Is ZM-4 still available?

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AF6TF
Posts: 2
Joined: Wed May 24, 2023 1:12 pm

Is ZM-4 still available?

Post by AF6TF »

I was reading through the list of QRP tuners that have been used by others in this group and saw the specs for the ZM-4 and how it is both a tuner and band pass filter at the same time. But it seem the QRPProject.de store site is not working. Am I late to the party? ;)
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dk7ux
Posts: 2
Joined: Sat May 20, 2023 2:41 pm

Re: Is ZM-4 still available?

Post by dk7ux »

Hello Tim,

And welcome to the QRPer Board!

Unfortunately, QRPProject has closed shop for good. There was a sale on in October (if I remember correctly) which went until the end of last year.

The ZM-4 was a modified/improved version of the ZM-2 tuner. I recall the price for the kit at around 100Euro, including an aluminium housing with drilled front/back plates. The manual is still online (click link on the left):

https://www.qrpproject.de/UK/ZM4.html

Maybe you can find a simlilarly-sized enclosure and source the parts yourself, with the variable capacitors perhaps being the hardest parts to come by. The circuit can be built on a piece of perfboard.

This is a small little project in itself. A very interesting one I may add with lots of things to learn. Should you decide to go down this path you may want to consider reading Lloyd's pages (VK5BR) on Z-Match tuners which I find really interesting:

http://users.tpg.com.au/users/ldbutler/
http://users.tpg.com.au/users/ldbutler/ ... ZMatch.htm
http://users.tpg.com.au/users/ldbutler/ZEfficiency.htm
http://users.tpg.com.au/users/ldbutler/ZDrop.htm
http://users.tpg.com.au/users/ldbutler/Zbalance.htm
http://users.tpg.com.au/users/ldbutler/ ... lCoreZ.htm
http://users.tpg.com.au/users/ldbutler/ ... 1.8MHz.htm
http://users.tpg.com.au/users/ldbutler/ZCurves.htm
http://users.tpg.com.au/users/ldbutler/ ... 5BRCct.htm

As an alternative, there is still the venerable ZM-2 as a kit or readily built:

https://steadynet.com/emtech/zm2-kit-bnc-connectors

Or, if you would consider a transmatch, I can recommend Kanga Product's kit:

https://www.kanga-products.co.uk/oursho ... match.html

I built it and I love it.

Cheers,

Michael / dk7ux
AF6TF
Posts: 2
Joined: Wed May 24, 2023 1:12 pm

Re: Is ZM-4 still available?

Post by AF6TF »

Thanks for confirming my suspicions. I've already read through the build manual and am considering trying to make one from scratch. One of these days.

I shall look into the alternatives you've mentioned as well.
M0RGM
Posts: 38
Joined: Mon Jun 06, 2022 2:28 pm

Re: Is ZM-4 still available?

Post by M0RGM »

The Kanga products Tranzmatch is highly recommended; I have two, one of each style for the shack and field use respectively.

Richard M0RGM
Andrew (grayhat)
Posts: 118
Joined: Sat Jun 11, 2022 2:59 pm

Re: Is ZM-4 still available?

Post by Andrew (grayhat) »

AF6TF wrote: Fri May 26, 2023 1:51 am Thanks for confirming my suspicions. I've already read through the build manual and am considering trying to make one from scratch. One of these days.

I shall look into the alternatives you've mentioned as well.
if going for a build from scratch, consider this

https://pa0fri.home.xs4all.nl/ATU/FRIma ... tcheng.htm

for QRP a couple polyvaricons will be fine, add a pair of switches and a simple SWR indicator

https://pa0fri.home.xs4all.nl/ATU/FRIma ... cs%20s.jpg

https://pa0fri.home.xs4all.nl/ATU/FRImatch/pa4mf2.jpg

https://www.qsl.net/wb3gck/zmatch/bridge.gif

and you'll have a nice ATU working from 80 to 10 meters, also for "at home" use, that ATU can easily be built for QRO and is really easy to transform into a remote ATU (there's no inductance switching)
wa3jpg
Posts: 3
Joined: Wed Jun 28, 2023 4:55 pm

Re: Is ZM-4 still available?

Post by wa3jpg »

If the bandpass response is the crux of what you want, a pi-network design or "ultimate" transmatch design with qrp components will also do the job. I use a pi-network (looks a lot like the very common "T" match circuit with with components in a different arrangement and a somewhat more limited range for the same value components). Tuners are total magic and I like that.

Freyja Clark Turner
WA3JPG
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