Martin here is a relatively quick and dirty way of making a largish variable inductor. http://www.alan.melia.btinternet.co.uk/lfaecoil.htm varying the pie spacing changes the inductance However for r
Dear Martin, LF Group, The simplest type of variable inductance I have used was permeability tuned - It consisted of a coil of about 150 turns wound on a plastic tube about 60mm diameter, with a "tun
I use a decade inductance bridge to series tune my (approximately) 50m end-fed inverted U wire for 137kHz. It uses 3mH - 2mH is too little, 4mH is too much. Obviously I need to be able to vary this i
Hi Martin, Am 11.01.2012 21:44, schrieb Martin Evans: I use a decade inductance bridge to series tune my (approximately) 50m end-fed inverted U wire for 137kHz. It uses 3mH - 2mH is too little, 4mH i
Brings back memories, Andy - I used to buy old valve radios from junk shops in the late 50s, early 60s for 2 shillings and sixpence each....if I'd kept them all intact, I could be living in the Baham
Yes - I was given this tip by someone else yesterday, Kevin ( my apologies to the original tipster - I'm in another location now, and can't recall who it was!). As you say, the problem is to find suc
Hi Martin, Am 12.01.2012 12:02, schrieb Martin Evans: [...] Maybe my resolution for 2012 should be to stop daydreaming and actually *do* something! Martin GW3UCJ. That's my point :-) Sounds as if you
Hi Martin Just make a variometer two inductors one inside the other like piston and cylinder and adjust in and out to resonance (I think this design is the simplest form of variometer mechanically).
Hi again Martin The two other replies are from of the most experienced 136 ops (James and Stefan) and constructors around. I only play at it. Rather than use my slide rule oops sorry a scientific cal
Oh Wolf, please! - you'll have me fantasizing again! Martin GW3UCJ. build a really big former from the "brickwork" used for Renato's monster VLF induction coil ? From http://www.vlf.it/romero3/ics101
Morning, Pete. Thanks for this. Yes, this is what I should do. My problem is that I get carried away - I begin by thinking of making a variometer - then I decide that it *must* be the biggest one eve
Martin: Old Tube type A.M. radios from the 50's to the early 70's will be a very good source for high value, slug tuned Inductors.. I have 2 coils I use to tune my 160 meter Windom for 136 KHz.. Ea
Hi Martin, build a really big former from the "brickwork" used for Renato's monster VLF induction coil ? From http://www.vlf.it/romero3/ics101.html : worldwide from large distributors of electronic c
It uses 3mH - 2mH is too little, 4mH is too much. Obviously I need to be able to vary this inductance rather more finely and I thought of using a small variac (don't laugh!) as a variable inductance,
Thanks Stefan - this is what I feared. Guess that I'll have to be more conventional! I did look for you earlier this evening, but couldn't see your signal. I hope your new FETs arrive tomorrow. Marti
