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Old July 28th 16, 09:03 AM posted to rec.radio.amateur.antenna
Ian Jackson[_2_] Ian Jackson[_2_] is offline
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First recorded activity by RadioBanter: Nov 2007
Posts: 568
Default Anyone recommend a source of 36:50 ohm ununs?

In message , John S
writes
On 7/27/2016 4:43 PM, Ian Jackson wrote:
In message , Robert Smits
writes
Thanks for all the suggestions.

I'll see what it's like with 50 ohm coax first, and then make other
changes.

What about making the antenna somewhat longer than a quarterwave (which
presumably is what it is)? This will make the feedpoint impedance higher
resistive, and inductive. Make it long enough to get the resistance
close to 50 ohms, and then add series C to cancel the inductance.


Or, rather than fussing with the antenna, just use a 50 ohm .051
wavelength open stub located 0.113 wavelengths from the antenna. Use a
T-connector. Wavelengths are electrical lengths. Good for 1.8Mhz.

Feel free to check my numbers.


I'll believe you, as my Smith chart skills are rusty at the moment!

However, has it been determined why the OP wants to try and achieve a
perfect match?

If it is to reduce losses in the coax, unless the coax is really long,
on 160m the losses due to having a 2:1 SWR are probably negligible.

If it is to present the TX with a perfect 50 ohm load, this can be done
at the shack end with the appropriate simple matcher.
--
Ian