so i've been wanting to build a regen receiver for years and finally sat down and did it last month. based loosely on the AA1TJ style one-tube design but i adapted it for a FET since i don't really have a tube setup handy. got it on 40m mostly and it works way better than i expected honestly.

the regeneration control is kind of driving me nuts though. i've got it on a 10k pot and the sweet spot between oscillating and just-below-oscillation is maybe a quarter turn on a cheap pot. everything is crammed into this tiny range and it makes tuning really touchy. i've seen people talk about using a series resistor to spread out that range but i'm not sure what value to start with or if there's a better approach entirely. also wondering if shielding the coil more would help or if that just kills sensitivity.

the audio is actually surprisingly decent for what it is. running it into a little LM386 amp stage and it's pulling in stations i wouldn't have expected. SSB is a little rough but CW comes in clean. just want to tame that regen control before i build the enclosure.

yeah the touchy regen control thing is just kind of the nature of the beast with these circuits but there are some tricks. a lot of builders use a dual-gang pot where one gang is a coarse control and the other does fine adjustment — but honestly the easier fix is what you mentioned, putting a resistor in series with the pot. try something in the 4.7k to 10k range and just see how it spreads the curve, you might have to experiment a bit. some guys also use a vernier drive on the pot knob which helps a ton for usability even if it doesn't actually change the circuit behavior.

shielding the coil is a mixed bag. if you're getting hand capacitance effects then some partial shielding can help but yeah you'll trade off some Q and sensitivity. i'd get the regen control sorted first before messing with that. also what's your feedback winding ratio looking like? sometimes the oscillation threshold being super sharp is partly a coil geometry thing.

im building something similar right now actually, JFET regen on 80m, and i had the same exact problem. what i ended up doing was replacing the pot with a 5k trimmer set to find the right range and then putting a 1k linear pot in series for the actual tuning control. gives you way more usable throw on the knob. its still not perfect but its a lot less frustrating. the LM386 amp stage is the same thing im using, does yours have any motorboating issues at higher gain settings? mine oscillates like crazy above about 6x gain and i cant figure out if its the layout or if i need more bypassing on the supply rail.