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Crystal Filter Termination

Ravi Miranda
 

Hi,

Doing some further research, are there any off-the-shelf transformers
that can be used for T5 and T6 (Crystal filter Termination)
https://www.hfsignals.com/wp-content/uploads/2019/02/ubitx_v5.pdf

Such as this: https://www.minicircuits.com/pdfs/T2-1T-KK81.pdf

Would this work instead of winding one?

Best 73,

Ravi/M0RVI

--
I'm here to add more value to the world than I'm using up.

 

Go for it Ravi, good find! much smaller fooprint.

Raj

At 13/03/2020, you wrote:
Hi,

Doing some further research, are there any off-the-shelf transformers
that can be used for T5 and T6 (Crystal filter Termination)
https://www.hfsignals.com/wp-content/uploads/2019/02/ubitx_v5.pdf

Such as this: https://www.minicircuits.com/pdfs/T2-1T-KK81.pdf

Would this work instead of winding one?

Best 73,

Ravi/M0RVI

 

Hi Ravi,

I think the ohm ratio is wrong on that one.  From the schematic, the originals look like 2:1 winding ratio autotransformers which will give a 4:1 ohm ratio.  Otherwise I don't see why you can't switch.

73,


Mark.

 

The better way would be to use the primary and secondary windings to make a 1:4 transformer..

At 13/03/2020, you wrote:
Hi,

Doing some further research, are there any off-the-shelf transformers
that can be used for T5 and T6 (Crystal filter Termination)
https://www.hfsignals.com/wp-content/uploads/2019/02/ubitx_v5.pdf

Such as this: https://www.minicircuits.com/pdfs/T2-1T-KK81.pdf

Would this work instead of winding one?

Best 73,

Ravi/M0RVI

 

Hi,

I suspect to simplify construction, they wind all these transformers the same.  Then to use them in that part of the circuit (simplify the traces?) they used them as autotransformers.  Unless, the schematic is not following what was done in the actual construction.  T8 is like that too.  I most often see regular transformers used in situations like this -- not sure if one way is better than the other.

73,


Mark

 

Hi again,

Mini-circuits says (except for DC isolation) RF performance is similar between the types:

https://www.minicircuits.com/app/AN20-001.pdf

73,


Mark

iz oos
 

Mini Circuits transformers are really good and many really wideband. Having said this, I think up to 15mhz winding one is cheaper and will be adequate. For higher frequencies higher than 15mhz it is likely to notice a difference.


Il 13/mar/2020 13:01, "Ravi Miranda" <ravimiranda@...> ha scritto:
Hi,

Doing some further research, are there any off-the-shelf transformers
that can be used for T5 and T6 (Crystal filter Termination)
https://www.hfsignals.com/wp-content/uploads/2019/02/ubitx_v5.pdf

Such as this: https://www.minicircuits.com/pdfs/T2-1T-KK81.pdf

Would this work instead of winding one?

Best 73,

Ravi/M0RVI

--
I'm here to add more value to the world than I'm using up.