Mail Archive Search: <+from:w4eto@rmii.com>

Results:

References: [ +from:w4eto@rmii.com: 108 ]

Total 108 documents matching your query.

1. [AMPS] Re:HV on tube w/o filament voltage (score: 1): Author: w4eto@rmii.com (Richard W. Ehrhorn); Date: Wed, 31 Mar 1999 22:11:15 -0700; Years ago when we used ordinary plate ammeters before going to fast-responding LED bars, the bias supplies discharged quite rapidly at power-off, perhaps T~100ms or so. Seemingly immediately upon pus; /archives//html/Amps/1999-04/msg00000.html (8,051 bytes)
2. [AMPS] HV Safety (score: 1): Author: w4eto@rmii.com (Richard W. Ehrhorn); Date: Tue, 6 Apr 1999 11:17:41 -0600; Hi Marv... The exact system you describe - a BIG neon bulb in a relaxation oscillator, blinking near the rf section of a PP 813, may well have saved my life about 40 years ago while I was W0FID and i; /archives//html/Amps/1999-04/msg00105.html (9,978 bytes)
3. [AMPS] parasitic suppressors (score: 1): Author: w4eto@rmii.com (Richard W. Ehrhorn); Date: Tue, 6 Apr 1999 12:43:39 -0600; Thanks, Ian... Extremely well put! All should read and try to comprehend. Both Peter's posting and yours should remind us all of the fundamental fact that equivalence of any pair of simple series and; /archives//html/Amps/1999-04/msg00110.html (13,339 bytes)
4. [AMPS] parasitic suppressors (score: 1): Author: w4eto@rmii.com (Richard W. Ehrhorn); Date: Wed, 7 Apr 1999 15:14:15 -0600; *Sigh!"* Ian was right after all, Peter - you awakened the monster and now he's on the rampage again. Rich, I think you have your Dick's mixed. The first short posting below was mine - a basic observ; /archives//html/Amps/1999-04/msg00141.html (18,281 bytes)
5. [AMPS] YC156 whats the point (score: 1): Author: w4eto@rmii.com (Richard W. Ehrhorn); Date: Tue, 2 Mar 1999 09:47:33 -0700; Hi Andy... TheYC-156 (as I think has been mentioned numerous times in the past here) is actually a 3CX15000B7 outfitted with a 5kW cooler specifically for highly linear MRI rf pulse use. (High field; /archives//html/Amps/1999-03/msg00017.html (9,024 bytes)
6. [AMPS] PCBs (score: 1): Author: w4eto@rmii.com (Richard W. Ehrhorn); Date: Thu, 11 Mar 1999 15:43:22 -0700; AMEN, Peter ... And I think the point has already been made that BeO is not much of a health threat (except to those machining it) if handled with just half-way decent care. It's not politically corr; /archives//html/Amps/1999-03/msg00240.html (8,103 bytes)
7. [AMPS] Chokes and Dipping chokes? (score: 1): Author: w4eto@rmii.com (Richard W. Ehrhorn); Date: Sun, 14 Mar 1999 19:31:35 -0700; Hi Bill... I agree with both Vic and Carl, but to add a few tidbits: 1) I prefer Carl's approach of checking the frequency with a receiver, as that eliminates one variable (the coupling loop to the f; /archives//html/Amps/1999-03/msg00293.html (11,298 bytes)
8. [AMPS] IT WORKS!!! (score: 1): Author: w4eto@rmii.com (Richard W. Ehrhorn); Date: Sun, 14 Mar 1999 19:46:20 -0700; Hi Jon... Congratulations! But I suspect you can squeeze another 5-10% efficiency out of it with more work. I mean, we're never satisfied, are we? I didn't participate in earlier discussions of gg ef; /archives//html/Amps/1999-03/msg00294.html (13,616 bytes)
9. [AMPS] Chokes and Dipping chokes? (score: 1): Author: w4eto@rmii.com (Richard W. Ehrhorn); Date: Mon, 15 Mar 1999 11:08:18 -0700; Did I miss something? How can you inductively couple a dipper to any inductor's series resonance without shorting the subject L end-to-end? Any dips you get with the RFC just sitting there, wired int; /archives//html/Amps/1999-03/msg00317.html (10,732 bytes)
10. FW: [AMPS] 87A Ip Meter Problem (long) (score: 1): Author: w4eto@rmii.com (Richard W. Ehrhorn); Date: Mon, 15 Mar 1999 11:57:38 -0700; Hi Dick... You're absolutely right - when HV is physically disconnected from both tubes' anodes, it's just really improbable that those mystical little gold balls we so often hear about -- the ones t; /archives//html/Amps/1999-03/msg00318.html (9,788 bytes)
