Tank Coil

[Barrie]

I'm in the process of rebuilding a push-pull transmitter that I first built in the early 1990s.  The tank coil I wound then, used number 6 wire, didn't turn out too well.

I have a large, edgewound coil from a BC transmitter that I'm thinking of using this time.  It's too large, being 104 uh, but, by shorting out 6 turns on either side, and tapping in at those six turns, it's about right for 160M.  That's according to a inductance meter, and a GDO.

It's just one long coil, not seperated in the center.  I'd have to wind the link over the center.

Anyone tried this?  Will it work?  Any advice?

73, Barrie, W7ALW

[k4kyv]

Instead of shorting out the extra turns at the end, I would split the coil in the middle and install the link there.  If you prefer a fixed link, it could simply be a few turns of the same coil stock as the original coil, with a slot of spacing in between on both  sides.  I would simply remove any left over turns at the end instead of shorting them out.

If you want a swinging link, you could modify the  coil to leave a gap in the middle to allow for the link to swing in and out, similar to the HDVL series.  This would require modifying the support structure as well as the coil itself.

[WA1GFZ]

I bought a couple big coils like that.
Options:
1.Ground the center of the coil and attach the input coax up one side of the coil as a shared primary secondary. (least damage to the coil)
2.Cut the center X? turns in 2 places as Don said to make the primary
3.Wind a primary over the coil with copper tubing (no damage to coil)
4.Cut the center and drive both halves with a balun directly connected to 50 ohm coax. This makes a balanced / balanced tuner if you think about it.
I have not decided which way to go yet