[georgetownjohn]

Happy Thanksgiving, 
I have attche a photo of a very thin wire with black plastic-looking insulation(some of it has come off) and it is attached to terminal 5 on the 6K7G IF amp and the goes up into the bottom of the IF transformer.  In the Ron Ramirez video of the 37-640 I have been following, he had a yellow wire going to somwhere in the RF unit instead of what I am finding.  Can someone help with my confusion of what type of wire I should use to replace taht thin black wire?  Thanks so much--John

[morzh]

You can possibly use a heatshrink tubing.
If you decide to replace the wire, anything gauge 24, 300V rated will do (it can be thinner but 24 solders an handles better).
Color and AWG are not very important, nor is the insulation type, as long as it has the mentioned V-rating and temperature rating (in case it goes by a place that is hot).

[georgetownjohn]

Thanks so much for your help!  I really could not have gotten this far without the kindness of you and other members.  Thanks again and Happy and Safe Thanksgiving!---John