Forgot Password
Pentax Camera Forums Home
 

Reply
Show Printable Version Search this Thread
12-14-2011, 09:54 AM   #1
New Member




Join Date: Dec 2011
Location: london, ontario
Posts: 11
Can't find batteries for older spotomatic

for the pentax spotomatic :
the batterie "PX-400" or "S400-PX" (1.3 V ) have been discontinued !??
suggested replacement is the Energizer "E-387S"
for the gossen lunasix light meter it is : "PX-13"
I CAN NOT FIND THEM ANYWHERE !!
CAN ANYONE HELP WITH FINDING THEM ??
......JIMMY

12-14-2011, 10:17 AM   #2
Loyal Site Supporter
eddie1960's Avatar

Join Date: Aug 2010
Location: Toronto
Photos: Gallery | Albums
Posts: 12,270
Weincell makes one

http://www.smallbattery.company.org.uk/sbc_mrb400.htm
12-14-2011, 10:19 AM   #3
Site Supporter
boriscleto's Avatar

Join Date: Dec 2009
Location: Liverpool, NY
Photos: Gallery
Posts: 12,872
The Spotmatic used Mercury batteries, you will not be able to find them as they are illegal now.

You can use 1.5v Silver Oxide batteries in their place ie. Energizer 387S. You can't buy them at the store anymore, but you can get them online.

http://www.amazon.com/Energizer-Low-Drain-Silver-Oxide-Button-Battery/dp/B00006G9SE
12-14-2011, 10:20 AM   #4
Loyal Site Supporter
eddie1960's Avatar

Join Date: Aug 2010
Location: Toronto
Photos: Gallery | Albums
Posts: 12,270
QuoteOriginally posted by boriscleto Quote
The Spotmatic used Mercury batteries, you will not be able to find them as they are illegal now.

You can use 1.5v Silver Oxide batteries in their place ie. Energizer 387S. You can't buy them at the store anymore, but you can get them online.
the weincell is the correct voltage, but also an online only item AFAIK

12-14-2011, 12:02 PM   #5
Veteran Member
magkelly's Avatar

Join Date: May 2010
Photos: Gallery
Posts: 5,905
FYI, Energizer 387S can be found in bulk or single on Amazon and at most Batteries Plus stores if you have those? I've also found them at the watch repair shop near me. There's a Duracell equivalent too but I don't recall the #. If you hit Amazon though there are several suppliers and they come cheap. That's where I usually get mine. Most Spotties though can run fine without batteries. It's just for the meter. When I run out I just use a hand meter instead. You won't find them at the drug stores et all though. It's not a battery that's used for hearing aids or toys a lot do most stores won't stock it. It's available but it is considered a bit of a specialty battery.
12-14-2011, 12:23 PM - 1 Like   #6
New Member




Join Date: Dec 2011
Location: london, ontario
Posts: 11
Original Poster
Thanks eddie !

everyon that has a spotomatic should read the first page re: discontinued battery issue & solutions @

MRB400 WeinCell non-mercury replacement for PX400 EPX400 RM400 H-B V400PX E400N PM400R KX400 T400N.

jimmy
12-14-2011, 05:10 PM   #7
New Member




Join Date: Dec 2011
Location: london, ontario
Posts: 11
Original Poster
I could send you a lude,
01-19-2012, 09:51 PM   #8
New Member




Join Date: Dec 2011
Location: london, ontario
Posts: 11
Original Poster
Thank you all !
Jimmy

01-19-2012, 10:07 PM   #9
New Member




Join Date: Dec 2011
Location: london, ontario
Posts: 11
Original Poster
Spotomatic batteries question . . .

CAN ANYONE CONFIRM THAT, WHEN THEY USED THE "E 387S " BATTERY in their "SPOT./1000"
& "SPOT.- -2", that the light meter worked as it should, without apperture adjustment ??!!
01-20-2012, 05:47 AM   #10
Site Supporter




Join Date: Jun 2011
Location: Texas
Photos: Gallery
Posts: 1,149
QuoteOriginally posted by bulic Quote
CAN ANYONE CONFIRM THAT, WHEN THEY USED THE "E 387S " BATTERY in their "SPOT./1000"
& "SPOT.- -2", that the light meter worked as it should, without apperture adjustment ??!!
Yes. I've used both the 1.33 V Wein cell and the E387S 1.5 V with no difference in exposure reading in both the Spotmatic and Spotmatic II.
Most cameras of that era designed for a mercury cell need the 1.3 voltage (or a reworked-meter), but not the Spotmatic. It's meter circuit is balanced for voltage variations.
01-20-2012, 08:08 AM   #11
New Member




Join Date: Dec 2011
Location: london, ontario
Posts: 11
Original Poster
THANK YOU TOM !!
although i read this, ( balanced circuit info ), somewhere, it was some time ago,
. . . and could not find the article again,.
i could not completely rely on the info, as i have 7 various spotmatic models to fit with the batteries.
*** i did not want to damage the electronics in the meter, for example.
and . . . the "WEIN cell costs almost $15. ( each ) with taxes - ( X 7 ) ! !
YOU gave me the experienced information i was looking for.
. . . hopefully other members will benefit from this as well !
JIMMY
01-22-2012, 09:37 PM   #12
Pentaxian
Cee Cee's Avatar

