I’m looking for an ATU to use with my SW3B & my FT818.Unfortunately we struggle to get any Elecraft products in the UK, so that options out.So can anybody recommend a decent ATU for use with different QRP radios?
It was not that bad. It doesn’t have the matching performance of the KX2 tuner, but you could have operated on all the bands that the KX2 did.
I’m even thinking of buying one…
For example, this could be a good and inexpensive option, and even from a local ham/dealer.
It is a classic and well-tried circuit and would be repairable if necessary.
I don’t think so.
I use a mAT-10 auto atu with both my FT817ND and SW3B , it is a bit pricey but works nicely.
I also have an Emtech ZM2 manual tuner which you can buy either as a kit or assembled depending on your budget (not expensive)
Plenty of videos on YouTube on both these tuners you can check out.
Waters & Stanton are the official UK Elecraft importers and the only unit they have on sale is a b stock KX3,unless you know some else UK based that stocks Elecraft products,because importing from Italy is very expensive
Like Declan I’m using mAT-10 with my FT-817ND
You can find all info here :
Welcome to the list.
Echoing somewhat, what Heinz says above - a manual Antenna Tuner Unit will work with any radio and kits are around starting at €20 (UKL16) out of China.
1-30 Mhz Manual Antenna Tuner kit HAM RADIO QRP DIY Kit BSG | eBay?
If however you want an AATU - an Automatic ATU, then you have the issue of interfacing it to the radio and with multiple makes of radio, you will normally have slightly different interface requirements.
73 Ed DD5LP.
There’s a worldwide shortage of components right now that makes buying many electronic items very difficult. If you check Elecraft’s shipping status page you’ll see that KX2 and KX3’s are on a 12-16 week lead time from ordering direct with Elecraft. That is going to impact deliveries to dealers all around the world.
However, there are an almost unlimited number of ATU designs floating about that you can build easily. Many available as kits with the hard casework already done. Lot’s of variable quality available on eBay and also the G-QRP group have a good tuner kit available.
Here’s a simple to build and versatile QRP ATU… GQRP Club - Low Power Amateur Radio and offers balanced and unbalanced outputs.
One advantage of these little manual ATUs is that they protect the transmitter while you are tuning them, because they use a resistive SWR bridge, switched in with the tune / operate switch. Of course they don’t need any batteries either!
If you do get an automatic tuner, you don’t have to interface it with the radio, although that is a nice thing to do if you are frequently hopping around the bands.
I use an Elecraft T1 with my FT817, and just press the “tune” button while transmitting a signal (reducing power if I remember). I expect this is possible with other AATUs. The main thing would be to check the minimum power that it needs in order to tune, though any that are designed for portable / QRP use should be fine.
Andy’s link above has prompted me to join the GQRP club at last - its funny where these threads lead!
I made an SWR meter for use with my QCXs and the AA5TB tuner. For the cost versus speed I bought a Kanga kits item rather than design one myself… It has a 6dB pad in the circuit so it’s harder to fry the radio when setting up.
That GQRP Club ATU that Andy refers to is another Z-match tuner, like the ZM-2.
Here is my version, it is something between the ZM-2 and ZM-4 (improved circuit that includes 160m for those that need it, and has a wider impedance range).
A link to the ZM-4 circuit diagram is in my post.
Here is another nice, highly portable kit sold by Kanga in the UK.
73 de Greg DL3GJ
I have an ATU-10 which I bought after my Elecraft T1 tuner stopped working. I am very happy with it, and would recommend it. It’s small, light, and works. Tuning is automatic, and the firmware is being actively developed (here: groups.io and github).
I have had a go at fixing my T1, but so far without success. Now I have the ATU-10, the motivation to complete the repair has faded!
I was recommended one of these and have used it with my FT-817 with
True, but to be honest, I expected a better result.
Looking at the schematics of the ATU-10, it has a max. inductance of 18.47uH and a max. capacitance of 4059pF, which is actually more than the internal KX3 tuner and much more than the one of the KX2. Since only 7 relays for the Ls and Cs are used (14 in total), maybe there are wider gaps for certain in-between matches, but I don’t know about the possible steps used in the KX2/KX3 internal ATU.
I tried to avoid the need for reducing the impedance at the feed point first (e.g. with a 1:4 or 1:9 UnUn), since that would not work very well when using a short wire on a lower band - at least in theory. So I’m not quite sure what I will try next.
This was the main selling point of the ATU-10 for me.
I wanted a QRP ATU that is not only light and small, but also one that doesn’t need any interfacing, apart of the coax. Like that you can put the ATU at the feed point of your antenna and some meters away press the PTT or key to start the tuning process. Also there is no need to press a button while operating. All can be done automatic and remote by default.
If you own an IC-705, however there is the possibility to connect it with a 3.5 mm plug.
Another positive point of the ATU-10 is its USB-C connector that can be used to charge the internal LiIon or updating the firmware that is available at GitHub - Dfinitski/ATU-10-10W-QRP-antenna-tuner.
A manual ATU is definitely a robust solution that never lacks battery power. However, if you use a feeder, you’ll include the feeder cable in the matching system, which is the way most ATUs are probably used in the field anyway.
Have you tried the latest firmware? Comments in the ATU-10 forum seem to suggest a better matching performance? I have loaded the latest firmware in mine, but having not used it until now, I can’t comment on the matching performance before/after the latest firmware.
I use this MFJ a long time ago, is not ATU but It is reliable, small and good quality built.
Also I had LDG ATU for 817 but prefer the manual MFJ.
The latest version 1.6 firmware was already installed when I received it. Otherwise that would have been my #1 task before giving it a try.
I also asked David and others on groups.io, but it seems normal behavior. It matches many loads well, but I expected a bit a wider range, e.g. better than the KX2 or KX3 internal tuner, when looking at the max L and C that can be used.