Z-match Tuner modded: a well-tuned doublet gave me New Zealand in the log with 10W IC-705!

The Z-Match (Z stands for “impedance”) antenna tuner design is known for many years and has got numerous incarnations. This commercially available QRP Z-Match antenna tuner is based on an iron-powder toroid core T130-6. I have modded this tuner to be able to tune the open-air-line feeders, like in doublet antenna. It’s a 1 EUR/ USD worth of investment but it brings a huge advance for this tuner! It is my most favorite tuner in the shack now!
Design and construction of my Doublet antenna is here:
• SEITENSCHNEIDER SHORT...
Z-Match tuner (as an Amazon partner I will earn a small amount of money , at no cost for you, if you buy through this Amazon-provided link):
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73! @Linas_LY2H

[@frankartieta4887]

This the circuit as the QRP Guys QRPGuys Multi-Z Tuner This circuit is old as methuselah :) I think a fella buy one of these open it up to check the solder connections ! Add the balanced line binding plugs and a fella got a fine little tuner ! 73

[@Linas_LY2H]

Great, thanks for your comment! I saw the files of the simmilar tuner on Github as an open source project, so it's no surprise many manufacturers could offer similar products with minor difference in components and some specs. I'd love to see someone offering the 100W version in a smallest possibly package :) 73! Linas LY2H

[@markusm.lambers8893]

What a beautiful set-up! I have an "original Z-Match" made by Emtech. (I buildt the kit-version, about 25 years ago!) I use this 'device' mostly with my FT817, (now a FT-818N and 6W now! - Hi Hi ! ! ! - ) and never had any problems. In the Emtech version there are also two banana-plug type outputs, for an aerial, that is symetrical feeded. You can 'switch off' the ground-connection, for a real 'floating' 2-wire flat-band cable feed. So you can choose the 'real 2-wire' (chicken-wire), or the coaxial-output! What ever you want, ... ! Only a little problem is: The shorter the wave-lenghts gets, the more problematic the efficenicy of the system is ! No problems from 160/80/40m band ..., but at 12/10 and 6m, the efficency get's a little more worse. But not too much! (When doing some directly comparison , from one to an other 'matching-system', you might see some differencies. - But at most, the Z-match is the best of all choises.) You are absolute right, when you say, that you can't 'match' every lenghts of antenna-wire, to SWR 1:1 ! You have to 'spare' out, such lenght's of 1/2 lambda, or mutliples of that. That's absolute 'normaly', for the typ of 'match-box' you used here! Hope to meet you sometime on QRG, ... 72/73 de Markus - db9pz - (JN39fq 3miles/5km east of LX)

[@Linas_LY2H]

@@markusm.lambers8893 Fantastic! Thanks, Markus, for such a comprehensive comment! It's so much things to try out with open-air lines! CU on the bands! 73!72! Linas LY2H

[@sailingmakai2127]

After seeing this video I got the same tuner and have been using it with a random wire and qmx for pota. I'm getting a flat match 60 to 15 m. I'm super happy with it. Thanks for the video. 73 de KD6XU/MM

[@Linas_LY2H]

@@sailingmakai2127 Great news, thanks for sharing! Please keep in mind this tuner can also be easily modded for the balanced line , in case you happen to build or obtain a doublet antenna, or similar! Good DX! 73! Linas LY2H

[@DK5ONV]

Looks fantastic. With 100Ah Battery and the IC-705 you can transmitt 1 Week nonstop. Nice Video Linas. 73 de Uncle Günter 💯👍🙋‍♂

[@Linas_LY2H]

@@DK5ONV Yes, I feel secure with 100Ah! Thanks for watching! 73! Linas LY2H

[@someguy782]

I wish they made one of these for higher power.

[@Linas_LY2H]

@@someguy782 Would be just great! Let's hope for that!

[@chrisherd991]

Hi Linus good to see a doublet in the world communication with my country. By the way in the worst case “no antenna connected” the load on the transmitter is 100 ohms ie 2:1 SWR.

[@nine7295]

Please get a body mic so your audio level doesn't fluctuate all over. Thanks for your videos and 73

[@hcy0]

Manual tuner is great, I love my MFJ-971, tunes almost anything

[@ThumpMaster6]

Linus, could you just use a BNC-to-Binding Post adapter, aka 'Cobra Head", to accomplish the same antenna connection as your modification? This looks great! 73 de KN4HGI Alan/"Thumpy"

[@willian.direction6740]

Thanks Linus great video showing a very practical solution to portable operation. I will be trying out a tuner soon in similar style.

