Thanks, that is greatly appreciated. I assume those numbers are outside diameter and height? If so, then the closest sizes from Amidon would be:
T1 = FT-87: 0.870, 0.540, 0.250
T2 and T3 = FT-100A: 1.000, 0.610, 0.320
That is OD, ID and height.
It looks like I guessed right on the OD of all of them. However, there are three different height variations for the 1 inch toroid. I guessed it was the thinnest one, the FT-100, not the thicker FT-100A or FT-100B. I may have to order more toroids.
When you get a chance, please verify the number of turns on T1.
Joe.
Yes I will Mojoe.
Give me 'till tomorrow.
I have again measured the toroid dimensions for T1, T2 & T3, adding the sizes of the donut holes.
T1 o.d.=3/4" Th.=1/4" Hole=3/8"
T2 o.d.=1" Th.=3/8" Hole=1/2"
T3 same as T2
Now, onto the windings for T1, the RF input transformer.
The toroid stands upright hot-glued to the circuit card.
Primary - white wire 5-turns spread around entire circle;
red wire 5-turns spread around entire circle;
Primary Center tap: the white wire connects to the white wire at the top/center of the toroid.
Secondary - black wire 5-turns spread around the entire circle.
Primary center tap: the white wire connects to the red wire at the top/center of the toroid.
When I tapped into this thread with Post # 10 "CP-15 COUPLER ON THE BENCH," I hoped I'd get a response to the points raised, but no. The subject drifted to other areas.
So forgive my slapping everybody's face, but go read # 10 and tell me what you think about it.
I will say that the language quoted from the manual is exact, English mistakes intact.
OK, T1 could be one of two sizes. The FT-63A is just a bit smaller than what you measured and the FT-82 is just a bit larger.
For T2 and T3, it still looks like a FT-100A is the closest match.
Thanks for confirming that it is five turns on T1. It was hard to tell from the picture.
They are using three pieces of wire on T1 to make it easier to have a 2:1 winding ratio. Instead of winding ten turns on one wire and five on the other, they just wound five turns on three wires and connected two of the windings in series.
Joe
I thought I answered your questions. The 12.5 Ohm dummy load is correct, because of the 4:1 impedance transformer T1. And the 86% power dissipation in the dummy load that I calculated is very close to the stated 90%. That figure is less than 5% difference. The parts list does not state the tolerance of the resistors, but they are unlikely to be better than 5%.
Joe
Thank you mojoe for giving me that bit of explanation.
Now I can wake up in the morning with the feeling that my CP-15 doesn't contain a design flaw.
Maybe after coffee I will hook it up and see how it does.