I was stupid enough to buy a FT-221R from him that was advertised to be in "mint", "perfect", "brand new" [ad nauseum] condition. When it arrived, it was the dirtiest, smelliest piece of junk I'd eve
[huge snip, see below] ... Henry 3KA. (2x 3-500 model) Stock in good condition and choke runs 4KV from my 247VAC line with bleeder current. Sags some with load of course, 3600V or so. 73, Jim, N7CXI
Maybe I should start a tube marking service to put the new laser to work... ;-) Jim, N7CXI _______________________________________________ Amps mailing list Amps@contesting.com http://lists.contestin
. Tap the wire carrying the wife's eternal phone jabbering . Use the audio to modulate a chicken-band transmitter . Drive a nice dirty class C eBay special amp with the CB rig . Rectify the output, a
Interesting... What about a series low-pass instead right at the cathode? It would have to handle the drive power, but wouldn't it reduce the number of potential feedback paths? 73 Jim, N7CXI _______
I was thinking (perhaps in error) that if the parasitic network was right at the cathode connection it might be more effective in the case where there was imperfect shielding between the goesinna and
Not without revealing closet Mr. Rogers fans... We would occasionally sentence our children to watching it if it was -20F outside and they had been particularly obnoxious. 73, Jim, N7CXI ____________
Vic, Front panel marking was at least one of the things I wanted to be able to do when I recently bought a large-format laser engraver. There is a metal-marking compound called CerMark that can be us
Anyone have any experience (good or bad) with the RK2671A DC/AC Hipot tester, probably from Shenzen Meiruike Electronics? http://cgi.ebay.com/ws/eBayISAPI.dll?ViewItem&Item=390104450926&Category=4678
I'd considered a sign xformer and a variac, but by the time I put metering circuits and a current trip of some kind on it I'd be well on the way to buying one. Factoring laziness probably puts it ove
Hi Hsu, There's no way to tell what transformer is being used, but if I'm reading it right the digital leakage current meter will read (for DC) 0-2ma or 0-10ma, two different scales . Does that sound
I'm looking to buy a couple of YC156's for a project, either rebuilt or full-output pulls. There's a current eBay auction by "powergridtube" that lists 5 tubes "cleaned and laboratory tested to full
I'm not an expert on them, but all indications are that they're quite stable in multiband designs given reasonable care in layout and construction. I haven't as yet seen one require a parasitic suppr
There we go, that's the info I've been looking for. Thanks! 73, Jim, N7CXI _______________________________________________ Amps mailing list Amps@contesting.com http://lists.contesting.com/mailman/li
Good point Bill, which is why I'm going to try a different source first. 73, Jim, N7CXI _______________________________________________ Amps mailing list Amps@contesting.com http://lists.contesting.c
That's an intriguing question, but I wonder about harmonics of that sharp-ish waveform flying around the RF deck? 73, Jim N7CXI _______________________________________________ Amps mailing list Amps@
Thanks for the referral. Just ordered a copy from Amazon. For the group, does anyone have a well-maintained booklist for amps and general RF engineering? I recently dumped 30 years worth of Newark, A
This has no doubt been covered here before, but is there a "shotgun" equation or rule of thumb for this? (minimum Q for adequate flywheel effect) In the past I've started with a pi input network with
That works, thanks. Playing with the models shows that designs between 25 and 70 ohms cathode impedance meet the 13pf/meter criteria using a pi-net input with a Q of 4. Above 70 ohms not so much. If
Thanks, Jim W7RY. I did in fact find two used copies on Amazon, but the prices were up there with new engineering books. Perhaps the "eBay syndrome" for books? Also looks like I missed Jim VE7RF's co