11. [AMPS] Chokes and Dipping chokes? (score: 1): Author: w4eto@rmii.com (Richard W. Ehrhorn); Date: Wed, 17 Mar 1999 17:20:46 -0700; More often than not, the tune C is NOT of low enough Xc to be irrelevant. Dick In the tank circuit, the choke IS shorted in terms of RF. Rich is correct. At one end of the choke, you have the HV bypa; /archives//html/Amps/1999-03/msg00395.html (10,599 bytes)
12. FW: [AMPS] Alpha 89 SWR protection (score: 1): Author: w4eto@rmii.com (Richard W. Ehrhorn); Date: Fri, 19 Mar 1999 17:01:48 -0700; Dick... Load SWR protection is generally similar in both the ALPHA 87A and 89. Both respond to reflected power, rather than actual SWR, primarily in order to protect the T/R PIN diodes from abnormall; /archives//html/Amps/1999-03/msg00500.html (8,811 bytes)
13. [AMPS] More on the SB220 (score: 1): Author: w4eto@rmii.com (Richard W. Ehrhorn); Date: Fri, 19 Mar 1999 17:02:03 -0700; Hi Ian... I have no doubt that we saw many "Rocky Point effect" flashovers in the 3CV1500A7 (vapor cooled 3CX1000A7) tubes we used in our first amps - the ALPHA SEVENTY c. 1970. The BANG occurred muc; /archives//html/Amps/1999-03/msg00501.html (13,083 bytes)
14. FW: [AMPS] Alpha 89 SWR protection (score: 1): Author: w4eto@rmii.com (Richard W. Ehrhorn); Date: Sat, 20 Mar 1999 16:07:17 -0700; Thanks for the note, Dick... Bigger PINs are available but the cost goes up pretty sharply if one tries to do it "brute force." My preference is to protect and match - like your idea at the end. I us; /archives//html/Amps/1999-03/msg00515.html (10,963 bytes)
15. [AMPS] Fuses (score: 1): Author: w4eto@rmii.com (Richard W. Ehrhorn); Date: Tue, 23 Mar 1999 11:29:21 -0700; I never (knowingly, at least) experienced a "Rocky Point bang" until I began working external-anode, ceramic-metal tubes, Larry. First the 3CX1000A7/ 3CV1500A7, then 8877, 8874, 3CX800A7, 3CPX5000A7/; /archives//html/Amps/1999-03/msg00585.html (9,843 bytes)
16. [AMPS] Cathode Impedance Measurements (score: 1): Author: w4eto@rmii.com (Richard W. Ehrhorn); Date: Fri, 26 Mar 1999 18:06:35 -0700; Hi Jon & all.. Jon, no doubt you've got good, useful info. But, with all due respect, I think you're a little off the deep end dissing "the so-called experts who said it wouldn't work" without explai; /archives//html/Amps/1999-03/msg00633.html (12,233 bytes)
17. FW: [AMPS] Re:HV on tube w/o filament voltage (score: 1): Author: w4eto@rmii.com (Richard W. Ehrhorn); Date: Tue, 30 Mar 1999 09:49:49 -0700; Hi Jon, George & all... The underlying issue with respect to applying positive voltage to vacuum tube plates and/or screens prior to completion of cathode warm-up is this: until the cathode is unifor; /archives//html/Amps/1999-03/msg00696.html (10,612 bytes)
18. [AMPS] Re:HV on tube w/o filament voltage (score: 1): Author: w4eto@rmii.com (Richard W. Ehrhorn); Date: Tue, 30 Mar 1999 10:17:58 -0700; Don't you think the HV filter will generally discharge much faster than the cathode will cool down & lose emissivity, Peter...? Even if the HV contactor/relay takes 50 ms to open and the tube(s) look; /archives//html/Amps/1999-03/msg00698.html (9,196 bytes)
19. [AMPS] coil form plastics (score: 1): Author: w4eto@rmii.com (Richard W. Ehrhorn); Date: Sat, 13 Feb 1999 15:06:34 -0700; Hi Ian & all... For what it's worth, my experience is that Delrin is an excellent rf insulator, with very low loss at least in the HF range. It has reasonable mechanical stability (like nylon and unl; /archives//html/Amps/1999-02/msg00362.html (14,049 bytes)
20. [AMPS] coil form plastics (score: 1): Author: w4eto@rmii.com (Richard W. Ehrhorn); Date: Tue, 16 Feb 1999 11:11:36 -0700; Ian.. Catalogs from U.S. sources such as Dayton Plastics, Regal Plastics and Cadillac Plastics (and probably scores more by now) listed "glass-filled Teflon." I've never tried it. In a similar vein,; /archives//html/Amps/1999-02/msg00426.html (9,496 bytes)

Current List: 1 - 20
Page: [1] [2] [3] [4] [5] [6]