6 Meter long wire matching

Frank Gentges fgentges at mindspring.com
Thu Jan 3 18:30:27 CST 2008


Bob,

I am here looking at "Transmission Line Transformers" by W2FMI both the 
original version and the second edition.  9:1 unbalanced to unbalanced 
is covered but is HF with some roll off at 6 meters.  I think a tweak or 
two could reduce the loss at the expense of 160 meters.

I will dig through my collection of cores and see if a simple 
reproducible design can be made.  I have had good luck with these 
ferrite transformers in the past.  Hopefully, this luck will continue 
into the future.

Frank




Robert Bruninga wrote:
> For my long-wire 6m beam, I need to match my 50 ohm cable to
> about 400 ohms or so.  I remember you can use 1/4 wave sections
> in parallel to get impedances lower than readily availailable
> coax, but also, you can "series" coax lines to get higher
> impedances.  See attached drawing.
> 
> In other words, two 70 ohm lines can give a section of 140 ohm
> line.  I just cant remember how to hook them up (shields and
> grounds), etc...
> 
> Bob, WB4APR
> 
>> -----Original Message-----
>> From: Frank Gentges [mailto:metavox at earthlink.net] 
>> Sent: Thursday, January 03, 2008 4:51 PM
>> To: Tom Azlin, N4ZPT; Bob Bruninga; BOD AMRAD
>> Subject: 6 Meter Radios and Projects
>>
>> Tom, Bob and all,
>>
>> It looks like a lot of good ideas are coming together on 
>> this.  I see a 
>> lot of potential.  My lab has some good test equipment and I
> can make 
>> some space so we can set up a test bed to try out some of this
> stuff.
>> It seems we need to have some sort of get-together and see 
>> how to best 
>> proceed on various aspects.  Tacos some Saturday might work 
>> or perhaps 
>> something more is needed.  Thoughts?
>>
>> Frank K0BRA
>>
>>
>>
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