Browsing thru E bay I came across a 1kw
antenna tuner for sale from Cyprus.Now in my younger days I got hold
of one of these and intended to salvage a Icom AH2 to somehow make it
remote since I use Icom radios. After all there are only three motors
that have to be driven! Now I am retired I pulled my old one from
storage after seeing the same on E bay. Question is are there any
kits, salvage ideas out there that would get me going on this long
lost project?
I have never used a external tuner but this seems like a realistic
project to play with.
Of course if there is a unit out there that I can salvage a controller
that is all the better. There are very good photos of this particular
tuner on E bay but like mine it has no controller! I suppose I could
feed a 10 watt signal to it and control the motors by hand to tune but
I do like the idea of automation.
Regards
Art

On Oct 31, 7:49*pm, Art Unwin wrote:
Browsing thru E bay I came across a 1kw
antenna tuner for sale from Cyprus.Now in my younger days I got hold
of one of these and intended to salvage a Icom AH2 to somehow make it
remote since I use Icom radios. After all there are only three motors
that have to be driven! Now I am retired I pulled my old one from
storage after seeing the same on E bay. Question is are there any
kits, salvage ideas out there that would get me going on this long
lost project?
I have never used a external tuner but this seems like a realistic
project to play with.
Of course if there is a unit out there that I can salvage a controller
that is all the better. There are very good photos of this particular
tuner on E bay but like mine it has no controller! I suppose I could
feed a 10 watt signal to it and control the motors by hand to tune but
I do like the idea of automation.
Regards
Art

why would you need a tuner, isn't your super antenna flat from dc to
daylight?

On Oct 31, 3:00*pm, K1TTT wrote:
On Oct 31, 7:49*pm, Art Unwin wrote:



Browsing thru E bay I came across a 1kw
antenna tuner for sale from Cyprus.Now in my younger days I got hold
of one of these and intended to salvage a Icom AH2 to somehow make it
remote since I use Icom radios. After all there are only three motors
that have to be driven! Now I am retired I pulled my old one from
storage after seeing the same on E bay. Question is are there any
kits, salvage ideas out there that would get me going on this long
lost project?
I have never used a external tuner but this seems like a realistic
project to play with.
Of course if there is a unit out there that I can salvage a controller
that is all the better. There are very good photos of this particular
tuner on E bay but like mine it has no controller! I suppose I could
feed a 10 watt signal to it and control the motors by hand to tune but
I do like the idea of automation.
Regards
Art

why would you need a tuner, isn't your super antenna flat from dc to
daylight?

I knew that was coming!
My antenna project is finished and active on the grass Now winter is
coming I need another project. I wanted the antenna to pan up and down
for best angle automatically but I am short on ideas. So seeing the
tuner on Ebay reminded me of a project that got away. The antenna has
only been tested down to top band as I am not equipted to go down
lower and the mfj only goes up to 170. I suppose I can take the tuner
to a hamfest but it has been a few years since I went to one. I am
using a window
wiper motor for the up and down so it would be nice to make that
automatic if more gain is available.

In article
,
Art Unwin wrote:

Browsing thru E bay I came across a 1kw
antenna tuner for sale from Cyprus.Now in my younger days I got hold
of one of these and intended to salvage a Icom AH2 to somehow make it
remote since I use Icom radios. After all there are only three motors
that have to be driven! Now I am retired I pulled my old one from
storage after seeing the same on E bay. Question is are there any
kits, salvage ideas out there that would get me going on this long
lost project?
I have never used a external tuner but this seems like a realistic
project to play with.
Of course if there is a unit out there that I can salvage a controller
that is all the better. There are very good photos of this particular
tuner on E bay but like mine it has no controller! I suppose I could
feed a 10 watt signal to it and control the motors by hand to tune but
I do like the idea of automation.
Regards
Art

It isn't the tuner hardware that is going to be a problem, as much as
designing the tuning algorithm that drives the hardware. Mark Johnson
did a very good job, reverse engineering the stuff that Bill Shield
brought west from Motorola Military back in the 70's for the SEA
Autotuners. SGC copied the SEA Firmware & Design enbank, for their
stuff. The best stuff, was the stuff Collins did for their Military
Autotuners. Starting from scratch is going to be a BIG design project.

you wrote:


It isn't the tuner hardware that is going to be a problem, as much as
designing the tuning algorithm that drives the hardware. Mark Johnson
did a very good job, reverse engineering the stuff that Bill Shield
brought west from Motorola Military back in the 70's for the SEA
Autotuners. SGC copied the SEA Firmware & Design enbank, for their
stuff. The best stuff, was the stuff Collins did for their Military
Autotuners. Starting from scratch is going to be a BIG design project.

