First of all, I want to apologise to Alex for the delay in posting his article - I've been feeling pretty rough for the past couple of weeks, but here it is.
Alex is looking to move on this project, and a club member or website visitor may be interested in it. He says 'As to the value, it is difficult to say but I am open to sensible offers, taking into consideration the present purchase price of the capacitors in USA'.
You can either contact Alex directly if you already have his details, otherwise you may contact your webmaster, and I will pass on your info.
Berni M0XYF.
100 Watt KW E-Zee ATU for 160 to 10m
I suspect that some people will think that this ATU is 'out of date', but there are some good reports about it.
I built this piece of kit for my first 'Construction Competition', shortly after joining the club. ('Construction Competitions' - ah, now those were the days!). At the time, I did not have a LRC Meter so was not able to check the various component values. However, I have done this now (test frequency = 200kHz) and some of them are listed below, but the components are joined together which will probably affect their original values:
L1 - 160m Loading Coil
Impedance = 0.49uH
Transformer (T1)
Inner Coil (Primary) = 0.69 pF
Outer Coil (Secondary) = 1.05 pF
Transformer (T2)
Inner Coil (Primary) = 1.42 pF
Outer Coil (Secondary) = 1.49 pF
Variable Capacitor (C1)
4.6 kV RMS
Max. = 434 pF
Min. = 36 pF
Two-Gang Split-Stator Variable Capacitor (C2)
2 x 250pF, 3.18kV RMS
I believe the slow-motion drives are still available
Mutual Inductance for T1 and T2, using Inductance Difference Method
M = {{L(Aiding) minus L(Opposing)} / 4 Henries
I tried this method but the results were unreliable.
Similar variable capacitors are still available from the following company, priced at about US $150.0 each (Ex Stock):
Palstar Inc
9676 N. Looney Road
Piqua
OH 45356
USA
Phone: 937-773-6255
