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Total 15 documents matching your query.

1. [Amps] SB220 Improvements (score: 1): Author: 2 at vc.net (2); Date: Sat Mar 22 10:07:19 2003; 1500pF minimum will protect the grid fusing R from RF. Also, the 220 needs: 1. a 10-ohm 10W glitch resistor in series with the +hv line prior th the HV-RFC. 2. glitch diodes to protect the meter move; /archives//html/Amps/2003-03/msg00770.html (7,327 bytes)
2. [Amps] SB220 Improvements (score: 1): Author: redpines at cybrzn.com (Tom and Linda Hellem); Date: Tue Feb 11 23:49:27 2003; Gentlemen: The information I have read concerning improvements to the SB220 contain a recommendation to replace the grid chokes-to-ground with resistors and to replace the stock 200 pf mica capacitor; /archives//html/Amps/2003-02/msg00275.html (7,758 bytes)
3. [Amps] SB220 Improvements (score: 1): Author: n4zr at contesting.com (Pete Smith); Date: Wed Feb 12 05:33:19 2003; Hmmm ... I have also read repeatedly on this reflector the recommendation to ground the grids directly, removing all of those components. In the absence of problems with my amplifier, I have not chan; /archives//html/Amps/2003-02/msg00276.html (8,544 bytes)
4. [Amps] SB220 Improvements (score: 1): Author: realex at flash.net (realex); Date: Wed Feb 12 06:45:40 2003; Tom, In the mid 70's I went to work at Heathkit as a Ham Tech. One of the first rigs I had to work on was a SB220. I replaced burned chokes/caps on the tube sockets and sent the rig back to the custo; /archives//html/Amps/2003-02/msg00277.html (8,966 bytes)
5. [Amps] SB220 Improvements (score: 1): Author: 2 at vc.net (2); Date: Wed Feb 12 08:05:28 2003; ** A directly grounded grid (3-500Z) exhibits a grid resonance that is c. 90MHz. A capacitor-resistor grounded grid resonates at c. 90MHz. Grounded grid amplifiers are essentially neutralized below; /archives//html/Amps/2003-02/msg00278.html (9,457 bytes)
6. [Amps] SB220 Improvements (score: 1): Author: 2 at vc.net (2); Date: Wed Feb 12 08:05:35 2003; there. A ** that's because it doesn't, Bob. The only possible reason is that if the 3 grid caps are fairly small, they increase the grid resonance by a couple of MHz. However, this seemingly makes l; /archives//html/Amps/2003-02/msg00279.html (9,645 bytes)
7. [Amps] SB220 Improvements (score: 1): Author: vic at rakefet.com (Vic Rosenthal); Date: Wed Feb 12 11:07:36 2003; Didn't the 30L1 do this as well? Maybe they all copied Collins. As I understand it, the caps are series resonant with the grid lead inductance at some frequency, and -- at least at that frequency --; /archives//html/Amps/2003-02/msg00282.html (7,988 bytes)
8. [Amps] SB220 Improvements (score: 1): Author: MorgusMagnificen at aol.com (MorgusMagnificen@aol.com); Date: Wed Feb 12 11:47:55 2003; What is the origin of this grid resonance, and approx. what is its Q? Eric K8LV; /archives//html/Amps/2003-02/msg00289.html (7,498 bytes)
9. [Amps] SB220 Improvements (score: 1): Author: 2 at vc.net (2); Date: Wed Feb 12 15:15:26 2003; ** Good point, Vic. Yes. Maybe Bill Orr copied the idea from Collins Radio? My take on Orr is that he was more of a merchandiser than an innovator. ** True, however, my guess is that the added XC on; /archives//html/Amps/2003-02/msg00296.html (8,611 bytes)
10. [Amps] SB220 Improvements (score: 1): Author: 2 at vc.net (2); Date: Wed Feb 12 15:19:50 2003; ** I have never measured grid resonance of a g-g 3 by 3, Ken. - R. L. Measures, a.k.a. Rich..., 805.386.3734, AG6K, www.vcnet.com/measures. end; /archives//html/Amps/2003-02/msg00297.html (7,633 bytes)
11. [Amps] SB220 Improvements (score: 1): Author: 2 at vc.net (2); Date: Wed Feb 12 15:58:35 2003; The combined effect of the grounded-grid to cathode C (9pF) and the combined L of the gid-cage, the grid-header, and the extenal pins (320nH). I have no idea what the Q is, but the sharp dip suggests; /archives//html/Amps/2003-02/msg00303.html (7,720 bytes)
12. [Amps] SB220 Improvements (score: 1): Author: MorgusMagnificen at aol.com (MorgusMagnificen@aol.com); Date: Thu Feb 13 08:21:46 2003; I just tried to locate an official data sheet for this tube, but I could not find one anywhere. However, my Radio Amateur's Handbook lists this tube as having an 'operating range' of 110MHZ, which I; /archives//html/Amps/2003-02/msg00312.html (7,953 bytes)
13. [Amps] SB220 Improvements (score: 1): Author: 2 at vc.net (2); Date: Thu Feb 13 14:51:55 2003; Eric -- You need to quote back the lines which you are responding to. Fairure to do so on a discussion group is not considered to be very Magnificent. Correct. The spec sheets say full ratings to 110; /archives//html/Amps/2003-02/msg00314.html (9,536 bytes)
14. [Amps] SB220 Improvements (score: 1): Author: 2 at vc.net (2); Date: Fri Feb 14 11:49:53 2003; ** There is very little C between the anode and the cathode pins on the socket unless a Masonite? chassis is employed. ** The subject of human foibles can make for some fairly good laughs. ** As I u; /archives//html/Amps/2003-02/msg00325.html (12,644 bytes)
15. [Amps] SB220 Improvements (score: 1): Author: 2 at vc.net (2); Date: Tue Feb 18 10:47:41 2003; ** the amount of grid bypass C determines the 28MHz V-drop coupled (by the 5pF anode-grid C) to the grid's fusing resistor. 1800pF or so is enough to protect the resistor from getting toasted on 10m; /archives//html/Amps/2003-02/msg00357.html (8,548 bytes)

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