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Total 523 documents matching your query.

381. Re: [Amps]Edgewound inductor mfrs tspa (score: 1)
Author: Peter Chadwick <g3rzp@g3rzp.wanadoo.co.uk>
Date: Mon, 26 Feb 2007 19:48:46 +0100 (CET)
How do they wind edge wound inductors? I can conceive of a cylindrical former with a helical slot in it, and the well anealed strip being wound into it, but I would have thought that getting the stri
/archives//html/Amps/2007-02/msg00393.html (7,373 bytes)

382. Re: [Amps] Berkshire (score: 1)
Author: Peter Chadwick <g3rzp@g3rzp.wanadoo.co.uk>
Date: Sat, 3 Mar 2007 10:42:42 +0100 (CET)
And there was me thinking that a reference to Berkshire is to either a 2-8-4 steam locomotive, or a county in England just to the east of me! 73 Peter G3RZP __________________________________________
/archives//html/Amps/2007-03/msg00018.html (7,132 bytes)

383. Re: [Amps] Plate Load Calc. (score: 1)
Author: Peter Chadwick <g3rzp@g3rzp.wanadoo.co.uk>
Date: Sat, 3 Mar 2007 10:50:00 +0100 (CET)
backwards. If you get it too high the tuning will be needlessly sharp and there will be a little more tank heat.< Another problem if the Q gets too low is that the harmonic output tends to start risi
/archives//html/Amps/2007-03/msg00019.html (7,515 bytes)

384. Re: [Amps] L-4B blade/blower replacement (score: 1)
Author: Peter Chadwick <g3rzp@g3rzp.wanadoo.co.uk>
Date: Sat, 17 Mar 2007 18:51:50 +0100 (CET)
Garry asked: blade has gotten out of round and slightly rubbing the back of the blade housing< My guess would be that there's a bearing worn out, which is why the fan blades can rub. If you have a ma
/archives//html/Amps/2007-03/msg00204.html (7,375 bytes)

385. Re: [Amps] (Amps) This reflector. (score: 1)
Author: Peter Chadwick <g3rzp@g3rzp.wanadoo.co.uk>
Date: Tue, 20 Mar 2007 17:33:55 +0100 (CET)
I would argue that although the quantity of material has reduced, the accuaracy of the technical information is vastly superior, being untainted by pseudo science or personal (arguably undefensible)
/archives//html/Amps/2007-03/msg00254.html (8,242 bytes)

386. Re: [Amps] AMP Reflector Quality of Information (score: 1)
Author: Peter Chadwick <g3rzp@g3rzp.wanadoo.co.uk>
Date: Wed, 21 Mar 2007 10:43:50 +0100 (CET)
It must be remembered that if the list members disagree with the administrator, PROVIDED you've helped fund this list by subscribing/donating to eham.net (you all have, haven't you?), even administra
/archives//html/Amps/2007-03/msg00275.html (8,438 bytes)

387. Re: [Amps] Surge resistor (score: 1)
Author: Peter Chadwick <g3rzp@g3rzp.wanadoo.co.uk>
Date: Thu, 22 Mar 2007 10:07:54 +0100 (CET)
Over 40 years ago, as an apprentice, I worked on a TWT ground station transmitter where we had a crowbar on the high voltage supply. By K5PRO standards, it would be pretty small, being only (!) 22kV
/archives//html/Amps/2007-03/msg00297.html (8,342 bytes)

388. Re: [Amps] Tank Coil spacing (score: 1)
Author: Peter Chadwick <g3rzp@g3rzp.wanadoo.co.uk>
Date: Mon, 26 Mar 2007 14:38:52 +0200 (CEST)
Steve asked: To meet the current requirements of the FCC and the Radio Regulations on spurious emissions, yes. The Class AB stage produces a harmonic content in the plate current that is 6 dB down on
/archives//html/Amps/2007-03/msg00341.html (7,815 bytes)

389. Re: [Amps]out of band emissions was Re: Tank Coil spacing (score: 1)
Author: Peter Chadwick <g3rzp@g3rzp.wanadoo.co.uk>
Date: Wed, 28 Mar 2007 20:18:13 +0200 (CEST)
specified frequency delta. They are well in excess of that, but the emissions are still strong enough to affect an adjacent carriers' base station receive.< Is this a case of Out of Band emissions, o
/archives//html/Amps/2007-03/msg00374.html (7,362 bytes)

390. Re: [Amps] Pi-L Network (score: 1)
Author: Peter Chadwick <g3rzp@g3rzp.wanadoo.co.uk>
Date: Wed, 28 Mar 2007 20:38:11 +0200 (CEST)
Interesting comments on harmonic suppression. There are a lot of variables, especially regarding the parasitic reactances, which as Tom says, substantially modify the result. My experience for what i
/archives//html/Amps/2007-03/msg00375.html (9,082 bytes)

