- 1. [Amps] Need help with HB 8877 project (score: 1)
- Author: 2@vc.net (2)
- Date: Wed, 1 Jan 2003 18:11:53 -0800
- If you need c. 5 out, a single, larger tube would be less problematic and less costly. The 226 will do ok at this level if one drills a grid of small holes in the chassis below the coil to let coolin
- /archives//html/Amps/2003-01/msg00002.html (8,140 bytes)
- 2. [Amps] Alpha 87A reliability problem (score: 1)
- Author: 2@vc.net (2)
- Date: Thu, 2 Jan 2003 08:34:46 -0800
- I have not, Rag, but this seems like a good idea since PIN diodes are easily shorted by lightning and by high SWR. However, for >40wpm CW, relays are not fast enough. Modifying with high-speed relay
- /archives//html/Amps/2003-01/msg00007.html (8,532 bytes)
- 3. [Amps] Question: AL-80A (score: 1)
- Author: 2@vc.net (2)
- Date: Thu, 2 Jan 2003 14:53:03 -0800
- Even if you buy a new one, there are some worthwhile circuit improvements. Also, running more than c. 420mA plate/anode current to s single 3-500Z is guaranteed to cause rotten splatter. cheers, Dal
- /archives//html/Amps/2003-01/msg00019.html (6,693 bytes)
- 4. [Amps] Filament Choke Inductance (score: 1)
- Author: 2@vc.net (2)
- Date: Fri, 3 Jan 2003 17:23:54 -0800
- The SB-220 uses 9uH. This even works well on 160m if c. 900pF is added to C-out in the 160m tuned input pi-network. chokes in To save real estate and greenbacks. float the 3cx3000A7 filament xfmr on
- /archives//html/Amps/2003-01/msg00030.html (7,429 bytes)
- 5. [Amps] AL-572 (score: 1)
- Author: 2@vc.net (2)
- Date: Fri, 3 Jan 2003 17:23:58 -0800
- Heath and Gonset Once had "neutralized" g-g amplifiers. Both had a well deserved reputation for squirreliness. Gonset disappeared. Heath apparently saw their error and never again designed a "neutra
- /archives//html/Amps/2003-01/msg00031.html (7,959 bytes)
- 6. [Amps] Filament Choke Inductance (score: 1)
- Author: 2@vc.net (2)
- Date: Sat, 4 Jan 2003 04:57:27 -0800
- This is the way commercial amp mfgs do it. For example, a triode with a 7.5v/160a filament is not easy to build a filament choke for unless the choke goes in the 240v primary of the fil xfmr. -- I w
- /archives//html/Amps/2003-01/msg00037.html (9,292 bytes)
- 7. [Amps] AL-572 (score: 1)
- Author: 2@vc.net (2)
- Date: Sat, 4 Jan 2003 05:01:44 -0800
- Peter -- Did the tungsten filament wires break inside the envelopes? - R. L. Measures, a.k.a. Rich..., 805.386.3734,AG6K, www.vcnet.com/measures. end
- /archives//html/Amps/2003-01/msg00038.html (10,091 bytes)
- 8. [Amps] KVAR Caps Rating (score: 1)
- Author: 2@vc.net (2)
- Date: Sun, 5 Jan 2003 17:37:11 -0800
- ** With ceramic-dielectric caps, unlike mica-dielectric caps, the RF current handling ability increases between 1MHz and 30MHz. - R. L. Measures, a.k.a. Rich..., 805.386.3734,AG6K, www.vcnet.com/mea
- /archives//html/Amps/2003-01/msg00049.html (6,925 bytes)
- 9. [Amps] The Y series (score: 1)
- Author: 2@vc.net (2)
- Date: Fri, 10 Jan 2003 08:33:04 -0800
- Most of the cold-war, real-secrety Y series / black-project tubes are fairly similar to the ordinary tube they resemble. For instance, the Y-448 looks like a 4-1000A/8166 and it acts like a 4-1000A.
