50 ohm to 75 ohm impedance converter

[txdao]

how can I build an impedance converter used for transforming 50 ohms to 75 ohms or 75 ohms to 50 ohms with virtually no loss. Does anyone know schematic?
thanks for any help in advance

 

[Snoogans]

What frequency is it using?

 

[VEBill]

Depending on the application, the best solution ~might~ (?) be to simply connect them directly together (ignoring the slight mismatch). In the real world, things are rarely exactly 50 or 75 ohms. And it often doesn't matter.

More details ?

 

[ScottyUK]

I know I posted a reply to this question over the weekend. Was the thread deleted?

Use a transformer: transformers change impedance according to the relationship Z₁/Z₂ = (N₁²/N₂²) where Z_x is impedance and N_x is number of turns for the primary and secondary windings respectively.

Transformers can be made very efficient by careful winding design and choice of core material.




----------------------------------

If we learn from our mistakes,
I'm getting a great education!

 

[itsmoked]

I saw it ScottyUK! Your mind is intact. New poster maybe... violated the functional email requirement.

 

[ScottyUK]

Hi ItSmoked,

Don't take this as evidence of my sanity. You wanna see the evidence in the other pile...



----------------------------------

If we learn from our mistakes,
I'm getting a great education!

 

[zeitghost]

Scotty, I thought I saw your transformer post in another thread...

 

[Skogsgurra]

I think that we all know what happened to that post. The question is a typical student question. Especially the wording "with virtually no loss" points to that. That is not something that a working man would put in his question. It is also clear that the assignement was about HF/VHF and that the expected answer was a stub with a certain length.

I think that txdao(industrial) should do his homework on his own.

Gunnar Englund

http://www.gke.org

 

[zeitghost]

Scotty, I think that your transformer post is in this thread...

http://www.eng-tips.com/viewthread.cfm?qid=128783&page=1

 

[ScottyUK]

How on earth did it end up in there...?

Wierd!!


----------------------------------

If we learn from our mistakes,
I'm getting a great education!

 

[analogkid2digitalman]

Soctty's post must have been transformed with virtually no loss.

Wheels within wheels / In a spiral array
A pattern so grand / And complex
Time after time / We lose sight of the way
Our causes can't see / Their effects.

 

[itsmoked]

Ah... Now someone owes someone a beer!

 

[Skogsgurra]

good good

Gunnar Englund

http://www.gke.org

 

[stevenal]

ScottyUK,

You answered a new irrelevant question in an existing thread. After answering, you mentioned that he should begin a new thread. Looks like he did. The irrelevant question has been deleted. The answer is gone now too after I RFed it. It looked a little lonely out there without a corresponding question.

 

[ScottyUK]

Stevenal,

Thankyou for clearing up my mess!


----------------------------------

If we learn from our mistakes,
I'm getting a great education!

 

[boreholelogger]

Use a stub matching circuit which will require a piece of double-sided PCB, Protel and a smith chart!. Look up stub matching on google or get a textbook written by CHENG to show you how to do it.

 

[boreholelogger]

You will also need to know what frequency you want to match the 50 to 75 ohm line too.

 

[VEBill]

Very nice freeware: Transmission Line Details

Link:

http://www.qsl.net/ac6la/tldetails.html