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Yet Another Question on the 4W Transmitter


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RE: The one with the PCB diagram.


The cct schematic calls for a VK200 ferrite bead with 6 holes.  ???

Where can I order this, I searched on digikey and main electronics(I'm in Canada) and they don't list it.
Is there a generic cross reference for it or something???

OK thanks in advance!

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ANYBODY???? :-\

DigiKey doesn't have it, and this is the closest I could find but it doesn't even have the six holes.. so what's the deal???????? ??? ??? ??? ??? ??? ???

Some of you have built this thing right?  WHERE DID YOU GET THE VK200 CHOKES and what can one substitute if anything??????????????  :-[ :-[ :-[ :-[ :-[ :-[ :-[ :-[ :-[ :-[ :-[ :-[


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Hi S_M,
If you are really desperate then pay the high minimum order charge and get some VK200-3A from RF Parts.

What are you going to do with this old 4W transmitter that will cause severe radio and TV interference, drifts its RF frequency all over the dial, is mono not stereo and sounds bad like an AM radio?
Where are you going to find its old fashioned microphone?

I am in Canada too and know that the RF cops will be after you when people complain about your interference.

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Hey AG, thanks for answering buddy!!

So it sucks is what you're saying... well I'll just build it for the experience I guess... :P

Looking at this thing, http://www.rfparts.com/choke.html#vk200 
I didn't think it looked right, as there are supposed to be six holes according to the schematic and I thought it would be like one of those tin can looking inductor thingies, but if it'll work!!  Are you sure it's the same thing???

I'm going to build yours really soon, just been skateboarding and stuff for the summer 8) , but now that it's getting cold my electronics senses are activated again... as soon as I get an order in to Main I will be getting a bunch of copper-clad boards and some of those low-dropout voltage regulators for your project...

SM 8)

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Look closely at the pics and you will see 6 holes in the ferrite of the chokes.
The one at the top shows one and one-half turns, but says two and a half turns. Get it so it fits on the pcb. Its impedance is fine.

Be nice to the RF cops when they come after you. They might just give you a warning about making severe interference to radio and TV.

I designed my FM transmitter before I found out about the Stereo Micromitter. It is nearly perfect. Products are sold for transmitting an MP3 player to a car radio and use that circuit.

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"Be nice to the RF cops when they come after you. They might just give you a warning about making severe interference to radio and TV"
Heck, it will be a miracle if I even get it working even with drift... so I won't be worried about the DOC for a while I think... a friend of mine who used to be a real bad CB terrorizer got visited by them and got a warning, but then he kept harrassing people until a bunch of goons from a CB'er club came to his house with baseball bats and took his equipement!  No joke! :'( 

So I do know the dangers of interference!!! :o

Now he lives in the Yukon with lots of space around him, a large antenna and a 1000W linear.

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