391. Re: [Amps] Pi-L Network (score: 1)
Author: Peter Chadwick <g3rzp@g3rzp.wanadoo.co.uk>
Date: Thu, 29 Mar 2007 03:56:03 +0200 (CEST)
harmonic advantages of a pi-L in the real world of multi-band amps. It's much cheaper to do it other ways.< So why did so many professional continuous coverage QRO amps (7.5kW and up) go to the troub
/archives//html/Amps/2007-03/msg00382.html (8,063 bytes)

392. Re: [Amps] *** SPAM *** Re: Pi-L Network (score: 1)
Author: Peter Chadwick <g3rzp@g3rzp.wanadoo.co.uk>
Date: Thu, 29 Mar 2007 14:38:19 +0200 (CEST)
aren't assuming marine rigs used pi-Ls are you....when they actually commonly used double L's?< No, I was thinking of 7.5kW and upwards transmitters, where frequency changing wasn't that common ( onc
/archives//html/Amps/2007-03/msg00391.html (7,607 bytes)

393. Re: [Amps] *** SPAM *** Re: Pi-L Network (score: 1)
Author: Peter Chadwick <g3rzp@g3rzp.wanadoo.co.uk>
Date: Fri, 30 Mar 2007 06:01:55 +0200 (CEST)
Tom asked: some other reason?< It's known they were pi-L networks because in 2 cases the designer told me, in three other cases, they said so in the published conference papers, and in yet another tw
/archives//html/Amps/2007-03/msg00408.html (7,363 bytes)

394. Re: [Amps] 8877 blower requirement ? (score: 1)
Author: Peter Chadwick <g3rzp@g3rzp.wanadoo.co.uk>
Date: Fri, 6 Apr 2007 07:56:15 +0200 (CEST)
What's the mechanism whereby too much air affects the emission? Is it that the tube structure is normally well above ambient by conduction from the cathode, and excess air reduces this temperature, a
/archives//html/Amps/2007-04/msg00016.html (7,770 bytes)

395. [Amps] blower requirements (score: 1)
Author: Peter Chadwick <g3rzp@g3rzp.wanadoo.co.uk>
Date: Sat, 7 Apr 2007 08:02:33 +0200 (CEST)
To what extent is the temperature of the outlet air any use? I suspect that probably not much becasue you can measure it readily easily, and the best arbiter must be the use of Tempilaq or similar. 7
/archives//html/Amps/2007-04/msg00025.html (6,861 bytes)

396. Re: [Amps]8877 blower requirement...TXN ! Now..Airflow sensing ? (score: 1)
Author: Peter Chadwick <g3rzp@g3rzp.wanadoo.co.uk>
Date: Mon, 9 Apr 2007 22:01:20 +0200 (CEST)
One simple method is a small fan, free to rotate in the air stream. An LED- opto transistor arrangement then gives a series of pulses when the fan is arranged to interrupt the light beam, and a re-tr
/archives//html/Amps/2007-04/msg00039.html (7,293 bytes)

397. Re: [Amps]8877 blower requirement...TXN ! Now..Airflow sensing ? (score: 1)
Author: Peter Chadwick <g3rzp@g3rzp.wanadoo.co.uk>
Date: Tue, 10 Apr 2007 08:32:01 +0200 (CEST)
There is nothing as simple and reliable as that.< Provided that you can get a big enough vane for the airflow to provide the necessary force to operate the microswitch, and the vane doesn't add so mu
/archives//html/Amps/2007-04/msg00046.html (7,812 bytes)

398. Re: [Amps] amp hardware (score: 1)
Author: Peter Chadwick <g3rzp@g3rzp.wanadoo.co.uk>
Date: Tue, 10 Apr 2007 15:33:44 +0200 (CEST)
Steve asked: Is it going to be in the shack, or outside in a damp shed? If in an indoor shack, I wouldn't bother. Even in a damp shed, I've had no problems with aluminium and BZP (bright zinc plated)
/archives//html/Amps/2007-04/msg00048.html (8,314 bytes)

399. [Amps] RE : amp hardware (score: 1)
Author: Peter Chadwick <g3rzp@g3rzp.wanadoo.co.uk>
Date: Tue, 10 Apr 2007 22:02:15 +0200 (CEST)
I've gotten somewhat cynical (what me? never! - before GM3SEK says it!) about tapping holes in aluminium unless there's plenty of thread depth available. Another problem is using the wrong thread, an
/archives//html/Amps/2007-04/msg00061.html (8,404 bytes)

400. Re: [Amps]8877 blower requirement...TXN ! Now..Airflow sensing ? (score: 1)
Author: Peter Chadwick <g3rzp@g3rzp.wanadoo.co.uk>
Date: Tue, 10 Apr 2007 22:05:19 +0200 (CEST)
Do you have a manufacturer and part number? I've never found any that sensitive. What's the price? My LED, 74123 and fan costs well under 1................. 73 Peter G3RZP ___________________________
/archives//html/Amps/2007-04/msg00062.html (8,191 bytes)


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