Dave,
You're onto something, but to match 25 ohms to 50 ohms you need 1/4
wavelength (electrical length) of 37 ohm (not 75 ohm) coax.
This is easily achieved with two 75 ohm coaxes in parallel.
I've used this many times and works great!
A word to the wise: if you use foam dielectric coax the velocity
factor may be wildly different than the published value
Good luck!
73
Frank
W3LP
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----- Original Message -----
From: "Dave Robinson via groups.io" <kb7gp@...>
To:
[email protected]Sent: Saturday, November 9, 2024 5:33:30 PM
Subject: Re: [nanovna-users] Dipole antenna with Low Z0 feed point Impedance
One thought would be to use a 1/4 wavelength of RG59 for example at the frequency your dipole is cut for. I did not notice that reference in your original message. This should perform the proper transition from a 50 Ohm feedline to the 25 Ohme impedance at your dipole center.
DaveR KB7GP
