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Electronic parts Identification please

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shutter
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Electronic parts Identification please

Hoping that someone can give me some information about the "types" of capacitors should be used in the circuit shown.

the only one`s I can recognise are c7    c8   &  c9   (all three with a small + to one end indicate electrolytic type).. and C1 which is a Variable Capacitor, used for tuning the radio.

 

If anyone has a "junk box" with the capacitors and resistors wasting space (! !).. I would much appreciate them, to "lighten your load"....  ( green stamps available for post & packing , if desired,... PM. for address )

 

 

 As regards the 9volt battery.... I assume that the negative side of the battery would be connected to "chassis" ( earth )  ? ? ? 

Thanks for help.

 

Shortwave radio cct diag LARGE.png

7 REPLIES 7
VileReynard
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Re: Electronic parts Identification please

The 9V is connected to the + side of a couple of electrolytic capacitors - so the - side must be earth.

I would guess it doesn't matter what kind of capacitor you use for the small values.

It looks very dodgy providing one that is "1 - 5pF" though - isn't that just a piece of wire?

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shutter
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Re: Electronic parts Identification please

I could guess too.... but I wanted someone to give me a more definitive expert approach answer, to my original post.... rather than speculative guesswork.

wisty
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Re: Electronic parts Identification please

Fix

 

9V plus goes to where it says on the circuit diagram. 9V negative goes to earth as you surmise.

The non electrolytic are simply standard low capacitance devices. They come in many forms depending on what you want to do with them. See Wikipedia picture of capacitors. The ones you will probably get are the ones on the left of the picture. For what you want almost any with the right capacitance will do - for higher voltages you have to take that into consideration as well. 

Electrolytics (on the right of the picture) are used to give high capacitance in a small package - but have the disadvantage that you have to be careful with polarity( as well as voltage) 

The 1-5pf C3 capacitor provides DC isolation while passing high frequency signals.

shutter
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Re: Electronic parts Identification please

@wisty Thanks for your reply....  and the linky.... it  is many years since I worked with electronic components, way back in the days of valves... and they were much bigger physically, and many types that could be used, depending on the frequencies/voltages/ etc... hence my question.

Now I know what to look for, I think I will enjoy making this radio... just for the fun of it !...

Baldrick1
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Re: Electronic parts Identification please

In terms of schematic layout this has to be the weirdest (and worst) that I have ever seen, it's just bizarre! You may have problems getting a 1-5pf capacitor. If you can only find 10pf devices then connect two of them in series to get 5 pf .

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shutter
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Re: Electronic parts Identification please

@Baldrick1  I found it on a page  here....

 

http://www.electroniq.net/radio-frequency/shortwave-radio-reciver-using-2n2222.html

 

If you think you could "modify" it... to improve the circuit, either for layout, or for efficiency, then I would appreciate any help...

Am assuming the 0.01  is uf and not pf  ?  (c2 c4 c5 & c10 )

Thanks for the tip about two 10pf in series......

wisty
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Re: Electronic parts Identification please