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161. [AMPS] another myth on EMF (score: 1)
Author: Peter.Chadwick@zarlink.com (Peter Chadwick)
Date: Mon, 5 Nov 2001 16:55:12 -0000
Further to John's comment, with which I wholly agree... In 1994, the BBC presented a paper to CEPT Project Team SE21, in which they looked at the field strengths of TV signals in London. The 4 TV cha
/archives//html/Amps/2001-11/msg00050.html (9,408 bytes)

162. [AMPS] another myth on EMF (score: 1)
Author: Peter.Chadwick@zarlink.com (Peter Chadwick)
Date: Tue, 6 Nov 2001 11:51:35 -0000
The radar at Heathrow airport is supposedly about +93dBW EIRP (that's QRO - even by John Lyle's standards!) at around 1230MHz. It's been there for a good many years, and thus workers at Heathrow must
/archives//html/Amps/2001-11/msg00067.html (9,431 bytes)

163. [AMPS] another myth on EMF (score: 1)
Author: Peter.Chadwick@zarlink.com (Peter Chadwick)
Date: Tue, 6 Nov 2001 12:44:56 -0000
Yup. There's about 500kW to 1MW of RF out of the waveguide, as I understand it. Pulse, of course, but even so, the average is reasonably high with that much peak power. It's a cosec squared antenna,
/archives//html/Amps/2001-11/msg00072.html (9,202 bytes)

164. [AMPS] re: another myth on EMF (score: 1)
Author: Peter.Chadwick@zarlink.com (Peter Chadwick)
Date: Tue, 6 Nov 2001 15:44:50 -0000
You have to take levels into account. If you're out in the sun too long, you can get sunstroke. Same principle with too high a level of RF - probably in Howard's case, a high voltage field. FCC allow
/archives//html/Amps/2001-11/msg00082.html (7,500 bytes)

165. [AMPS] Thunderbolt questions (score: 1)
Author: Peter.Chadwick@zarlink.com (Peter Chadwick)
Date: Tue, 6 Nov 2001 16:27:28 -0000
MBA? Usually means Much Bigger A**! 73 Peter G3RZP -- FAQ on WWW: http://www.contesting.com/FAQ/amps Submissions: amps@contesting.com Administrative requests: amps-REQUEST@contesting.com Problems: ow
/archives//html/Amps/2001-11/msg00086.html (7,987 bytes)

166. [AMPS] another myth on EMF (score: 1)
Author: Peter.Chadwick@zarlink.com (Peter Chadwick)
Date: Tue, 6 Nov 2001 16:54:10 -0000
Yup. Reckon that would defrost the frozen chicken pretty quickly. Having seen what happens when some fool stacks timber between two open wire (actually 3 inch diameter copper tubes) feeder lines with
/archives//html/Amps/2001-11/msg00089.html (8,513 bytes)

167. [AMPS] More t'bolt questions (score: 1)
Author: Peter.Chadwick@zarlink.com (Peter Chadwick)
Date: Wed, 7 Nov 2001 07:42:47 -0000
This is not strictly true. AB2 can be more linear than AB1 - see the classic work by Pappenfus et al. In order to get that performance, you need a well (shunt) regulated bias supply, a low impedance
/archives//html/Amps/2001-11/msg00110.html (8,933 bytes)

168. [AMPS] Non-Inductive Carbon Resistors (score: 1)
Author: Peter.Chadwick@zarlink.com (Peter Chadwick)
Date: Wed, 7 Nov 2001 07:44:34 -0000
I usually figure 20 gauge wire as 20nH per inch. As Rich says, all resistors are inductive - it's just a matter of degree. 73 Peter G3RZP -- FAQ on WWW: http://www.contesting.com/FAQ/amps Submissions
/archives//html/Amps/2001-11/msg00111.html (7,598 bytes)

169. [AMPS] SB200 Filament Voltage (score: 1)
Author: Peter.Chadwick@zarlink.com (Peter Chadwick)
Date: Wed, 7 Nov 2001 11:53:03 -0000
A series resistor of 0.1 ohm - or if you prefer, 0.05 ohm in each filament leg. Easy way to get one is a bit of galvanised guy wire, split down to the individual strands, and a few inches at most of
/archives//html/Amps/2001-11/msg00114.html (8,100 bytes)

170. [AMPS] SB200 Filament Voltage (score: 1)
Author: Peter.Chadwick@zarlink.com (Peter Chadwick)
Date: Wed, 7 Nov 2001 12:59:50 -0000
I think Carl has hit it on the head. One advantage of series filament resistance is that it helps cut down the surge when first switching on. 73 Peter G3RZP -- FAQ on WWW: http://www.contesting.com/F
/archives//html/Amps/2001-11/msg00119.html (7,852 bytes)

