LDG Z100+ Custom enclosure

Hello Operators

Today’s topic is antenna tuners for portable Ops. Specifically the Z100 plus from LDG. The z100+ is an extremely popular choice for Yaesu FT-857 and FT-891 operators, taking QRO ops man-portable, to the field.

Scroll down for instructions

Many of you have seen the antenna tuner I use with the Yaesu ft-891. It looks very similar to the old style Z100 discontinued a few years ago by LDG. When I purchased the Yaesu FT-891, I automatically assumed the Z100 ( in its original enclosure) would be available for purchase. This is the one that looks very similar to the z817, but having 125w capabilities. It wasn’t, so I simply didn’t buy another LDG tuner.

Why not buy the updated z100plus?

Other than not liking it, and having to add more weight to my pack ,…

  • It’s 4oz heavier
  • It’s unnecessarily bulky
  • And it’s ugly as all heck (subjective).

The original design was perfect!

Perhaps LDG was trying to maintain some continuity with its products when it updated the Z100enclosure, but I really don’t know.


This post is an extract of an email sent to me by John N0JDS. It’s augmented with pictures of the modified tuner, so that others can do this modification themselves.

I completely agree on the form factor of the new z100+. That metal case is bulky and heavy, I have no idea what possessed them to change it. I have the original Z100 which is what gave me the idea for the conversion in the first place and, truth be told, the converted tuner is a better tuner than the original Z100.

I don’t have a lot of time right now to build one however, I will point you in the right direction on getting the case and give you a few pointers about what I encountered.
Overall the build was quite easy. There are two things you will need.

  • First obviously is a new case.
  • Second which is less obvious is a 6 battery AA battery tray to replace the 8 battery tray that comes with the z100+.

Circuit board

The circuit board will screw straight in to the new case as if it were made for it. All of the stand offs are in the correct locations. There are also some standoffs in the lid of the new case which have to be dremeled off in order to clear the batteries. This just took a few seconds.

Battery tray

The 8 battery tray will not fit in the tapered case. It requires some very simple soldering to change that tray out.

Also I used some of that very heavy duty Gorilla double sided tape to fasten the battery tray to the top of the relays. I found it at Home Depot.


The most challenging part of the entire thing was trying to locate the holes for lights and buttons in the correct spot. This is more critical on the front as there is some wiggle room on the back, particularly for the RF connectors. For drilling the holes in the plastic I recommend a set of the tapered step bits from Harbor Freight. They make very clean holes in the plastic face.

One way that worked OK for me was to tape the new face to the front or rear of the metal case and use a fine pencil to scribe the hole locations. Just be sure that the new face is lined up perfectly left to right on the new case. Just make sure that the inside (shiny side) of the new face is taped against the case. and not the textured side.

You will also need some tiny machine screws for the holes in the corners of the RF connectors. I only put two in each, diagonally. Four was overkill. I don’t recall the exact size of those machine screws but I bought them at the local hardware store. M3 comes to mind but not sure if that is correct, it’s been a while since I did the conversion.
Here is the link to the case I used:


Let me know how it goes and if you run into any other questions feel free to ask.
John N0JDS


julian oh8stn

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