about the witcher

[New THer]

Does anyone knows how can i replace the parts that i can't find (Q1,Q2 from the trnsmitter and IC1 from the receiver)?Thanx in advance

[Sean Goddard]

Re: about the witcher

Hi,

Q1, Q2, and IC1 from WHAT circuit mate?

What machine are you talking about?

Send me a cct diagran if possible and I'll source the parts for you.

[New THer]

Re: about the witcher

Sorry, I mean the two box IB detector from this page.Please take a look because i'm planning to build it and i don't know how(I'm a beginer in electronics and i don't know what changes to make.I looked about Q1,Q2,IC1 and i can't find them.)thanx

[Carl]

Re: about the witcher

Here is a replacement circuit I came up with for the CA3035... I posted it some time ago for someone else, never heard back if it works.

I think Q1 is non-critical, about any gen. purpose device will do. Q2 is a UJT, don't know where you can pick these up nowaday, probably DigiKey.

Honestly, the Witcher is an antique, someone needs to come up with a modernized design.

- Carl

[Dave J.]

Re: about antique 2-box units

I haven't looked at the "Witcher", so this comment does not pertain to it specifically. But.... for many purposes, modern 2-box units aren't a huge improvement over the better "antiques", and in some cases the "antiques" are actually superior.

--Dave J.

[Sean Goddard]

Re: about the witcher

Try FAIRCHILD semiconductors, they still make this transistor.

You could ask for a couple of "samples". Usually works.

Tell them you are working on an R & D project with a view to marketing the products if all goes according to planned.

[C.Pruysers]

Re: about the witcher

New THer Could you be a little more specific about the transistors . Are they PNP or NPN . Do you have any old numbers for them ( look on the body ! ) We will find replacements but guessing is never good . ICI must also have a number on it . Regards Kees

[Carl]

Re: about antique 2-box units

True, but I was thinking more in terms of antique components. The CA3035 has been obsolete for years and is impossible to find. The UJT in the TX is available but not easy to get.

There ain't much to a 2-box, even the new ones... basically just an all-metal circuit. It would be quite easy to come up with a new 2-box design using modern components. The hard part is alignment of the orthogonal coils.

BTW, I have a Fisher Model 47 (I think) 2-box... all-wood construction, tube circuits, 6 big-honkin' batteries... anyone know how old it might be?

- Carl

[Carl]

Try again...

Circuit did not show up the first time.

[Carl]

Now what???!!!

Damned forum software ain't working right. Who wrote this junk?

[pawel]

Re: about antique 2-box units

Carl, I don't remember where I found this article, but have a look...

Regards,
pawel



Click Here

[pawel]

Another antique

This is a picture from the Russian edition of the Polish book "Modern Toys" by J. Wojciechowski (the 70-ties). I should have the original somewhere as well...
Have a look at the dynamite sender.

Regards,
pawel

[Dave J.]

Fisher Model 47

Carl,

Maybe someone at Fisher can tell you how old it is. They might even be interested in buying it or accepting it on loan, for their museum.

--Dave J.

[New THer]

Re: about the witcher

I mean the two box ib detector from Carl's page.Sorry i didn't mention it .

[New THer]

Re: Now what???!!!

Thanx Carl