filenaam: Lunasix reparatie CM
I've trouble with
self rotating ISO
scale if I rotate the
number scale. !
So did cleaning,
removed all the old
grease !
I put new grease in
the 2 lower discs. I
use Molykote 44
grease.!
Now everything
runs very smoothly
again. Butter-soft
as the German say
CM
maandag 1 juli 2019
Filenaam: Lunasix reparatie CM
CM
maandag 1 juli 2019
Filenaam: Lunasix reparatie CM
Offset
Slope
Offset
Low Range
High Range
No ND Filter
Low Range
Battery
Light value
Value Gossen scale
Resistor Value*
Adjust potmeter
EV5
10
25,3 k Ohm
Low range pot Slope
EV0
5
229 k Ohm
Low range pot Offset
Light value
Value Gossen scale
Resistor Value*
Adjust potmeter
EV14
19
6,73 k Ohm
High range pot Slope
EV8
13
95 k Ohm
High range pot Offset
*= custom value only
for my 3S
Slope
High Range
ND Filter
0,10 kΩ
1,00 kΩ
10,00 kΩ
100,00 kΩ
1000,00 kΩ
10000,00 kΩ
-4,0
-2,0
0,0
2,0
4,0
6,0
8,0
10,0
12,0
R expected
R measured
R computed
↓ Schematic PCB PCB side view
Geprobeerd met curve opmeet
techniek de meter in te regelen.
Niet gelukt. o.a. denk ik omdat
metingen met gloeilamp licht zijn
gedaan denk ik.
CM
maandag 1 juli 2019
Filenaam: Lunasix reparatie CM
Tip 1) Do not place diodes (conversion from mercury to silver battery) if you adjust the
meter again.!
Tip 2) Adjusting the potentiometer with the housing open does not work. close each
time again the case before reading your value!
Tip 3) The quality of the light matters a lot. First I used a soft box where I put the light
bulb with a variac at a very low voltage. That does not work the light becomes too red.!
Use light as naturally as possible (read daylight) to adjust the meter
Offset
Slope
Offset
No ND Filter
Battery
Slope
Low Range
High Range
Low Range
High Range
ND Filter
EV5
EV0
EV8
EV14
Scale
10
Scale
5
Scale
13
Scale
19
↓ Schematic PCB PCB side view
Recalibrate the meter with normal daylight sources!
As reference meter I used an Gossen 'Sixtomat Digital'
I use direct light, so the white dome in place !
I start with my reference meter 'Sixtomat Digital' and find a place with EV8 !
Set the Lunasix at same place and adjust the potentiometer 'Offset High' to 13!
With my reference meter 'Sixtomat Digital' again, now find a place with EV14!
Set the Lunasix at same place and adjust the potentiometer 'Slope High' to 19!
Repeat this steps
CM
maandag 1 juli 2019
Filenaam: Lunasix reparatie CM
↑ Schematic
← Schematic PCB!
component side view
↓ Circuit Lunasix 3S
CM
maandag 1 juli 2019
Filenaam: Lunasix reparatie CM
↓ Circuit Lunasix 3 according to Alessandro Lambardi
↓ Circuit Lunasix 3 according to Georg Holderied!
It is different from my 3S version, #
Hmmm. . . I think better, !
but I think this circuit diagram may
still have a mistake.
It is different from my 3S version, #
Hmmm. . . I think, !
this circuit diagram may have a
mistake.
CM
maandag 1 juli 2019
Filenaam: Lunasix reparatie CM
↓ Spectral respons of an (random type) CDS cel
Battery options#
• (Not recommend) Buy in Russia an mercury battery. http://www.px625.ru#
• (Difficult) Buy an 625 Silver-Oxide battery and recalibrate your light meter!
• (Easy) Buy an PR625 or LR44 Zinc Air battery + adapter (expect ¼ to ½ year life ?)!
• (Average) Buy an LR44 Silver-Oxide battery + adapter and recalibrate your light meter#
• (Expensive) Buy an Wein Cell EPX PX625!
• Do NOT use a alkaline battery (example V625U)
Battery adapter 'trouble'#
I got trouble with LR44 battery and the adapter. The battery clamp from my Lunasix
was to big and short circuit between the two poles of the battery. !
So I made an adapter from very thin (0.3mm) double sided PCB. One side I etched the
copper circle to 8.0 mm. Other possibility was I made a ring from teflon (PTFE).
↑ Adapter
clamp side↑
diameter#
14,8 mm
Battery side↑
diameter#
8 mm
cupper
Isolator
CM
maandag 1 juli 2019
Filenaam: Lunasix reparatie CM
↓ Photo's from Lunasix 3 scale.
I've a dirty/smutty scale. So I did a cleaning, plus I've removed all the old grease !
I put new grease in the lower disc. If I use Molykote 44 grease I find that the ring is
rotating too stiff. So I changed the grease to Nyogel 744!
Now everything runs very smoothly again.
CM
maandag 1 juli 2019
Filenaam: Lunasix reparatie CM
↓ Photo's from https://photobutmore.de/vintagephoto/belichtungsmesserspez/index.php
CM
maandag 1 juli 2019
Filenaam: Lunasix reparatie CM
↓ Drawings from Rick_Oleson.
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