[@Linas_LY2H]

@@willian.direction6740 Good luck, have fun experimenting! 73! Linas LY2H

[@DL1GKC]

With your modification, you now have the little QRP Pocket Transmatch tuner of Kanga 😊 There is a switch balanced/unbalanced and you can feed it with balanced line using a BNC / banana adapter…

[@Linas_LY2H]

@@DL1GKC No, I think, I have better :). Kanga uses smaller ( too small for 10W, IMHO) T68-2 toroid and only one secondary winding which makes the tunable impedances range a bit limited, compare to my Z-Match. And there is also an EMTECH transmatch, kinda' the same type of tuner, just they don't provide the schematics, so I can't compare. But I'd love to if I had all three of them :) 73! Linas LY2H

[@WECB640]

Well done Linas. I too prefer balanced line over coax. Your modification is very good. 73 OM

[@brianfields4479]

Thanks for sharing, well done on your great set up. It's my best dx this year, I am very privileged to get you in my log. Amps and big ants not required. 73.

[@Linas_LY2H]

@@brianfields4479 Thanks for the QSO, Brian! You've got good ears OM! Hope to see you again! 73! Linas LY2H

[@DaDitDa]

I wonder how much time will pass before the Chinese manufacture sees this video and then produces a new-and-improved version of their Z-Match tuner?

[@Linas_LY2H]

@@DaDitDa Tomorrow, probably? Would be great! :) 73! Linas LY2H

[@Panoramix0874]

I use the GQRP Z match, which is the same tuner as your modified version. I find that the trick to a quick tune is to operate it with your 2 hands.

[@rst5nn]

Hello, Linas Do you have a videos or you can give me a peace of advice how to DIY or google landing line for doublet antenna like in your video? Thank you for video, this is great result! Updated: found your video with details about antenna.

[@antoniolavanco3718]

beautiful setup CT1DZE

[@charlesschuler1460]

Brilliant once again OM!

[@cyclicalobsessive]

Antenna NOOB here: I put this Z-Match tuner and 40' random wire on my new toy - a NanoNVA. I can get a nice wide 20m dip to 1:1 at the desired frequency (14.060), but the shape changes somewhat and SWR changes to 1:1.4 after I take my hand away. Is this normal or does my unit have a problem?

[@Linas_LY2H]

@@cyclicalobsessive Hello there, thanks for your comment! No, the unit shouldn't be a problem as it is normal behaviour for the configuration like yours. Your hand, an entire you, actually, act as a part of the antenna system. In addition to that there is also an invisible stray capacitance involved between the VNA ant the ground. All this because of the way the RF currents circulate in your antenna wire and everything what is linked to it. If you connect a real radio this way, and transmit more than 2-3 W into the tuner, you might get your finger burned when touching the knobs, or the case of the tuner, or the case of the radio. At some 10W it could be unpleasantly painful, at more... Please, don't do it at more. To cure this, at least partially, the counterpoise wire should help, connected to the ground of the tuner or to the ground of your RF source ( the radio or the VNA, in your case). Any length of wire will do, to some extent, but no less than 1/4 of wavelength is recommended. One counterpoise wire is ok, three would be better, more- even more better! This is just for starter. While reading more about the antennas you might come up with your own ideas for experimenting, using coax cable, open wire lines , direct feeding etc. And, of course, safety first! Good luck! 73! Linas LY2H

[@cyclicalobsessive]

@@Linas_LY2H Thank you for the comeback. My rig is a QMX with 5W max output so I am not expecting any RF burns (or to burn out the tuner). I read somewhere about various counterpoise lengths, the amateur decided 7 feet was sufficient so I connected a 7 foot wire with a giant alligator clip for attaching to any nearby "ground". Antenna science is beyond my commitment to learn, so your tips and videos are very much appreciated.

[@g4lmn-ron401]

I totally agree, 👍

[@DK1ELD]

Very usefull mod, thank you!

[@Linas_LY2H]

@@DK1ELD Thanks for watching!

[@om0wt]

Hi Linas! Thanks for very informative video, just an observer’s advice… do not shake too much with the camera, give us a chance to digest moments you want to share with us… :) too much movements are disturbing a bit ;) 73, Pavol OM0WT

[@wojciechb7896]

I'm not a good electronics engineer, I understood from the video that the first banana goes to the middle entrance of the hot wire socket, and the second one goes where and how to solder it? Could you post a photo of the second banana? for the layman. sp9dlk

[@Linas_LY2H]

@@wojciechb7896 Hello Wojciech! You are right, the first banana is connected to the central pin of the Antenna BNC connector. The second banana is connected to the pin2 of the SW2A switch ( as it is numbered in the schematic diagram of the tuner). This is a LOW/HIGH switch on the pcb. Before doing this, the pin2 is cut and lifted slightly to disconnect it from the ground. The banana is connected to this slightly lifted part of the pin. Your new small ON/OFF switch is also connected to the lifted part of the pin with one end, and to the remaining grounded part of the pin with the other. This switch is used to disconnect/reconnect the pin2 from the ground. HTH, I can't post pictures here, but I could send you an email or messenger msg if you like. 73! Linas LY2H

[@wojciechb7896]

@@Linas_LY2H ​ @Linas_LY2H Cześć Linas. Tak, dziękuję za wyjaśnienie i odpowiedź. Jeśli to nie będzie dla Ciebie problemem, chętnie zobaczę to na zdjęciu, jeśli to nie problem. Będę wdzięczny, my @ is on QRZ. Pozdrawiam, Wojtek SP9DLK