Join Date: Aug 2011
Location: Glenroy, Melbourne
Photos: Gallery | Albums
Posts: 2,992
the light meter is indeed a balanced bridge circuit with the meter connected between bridge output, the beauty of this type of configuration (cudos to pentax engineers) is that it is in fact voltage independent and in fact as long as you have enough voltage to deflect the meter it should give correct readings. This is why the meter always gives correct readings as the battery is ageing right up to the point of battery exhaustion. I have a Spotmatic F which uses slightly different size battery size, I use Vatra 625U Alkaline 1.5V as replacement for original 1.3V mercury battery with no problems at all. In any case as long as its 1.5V and it physically fits, it should work.

cheers
CC.
01-22-2012, 11:06 PM   #13
Pentaxian
Cee Cee's Avatar

Join Date: Aug 2011
Location: Glenroy, Melbourne
Photos: Gallery | Albums
Posts: 2,992
electronics, even the simplest of circuits is not always simple!

after I posted the above I thought this would be simple enough to prove with a simple experiment, so I connected a variable power supply to the battery terminals of my spotmatic F and checked the light meter at 1.3V and 1.5V as expected there was no variation in the light meter reading on the same correctly exposed scene ( light meter in the middle) what was noticeable was that with an incorrectly exposed scene the amount of meter deflection varied - the higher the voltage the more the deflection. This is not really a problem as the meter is marked + / - and is not calibrated as to how much +/- it is.
Now here's the kicker, in my Spotmatic F the natural physical resting place of the meter is in the center. ( this is confirmed by removing the battery and the meter still sits in the middle)
Looking at the Spotmatic service manual it indicates the natural resting place for the meter is in the negative region ( no battery fitted) and it requires a current of 300uA to to bring the meter pointer to read zero, that being the case the battery voltage may just make a slight difference to the reading, perhaps 1/4 to 1/2 stop. Unfortunately I do not have a Spotmatic to carry out the same test.

In any event you can put this to the test by testing with both types of batteries (1.3V & 1.5V) on the same controlled scene and seeing if there is a difference in the meter indication!

cheers, I hope this helps!
CC.
01-23-2012, 02:31 AM   #14
Veteran Member




Join Date: Apr 2010
Location: PGH PENNA
Posts: 340
I've been using a small 392 in mine if you must get a little foil as a spacer.
01-23-2012, 05:30 AM   #15
Site Supporter




Join Date: Jun 2011
Location: Texas
Photos: Gallery
Posts: 1,149
QuoteOriginally posted by Cee Cee Quote
electronics, even the simplest of circuits is not always simple!

after I posted the above I thought this would be simple enough to prove with a simple experiment, so I connected a variable power supply to the battery terminals of my spotmatic F and checked the light meter at 1.3V and 1.5V as expected there was no variation in the light meter reading on the same correctly exposed scene ( light meter in the middle) what was noticeable was that with an incorrectly exposed scene the amount of meter deflection varied - the higher the voltage the more the deflection. This is not really a problem as the meter is marked + / - and is not calibrated as to how much +/- it is.
Now here's the kicker, in my Spotmatic F the natural physical resting place of the meter is in the center. ( this is confirmed by removing the battery and the meter still sits in the middle)
Looking at the Spotmatic service manual it indicates the natural resting place for the meter is in the negative region ( no battery fitted) and it requires a current of 300uA to to bring the meter pointer to read zero, that being the case the battery voltage may just make a slight difference to the reading, perhaps 1/4 to 1/2 stop. Unfortunately I do not have a Spotmatic to carry out the same test.

In any event you can put this to the test by testing with both types of batteries (1.3V & 1.5V) on the same controlled scene and seeing if there is a difference in the meter indication!

cheers, I hope this helps!
CC.
Good points! I have also noticed that the "rest" needle position of the meters on my Spotmatics varies, with some centered and some not. I also notice some deflect more "per f-stop" change than others, even with the same battery. Even so, all seem capable of correct exposure using the 1.5V batteries.
Reply

Bookmarks
  • Submit Thread to Facebook Facebook
  • Submit Thread to Twitter Twitter
  • Submit Thread to Digg Digg
Tags - Make this thread easier to find by adding keywords to it!
pentax help, spotomatic
Thread Tools Search this Thread
Search this Thread:

Advanced Search


Similar Threads
Thread Thread Starter Forum Replies Last Post
Older guy with a new K-5 robtcorl Pentax K-5 10 04-22-2011 03:33 PM
Nature An older photo OrenMc Post Your Photos! 5 02-25-2011 03:51 PM
older fisheye? littledrawe Pentax SLR Lens Discussion 14 12-16-2010 04:32 AM



All times are GMT -7. The time now is 09:36 AM. | See also: NikonForums.com, CanonForums.com part of our network of photo forums!
  • Red (Default)
  • Green
  • Gray
  • Dark
  • Dark Yellow
  • Dark Blue
  • Old Red
  • Old Green
  • Old Gray
  • Dial-Up Style
Hello! It's great to see you back on the forum! Have you considered joining the community?
register
Creating a FREE ACCOUNT takes under a minute, removes ads, and lets you post! [Dismiss]
Top