Replacing capacitors in yr scope lately?

[Spica]

Hi. been recommended to change all (5 pcs?) of capacitors in my old (first generation) LX200 Classic to avoid increased risk of getting a burnt down 'scope. Would this be a big deal? Not a professional electrician, but have some soldering experience but not really into fine electronics. I assume some "coolingclamps" (or what you call them in English - we call them "Crocodileclamps" at home) are needed to spare the surrounding parts from intense heat.

Which is the easiest part to start to gain some experience before hitting the more nasty capacitors (sure there must be one that is most tricky to reach etc)?

Maybe in the handcontroller?

Can those capacitors be found today? What are they marked?

Tnx a million

[RogerTheDodger]

Googled around and found you some info on this...

Telescope Reviews: 12" LX200 classic with fuse problems

LX200 Faults

[cowasaki]

What is on the caps? You should be able to get any value but there are thing that you can substitute. The important things are Type, Value (F) and voltage. If the type and value are correct the voltage can be anything the same or higher.

[Spica]

Tnx to both of you - forgot abt this thread until this morning!

Problem solved, hooked up with the LX200 Classic-group on Yahoo, they have answers to just about anything related this type of telescope!

What I needed was caps rated no less than 6.8uF and no less then 35V, so I went with 10uF & 35V which was what the electrian had at home. I would have liked to put back tantalums again, but the Yahoo-group said type is of less importance so I have another sort of caps now (are they called electrolytic?)

It was definately not a job for me, taking out the circuitboards I noticed that it was so crowded and the components so tiny - not leaving any room for errors. Including material and labour/work, I paid the retired electro-engineer 20 Euro (abt 25 dollars) which is to be considered as a VERY good and cheap insurance as compared to a total meltdown.

Telescope seem to work fine after a thorough testrun, and now ready for dim lights again. Yeeeeay!

[cowasaki]

Brilliant, at least it is sorted.

[Reggie]

Tantalum's are a type of electrolytic capacitor but they're better than the standard electrolytics which have the round barrel shape.

Tantalums are higher capacitance by volume/weight, have a lower resistance, low leakage and can work at higher temps. than standard electrolytic caps, although they are usually more expensive.

Personally if they were tants in the mount, i would've replaced with tants, especially if worried about burning the mount.

[Spica]

Hi Reggie. Tnx yr input, yeah, don't know much about electronics, so maybe they are tants then afterall as they have a cushion-like look. I don't think the heat itself is an issue here, it was more that the old tants were underrated (25V) and the voltage spikes top more than that occasionally, making the tants go kaboom. What I have learnt tants are a bit sensitive to small chocks in the voltage... should be ok now though.

[pete_l]

I'm surprised there is enough room to replace a tant with an electrolytic. Usually tants are used because they're so much smaller, and people are prepared to pay extra to squeeze them on to the board.

The other thing is that tantalum capacitors have a wider temperature range than electrolytics (which is why they're preferred in mil-spec kit), which could be significant if your 'scope gets particularly cold.