There's a fair amount of moderately recent literature on efficient
algorithms for adjusting a tuner. I have a recent paper from Sun and
Fidler at Univ of York that looks interesting, but I haven't read it yet.
"High Speed Automatic Antenna Tuning Units" IEE Conf on Ant and Prop,
4-7 April 1995, page 218ff

On Nov 1, 12:34*pm, you wrote:
In article
,
*Art Unwin wrote:



Browsing thru E bay I came across a 1kw
antenna tuner for sale from Cyprus.Now in my younger days I got hold
of one of these and intended to salvage a Icom AH2 to somehow make it
remote since I use Icom radios. After all there are only three motors
that have to be driven! Now I am retired I pulled my old one from
storage after seeing the same on E bay. Question is are there any
kits, salvage ideas out there that would get me going on this long
lost project?
I have never used a external tuner but this seems like a realistic
project to play with.
Of course if there is a unit out there that I can salvage a controller
that is all the better. There are very good photos of this particular
tuner on E bay but like mine it has no controller! I suppose I could
feed a 10 watt signal to it and control the motors by hand to tune but
I do like the idea of automation.
Regards
Art

It isn't the tuner hardware that is going to be a problem, as much as
designing the tuning algorithm that drives the hardware. Mark Johnson
did a very good job, reverse engineering the stuff that Bill Shield
brought west from Motorola Military back in the 70's for the SEA
Autotuners. SGC copied the SEA Firmware & Design enbank, for their
stuff. The best stuff, was the stuff Collins did for their Military
Autotuners. Starting from scratch is going to be a BIG design project.

My problem as far as I can see is that the control for the AH2 is that
the innards are transferable but it only controls two motors where as
my tuner has three.
I suppose I could just use two and not utelise the fine tune inductor.
Will sleep on it for a while and look at the AH4 version or in the
worst case fine tune by hand if necessary. I suspect the fine tune is
not really necessary in most cases other than satisfy the over
zealious swr users

Art Unwin wrote:
On Nov 1, 12:34 pm, you wrote:
In article
,
Art Unwin wrote:



Browsing thru E bay I came across a 1kw
antenna tuner for sale from Cyprus.Now in my younger days I got hold
of one of these and intended to salvage a Icom AH2 to somehow make it
remote since I use Icom radios. After all there are only three motors
that have to be driven! Now I am retired I pulled my old one from
storage after seeing the same on E bay. Question is are there any
kits, salvage ideas out there that would get me going on this long
lost project?
I have never used a external tuner but this seems like a realistic
project to play with.
Of course if there is a unit out there that I can salvage a controller
that is all the better. There are very good photos of this particular
tuner on E bay but like mine it has no controller! I suppose I could
feed a 10 watt signal to it and control the motors by hand to tune but
I do like the idea of automation.
Regards
Art
It isn't the tuner hardware that is going to be a problem, as much as
designing the tuning algorithm that drives the hardware. Mark Johnson
did a very good job, reverse engineering the stuff that Bill Shield
brought west from Motorola Military back in the 70's for the SEA
Autotuners. SGC copied the SEA Firmware & Design enbank, for their
stuff. The best stuff, was the stuff Collins did for their Military
Autotuners. Starting from scratch is going to be a BIG design project.

My problem as far as I can see is that the control for the AH2 is that
the innards are transferable but it only controls two motors where as
my tuner has three.
I suppose I could just use two and not utelise the fine tune inductor.
Will sleep on it for a while and look at the AH4 version or in the
worst case fine tune by hand if necessary. I suspect the fine tune is
not really necessary in most cases other than satisfy the over
zealious swr users

If you can guarantee that the real part of the feed point impedance is
always higher or lower than your transmission line Z, then you can use
an L network, which only requires 2 adjustable components.

You see a lot of these sorts of schemes with physically short radiators,
where the Rfeed is always less than 50 ohms.

L networks have the nice property that there's only one setting that
"works" which is nice in an automated system. I think the usual scheme
is to spin the C pretty fast and slowly ramp the L, and then stop both
motors when the match is "good enough".

