On Tue, 10 Nov 2015 11:40:43 -0600, amdx wrote:

You want to see guys reaching for lowest losses, highest Q, follow a
crystal radio group.
Some there claim Q's of 2000, (I believe them) Using 2 and 3 parallel
pieces of 660/46 Litz wire. AMBCB.
The 2000Q thread; http://tinyurl.com/q2hc6ga

That's the unloaded Q measured in an HP4342A Q meter. Putting a load
across the coil will drop the Q considerably.

The equivalent parallel resistor across a perfect 120uHy inductor and
resonating capacitor a

R = Q * 2*Pi*f*L
R = 2000 * 2 * 3.14 * 1*10^6 * 120*10^-6
R = 1.5Meg

So, all it would take is a 1.5Meg load across the parallel coil and
capacitor, and the Q would get cut in half. That doesn't sound very
practical.

I used an HP4342A at a former employer. Nice machine but really
unstable for high-Q measurements. I'm not surprised that he had to
leave it running for a while to stabilize:
http://www.radiomuseum.org/r/hewlett_pa_q_meter_4342a4342.html
$300 to $500 on eBay. Ouch.

Drivel: The MFJ-259a is now fixed. It was the usual blown diodes,
along with cleaning up the mess left by the leaky batteries.



--
Jeff Liebermann
150 Felker St #D http://www.LearnByDestroying.com
Santa Cruz CA 95060 http://802.11junk.com
Skype: JeffLiebermann AE6KS 831-336-2558