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

MrBungle · 22nd Jan 2018, 10:33 am

Thanks - I just tried that and cut my finger open (doh!) so doing a more scientific method first.

I stuffed the 2u6L I have across a 100pF mica 1% capacitor and put a 47k resistor in series with the tuned circuit and stuffed it on my scope and signal generator. Solved resonant circuit equation for the two limits of the coil and it gives:

2u6L tuning range of 1.72uH to 4.17uH.

That's well within the tuning range of what I need so I'll probably grab some 2u6L's and just tune them appropriately.

I was half asleep last night at half past midnight when I was thinking this through. This morning I woke up with a "there must be an easier way here".

I'll grab some 5u3L's as well just in case they don't all tune into that range and I need some headroom.

22nd Jan 2018, 10:33 am	#5
MrBungle Dekatron Join Date: Jun 2016 Location: London, UK. Posts: 3,687	Re: Rewinding slug tuned IFTs Thanks - I just tried that and cut my finger open (doh!) so doing a more scientific method first. I stuffed the 2u6L I have across a 100pF mica 1% capacitor and put a 47k resistor in series with the tuned circuit and stuffed it on my scope and signal generator. Solved resonant circuit equation for the two limits of the coil and it gives: 2u6L tuning range of 1.72uH to 4.17uH. That's well within the tuning range of what I need so I'll probably grab some 2u6L's and just tune them appropriately. I was half asleep last night at half past midnight when I was thinking this through. This morning I woke up with a "there must be an easier way here". I'll grab some 5u3L's as well just in case they don't all tune into that range and I need some headroom.