Tag Archives: Tuners

Many thanks to Joshua (KO4AWH) who shares the following update to his previous guest review of the ATU-10 automatic antenna tuner:

Update on the ATU-10: new firmware released

by Joshua (KO4AWH)

The short story is that David N7DDC has a Firmware update with a new tuning algorithm that seems to fix the previously seen failure to find a decent match. As noted earlier in comparison with the Elecraft T1, the ATU-10 still does not necessarily get as close a match to 1:1 SWR but it now does indeed find a good match making this tuner my go to for use with my IC-705.

Not previously mentioned, the ATU-10 is also designed to work with the IC-705 for tuning commands when connected with a TRS 3.5mm cable, not just as an auto tuner when given a signal. And, in practice it works just as it should. I actually took the IC-705 and the ATU-10 and worked a SOTA/POTA with the beta version of this new firmware. I ran a 35’ wire and it worked great allowing me to work 40m, 20m, 15m and 6m for a total of 26 contacts. As a followup to my previous testing with the prior firmware 1.4, below are my results with the current new 1.5 firmware.

Testing on August 20th, 2022

The only difference from the original testing is the 31.5’ radiator was replaced with a 35’ and I did not tune and record results with the T1.

Conclusion on the ATU-10

I now feel very comfortable recommending this ATU. newdiytech.com has a great price and the build quality seems just fine. With the new algorithm update, a good match is found. The ATU-10 works great stand alone and also works fully automatically when used with a IC-705. This configuration means you can put the ATU at the antenna feed point and run a control cable back to the IC-705 and have a 50 ohm across the coax to help minimize loss, making for a nice portable setup with great band hopping flexibility.

Of course, if interested, I sell a protection cover for the ATU-10 just as I do for the T1.

If your curiosity is strong, here is some testing I did for David as he was updating the Algorithm now used in firmware 1.5.

UPDATE August 3rd 2022:

David Fainitski N7DDC has released a test firmware with a new tuning Algorithm with some promising initial results. A quick test on each band in the table has been added to reflect the new algorithm. This is not a firmware update yet but I suspect it will be soon. Results are great as tested. I hope to see this in a new FW soon.

August 6th, 2022

A second test firmware from David Fainitski N7DDC with the ability to increase or decrease the L and C manually allowed me to verify if a better match could be made. Turns out in a few cases it could. After testing again with a Tufteln 9:1 T80-2X2 on a 41ft sloping radiator I was able to achieve much better results than with the current version 1.4. In two cases I was able to find a better match manually. I realized later that if I were to tune a second time the ATU-10 would find the same, better match, on its own. Again, not a full firmware update, i.e. you have to flash back to 1.4 if you want to be able to turn off the turner.

August 7th, 2022

Another test firmware David asked me to check. This version seemed more likely to find the best match. I did have the ATU go to L0, C0 twice but then find a match on a second try. This happened once on 40m and once on 10m. Almost like it faulted but there was some switching/clicking involved before stopping, it just landed at a 3:1 or higher with 0 for L and C. A second tune however straightened it out. I did not record those two cases. Below are the results. I was able to find a slightly better match twice but I am sure one would never notice the difference during normal use. The improvement both times was within the error of SWR across the three device measurements.

Accessories, Antenna Tuners, Antennas, News, Reviews

Joshua tests the ATU-10 portable automatic antenna tuner

July 12, 2022 Thomas Witherspoon 19 Comments

Many thanks to Joshua (KO4AWH) who shares the following guest post:

UPDATE: Please check out Joshua’s most recent review after updating the ATU-10 with new firmware. The results have improved dramatically.

ATU-10 Random Wire Testing

by Joshua (KO4AWH)

I had a bit of time to do some field tests and I recently acquired an ATU-10. So I jumped right in and did some ATU-10 Random Wire Testing. The testing was completed with a Tufteln 9:1 QRP Antenna configured with an elevated feed point sloper and a counterpoise hanging straight down. The coax feed was RG316 17′ with the ATU at the radio with a short jumper. Several different radiator lengths are used as mentioned below. The ATU-10 was sourced from newdiytech.com, price was $120.24 shipped to me in GA USA, Ordered June 25, delivered July 8th.

A quick list of ATU-10 Features:

0.91″ OLED Display that shows Power, SWR and internal battery remaining.
USB-C Rechargeable LiPo 1.7Ah
Grounding Lug
Bypass Mode (When I set to this mode however it would tune anyways)
Latching Relays (No power needed to keep in position. Hold tune with ATU off)
Input port for communication with IC705 (and potentially others)
7 Inductors, 7 capacitors
- (Elecraft QRP)
  - C array, pF 10, 20, 39, 82, 160, 330, 660
  - L array, uH 0.05, 0.11, 0.22, 0.45, 0.95, 1.9, 3.8
- ATU-10
  - C array, pF 22, 47, 100, 220, 470, 1000, 2220
  - L array, uH 0.1, 0.22, 0.45, 1.0, 2.2, 4.5, 10.0
USB-C firmware update (ATU shows up as a drive, simply copy the new firmware file to the device and it will automatically update)
Weight 232g (8.1oz)
- Tufteln Case adds 23g (.8oz) for a Total of 255g (8.9oz)
- Compared to the T1 with cover for a total weight of 187g (6.5oz)

SWR measured with a RigExpert RigStick 320, Lab599 Discovery TX-500 and the ATU-10

The test process was to first check the SWR on the antenna with no tuner. SWR values recorded from the TX500 and RigExpert Stick 320. Values recorded in the 2 columns under the “No Tuner” section. This was completed for each of the Bands listed in the table rows (see below). SWR values were the lowest in the band range for all recorded numbers. Continue reading Joshua tests the ATU-10 portable automatic antenna tuner →

Kits, News, QRP

New kit by NM0S: the 4S-Tuner/Antenna Coupler

November 10, 2015 k4swl 2 Comments

(Via the SWLing Post)

Dave Cripe (NM0S) has designed yet another QRP kit for the 4 State QRP Group: the 4S-Tuner/Antenna Coupler.

Description (per Four State QRP Group):

This excellent random wire antenna tuner is the classic T-Match design which is known for wide matching range and smooth operation. Dave has added a nice wrinkle – the SWR indicator employs TWO leds, not the normally seen single red LED. A green one indicates output power with a red one indicating reflected power. The beauty of this arrangement is that the operator sees the output power peaking as the SWR goes down, just like a power meter with dual meters – very intuitive. This makes tuning easier and leaves no doubt that it’s tuned for maximum power output. For a high SWR the red LED is at full brightness and the green LED is off. At 2:1 both are at equal brilliance. At 1:1 the green is full on and the red is off. The small size is perfect for portable operations. Add this dandy little tuner to your portable ops go bag, or use it at home. It’s equally at home on a picnic table, in a tent or camper, as well as on the operating desk in your shack.

Specifications and Design Features

Wide tuning range: 80 meters thru 10 meters. Tested on EFHW and 100′ wire.

Maximum Power Throughput: tested at 10 Watts.

Low loss large toroid

Twelve taps for small inductance step selection.

Low insertion loss when matched.

Enclosure Size: 3″x3″x2″.

Pittsburg Construction.

Shipped price is $51.00 (US), $55.00 (Canada), $60.00 (Outside US/Canada).

Dave Cripe designs excellent kits for the ham radio community; they’re easy to build, fun and functional. If this kit is as popular as his past kits, the first run will most likely sell out in short order.

Click here to check out the 4S-Tuner/Antenna Coupler at the Four State QRP Group website.