8mm Forum: Elmo Gs1200 recording capacitors

This is topic Elmo Gs1200 recording capacitors in forum 8mm Forum at 8mm Forum.

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Posted by Flavio Stabile (Member # 357) on March 25, 2017, 03:29 AM:

Hello,

Does anyone know where to find the "3300pf 600v dc 5% max toler. polystyrene (or polyester) capacitors" to be replaced in the Elmo Gs1200 to get recording capabilities again?

Thanks
Flavio

Posted by Steve Klare (Member # 12) on March 25, 2017, 03:45 AM:

These should do the job, and I'm pretty sure they ship to Europe too.

3300pF, 600V

The question is are they the right size and shape to to fit.

Posted by Phil Murat (Member # 5148) on March 25, 2017, 06:17 AM:

Hi Flavio,

Any of these works, depending of the size and room you get for installation:
From 100v to..... xxxx V !!

"J" means +/- 5%
It can be labelised 3n3J400 for exemple

Polyester, ceramical, Polypropylene,etc, they work all, may be only sound "Color" could change a bit (Trebble / Bass).....to be confirm

3300 pF

Also, 3300pf = 3,3nf : This could help you for an extended research.
or, also :
3n3 Polyester

NB
If same capacitors are found on both chanels, I suggest you to replace both as a set and from the same batch.....

[ March 25, 2017, 07:31 AM: Message edited by: Phil Murat ]

Posted by Steve Klare (Member # 12) on March 25, 2017, 06:50 AM:

Does anybody know what the real voltage is on this cap?

If 600V is overkill you could find a lot of alternatives at lower voltage ratings.

Posted by Phil Murat (Member # 5148) on March 25, 2017, 07:28 AM:

Hi Steve,

There is a high probability the voltage is not very important probably capability is higher than 50V......

Only size icrease a lot from 400, 600, 1250v, etc.....

400v is very common for these capacitors.
Only an "Audio" specialist could help us to confirm how technology of capacitor (i/e polyprop, ceramica, etc...) could have an effect on quality of sound (saturation, etc....)

Posted by Paul Browning (Member # 2715) on March 25, 2017, 08:17 AM:

I have replaced one these on the GS, there is only one to replace. The original cap measures 50 odd volts before the change across it, after you replace with new 80 odd volts, can't remember the exact measurement but it is more, and it improved the recording's, so worth doing, but there are bias settings that can be adjusted on these too, which improves this again, and balance's up correctly the recording on the 2 channels.

Posted by Phil Murat (Member # 5148) on March 25, 2017, 08:32 AM:

Hi Paul,

Do you mean voltage measured between cap terminals was 50V before replacement ?

Posted by Paul Browning (Member # 2715) on March 25, 2017, 08:44 AM:

Hi Phil, yes that's correct, I like to know that the component replacement has at least made a difference, as this is part of the recording circuit, ac across this. These have some odd solder on them I found difficult to remove, so you need a good quality soldering iron, by that I mean, a weller style with power station and a means of getting the solder off or at least removed.

Posted by Flavio Stabile (Member # 357) on March 25, 2017, 03:27 PM:

Thanks for all suggestions!

Indeed I was trying to find exactly the model I wrote, having read an old post where this argument had been already treated

http://8mmforum.film-tech.com/cgi-bin/ubb/ultimatebb.cgi?ubb=get_topic;f=1;t=001033# 000000

and where it is suggested the type, the minimum voltage and the tolerance...

[Roll Eyes]

Posted by Renzo Dal Bo (Member # 5688) on March 26, 2017, 02:29 AM:

Hi Flavio,

I found one capacitor on eBay that could work: 3300pF 630V 1% Polystyrene

http://m.ebay.it/itm/1pcs-PHILIPS-KS-3300P-40-3300pF-3-3nF-41-630V-1-Axial-Polystyrene-Capacitor-/151664766262?txnId=1527320151005

Posted by Phil Murat (Member # 5148) on March 26, 2017, 03:52 AM:

Hi Flavio,

Your link is very instructive!

Looking for 1% instead of 5% leads to increase price x10 approx....

What you can do is to get a batch for 5% and measuring each of them, you keep caps which are closed to nominal value.

As I understand there is a "precize" and "tight" frequency target to reach. So there is a high possibility there is somewhere a "variable" component to adjust this frequenecy (needs probably Oscillo Tool)

In the link on A/M ref it is mentionned 60KHz Frequency approx as a work range.
So to stay on a safe side you can install 2 or 3 (ex: 3 x 1,1nf) caps in a parallel fitting to decrease impedance and allows caps for better work....

[ March 26, 2017, 04:53 AM: Message edited by: Phil Murat ]

Posted by Flavio Stabile (Member # 357) on March 26, 2017, 03:36 PM:

Ciao Renzo!

many thanks for the link even if it is located in Taipei, Taiwan!
Anyway this is the closest to the one mentioned in the post so I'm very happy to buy it (more than one, of course...) !

Grazie!!!

[Wink]

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