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Total 523 documents matching your query.

281. Re: [Amps] Parasitics & Filament Sag (score: 1)
Author: Peter Chadwick <g3rzp@g3rzp.wanadoo.co.uk>
Date: Wed, 30 Aug 2006 09:56:24 +0200 (CEST)
Bill said: (re 6AG7) in the early black and white TV sets< I think it was out shortly before the end of WW2 as a video amp/driver for radar purposes - a very similar application. Its little brother i
/archives//html/Amps/2006-08/msg00791.html (8,791 bytes)

282. Re: [Amps] Question about TPTG oscillators (score: 1)
Author: Peter Chadwick <g3rzp@g3rzp.wanadoo.co.uk>
Date: Wed, 30 Aug 2006 10:07:54 +0200 (CEST)
oscillator, if the anode resonant frequency was lower than the grid resonant frequency, the tube would not oscillate. Did I catch that right? And does this apply in a grounded grid oscillator as well
/archives//html/Amps/2006-08/msg00792.html (8,540 bytes)

283. Re: [Amps] Parasitics & Filament Sag (score: 1)
Author: Peter Chadwick <g3rzp@g3rzp.wanadoo.co.uk>
Date: Wed, 30 Aug 2006 10:13:12 +0200 (CEST)
Made of resistance wire, it is. If it isn't, then the measurements Wes did, which show an impedance that increases with frequency, are wrong. 73 Peter G3RZP __________________________________________
/archives//html/Amps/2006-08/msg00793.html (8,290 bytes)

284. Re: [Amps] Cutting G-10 Board (score: 1)
Author: Peter Chadwick <g3rzp@g3rzp.wanadoo.co.uk>
Date: Wed, 30 Aug 2006 12:54:33 +0200 (CEST)
material(actually, it is G-11 but very close to being the same as G-10)? < If you're cutting much of it, get a diamond saw. Fibreglass plays merry hell with saw blades - and guillotine (shear) blade
/archives//html/Amps/2006-08/msg00797.html (8,109 bytes)

285. Re: [Amps] Suppressors (score: 1)
Author: Peter Chadwick <g3rzp@g3rzp.wanadoo.co.uk>
Date: Wed, 30 Aug 2006 14:57:04 +0200 (CEST)
blocking cap/tune C at hf, and high resistance at vhf. Given that there's a series circuit from the anode through the suppressor, blocking cap and tune C to ground, looking at the series resistance t
/archives//html/Amps/2006-08/msg00804.html (8,050 bytes)

286. Re: [Amps] Suppressors (score: 1)
Author: Peter Chadwick <g3rzp@g3rzp.wanadoo.co.uk>
Date: Wed, 30 Aug 2006 15:52:43 +0200 (CEST)
are amplifiers unstable if you disconnect the blocking cap and introduce infinte R?< As usual - it depends! Because there's inherent inductance and shunt capacitance, there's obviously an impedance a
/archives//html/Amps/2006-08/msg00807.html (8,041 bytes)

287. Re: [Amps] Question about TPTG oscillators (score: 1)
Author: Peter Chadwick <g3rzp@g3rzp.wanadoo.co.uk>
Date: Wed, 30 Aug 2006 16:37:21 +0200 (CEST)
restoring these old examples of the radio art. It would truly be a shame if someday the last one disappeared.> There is a military electronics museum organisation over here: I gave them the remains o
/archives//html/Amps/2006-08/msg00812.html (8,268 bytes)

288. Re: [Amps] *** SPAM *** Re: Parasitics & Filament Sag (score: 1)
Author: Peter Chadwick <g3rzp@g3rzp.wanadoo.co.uk>
Date: Wed, 30 Aug 2006 17:08:00 +0200 (CEST)
dull red glow from the resistance-wire on 10m RTTY. Obviously, this can melt the 221C silver-solder we furnish with our retrofit kits the kits-- < That is a soft silver solder, then? A hard silver so
/archives//html/Amps/2006-08/msg00814.html (7,861 bytes)

289. Re: [Amps] *** SPAM *** Re: Suppressors (score: 1)
Author: Peter Chadwick <g3rzp@g3rzp.wanadoo.co.uk>
Date: Wed, 30 Aug 2006 18:17:36 +0200 (CEST)
lower gain.< Not so. The gain is determined by the total anode load impedance, not just the resistance in the network. A given length of resistance wire in a coil has a certain reactance and a certai
/archives//html/Amps/2006-08/msg00816.html (7,912 bytes)

290. Re: [Amps] *** SPAM *** Re[2]: Parasitics & Filament Sag nowSoldering (score: 1)
Author: Peter Chadwick <g3rzp@g3rzp.wanadoo.co.uk>
Date: Thu, 31 Aug 2006 09:00:37 +0200 (CEST)
Will, There's also a higher melting point soft solder called Comsol: goes about 270 C from memory. It's useful for caulking seams and so on in small copper boilers, but I could see uses for it in tan
/archives//html/Amps/2006-08/msg00834.html (7,800 bytes)

