Topband: 75 ohm RG6 to 50 Ohm radio

Tree tree at kkn.net
Wed Sep 28 14:09:45 EDT 2016


One easy thing you can do to test your transformer is to put a 75 ohm
resistor on the proper side - and then use an SWR meter to measure the
impedance on the 50 ohm side.  I like to also see how high in frequency I
can go before the SWR starts to rise.  Most of the transformers I wind
typically work pretty well up to 7 or 10 MHz.

If you don't have an SWR meter - you can use your transmitter set for a
power level that won't burn up your resistor.

Tree N6TR

On Wed, Sep 28, 2016 at 10:58 AM, Ed Stallman <ed.n5dg at gmail.com> wrote:

> Thanks all for your wisdom . Some say not needed and some say to use the
> 75 / 50 transformer . I figure it's easy enuf to do . So now I'll try it
> and see for my self .
>
> Thanks again, Ed N5DG
>
>
> On 9/27/2016 10:35 PM, Ed Stallman wrote:
>
>> My receive antenna is 75 Ohm RG6 connected to my radio and I want to wind
>> a 2873000202 binocular core to step 75 to 50 Ohm's . I seen this info on
>> W8JI web page but can't seem to find it again.
>>
>> I do remember it's 4 turns 50 Ohm and 5 turns 75 Ohm and all wires come
>> out the same side of the core . Am I correct so far?
>>
>> Does it make a difference which winding I wind first ?
>>
>> Thanks in advance , Ed N5DG
>>
>>
>>
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