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Total 419 documents matching your query.

341. Re: [Amps] new amp race (score: 1)
Author: Manfred Mornhinweg <manfred@ludens.cl>
Date: Mon, 22 May 2017 02:02:59 +0000
Ron, and all, I learned: Natural noise (lightning) is vertically polarized because lightning is a vertical event. I have seen lots of horizontal lightning, from cloud to cloud, or inside the same clo
/archives//html/Amps/2017-05/msg00238.html (11,835 bytes)

342. Re: [Amps] new amp race (score: 1)
Author: Manfred Mornhinweg <manfred@ludens.cl>
Date: Mon, 22 May 2017 02:09:51 +0000
Jim, a piece of advice to solve that tree climber problem: Get a drone! A good stabilized drone will get a fishing line exactly over the branch where you want it, and its FPV camera system allows you
/archives//html/Amps/2017-05/msg00239.html (8,243 bytes)

343. Re: [Amps] Real time tests to see if an RF transformer is saturating? (score: 1)
Author: Manfred Mornhinweg <manfred@ludens.cl>
Date: Tue, 23 May 2017 19:55:32 +0000
Chris, I await the cores and wire patiently, I have a lot of practice in awaiting parts. Chilean customs is delaying everything by 2 to 3 months... in the meantime i am wondering if this transformer
/archives//html/Amps/2017-05/msg00264.html (12,241 bytes)

344. Re: [Amps] new amp race (RFI polarization) (score: 1)
Author: Manfred Mornhinweg <manfred@ludens.cl>
Date: Tue, 23 May 2017 20:21:03 +0000
Tom, I have tracked down a lot of man made RFI (mostly from grow light ballasts) and without exception the signal is vertically polarized until you get very close to the source. I found this very int
/archives//html/Amps/2017-05/msg00265.html (10,204 bytes)

345. Re: [Amps] Tube amps are not a thing of the past - nor is the 2N2222 (score: 1)
Author: Manfred Mornhinweg <manfred@ludens.cl>
Date: Mon, 05 Jun 2017 16:18:55 +0000
Cathy, and all, Yes, ham gear needs to be based on the RF PA equivalent of the 2N2222 and 2N3055; devices that have many uses, are fully mature, and won't be readily obsoleted by new tech. And why us
/archives//html/Amps/2017-06/msg00046.html (9,075 bytes)

346. Re: [Amps] Tube amps are not a thing of the past - nor is the 2N2222 (score: 1)
Author: Manfred Mornhinweg <manfred@ludens.cl>
Date: Tue, 06 Jun 2017 16:25:04 +0000
Bill, Don, It's just a matter of coming up with a clever layout that keeps phasing problems under control, then having the patience to solder all those parts, and there you are, with a legal-limit 2N
/archives//html/Amps/2017-06/msg00086.html (8,457 bytes)

347. Re: [Amps] LDMOS availability (score: 1)
Author: Manfred Mornhinweg <manfred@ludens.cl>
Date: Wed, 07 Jun 2017 17:29:50 +0000
Roger, and all, I'm becoming attached to the idea that the word "linear" should be banned from the advertising Ham Amps, unless they (the seller) can show proof that the amp is truly linear, neglecti
/archives//html/Amps/2017-06/msg00112.html (11,526 bytes)

348. Re: [Amps] LDMOS availability (score: 1)
Author: Manfred Mornhinweg <manfred@ludens.cl>
Date: Thu, 08 Jun 2017 02:34:36 +0000
Bill, A linear class C amp is quite a trick. Yes, it's tricky, but it can be done. Variable bias controlled by an error amplifying loop is one way to do it. REPLY: If you're varying the bias to make
/archives//html/Amps/2017-06/msg00116.html (10,397 bytes)

349. Re: [Amps] Real time tests to see if an RF transformer is saturating? (score: 1)
Author: Manfred Mornhinweg <manfred@ludens.cl>
Date: Mon, 12 Jun 2017 01:32:57 +0000
Hi Chris, well, I'm glad that the transformer project was successful. I believe I am being a bit thick and probably not understanding how you intended the wires to appear off the bobbin. If I follow
/archives//html/Amps/2017-06/msg00179.html (8,541 bytes)

350. Re: [Amps] Real time tests to see if an RF transformer is saturating? (score: 1)
Author: Manfred Mornhinweg <manfred@ludens.cl>
Date: Tue, 13 Jun 2017 15:37:37 +0000
Chris, Thanks for clarifying that, I have the 20 turn winding with the grounded end coming out on the side of the core with no terminal pins and joining the 8 turn winding on the side with the pins.
/archives//html/Amps/2017-06/msg00197.html (17,985 bytes)

