Jaycar/Silicon Chip troubleshooting part 2

Well looks like the other one got full, as a continuation from the first:

Mel

I have only ever been told of one Theremin that is “irreparable” but what was meant was, I don’t know how to do it and I’m not going to let you have a go in case you succeed.

Wolis

Sometimes measuring resistors “in circuit” will give odd readings as you will be measuring the whole of the circuit, not just the resistor.

But as you are both with non-working instruments and we have tried the most obvious things, I now suggest either getting a local technician to look at it or I can do so.
I have just fixed Sami’s from Finland and if you want to proceed please contact Sami for my email address or post yours here. Think this might be the quickest way to get you up and running.

Regards

MarkT

I got a jaycar hoping i could do the mods and it would be all dandy and good. But no. I spent hours and hours, days researching and studing trying to figure it all out. I finnaly got it all together and it doesnt work. I think I'm just going to take the mods off and see if it works. I did all of maxs mods but the two 1mm wires, the coil before the tone attenna, the low pass filter because i didnt get that at all everything was mixed up and I didnt put the 220 k to increase range because the kit i got had changed the i meg to a 100 k.


W/e I hope to figure this thing out.
:)

Hi
I would suggest getting the thing working WITHOUT the mods first, this is the best way as it will be easier to find the faults later as you are about to find out!

Are you getting anything out of the speaker at all?

Regards

MarkT

Yea its been makeing noise all kinds of ways, but today i finally got the volume plate to work.
The tone antenna still does close to nothing. Its a constant tone til i touch it then its a higher tone. I took all the mods off, but the power mode which changed the capaciters. I think i should change that to the original too.

Also T2 doesnt look right and its what the tone antenna goes through. T1 and T3 are really white, but T2 has like some blackish gray and the white flaked off, also T2 is made buy a different company it has writing on the top while the rest dont.It has GOOD PLAN writen on it. I'm thinking of getting a new coil but the kit says its special order or something.

Coils normally don't break. They only can be damaged by overheat, when the current which passes through is much too high.

I Think it came broken or wrong in some way. It looks completely different from the two other coils that are suppose to be the same.
But I don't know what is wrong, I'm new to circuitry and all that for the most part. So I could be way off. haha
help!!

HI MarkT,

Lets pursue this sending-to-england concept.

My email is wooolis @ gmail.com

Thanks

Thanks a lot MarkT for fixing my Theremin. It works pretty well now only thing I need to adjust is the T2 and I think that's not so big problem as I suppose I can fix it in one day or something.

If you have prolems with your Jaycar kits MarkT does very good job fixing them. Thanks

Sami

Hi all,

Just letting you know that my Theremin is working, thanks to MarkT.

I diligently followed the instructions but still managed to get a few things the wrong way round and a few dodgy solder joints. So I sent it over to MarkT in England (from Australia) and he fixed all of my mistakes.

Surprisingly it was not confiscated during transit as it sort of looks like an explosive device.

So it all ended happily and I recommend anyone do the same if they cant solve their Theremin troubles by themselves.

Hi there, im a total newbie to electronics but ive been building this theremin kit over the weekend and put the diodes in the wrong way round, in taking them out the legs got snapped off cos my desoldering skills arent great. the diodes were 1N4004 so i went to maplin to get replacements but they gave me 1N4006 diodes, will putting these in my circuit damage it and will i need to get the correct replacement diodes?