I used to use a homebrew tapped transformer like the Palomar, wound on
a Philips 4C6 toroid, around late 70's to match my homebrew helical
mobile whips to my Atlas 210X installed in my Austin 1800 (like a Mini
on steroids and affectionately known as the "land crab").

The separate whips, for 80 40 and 20 metres, could all be matched to
50 ohms, all I had to do when changing bands was to change the whip,
turn the selector switch to the appropriate tapping and away we went.
Best dx - when mobile one afternoon, I heard a VK4 (across the pond
in Aus) calling CQ on 40m, but when I went back to him found he was a
DK4.

MikeN ZL1BNB











bnb


On 29 Jul 2003 08:50:27 -0700, (Art Unwin KB9MZ)
wrote:

Seems like a lot of hams with limited resources are still compelled
to operate on many bands with just a long wire and a tuner.
The wire is inexpensive but the tuners are not. Thus my present
project.
I was given a Palomar enginnering balun with 5 female connenection
which by selection can match a antenna in steps from 5 ohms to over
450 ohms
in a series of steps. I am presently rigging it up so that all
steps can be switched thru remotely by a single motor. The switching
arrangement
is the main challenge since inexpensive means simple.
Now I have not measured losses of the balun before hand because the
switching
challenge is what is driving me.
Anybody have any thoughts about what I should expect from this
balun other than knowing that it is not a tuner as is generally known
since
it does not have the ability to obtain the priceless 1:1 condition
that so many desire?
Regards
Art

Mike.
Why I chose a switchable transformer is the antenna I use
is always made resonant because of remote variable lumped
constants. ( The loop antenna is a similar type antenna )
Thus for me I only have to deal with RESISTIVE resonant
impedances that vary from frequency to frequency.
The Palomar provides a lot of different ratios between all
inputs and outputs thus SWR of less than 1.3 is really a snap.
As far as efficiency goes I should have defined efficiency but
then it comes down to compared to what.
I suppose a telephone call would be the best no matter how
efficiency is defined. As far as radio goes a remotely switchable
TRANSFORMER placed at the antenna input would be hard to beat
no matter how one defines efficiency.
Now a wag will enter bringing up the subject of inter
coil capacitances in a transformer.
Regards
Art



MikeN wrote in message . ..
I used to use a homebrew tapped transformer like the Palomar, wound on
a Philips 4C6 toroid, around late 70's to match my homebrew helical
mobile whips to my Atlas 210X installed in my Austin 1800 (like a Mini
on steroids and affectionately known as the "land crab").

The separate whips, for 80 40 and 20 metres, could all be matched to
50 ohms, all I had to do when changing bands was to change the whip,
turn the selector switch to the appropriate tapping and away we went.
Best dx - when mobile one afternoon, I heard a VK4 (across the pond
in Aus) calling CQ on 40m, but when I went back to him found he was a
DK4.

MikeN ZL1BNB











bnb


On 29 Jul 2003 08:50:27 -0700, (Art Unwin KB9MZ)
wrote:

Seems like a lot of hams with limited resources are still compelled
to operate on many bands with just a long wire and a tuner.
The wire is inexpensive but the tuners are not. Thus my present
project.
I was given a Palomar enginnering balun with 5 female connenection
which by selection can match a antenna in steps from 5 ohms to over
450 ohms
in a series of steps. I am presently rigging it up so that all
steps can be switched thru remotely by a single motor. The switching
arrangement
is the main challenge since inexpensive means simple.
Now I have not measured losses of the balun before hand because the
switching
challenge is what is driving me.
Anybody have any thoughts about what I should expect from this
balun other than knowing that it is not a tuner as is generally known
since
it does not have the ability to obtain the priceless 1:1 condition
that so many desire?
Regards
Art