[Radioroslyn]

This has always bothered me, where do i go to know the correct ohms readings per coil, to quote " I'd still measure ## 2,5,6,12 and 15 continuity."  Mine read within that range but i don't know which "one" matches the 3 coils.  


Also, does this measure correctly in circuit or like resistors, can the only true measure occur when removed from the radio?    
thanks for the help,
Rich 

Hi Rich,
>This has always bothered me, where do i go to know the correct ohms readings per coil.

We are not necessarily looking for an exact resistance per say but continuity. Does the winding have a much higher resistance that it should? Physics tells us the the lower the frequency the more turns of wire you'll need on a coil. Your IF transformer coils @ 175kc are going to have more resistance than your antenna coil @550-1700kc. In rough numbers this equals about 5 ohms or so for the antenna secondary and the primary much less because it's a non resonate winding it's used to couple the rf signal from the antenna to the secondary and is much smaller. It's going to be just an ohm or two. IF coils are going to be around 15-40 ohms again depending on the frequency. The resistance specifications are nice to have but not a necessity. A bad coil will measure a high resistance like 1000 ohms or high like open

>Also, does this measure correctly in circuit or like resistors, can the only true measure occur when removed from the radio?   

Well this depends. When you have two components in parallel they will have some sort of interaction. For instants let's look at #1 and 2 on your 52. What you have is the volume control and the primary of the antenna coil. Can you measure the coil with the volume control connected to it? As long as the volume control is not turned full up (shorting the coil) since the coil has a much lower resistance than the control what your ohm meter will see is the lower resistance. A little different story with resistor and caps in parallel. There you have a resistance and a device that stores electricity. Your ohm meter applies a small voltage to what you are measuring in this case, the cap will try the store the applied voltage and the resistor will try to discharge the volt confusing your ohm meter. So best to separate them for an accurate reading. You don't have to remove the part just disconnect one end and your good. Generally parts in series don't have much of an interaction so you don't have to disconnect them. Rule of thumb is if it measure way out in circuit disconnect one end and remeasure.