For relay based systems there are better algorithms for finding the best
match that take less time.

On Nov 1, 7:59*pm, Jim Lux wrote:
Art Unwin wrote:
On Nov 1, 12:34 pm, you wrote:
In article
,
*Art Unwin wrote:

Browsing thru E bay I came across a 1kw
antenna tuner for sale from Cyprus.Now in my younger days I got hold
of one of these and intended to salvage a Icom AH2 to somehow make it
remote since I use Icom radios. After all there are only three motors
that have to be driven! Now I am retired I pulled my old one from
storage after seeing the same on E bay. Question is are there any
kits, salvage ideas out there that would get me going on this long
lost project?
I have never used a external tuner but this seems like a realistic
project to play with.
Of course if there is a unit out there that I can salvage a controller
that is all the better. There are very good photos of this particular
tuner on E bay but like mine it has no controller! I suppose I could
feed a 10 watt signal to it and control the motors by hand to tune but
I do like the idea of automation.
Regards
Art
It isn't the tuner hardware that is going to be a problem, as much as
designing the tuning algorithm that drives the hardware. Mark Johnson
did a very good job, reverse engineering the stuff that Bill Shield
brought west from Motorola Military back in the 70's for the SEA
Autotuners. SGC copied the SEA Firmware & Design enbank, for their
stuff. The best stuff, was the stuff Collins did for their Military
Autotuners. Starting from scratch is going to be a BIG design project.

My problem as far as I can see is that the control for the AH2 is that
the innards are transferable but it only controls two motors where as
my tuner has three.
I suppose I could just use two and not utelise the fine tune inductor.
Will sleep on it for a while and look at the AH4 version or in the
worst case fine tune by hand if necessary. I suspect the fine tune is
not really necessary in most cases other than satisfy the over
zealious swr users

If you can guarantee that the real part of the feed point impedance is
always higher or lower than your transmission line Z, then you can use
an L network, which only requires 2 adjustable components.

You see a lot of these sorts of schemes with physically short radiators,
where the Rfeed is always less than 50 ohms.

L networks have the nice property that there's only one setting that
"works" which is nice in an automated system. *I think the usual scheme
is to spin the C pretty fast and slowly ramp the L, and then stop both
motors when the match is "good enough".

For relay based systems there are better algorithms for finding the best
match that take less time.

I think that is what the Icom radios use as a internal tuner which I
believe is the same as the external AH 2. So with not wanting to
invent the wheel, all I need to do is uprate the motor supply of the
external tuner and transfer the wiring from the icom internal tuner.
As I said previously, I will sleep on it for a while to be sure
Regards
Art

On Nov 1, 7:59*pm, Jim Lux wrote:
Art Unwin wrote:
On Nov 1, 12:34 pm, you wrote:
In article
,
*Art Unwin wrote:

Browsing thru E bay I came across a 1kw
antenna tuner for sale from Cyprus.Now in my younger days I got hold
of one of these and intended to salvage a Icom AH2 to somehow make it
remote since I use Icom radios. After all there are only three motors
that have to be driven! Now I am retired I pulled my old one from
storage after seeing the same on E bay. Question is are there any
kits, salvage ideas out there that would get me going on this long
lost project?
I have never used a external tuner but this seems like a realistic
project to play with.
Of course if there is a unit out there that I can salvage a controller
that is all the better. There are very good photos of this particular
tuner on E bay but like mine it has no controller! I suppose I could
feed a 10 watt signal to it and control the motors by hand to tune but
I do like the idea of automation.
Regards
Art
It isn't the tuner hardware that is going to be a problem, as much as
designing the tuning algorithm that drives the hardware. Mark Johnson
did a very good job, reverse engineering the stuff that Bill Shield
brought west from Motorola Military back in the 70's for the SEA
Autotuners. SGC copied the SEA Firmware & Design enbank, for their
stuff. The best stuff, was the stuff Collins did for their Military
Autotuners. Starting from scratch is going to be a BIG design project.

My problem as far as I can see is that the control for the AH2 is that
the innards are transferable but it only controls two motors where as
my tuner has three.
I suppose I could just use two and not utelise the fine tune inductor.
Will sleep on it for a while and look at the AH4 version or in the
worst case fine tune by hand if necessary. I suspect the fine tune is
not really necessary in most cases other than satisfy the over
zealious swr users

If you can guarantee that the real part of the feed point impedance is
always higher or lower than your transmission line Z, then you can use
an L network, which only requires 2 adjustable components.

