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Post by crackle » Sun Jul 21, 2013 11:25 am

I wondered if someone could take a guess for what use this ATU would have been used for, TX, RX or both and what frequencies.
I have drawn out the circuit.
aerial tuning unit 1.jpg

aerial tuning unit 2.jpg

aerial tuning unit 3.jpg

aerial tuning unit.png
aerial tuning unit.png (3.84 KiB) Viewed 1285 times




Post by skywave » Sun Jul 21, 2013 12:46 pm

This helps:

Al. / Skywave / July 21, '13 //

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Post by Andrewausfa » Sun Jul 21, 2013 12:49 pm

Mike, there's a manual available on-line for this ATU. Search for Decca HW EZee Match


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Post by crackle » Sun Jul 21, 2013 12:57 pm

Hi Andrew
I have just found the same page of reviews.

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Post by Michael Watterson » Sun Jul 21, 2013 2:44 pm

I have a home brew version of that on my FT101ZD.

It's very very good. But even at 50W you can get 1000s of volts and arcing if you match a seriously bad aerial.

They are good on receive (just tune for maximum hiss just off station), but such match boxes are mandatory on HF transmit. I use a separate home brew Power & SWR (reverse power really) pair of meters and set the sensitivity to max.
First I find approximate point by ear (on receive), though for my "normal" two aerials I have pencil marks for the different bands.
Then adjust TX to just full scale on forward meter. Then adjust the knobs, for minimum on reverse meter while adjusting TX to FSD on Forward meter.

Only lunatics tune at full power!

I find that the "black" posts are good for a 22m long wire for 1.8MHz to 14MHz and the other posts for 6m vertical wire for 18MHz to 30MHz.
Approx. Both aerials can be left connect at the same time.

I have multiple local "ESB style" Earth rods for the "Earth".

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