[UK-CONTEST] Stacking Toroids

[Tom Boucher]

Chris,

If you haven't seen it, there has been an interesting discussion started by K2AV on inverted 'L's, transformer matched and using a folded counterpoise instead of the conventional radials, on the Topband Reflector recently . See www.w0uce.net/k2avantennas.html

On my inverted 'L' I just use a simple 1600pF/4KV fixed ceramic (RS or Farnell) from base of antenna to ground which gives a perfect match. It's actually an L network with the series inductance made by slightly increasing the antenna length.

73
Tom G3OLB

G3SJJ wrote:

<I want to stack a couple of T300-2 toroids for a project I am working on. A couple of questions -

1 - Should each toroid be wrapped separately or should the non-painted side of each touch each other and then the whole unit wrapped?

2 - The finished component will be a 4:1 transformer to match a 160m inv-L. Currently I am using one core which already had 14 turns bifilar wound as 
4:1 balun but I have just altered the connections, so that one free end is grounded, the other free end goes to a series C and the centre tap goes to 
the Tx. It works well, tuning nicely with the C, although the core saturates at a specific power area, hence stacking. What are the relative merits 
are a straight winding against bifilar.>