171. [AMPS] More t'bolt questions (score: 1)
Author: Peter.Chadwick@zarlink.com (Peter Chadwick)
Date: Thu, 8 Nov 2001 09:21:11 -0000
current? Did you follow all the requirements? That includes adjusting the zero signal plate current to the correct value for AB2. See the reference. I tend to believe guys who have designed large num
/archives//html/Amps/2001-11/msg00145.html (10,694 bytes)

172. [AMPS] Tuning question (score: 1)
Author: Peter.Chadwick@zarlink.com (Peter Chadwick)
Date: Fri, 9 Nov 2001 07:35:59 -0000
Conventional amps should be tuned at 100%, as Rich says. However, this doesn't necessarily apply if the amp has circuitry that allows correct tuning and loading to be achieved at lower power levels.
/archives//html/Amps/2001-11/msg00153.html (8,797 bytes)

173. [AMPS] Tuning question (score: 1)
Author: Peter.Chadwick@zarlink.com (Peter Chadwick)
Date: Fri, 9 Nov 2001 13:47:53 -0000
I think that depends. Let's assume that your amp can produce the full wack single tone when tuned for 10 seconds or more - then if you're reasonably quick, you can do quite well without. However, yea
/archives//html/Amps/2001-11/msg00155.html (8,812 bytes)

174. [AMPS] Coil Forms (score: 1)
Author: Peter.Chadwick@zarlink.com (Peter Chadwick)
Date: Mon, 12 Nov 2001 10:42:06 -0000
PVC isn't the best material for the job: if you can get some fibreglass, that's much better - less loss. I never throw out old (dead) tubes until the bases have been taken off.......I've got a number
/archives//html/Amps/2001-11/msg00179.html (8,171 bytes)

175. [AMPS] Coil Forms (score: 1)
Author: Peter.Chadwick@zarlink.com (Peter Chadwick)
Date: Mon, 12 Nov 2001 13:16:23 -0000
I've come across some black PVC tube that was conductive, so using that wouldn't be a good idea..... 73 Peter G3RZP -- FAQ on WWW: http://www.contesting.com/FAQ/amps Submissions: amps@contesting.com
/archives//html/Amps/2001-11/msg00183.html (7,982 bytes)

176. [AMPS] Coil Forms (score: 1)
Author: Peter.Chadwick@zarlink.com (Peter Chadwick)
Date: Mon, 12 Nov 2001 13:39:18 -0000
Around the Dayton flea market, you can still find the original 1-1/4 inch diameter 4 and 5 pin forms made by Hammarlund et al, usually stuffed in a box under the table. When I get around to it, I'm i
/archives//html/Amps/2001-11/msg00187.html (8,526 bytes)

177. [AMPS] Coil Forms (score: 1)
Author: Peter.Chadwick@zarlink.com (Peter Chadwick)
Date: Mon, 12 Nov 2001 15:39:39 -0000
At one time (some 30 years ago) there was a company in the UK called Codar, who made coil stock like B & W. they did move to a higher temperature material than polystyrene - from memory, I think it w
/archives//html/Amps/2001-11/msg00195.html (9,618 bytes)

178. [AMPS] Coil Forms (score: 1)
Author: Peter.Chadwick@zarlink.com (Peter Chadwick)
Date: Tue, 13 Nov 2001 07:35:23 -0000
etc] You don't need a tube tester to find an open circuit filament/heater, or shorts present when cold. Blue glow in the space between electrodes is a pretty good indicator of gas, too. I've never a
/archives//html/Amps/2001-11/msg00213.html (9,194 bytes)

179. [AMPS] Bandswitch parts? (score: 1)
Author: Peter.Chadwick@zarlink.com (Peter Chadwick)
Date: Tue, 13 Nov 2001 07:50:29 -0000
Fair Radio Sales, Lim, OH http://www.fairradio.com/03z9605.htm have: 6-POSITION CERAMIC TAP SWITCH for 100 W BC-375 xmitter; 2.3x2.3x1.8, 1 lb. NEW These switches will stand a lot of volts and amps.
/archives//html/Amps/2001-11/msg00214.html (7,799 bytes)

180. [AMPS] Coil Forms (score: 1)
Author: Peter.Chadwick@zarlink.com (Peter Chadwick)
Date: Tue, 13 Nov 2001 08:26:13 -0000
Not in my house. For several years, I've had a policy that people throwing tubes away can let me have them, rather than let them go to the dump. People needing a tube can come and get one if I've got
/archives//html/Amps/2001-11/msg00217.html (8,288 bytes)


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