291. Re: [Amps] Cutting G-10 Board (score: 1)
Author: Peter Chadwick <g3rzp@g3rzp.wanadoo.co.uk>
Date: Thu, 31 Aug 2006 09:05:08 +0200 (CEST)
Another tool that might do very well is one of these powered tile cutters - they have blades suitable for cutting concrete and the like. Go through it in no time! 73 Peter G3RZP _____________________
/archives//html/Amps/2006-08/msg00835.html (8,293 bytes)

292. Re: [Amps] Need Japan Radio Plate Transformer Info (score: 1)
Author: Peter Chadwick <g3rzp@g3rzp.wanadoo.co.uk>
Date: Fri, 1 Sep 2006 11:00:30 +0200 (CEST)
density. The transformer, other than having more voltage, sees no difference at all.< Isn't this what they call serendipity? 73 Peter G3RZP _______________________________________________ Amps mailin
/archives//html/Amps/2006-09/msg00004.html (7,501 bytes)

293. Re: [Amps] Parasitics & Filament Sag (score: 1)
Author: Peter Chadwick <g3rzp@g3rzp.wanadoo.co.uk>
Date: Fri, 1 Sep 2006 12:36:56 +0200 (CEST)
Re these ringing transients - is it possible to simulate (shudder!) the effect to determine its theoretical magnitude? 73 Peter G3RZP _______________________________________________ Amps mailing list
/archives//html/Amps/2006-09/msg00007.html (7,401 bytes)

294. Re: [Amps] Parasitics & Filament Sag (score: 1)
Author: Peter Chadwick <g3rzp@g3rzp.wanadoo.co.uk>
Date: Sun, 3 Sep 2006 08:57:37 +0200 (CEST)
Infinite Z-transformations, I refer to them as near-resonant or semiresonant circuits.< Only because of your definition of resonance. For other, more mathematically rigorous definitions, L networks a
/archives//html/Amps/2006-09/msg00051.html (8,735 bytes)

295. Re: [Amps] Parasitics & Filament Sag (score: 1)
Author: Peter Chadwick <g3rzp@g3rzp.wanadoo.co.uk>
Date: Sun, 3 Sep 2006 15:39:02 +0200 (CEST)
current would flow through it because the reactive components are equal, opposite, in series, and not in parallel.< Only because of your non-rigorous definition of resonance. AC theory tells us that
/archives//html/Amps/2006-09/msg00057.html (9,175 bytes)

296. Re: [Amps] Parasitics & Filament Sag (score: 1)
Author: Peter Chadwick <g3rzp@g3rzp.wanadoo.co.uk>
Date: Mon, 4 Sep 2006 11:26:31 +0200 (CEST)
It isn't on your side either, unless you're willing to accept an approximation that falls over completely for low Q in anything other than series circuits. If you use the definition that resonance is
/archives//html/Amps/2006-09/msg00065.html (8,701 bytes)

297. Re: [Amps] Parasitics & Filament Sag (score: 1)
Author: Peter Chadwick <g3rzp@g3rzp.wanadoo.co.uk>
Date: Mon, 4 Sep 2006 15:22:05 +0200 (CEST)
Show me concrete evidence that the voltage and current are not in phase when XL=XC. Basic AC theory demonstrates that resonance is the point where all that's left is Z=R, where R is the DC resistance
/archives//html/Amps/2006-09/msg00067.html (10,965 bytes)

298. Re: [Amps] *** SPAM *** Re: Parasitics & Filament Sag (score: 1)
Author: Peter Chadwick <g3rzp@g3rzp.wanadoo.co.uk>
Date: Mon, 4 Sep 2006 23:51:31 +0200 (CEST)
Whoa Nellie! The way reactances are taught here are: XL) XL=2**f*L where as = 3.14 (for all practical purposes), f= frequency, and L= inductance in henries. Then XL is the reactive component in ohms.
/archives//html/Amps/2006-09/msg00080.html (8,076 bytes)

299. Re: [Amps] *** SPAM *** Re: Parasitics & Filament Sag (score: 1)
Author: Peter Chadwick <g3rzp@g3rzp.wanadoo.co.uk>
Date: Mon, 4 Sep 2006 23:59:56 +0200 (CEST)
Karl-Arne, I had a different lecturer in the mid 1960's to your Professor, but we had homework to prove all six cases, too! Kept me out of the pub for a little while..... 73 Peter G3RZP _____________
/archives//html/Amps/2006-09/msg00081.html (7,385 bytes)

300. [Amps] Parasitics & Filament Sag (score: 1)
Author: Peter Chadwick <g3rzp@g3rzp.wanadoo.co.uk>
Date: Tue, 5 Sep 2006 09:47:14 +0200 (CEST)
waveform change so sharp it will "ring" a VHF circuit in the anode system of an HF amplifier is coupled with the fact that a spectrum analyzer could never capture a dampened waveform,< Is this totall
/archives//html/Amps/2006-09/msg00091.html (7,457 bytes)


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