More than 1 km av uhf TRANSMITTER

**p55xp** · 17th September 2009 03:26 AM

I got this project from a POST in a different thread. I think it can be a great project, and can easily be used in numerous other projects as a stand alone unit. But to be successful in making this project is difficult like other rf projects

. The project is not a very "hard nut to crack" but description is not understandable, at least the inductor making, and tuning process could have more clearly described.
I am on the way to make one for me. Please help me on inductor making and tuning process Above all who is not a transmitter enthusiast?
Please try to support almost everyone
Also recommend a substitute for BFY90, I think almost any high ft transistor will serve the purpose.
I re-attached the attachment here too.

**mneary** · 17th September 2009 08:22 AM

I think you should check in Calcutta first to see what high fT transistors you can get. (The author suggests BFR91a.) It would not help you if I suggest transistors that I have in Los Angeles.

Google helped with the procedure which seems to be written in Croatian:

All elements letovati directly on the plate (no drilling). Assembled unit tinfoil and make a barrier between the transistors (marked green) and L3 can 8navoja of copper wire 0.4mm wire on the body of a 5mm diameter spot BFY90 transistors can BFR91A

You should be able to make the coils using the description and the drawings; please read through it again.

**p55xp** · 17th September 2009 05:16 PM

First of all I must apologies for misplacing my thread; though I realised it just after posting, I was unable to move it under the heading where it is now placed. Thanks.

mneary,
Thanks a lot, you minutely looked at it. I saw the translation before. Practically GoogleTranslate was the only resort before I placed it here. The translation is very poor.
The meaning to me was: 8 turns of .4mm dia copper wire on a 5mm dia former(transistor body?).
Again if you go through the schematic "L3 5 CM wire 2.5 m/m silvered wire" is written on it. Confusion emerges.
Please guide me.

**mneary** · 17th September 2009 05:57 PM

I am not familiar with the term 'former' except from texts I receive from India. I think it means a support used for winding the coil and is removed once the coil is completed, e.g. any round object. (In America I would use the smooth end of a 3/16" drill bit.)

Silvered wire probably means he's suggesting wire plated with silver (Ag). I don't think it's necessary at this frequency and I think he used wire plated with tin (Sn) or lead (Pb) which looks the same. In either case I suggest a 5cm (50mm) length of 2.5mm dia. copper wire. Tin plating just keeps it pretty.

The Google translation provided all but two words. I was astonished at its excellence. Maybe I didn't find any errors because I don't speak Croatian as you do. English is a particularly bad language to construct in translation because of the strange places we use the word "be". You have to be prepared for this.

The units CM or m/m aren't Metric or Imperial. Probably relate to cm and mm in the text.

**p55xp** · 17th September 2009 06:17 PM

You rightly understood the former(that partains right form to the coil)!!
But you do not suggest the dia. of the coil. If it is 5mm then 50mm of length would give only little more than 2 turns!
Please give detail of the L3, otherwise I understand all your points.

**mneary** · 17th September 2009 06:37 PM

Please read everything again. Electronics is about detail. I haven't provided anything new to you. All I have done for you is read the same document you have, and repeated each detail to you as you ask a question.

L1 and L2 are 5 turns of 0.3mm wire. He does not specify the length of the wire used to wind these coils.

L3 is a straight heavy (2.5mm dia) wire 5 CM or 5 cm (I prefer 2 inches or 50mm) long per the drawing.

**mneary** · 17th September 2009 06:42 PM

I am sorry to say that I am the one who missed the detail this time. Apparently L3 can either be 50mm of heavy wire or an unspecified length of 0.4mm wire (wound?) "8 navoja" on a 5mm (spot). [edit: Google translates navoja as thread which confuses me further. [/edit]

I would use the 50mm piece of heavy wire.

**p55xp** · 18th September 2009 02:15 AM

There is heaven n hell difference in the inductance of a 50 mm, 2.5 mm dia. straight wire inductor and that of an 8 navoja (thread or turn) of .4 mm dia. copper wire on a 5 mm dia. former (smooth end of 5 mm drill bit).
Both is written on the schematic sheet about L3.
None of the above inductor is replaceable by each other.

**mneary** · 18th September 2009 07:20 AM

Maybe you could email the author?

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