351. Re: [Amps] Ferrite Core for 160M PI Output (score: 1)
Author: Manfred Mornhinweg <manfred@ludens.cl>
Date: Thu, 15 Jun 2017 17:20:24 +0000
Jim, Not right. 61 is good for absorption in the UHF range, and for relatively low loss applications on HF. It works great as balun, for example in the form of an FT-240-61 core with 12 turns of RG40
/archives//html/Amps/2017-06/msg00208.html (8,809 bytes)

352. Re: [Amps] Amps Digest, Vol 174, Issue 46 (score: 1)
Author: Manfred Mornhinweg <manfred@ludens.cl>
Date: Fri, 16 Jun 2017 21:19:18 +0000
Hi Jim, You are mistaken, Manfred. I've measured chokes like that wound on #61. They are NOT effective at MF or HF. #61 is FAR too high Q at HF. I understand that your point is that a high Q common m
/archives//html/Amps/2017-06/msg00216.html (16,302 bytes)

353. Re: [Amps] About LP100A (score: 1)
Author: Manfred Mornhinweg <manfred@ludens.cl>
Date: Tue, 20 Jun 2017 21:35:06 +0000
Bill, As a technician who used to work at Tektronix, I can assure you that Can a digital scope do Lissajous figures? The ones I have used cannot. They simply don't have a horizontal input! My own wor
/archives//html/Amps/2017-06/msg00245.html (9,774 bytes)

354. Re: [Amps] About LP100A (score: 1)
Author: Manfred Mornhinweg <manfred@ludens.cl>
Date: Thu, 22 Jun 2017 00:53:56 +0000
Hi all, thanks for the replies and suggestions. I will see if I can find a Tek 2465B on any of the local auction sites. Importing used goods to Chile has a bit troublesome, with extra high taxes and
/archives//html/Amps/2017-06/msg00258.html (8,183 bytes)

355. Re: [Amps] peak voltage rating for load cap (score: 1)
Author: Manfred Mornhinweg <manfred@ludens.cl>
Date: Sat, 19 Aug 2017 16:53:36 +0000
Conrad, and all, keep in mind that the voltage rating of the capacitor is just one part of the whole thing. The other is its current rating. Once you have found out what's the highest RF voltage the
/archives//html/Amps/2017-08/msg00028.html (9,552 bytes)

356. Re: [Amps] peak voltage rating for load cap (score: 1)
Author: Manfred Mornhinweg <manfred@ludens.cl>
Date: Sun, 20 Aug 2017 14:42:22 +0000
Hi Peter, The Russians doorknob capacitors do well. At least they look pretty robust. Do you happen to know the ratings? A quick look on the web showed very high voltage ratings, but I couldn't find
/archives//html/Amps/2017-08/msg00032.html (9,664 bytes)

357. [Amps] Lowpass filter inductor cores (score: 1)
Author: Manfred Mornhinweg <manfred@ludens.cl>
Date: Sun, 20 Aug 2017 17:46:14 +0000
Hi all, I'm puzzled by seeing many low pass filter boards offered on eBay and elsewhere, that are rated for 1kW, 1.5kW and even more, with some sellers stating that their filters can work in CW witho
/archives//html/Amps/2017-08/msg00036.html (7,739 bytes)

358. Re: [Amps] peak voltage rating for load cap (score: 1)
Author: Manfred Mornhinweg <manfred@ludens.cl>
Date: Sun, 20 Aug 2017 20:22:32 +0000
Hi Alan, Jim and all You've been quiet for a while. Yes, I have been building some stuff, so I was busy. I've mentioned a UK supplier before, Yes. I remembered the fact, but not the address... but fo
/archives//html/Amps/2017-08/msg00038.html (20,224 bytes)

359. Re: [Amps] ratings for caps for filters, for SSPA (score: 1)
Author: Manfred Mornhinweg <manfred@ludens.cl>
Date: Mon, 21 Aug 2017 18:52:29 +0000
Hi John, Another source of high Q low ESR ceramic RF power chip capacitors besides American Technical Ceramics: http://www.passiveplus.com/index.php I haven't priced them, though, they look expensive
/archives//html/Amps/2017-08/msg00041.html (7,529 bytes)

360. Re: [Amps] Apparent Arcing (Roger Parsons) (score: 1)
Author: Manfred Mornhinweg <manfred@ludens.cl>
Date: Tue, 05 Sep 2017 00:41:55 +0000
Roger, Obviously I'm missing something! Any ideas what? If I follow your story correctly, the noise appears only when there is actually some current flowing through the soft start circuitry. This poi
/archives//html/Amps/2017-09/msg00018.html (8,212 bytes)


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