QCX Build Tips

Toroids

I found the QCX manual from QRP-Labs to be extremely in depth. Unfortunately I found the toroid winding steps to be lacking a small piece of helpful information: the approximate length of wire needed for each toroid.
The length of each wire is taken from this wonderful toroid resource over at KitsAndParts.com. (Thanks to W8DIZ for reminding me about it!)
I hope you find the following information helpful.
Lengths are approximate. Be sure to give yourself a little margin of error. You don't have to be 100% exact on the measurement, you just dont want to run out of wire!

Should you run out or need more wire, the wire in the kit is #28 awg enamel-coated magnet wire.

Be sure to check the values of the toroids you've wound before soldering them in place.
I use a cheap LC meter I got off eBay long ago. There are also "transistor tester" kits you can build but many cheap multimeters can be found online that do inductance measurement.

T1 Toroid (transformer)

These lengths are very approximate.
I added the total number of turns and determined total length. Then added ~12" to the total to provide for 2" lengths (down and back) for the twisted loops between the Primary and S1 and S2.
Be extra sure to read and re-read the transformer directions before cutting or soldering anything!

Band	Toroid	Turns				Length
Band	Toroid	Primary	S1	S2	S3	Length
80m	T50-2 Red	5	5	5	68	~70" total
60m	T50-2 Red	5	5	5	46	~56" total
40m	T50-2 Red	5	5	5	38	~50" total
30m	T50-2 Red	4	4	4	30	~44" total
20m	T50-2 Red	3	3	3	30	~40" total
17m	T50-2 Red	3	3	3	22	~36" total

L4 Toroid

Band	Toroid	Value	Turns	Length
80m	T37-2 Red	2.3uH	24	14"
60m	T37-2 Red	2.3uH	24	14"
40m	T37-2 Red	1.0uH	16	10"
30m	T37-2 Red	0.78uH	14	9"
20m	T37-2 Red	0.40uH	10	7"
17m	T37-2 Red	0.32uH	9	7"

L2 Toroid

From Low Pass Filter kit

Band	Toroid	Value	Turns	Length
80m	T37-2 Red	3.0uH	27	16"
60m	T37-2 Red	2.3uH	24	14"
40m	T37-6 Yellow	1.7uH	24	14"
30m	T37-6 Yellow	1.3uH	20	12"
20m	T37-6 Yellow	0.90uH	17	11"
17m	T37-6 Yellow	0.67uH	15	10"

L1 & L3 Toroids

From Low Pass Filter kit

Band	Toroid	Value	Turns	Length
80m	T37-2 Red	2.3uH	25	15"
60m	T37-2 Red	2.3uH	23	14"
40m	T37-6 Yellow	1.0uH	21	13"
30m	T37-6 Yellow	0.78uH	19	12"
20m	T37-6 Yellow	0.40uH	16	11"
17m	T37-6 Yellow	0.32uH	13	9"