08-09-2015, 04:55 PM
(This post was last modified: 08-09-2015, 04:56 PM by Radio Fixer.)
Ah! found it!
Restoration of an HMV 650. I had some high IF coil resistances and these are my tests to see what difference in performance it would make..
"Another junk IFt was found that used three strand wire with a coil resistance of 33 Ohm, which had a measured Q of 41. With one strand cut, at the outer end, the results were 52 Ohm and a Q of 41. Finally with two wires cut the results were 101 Ohm and a Q of 33."
So the conclusion is that a few broken wires are not a disaster. "
"Later, I typed into Goggle “Litz wire broken strands” expecting to get nothing of value. Within minutes I found an article “Litz Wire - The Effect of Broken Strands”, by member Alan Douglas from back in 1997. In the article he gives the percentage reduction in Q for broken strands of 3 and 7 strand wire. It really is quite astonishing that 4 broken strands, in 7 strand wire, only reduced the Q by 10% and the result was the same if the wires were broken at the inner or outer ends of the winding. "
Gary
Restoration of an HMV 650. I had some high IF coil resistances and these are my tests to see what difference in performance it would make..
"Another junk IFt was found that used three strand wire with a coil resistance of 33 Ohm, which had a measured Q of 41. With one strand cut, at the outer end, the results were 52 Ohm and a Q of 41. Finally with two wires cut the results were 101 Ohm and a Q of 33."
So the conclusion is that a few broken wires are not a disaster. "
"Later, I typed into Goggle “Litz wire broken strands” expecting to get nothing of value. Within minutes I found an article “Litz Wire - The Effect of Broken Strands”, by member Alan Douglas from back in 1997. In the article he gives the percentage reduction in Q for broken strands of 3 and 7 strand wire. It really is quite astonishing that 4 broken strands, in 7 strand wire, only reduced the Q by 10% and the result was the same if the wires were broken at the inner or outer ends of the winding. "
Gary
