Is it just a #14 copper wire that is U-Turn bent tight to a length of .70"?

 

Does this do you any good?

 

Is it just a #14 copper wire that is U-Turn bent tight to a length of .70"?

What's your specific application? Is it a hairpin match - say for a Yagi antenna ....?

 

This might also be a useful link ....

http://vk1od.net/antenna/misc/BetaMatch.htm

 

Hello,

Are you refering to the 6 watt broadband amplifier?

Here I have taken some picturs of an other amplifier with different syles of hairpin coils.
The following one shows the thick wire hairpin as in your wanted schematic:

The other two pictures shows the hairpin made out of strip material:

The pictures are taken here at home.

Bertus

 

I made that circuit, it works, but not really good. I only had a 2-3 watt fm transmitter to try and amplify. When I connect the transmitter to the RF amp with the known good tuned antenna, it only draws between 0 - 150 ma. This seems like nothing for 6 watts. The output also is 1 mhz off from the transmitter output frequency. I have a small transmitter that is between 100 and 300 mw....it does no amplification at all on those. Does my circuit look ok?

Thanks.

 

Hello,

You have to long wires for a RF circuit.
There is a PCB drawin on the site of the schematic (although the coil numbering is wrong over there).
http://www.21say.com/2sc1971-6-watt-broadband-fm-amp/

Also the input power is to less, it needs 0,5 watts input for the 6 watts output.
If the input power is to less the output power will drop very fast.

Bertus