searching for info about Pentax spotmeter V

[Christophe1]

Hello everybody,
I'm new to this forum so greetings to all online.
My question:
I have recently bought a Pentax V spotmeter, but I have trouble with the so-called illuminator, the light being faint or not working at all. I have already managed to open the spotmeter but I'm looking for more information to repair it, like schematics or identification of parts. Is there someone who has experienced the same thing and/or has tried to fix this meter?Or someone who has information on the inside (or inside information?) of this meter?
Thank you very much,
Best Regards,
Christophe

 

[AgX]

Welkom bjj Apug!

https://fdocuments.in/document/pentax-spotmeter-1-21-repair-manual.html

 

[Christophe1]

Willkommen to you to!

 

[Christophe1]

Welkom bjj Apug!

https://fdocuments.in/document/pentax-spotmeter-1-21-repair-manual.html

Unfortunately I have already this document, and the circuit is not the same of the Spotmeter V.
Different system, different power source (1/21= two batteries, 9V and 1.3 V separate for low light reading and bright light reading,
while Spotmeter V= 4.5 v , scale numbers are continous from low to high)

 

[AgX]

I was not aware that both models (1°-21°Meter and Spotmeter V) were that much different that the repair manual is not helpful.

 

[Christophe1]

I was not aware that both models (1°-21°Meter and Spotmeter V) were that much different that the repair manual is not helpful.

No problem, it is kind that you want to help me out.
There are several models: https://www.pentaxforums.com/forums...bums/5660-pentax-collection/picture48792.html
(These are the - from the right to left- Spotmeter 3°/21° (mentioned by Ansel Adams in 'The negative',p.65),spotmeter III, digital spotmeter)
And this is the
Spotmeter V:
https://www.popscreen.com/prod/MTYwOTEzNDk4/Asahi-Pentax-Spotmeter-V-Light-Meter
And spotmeter 1°/21° is the one you mentioned, virtually indistinguishable from the Spotmeter V, although I believe there is also a black version of the latter.
Anyway, I listed them now in a jumbled way.The 3/21 was the first, the digital the last.And what happened to the IV version I don't know.

 

[Christophe1]

I was not aware that both models (1°-21°Meter and Spotmeter V) were that much different that the repair manual is not helpful.

And I believe by the way, that there is a difference between models of the same version, if I saw this correctly on the internet. The 1/21 has a version with fixed resistors, so no calibration possibility, and the other has variable resistors (or how do you call it, trimpots ?). I'm not sure what to make of the drawing in the document, but it looks like the vertical pcb has fixed resistors, but the circuit says otherwise if I'm not mistaken. But maybe this scan is also incomplete, I don't know, because there is no page that mentions the electronic components. Or perhaps it is custom in repair manuals of this type,I don't have the faintest idea.

 

[Christophe1]

And I believe by the way, that there is a difference between models of the same version, if I saw this correctly on the internet. The 1/21 has a version with fixed resistors, so no calibration possibility, and the other has variable resistors (or how do you call it, trimpots ?). I'm not sure what to make of the drawing in the document, but it looks like the vertical pcb has fixed resistors, but the circuit says otherwise if I'm not mistaken. But maybe this scan is also incomplete, I don't know, because there is no page that mentions the electronic components. Or perhaps it is custom in repair manuals of this type,I don't have the faintest idea.

And I'm rambling, sorry.

 

[MattKing]

And I'm rambling, sorry.

Welcome to Photrio.
And if you ramble here, you will find that you are in good company .

 

[Sirius Glass]

.

Welcome to APUG Photrio!!​

 

[Christophe1]

Welcome to Photrio.
And if you ramble here, you will find that you are in good company .

Ok, that is duly noted.

 

[AgX]

There are even functionally 2 versions of the 1°-21° Meter, one with scale illumination button, one without.

 

[Christophe1]

There are even functionally 2 versions of the 1°-21° Meter, one with scale illumination button, one without.

I see. I didn't know.

 

[Christophe1]

I do know that some of the meters were build by Honeywell photographic division in the US (the document you showed is from Honeywell), perhaps this explains it at well?

 

[Christophe1]

There are even functionally 2 versions of the 1°-21° Meter, one with scale illumination button, one without.

Anyway, the information I've found is really scarce. I even don't have specifications about the light bulb in it besides that it is sub miniature and probably not made anymore.

 

[AgX]

They are even still manufactured, down to 2.3mm diameter.

 

[Christophe1]

They are even still manufactured, down to 2.3mm diameter.

Really? The version with the screw thread base? Do you have a link by any chance for this?

 

[AgX]

At electronic stores you will only find a fraction, but likely the more standard types.

 

[Christophe1]

At electronic stores you will only find a fraction, but likely the more standard types.

Ok. And you are referring to photographic stores now I presume? Any recommendations?

 

[AgX]

Sent a pm

 

[Christophe1]

Sent a pm

I think I'm still limited for PM because I don't have enough posts? Or did I just reply to you in PM?

 

[Christophe1]

Ok, I replied in PM apparently, sorry about the confusion. Did you get my reply?

 

[Bill Burk]

My phone camera completely over exaggerates the light that the bulb provides. The light is barely visible when it’s working properly and it only lights a few numbers so you can see the needle when the light you are measuring only registers 1 or 2

 

[Bill Burk]

Your eye needs to be adapted to the dark to see it.

 

[cmacd123]

I do know that some of the meters were build by Honeywell photographic division in the US (the document you showed is from Honeywell),

Honeywell, was the US distributor, and had Pentax label some of the equipment sold in the USA market as "Honeywell". I understand this was intended to block US residents from Importing Pentax Equipment from other countries. (basically the nice customs folks were told that Honeywell Pentax was a Honeywell Trademark and they should block importation of anything that said ASAHI Pentax as being a fake)