The AT-100M is a further incarnation of the popular N7DCC type tuners which are widely available.
The AT-100M standard version on the right and the new AT-100M Pro on the left.
One thing which set this tuner apart was the quality of internal parts and the assembly which is more than acceptable especially given the price paid.
Certainly much better than some of the really shocking “assembled” ATU100 devices sold on the internet.
Both have internal battery packs which are charged by regular USB-C, one charge will last many many hours.
The AT-100M unit is not available as a kit.
The creator is a radio amateur from China BI3QWQ.
The official website for support and so on is linked below
http://www.atu-100.com/en.html
I purchased the original AT-100M back in June 2023, the agent Protolab supplied the goods to Banggood.
The cost at the time was £65 GBP around $83 USD.
All assembly is done by his appointed contractor and the units are sold by an official distributor on Aliexpress PROTOLAB STORE .
https://www.aliexpress.com/store/1100223851
The unit utilises original Amidon cores for the inductors (not clones) and stable NP0 smd capacitors.
The SWR bridge has a pair of LL60 shottky diodes.
I will not cover the features too much here as this has been done very well by others in various videos on youtube.
The firmware is a vast departure from the normal ATU-100/ATU-10 N7DCC types.
There are several new features to the normal display including an active swr graph.
Around October 2023 a new product was launched by BI3QWQ, the ATU100M Pro with increased internal parts and greater tuning range, plus increased quick tuned memory recall of 60 instead of 20 presets and a morse practice facility.
I obtained AT-100M Pro from Aliexpress Protolab Store during their Black Friday promotion week, it was priced less than I paid for the standard AT-100M back in June 2020, costing £63.30 or $80 USD and it took around 8 days to reach me here in the UK.
The pro version has a slightly longer enclosure to accommodate the extra internal parts/pcb but the other dimensions, screen etc remain the same. There is an extra 3.5mm jack at the rear for a morse key.
There is a bi colour red/green led for battery state when you power the unit by the supplied usb cable.
Both AT-100M and AT-100M Pro will boot up when powered by usb (if the internal battery is not functioning), just be sure to use the supplied accessory usb cable.
Do not try a normal phone type usb 3 cable, they do not work with this tuner.
One of the things I noticed was a new firmware on this unit (v1.23.8a) which has new features..mainly Manual Tuning.
I was contacted by BI3QWQ who informed me of new firmware also applied for the standard ATU100M so I was sent the file by email and upgrade was very easy using Pickit 3 device and plugging into the header on the PCB which is behind the front panel. There are no pins on the upgrade header, just 5 holes so a double male pin arduino style short cable is required to link the pickit 3 to the ATU100M .
The wiring, the connector of the pickit 3 the pin on the far left of the device is not connected.
Fitting to PCB holes for upgrade of firmware.
Once the firmware upgrade is completed, Manual tuning is possible..without transmitting..which may be useful for our SWL friends out there.
So whats inside the new AT-100M PRO ?
As far as I know there are no internal photos available on the internet of the AT-100M Pro version as I write this ammendment to this article Dec 2023.
Internal photos of Antuner AT-100M Pro, This reveals 2 pairs 8 relays in the chain instead of the regular 7×7.
The top view , everythings seems to be very neatly done here.
The bottom of the PCB is much the same, a good standard of construction.
The SWR bridge section close up with the pair of LL60 SMD diodes.
The rear of the front panel, The cabling to the controls & 0.91 inch diagonal OLED display.
The PIC IC , front panel connection headers and LiPo battery connector.
A closer view of the connection points just behind the front panel for firmware upgrade via PICKIT3 device.
The bottom line..
Pros : Both tuners work great, the AT-100m pro gives greater range and tunes 80m with ease, it also tuned 160m during testing and no problems. For the price paid there is nothing out there with anything like the quality. The units are constantly being improved firmware wise and as I write this there is another firmware beta (1.24.1a which is for AT-100M Pro version only) which displays max tx peak power. That I could try out, but for now I am happy with v1.23.8a on both units.
Cons: The one button for all functions can be a little frustrating, there are instances where you may want to “go one step back” in the menu ladder so to speak.. and you cannot, instead you have to cycle forwards back around the menu loop until you reach the setting you want to adjust. A 5 way push button , left right,up, down and centre select would be the answer..something like this perhaps
But we have to congratulate BI3QWQ on his achievements with these units.
They work very well, email support is fantastic and either unit represents superb value for money.
An excellent overview of these tuners. I also have the original version, and am somewhat considering getting the pro as well (as you have). I think it works quite well for things like well-tuned OFCDs or EFRW into 9:1s at an appropriate length.
When used on a multi-band doublet for portable ops, I had some success, but occasionally having to employ a 4:1 balun (to get a successful tune, if any), instead of a 1:1 balun. Unlike what you’d think, the impedances were already quite low (often <50ohms for a number of bands), so forcing a tune by adding the 4:1 balun likely reduced efficiency (i.e., increased losses) further, and perhaps dramatically.
I therefore wonder how the pro would have fared, and I’m not sure if there’s a way to know without comparing them side-by-side. I”m not sure if you have any anecdotal thoughts? 🙂
I’m appreciative that BI3QWQ provides the maximum inductance and capacitance values that can be achieved, so you know what additional capability you’re getting. It’s difficult for me to anticipate how much more tuning range will expand, given the additional inductance and capacitance values. And the increase of tuning range with the addition of only a pair of additional relays (hence the barely reduced case size), makes one wonder if the tuning steps are less granular? LDG seems to express their tuning range a little more practically (“ Tunes 6 to 1,000 ohm loads (16 to 150 on 6m), 6 to 4,000 ohms with optional 4:1 balun”, for the case of the LDG AT-1000proII). I think this is likely more useful than what you usually hear from hams (10:1, 3:1).