The ATU-100 Antenna Tuner

Equipment
1

Just before Christmas I bought a Chameleon MPAS 2.0 antenna setup when one came up on eBay second hand.

The antenna is in fact a ‘kit’ of a long-wire and vertical antenna that can be deployed in various configurations. I have favoured the vertical configuration, simply because my SOTABeams Band Hopper IV inverted-V dipole really takes some beating, being so capable but lightweight.

The Chameleon isn’t an antenna I’d recommend taking up any serious hills, it is pretty industrial in design and has the associated weight. I’ve been using it as a ‘chaser’ antenna, typically operating during my lunch ‘hour’ doing a bit of HF chasing. The vertical configuration is fairly resonant on all HF bands from 40m to 10m, however it does benefit from a tuner as some bands have SWR too high for comfort.

With this in mind, and a preference to use a few more watts when limited in time I took a chance and bought an ATU-100 from AliExpress. It was just over £50 delivered and took just over two weeks. I paid VAT at source, the £50 including that amount, so no charges on delivery.

I must say I’ve been very impressed with the unit. It has a built in battery which is charged using USB-C and lasts for a couple of hours when in use. The display indicates power, SWR, capacitance and inductance as well as efficiency. It works via RF sensing and seems happy tuning with anything from 5w to 100w (although I try to remember to drop the power when tuning).

This afternoon with the WX so terrible in the Lakes all weekend to get my radio fix I did some chasing from my car for a couple of hours, and the tuner together with my IC-705 and RM Italy HLA-150 amp didn’t miss a beat. It was great not having to leave the car to switch between bands, which is what I would have had to do with the Super Antenna MP1. The MPAS 2.0 vertical mounts on a ground spike and is very sturdy, no issue with the rain and wind this afternoon.

All bands from 40m to 10m had activity. There was a fair bit of DX on all the bands, including South American stations on 10m. The HF bands have been very lively the past few weeks.

I got a CW 20m Park to Park contact with a USA activator. I had several SOTA, WWFF and POTA chases as well as what I suspect is my first GMA chase.

Regards, Mark.

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HF Contacts today, IC-705, HLA-150 amp, ATU-100, MPAS2.0, 60w

DATE TIME CALLSIGN FREQ BAND MODE RST RSR SOTA-TX OPERATOR SIG REF COMMENT MHL
2022.02.13 13:40 OK4KOP/P 20m SSB 45 55 David Kopecky GMA OL/JM-107 GMA: OL/JM-107 JN89HJ
2022.02.13 13:53 IT9FJM 21.270 15m SSB 57 53 Roberto Rizzo
2022.02.13 13:57 UT1IT 24.948 12m SSB 59 59 Tereshenko Igor A.
2022.02.13 14:34 LY5AX 14.203 20m SSB 59 55 Arnas Undraitis
2022.02.13 14:36 IW1FGY 14.180 20m SSB 59 55 Franco Saffioti
2022.02.13 14:38 EA3/F4IXC/M 14.219 20m SSB 58 57 Greg OP: Greg, COORD: 41.22713547 JN01VF
2022.02.13 14:43 DL1MP/P 14.253 20m SSB 55 53 Martin Pfeiffer SOTA DM/BW-193 JN47HV
2022.02.13 14:46 LB9HI/P 14.305 20m SSB 59 57 Mihai Suciu SOTA LA/OL-086 JP50GQ
2022.02.13 14:54 SA0AQT/P 14.268 20m SSB 59 59 Magnus Samuelsson WWFF SMFF-1537 WWFF: SMFF-1537 JO99JV
2022.02.13 14:57 EA1FDZ 14.250 20m SSB 59 59 Joaquin E Fernandez
2022.02.13 15:04 WC1N 14.059 20m CW 229 559 ROBERT C FARQUHARSO POTA K-2420 POTA: K-2420 FN42KB
2022.02.13 15:12 DL/HB9DIZ/P 14.338 20m SSB 59 59 Markus SCHULER SOTA DL/AL-276 JN57AN
2022.02.13 15:15 PA44WFF 10.124 30m CW 559 599 - Tonnie - WWFF PAFF-0013 WWFF: PAFF-0013
2022.02.13 15:25 OE6CBX/P 18.130 17m SSB 57 56 Marcus SOTA OE/KT-077 OP: Marcus JN76LS
2022.02.13 15:27 II3WRTC 18.135 17m SSB 59 59 George OP: George
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Oh and I took some photos of the passing Eagles the other day whilst on Queen Adelaide’s Hill playing radio…

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N7DDC design Mark? Someone in the (tr) uSDX group buy has a couple of populated boards for sale and one of the photos look very similar to yours.

Wx is rubbish and is spoiling my time off work. Still, got some other stuff done. Not much rf happens at my qth due to the geography so can’t even have a chat with Reg without driving up the hill :joy:

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Hi Alex

Crap when you have time off and the WX doesn’t play ball. That happens more often than I’d like.
Yes, I believe these are all clones of that design. The quality may vary one unit to the next, which is why ‘caveat empor’ applies. I have high noise at my QTH on HF so not much goes on here. FT8 is fun to watch for a while, and I have the odd SSB and CW QSO.

I’ve played with RTTY and PSK31/63 with @G8CPZ and Rick 2E0FRS but it is mostly them hearing me, not the other way around :roll_eyes:

Regards, Mark.

5

Might manage a low one on Saturday but even that is a bit sketchy. Still, fells aren’t going anywhere soon.