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Would it be crazy to power a feed cooling fan with the RF I'm sending to it? As in, rectify the RF AC and use a DC fan. #AmateurRadio #HamRadio
in reply to Neil E. Hodges

Not so much crazy as why exactly would you need to cool a feedline or matching balun? Have you got an extraordinary mismatch? Shouldn't your RF be radiating instead of making heat? And the same comment for running a fan! Fairly extraordinary situation you have there, Neil.
in reply to Comrade Weez

The issue is that the radiation resistance is around 5 ohms, so I need to step the impedance down a ton to get a match. The loading coil between the matching transformer to get this 6m dipole down to the 10m band is what's overheating because of all the resulting current. :(
in reply to Neil E. Hodges

add some 10m elements, fan dipole style, even if you have to coil load them for space requirements. You'll lose a lot less RF to heat.
in reply to Comrade Weez

Wish I could. Even the dipole as-is barely fits on my balcony. :(
in reply to Neil E. Hodges

You absolutely can make the 10m elements fit. Use the K7MEM short dipole calculator. https://k7mem.com/Ant_Short_Dipole.html
in reply to Comrade Weez

Ah, now I see. Couldn't I just add more 6m elements with a single set of loading coils at the base?
in reply to Neil E. Hodges

You're talking about a trap dipole which will require capacitors to fit up the impedances. A fan dipole is easier and will work the first time. Just wind up your excess length on the loading coils.
in reply to Neil E. Hodges

Why? Not even the commercial guys are doing that. If you need cooling, your transmission line is faulty somewhere.
in reply to Neil E. Hodges

Almost certainly. Especially when you can put an RF choke inline with the fan and send DC down the coax with a bias tee =)
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