For Sale -Home brew balanced line tuner - Twin Roller Inductors
 

A magnificently built, balanced output antenna tuner for use with
ladder line, open wire line.

Item is for sale on e-bay Item # 290185692713 Auction ends
Sunday 12/2 at 19:00 Z



Highlights & Features of this tuner:

The twin inductor/current balun design provides a truly balanced
output.

(2) 14 uH roller inductors, coupled to a WW II vintage dial with 25
turns, 1/100 turn markings.

High/Low Impedance Switching: Switches the capacitor bank to
tuner's input or output. "HI" position is used for impedances above
50 ohms; "LO" is used for impedances below 50 ohms.

Variable and fixed capacitance controls - continuous range is from 25
to 1250pf @ 4500 Vpk.

Variable capacitor dial is the classic 4-inch National Velvet Vernier.

Beautiful, real wood venier over aluminum front panel.



In Photo 1, the large coil on the right is a coaxial choke balun that
goes between the output of the rig and the input of the tuner. Please
indicate if you do not plan to use this coil, I will be happy to
install a ferrite choke balun inside the cabinet.

Dimensions: H,W,D = 8 X 19 x 15 inches, approximate weight = 30 lbs

Good luck with the bidding,

Bob WB2ICQ

For Sale -Home brew balanced line tuner - Twin Roller Inductors
 

On Nov 25, 3:17 pm, "
wrote:
A magnificently built, balanced output antenna tuner for use with
ladder line, open wire line.

Item is for sale on e-bay Item # 290185692713 Auction ends
Sunday 12/2 at 19:00 Z

Highlights & Features of this tuner:

The twin inductor/current balun design provides a truly balanced
output.

(2) 14 uH roller inductors, coupled to a WW II vintage dial with 25
turns, 1/100 turn markings.

High/Low Impedance Switching: Switches the capacitor bank to
tuner's input or output. "HI" position is used for impedances above
50 ohms; "LO" is used for impedances below 50 ohms.

Variable and fixed capacitance controls - continuous range is from 25
to 1250pf @ 4500 Vpk.

Variable capacitor dial is the classic 4-inch National Velvet Vernier.

Beautiful, real wood venier over aluminum front panel.

In Photo 1, the large coil on the right is a coaxial choke balun that
goes between the output of the rig and the input of the tuner. Please
indicate if you do not plan to use this coil, I will be happy to
install a ferrite choke balun inside the cabinet.

Dimensions: H,W,D = 8 X 19 x 15 inches, approximate weight = 30 lbs

Good luck with the bidding,

Bob WB2ICQ

Hi, Bob.
Care to tell us what frequencies,antennas and types of feed lines you
have used the tuner on? Have you ever put RF ammeters in the feed line
to see if it's really balanced?

Did you gear drive or chain drive the two coils? Looks like a nice
job!

Best regards,

Paul, KD7HB

For Sale -Home brew balanced line tuner - Twin Roller Inductors
 

Hi, Bob.
Care to tell us what frequencies,antennas and types of feed lines you
have used the tuner on? Have you ever put RF ammeters in the feed line
to see if it's really balanced?

Did you gear drive or chain drive the two coils? Looks like a nice
job!
===============
To check whether the feed line is truly balanced also depends on the
symmetry of the antenna. Any 'unbalance can best be determined by
clamping a RF current sensor/meter across both feed lines at the same
time, not by measuring the difference between the 2 lines.

Frank GM0CSZ / KN6WH

For Sale -Home brew balanced line tuner - Twin Roller Inductors
 

On Nov 26, 6:26 am, Highland Ham
wrote:
Hi, Bob.
Care to tell us what frequencies,antennas and types of feed lines you
have used the tuner on? Have you ever put RF ammeters in the feed line
to see if it's really balanced?

Did you gear drive or chain drive the two coils? Looks like a nice
job!

===============
To check whether the feed line is truly balanced also depends on the
symmetry of the antenna. Any 'unbalance can best be determined by
clamping a RF current sensor/meter across both feed lines at the same
time, not by measuring the difference between the 2 lines.

Frank GM0CSZ / KN6WH

Hi, Frank.
I was just curious to see if Bob ever posted anything other than "for
sale" items. Guess not. Just looking at the pictures I would guess the
tuner doesn't work as described. I will keep my old Dentron.

73's
Paul, KD7HB

For Sale -Home brew balanced line tuner - Twin Roller Inductors
 

Hi, Frank.
I was just curious to see if Bob ever posted anything other than "for
sale" items. Guess not. Just looking at the pictures I would guess the
tuner doesn't work as described. I will keep my old Dentron.

73's
Paul, KD7HB

It is a good size example of Rich's tuner design... Probably works..
Is not a balanced tuner, however... It is a pair of of unbalanced L-
match's with a common mode input choke...

denny / k8do