Discussion in '"Boat Anchor" & Classic Equipment' started by KF5DDW, Sep 24, 2020.
Found the alignment tool, radio shack. For all IF/RF transformers, or so it says.
On making an alignment load the instructions are 1000 ohm non inductive resistor and .005 uuf cap. Is that a 5pf or what?
The instructions for the alignment load is 1000 ohm non inductive and .005 uuf cap. Is that supposed to be 5 pf ?
I believe that's a typo in the TR-3 and TR-4 manuals. TR-4C and R-4B manuals specify 0.005uF. I've used 0.0047uF for the alignments I've done.
Why did you change to the 0.0047uf?
.0047 is now an industry-standard value.
The EIA (Electronics Industry Association) has a standard-value list for resistors and capacitors.
Whereas .05, .005 uF was common, it is relatively unavailable in non-precision components today.
It's derived from statistical range of true value with 10% or 20% tolerance components and their overlap of values.
So, you see resistors at 15, 18, 22, 27, 33, 39, 47, 56, 68, 82 ohms--If you look at 10% variation, you've got the target values covered. In most
ordinary applications, the small divergence from a round number is inconsequential.
Same in capacitors, although some even-number values still common.
When you get to components with 5% or tighter tolerance, there are exact values available, often in military or special-order components,
and priced astronomically accordingly.
Old gear from WW II thru 1970's has round-number values prevalent, but that's now historically archaic.
Well ok. I try to learn something everyday, I believe this will check that box. Thanks