You see a lot of these sorts of schemes with physically short radiators,
where the Rfeed is always less than 50 ohms.

L networks have the nice property that there's only one setting that
"works" which is nice in an automated system. *I think the usual scheme
is to spin the C pretty fast and slowly ramp the L, and then stop both
motors when the match is "good enough".

For relay based systems there are better algorithms for finding the best
match that take less time.

Jim, thinking a bit more about the pre conditions you gave regarding
the feed line impedance. The only way I can think that you can be sure
that the antenna never goes below that impedance is to have a ladder
line of infinite length used as feeder and the load or the load in
Meander radiator form
The ladder line being Meander in form regardles of physical
arrangement. Of course it would have to shielded to prevent static or
proximitry effects. But the question remains as to why you imposed
your conditions! Can you share what you had in mind?
Regards
Art

Art Unwin wrote:
On Nov 1, 7:59 pm, Jim Lux wrote:
Art Unwin wrote:
On Nov 1, 12:34 pm, you wrote:
In article
,
Art Unwin wrote:
Browsing thru E bay I came across a 1kw
antenna tuner for sale from Cyprus.Now in my younger days I got hold
of one of these and intended to salvage a Icom AH2 to somehow make it
remote since I use Icom radios. After all there are only three motors
that have to be driven! Now I am retired I pulled my old one from
storage after seeing the same on E bay. Question is are there any
kits, salvage ideas out there that would get me going on this long
lost project?
I have never used a external tuner but this seems like a realistic
project to play with.
Of course if there is a unit out there that I can salvage a controller
that is all the better. There are very good photos of this particular
tuner on E bay but like mine it has no controller! I suppose I could
feed a 10 watt signal to it and control the motors by hand to tune but
I do like the idea of automation.
Regards
Art
It isn't the tuner hardware that is going to be a problem, as much as
designing the tuning algorithm that drives the hardware. Mark Johnson
did a very good job, reverse engineering the stuff that Bill Shield
brought west from Motorola Military back in the 70's for the SEA
Autotuners. SGC copied the SEA Firmware & Design enbank, for their
stuff. The best stuff, was the stuff Collins did for their Military
Autotuners. Starting from scratch is going to be a BIG design project.
My problem as far as I can see is that the control for the AH2 is that
the innards are transferable but it only controls two motors where as
my tuner has three.
I suppose I could just use two and not utelise the fine tune inductor.
Will sleep on it for a while and look at the AH4 version or in the
worst case fine tune by hand if necessary. I suspect the fine tune is
not really necessary in most cases other than satisfy the over
zealious swr users
If you can guarantee that the real part of the feed point impedance is
always higher or lower than your transmission line Z, then you can use
an L network, which only requires 2 adjustable components.

You see a lot of these sorts of schemes with physically short radiators,
where the Rfeed is always less than 50 ohms.

L networks have the nice property that there's only one setting that
"works" which is nice in an automated system. I think the usual scheme
is to spin the C pretty fast and slowly ramp the L, and then stop both
motors when the match is "good enough".

For relay based systems there are better algorithms for finding the best
match that take less time.

Jim, thinking a bit more about the pre conditions you gave regarding
the feed line impedance. The only way I can think that you can be sure
that the antenna never goes below that impedance is to have a ladder
line of infinite length used as feeder and the load or the load in
Meander radiator form
The ladder line being Meander in form regardles of physical
arrangement. Of course it would have to shielded to prevent static or
proximitry effects. But the question remains as to why you imposed
your conditions! Can you share what you had in mind?
Regards
Art

An L network match either RloadRgen or RloadRgen, depending on which
side the shunt element is on.

In autotuners using an L network (e.g. the LDG boxes), they have a relay
that switches the shunt C to either end of the series L.

In autotuners using a Pi network (e.g. the SGC boxes), there's shunt
elements on both ends, so you can match anything (subject to the
component ranges).

So if you have a motorized C and a motorized L, you'd need to add a
relay to switch the configuration to be able to "match anything"

By the way, a L or Pi network cannot match Rgen=Rload, but you can do it
trivially setting both C's to zero and the L to zero. It's not really an
L or Pi (or T) network then, which is why some automated network
calculators choke on it. A real autotuner doesn't care, because it
almost always starts in the "bypass" position anyway.