On Jan 14, 2:22 pm, cliff wright wrote:
Hi! I've been wanting to upgrade my old Zmatch ATU which is 30 years old
for a while but although I've come across several designs, both one and
2 coils I cannot find the actual inductance values required.
I seem to remember an article in a magazine some years ago that had them
but I haven't been able to locate it so far.
I have some very nice Silver plated coil stock that I would like to use
but as I have determined for myself the value of the coil is critical as
the network doesn't like the tuning position for any 2 bands to coincide.
Failing the use of an air cored coil I might try a Toroid, but The coil
stock is in my hands right now. Any help greatly appreciated!
Regards Cliff Wright ZL1BDA ex G3NIA

Hi, Cliff.
Are you sure about the age? I think I got mine about 1970 and it was
used then! I used it for years running about 100 watts and a dipole
fed with ladder line. Now it's just resting in the loft.

What are you wanting to upgrade? The capacitors won't take the voltage
of much higher power.

Can you measure the minimum and maximum capacitance? If so, and you
already know the frequency range, then you can compute the inductance
or read it off a chart. I am at work, so can't look at the manual.

Paul, KD7HB