Emtech ZM-2 tuner complete!

Started by raybiker73, November 22, 2012, 12:35:10 AM

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raybiker73

Just finished my latest project, an Emtech ZM-2 QRP antenna tuner:

http://emtech.steadynet.com/zm2.shtml

It was a pretty easy build overall, although there were a couple of pretty tiny cores to wind. I plan to spend Thanksgiving out in the back 40 giving it a try (FT-817 and SuperAntenna MP-1). When I bought my used FT-817, it came with an LDG Z11 tuner, which works great, but I want to make this rig as small, as packable and as power-efficient as possible. If the ZM-2 works as well as advertised, it will go a long way towards making that happen.

Mitch

I don't want to detract from the experience, but since I just went down the road you are traveling my opinion may be useful.

I switched to an end-fed and lost the tuner entirely! It's much lighter.

Have it in the BOL to tune those random wires and shopping carts, but for the hiking pack the tuner weight isn't worth it.

WA4STO

Quote from: Mitch on November 22, 2012, 11:33:12 AM

Have it in the BOL to tune those random wires and shopping carts.

Which begs the seriously obvious question of:  "do the shopping carts at Walmart achieve resonance any better than the ones at Target?". 

I'm guessing that it would depend on how much plastic is in the rear baby-sitting area.  Or whether the rubber wheels truly allow for a decent ground plane.

So many baskets; so little time.

73 de WA4STO


gil

A couple days ago I turned on my K2 and pressed the TUNE button. The ATU went through some clicking and ended with a 1.5:1 SWR, not bad... Then I realized my 25' coax cable wasn't plugged into anything! The Elecraft ATU had matched my coax cable!

Gil.

Lamewolf

Quote from: raybiker73 on November 22, 2012, 12:35:10 AM
Just finished my latest project, an Emtech ZM-2 QRP antenna tuner:

http://emtech.steadynet.com/zm2.shtml

It was a pretty easy build overall, although there were a couple of pretty tiny cores to wind. I plan to spend Thanksgiving out in the back 40 giving it a try (FT-817 and SuperAntenna MP-1). When I bought my used FT-817, it came with an LDG Z11 tuner, which works great, but I want to make this rig as small, as packable and as power-efficient as possible. If the ZM-2 works as well as advertised, it will go a long way towards making that happen.

I think you will like the ZM2, I hombrewed a clone of it and it works super !  Especially with the 44' doublets and 88' doublet when fed with 300 ohm twinlead.  I've also had good luck with mine tuning random wires and a 31' vertical called the Eagle One from  www.w8afx.com