Re: antenna tuner for uBitx

Tim Gorman


Are you sure the ZM-2 has air variables? Based on the pictures at their
site it sure looks like they use poly-type variables caps as well.

I also question their claim that they can tune anything using no
switched inductor. I'm pretty sure there are antenna configurations,
especially with low values of capacitive reactance, that it will have a
hard time tuning unless the inductor can be changed.

tim ab0wr

On Tue, 20 Mar 2018 05:46:41 -0400
"David Wilcox via Groups.Io" <> wrote:

I think that is a good choice. I like the Emtech ZM-2 one better as
it has air variables whereas the 4SQRP one uses poly variables. I am
old fashioned and just like the larger "tougher" air variables,
especially if running over 10 watts.

Dave K8WPE

On Mar 19, 2018, at 6:08 PM, Tim Gorman <tgorman2@...> wrote:

This tuner is not automatic but it does provide a good load to the
transmitter while adjusting the tuner.

As soon as I get a little money ahead I'm going to order one.

tim ab0wr

On Mon, 19 Mar 2018 09:00:24 -0400
"David Wilcox via Groups.Io" <> wrote:

While I agree somewhat I am not in favor of an automatic antenna
tuner because if your wire (especially with a new antenna or
experimental antennas) and supporting arrangement leave you
without a close match the time it takes the automatic tuner to get
a match it may be too long out of tune and blow your finals. With
a manual tuner you can key down for a short time while tuning, let
it rest a few seconds, try again getting closer, and finally get
your match. Keeps the finals cool and prevents the smoke from
being released.

I have a Z 11 Pro and while I have not blown any finals I am very
touchy with my antennas and check them with an analyzer before
using it, just to make sure I am close.

I prefer a small Z match like the Emtec, 4SQRP tuner, GQRP tuner,
etc. At the home shack I use an MFJ 300 watt roller inductor
tuner. The reason I like manual tuners at home is I can look at
the numbers on the dials and if they are different from what I
usually see I look for antenna trouble, ie., antenna down, ice
coated, wrong antenna, a short somewhere. With the automatic
tuner it just tunes and you don't know if its the antenna or the
tuner that is making your xmtr happy. And even at 5 watts or less
we can fry a 510.

I admit I am a nerd and like to tinker versus those who like to
"just get on the air and make a contact". My preference. This is a
wonderful hobby and we all are different.

Dave K8WPE

On Mar 19, 2018, at 6:37 AM, Curt M. <Kc3hjp@...> wrote:

I use my LDG Z-11ProII with an end fed wire and my Bitx40. The
tuner only requires 100mW of signal to auto tune.

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