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Author Topic: LPF for whip, matcher, or whats-it?  (Read 988 times)
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Patrick J. / KD5OEI
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« on: February 18, 2024, 02:14:54 PM »

This came to me with a box of thyratrons. Auction called it a 'balun' but it doesn't look like it and the thyratrons don't seem related.

Could it be a LPF for a whip or wire? but don't those want to see a definite impedance over their frequency range?


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Radio Candelstein - Flagship Station of the NRK Radio Network.
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« Reply #1 on: February 18, 2024, 03:58:59 PM »

Looks like a LPF for the ham bands.

Rod


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« Reply #2 on: February 18, 2024, 07:23:53 PM »

Looks like one of the high dollar Henry low pass filters.  Rated 10kw.

Those go for big bucks nowadays.

--Shane
WP2ASS / ex KD6VXI
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« Reply #3 on: February 19, 2024, 01:10:11 AM »

Thanks guys! Maybe the best thing to do is try it safely at low power with a 50 Ohm load.

I've never seen a HF LPF with a ceramic insulator on one end but that doesn't mean anything. It would be great if it is one of those higher power units - more than ham-rated anyway bc I have blown up a couple on AM, no idea why.
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« Reply #4 on: February 19, 2024, 09:17:11 AM »

Maybe a Harmonic Hemorrhoid, aka a reoccurring radio pain in the ass...

73DG
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« Reply #5 on: February 22, 2024, 02:46:33 AM »

Possibly. It has had issues at times and tricky to tune up. At least it hasn't blown itself up.. just filters. And the MFJ 989, twice. For these reasons it hasn't been on the air for some time >2 years. No time due to work.
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