UK Vintage Radio Repair and Restoration Discussion Forum - View Single Post

G6Tanuki · 23rd Sep 2020, 2:52 pm

Good point - I don't remember the resistive component the VNA gave - should have taken a photo of the screen rather than writing-down what I thought I needed to remember using a biro on the back of my hand!

But the suck-it-and-see approach seems to work OK - no flashovers or things-getting-hot, unlike a friend who built an ATU using similar 'design' ethics and ended up with a crazily-high 'Q', so high that one end of the coil unsoldered itself due to the massive circulating RF current.

23rd Sep 2020, 2:52 pm	#3
G6Tanuki Dekatron Join Date: Apr 2012 Location: Wiltshire, UK. Posts: 13,998	Re: A 'Modern Vintage" 3.5MHz ATU. Good point - I don't remember the resistive component the VNA gave - should have taken a photo of the screen rather than writing-down what I thought I needed to remember using a biro on the back of my hand! But the suck-it-and-see approach seems to work OK - no flashovers or things-getting-hot, unlike a friend who built an ATU using similar 'design' ethics and ended up with a crazily-high 'Q', so high that one end of the coil unsoldered itself due to the massive circulating RF current.