- /archives//html/Amps/2003-01/msg00076.html (7,188 bytes)
- 10. [Amps] Thunderbolt Linear amp (score: 1)
- Author: 2@vc.net (2)
- Date: Fri, 10 Jan 2003 08:33:03 -0800
- The anode supply needs to be converted to resonant choke filtering. Swinging-choke filters cause wild Swings in output V in CW and SSB modes -- but for AM linear and RTTY, the anode V will be stable
- /archives//html/Amps/2003-01/msg00077.html (7,996 bytes)
- 11. [Amps] T'bolt ideas (score: 1)
- Author: 2@vc.net (2)
- Date: Fri, 10 Jan 2003 11:09:46 -0800
- AB2 grid-driven makes rotten splatter with 4-400s. ... - R. L. Measures, a.k.a. Rich..., 805.386.3734,AG6K, www.vcnet.com/measures. end
- /archives//html/Amps/2003-01/msg00079.html (7,626 bytes)
- 12. [Amps] Re: Thunderbolt (score: 1)
- Author: 2@vc.net (2)
- Date: Sat, 11 Jan 2003 09:51:20 -0800
- A 200-ohm grid terminator fed through a 1 to 4 bifilar transformer should work ok with c. 100w drive. The original circuit can be improved. There is no such thing as a perfect commercially mfg ampli
- /archives//html/Amps/2003-01/msg00083.html (7,777 bytes)
- 13. [Amps] Re: Thunderbolt (score: 1)
- Author: 2@vc.net (2)
- Date: Sat, 11 Jan 2003 10:34:06 -0800
- ** A 50-ohm terminator needs to see c. 200w drive in order to provide enough peak grid V in order to drive a 4-400 in AB1. It's no more than basic Ohm's-Law. - R. L. Measures, a.k.a. Rich..., 805.38
- /archives//html/Amps/2003-01/msg00084.html (7,987 bytes)
- 14. [Amps] Re: Thunderbolt (score: 1)
- Author: 2@vc.net (2)
- Date: Sat, 11 Jan 2003 10:37:42 -0800
- I have no experience with Harris amps. A friend who visited the plant said they were experimenting with vhf parasitic suppressors not made with Cu or Ag conductors. cheerz, Lane - R. L. Measures, a.
- /archives//html/Amps/2003-01/msg00086.html (7,397 bytes)
- 15. [Amps] T'bolt ideas (score: 1)
- Author: 2@vc.net (2)
- Date: Sat, 11 Jan 2003 13:00:01 -0800
- ** with cathode driven, both grids would normally be at RF-ground. If the anode supply was c. 3500V, no DC grid V would be needed. With 3000VDC, c. 6V+ on the screen would be needed to get the corre
- /archives//html/Amps/2003-01/msg00092.html (9,217 bytes)
- 16. [Amps] Re: Thunderbolt (score: 1)
- Author: 2@vc.net (2)
- Date: Sun, 12 Jan 2003 14:54:17 -0800
- ** 350-ohms is about right for 40W of drive. ** The number of Extra-Class Hams who do not understand Ohm's Law is not small. - R. L. Measures, a.k.a. Rich..., 805.386.3734,AG6K, www.vcnet.com/measur
- /archives//html/Amps/2003-01/msg00098.html (9,002 bytes)
- 17. [Amps] T'bolt input (score: 1)
- Author: 2@vc.net (2)
- Date: Mon, 13 Jan 2003 09:18:52 -0800
- ** In grid-driven config., plenty grid current make plenty IMD in SSB. - R. L. Measures, a.k.a. Rich..., 805.386.3734,AG6K, www.vcnet.com/measures. end
- /archives//html/Amps/2003-01/msg00102.html (6,658 bytes)
- 18. [Amps] T'bolt ideas (score: 1)
- Author: 2@vc.net (2)
- Date: Tue, 14 Jan 2003 04:23:31 -0800
- ** So why doesn't either Eimac or Amperex recommend AB2 grid-driven for the 4-400A? The two tetrodes Eimac recommends for AB2 grid-driven are the 4cx1500B and the 4cx600, and even then, the specifie
- /archives//html/Amps/2003-01/msg00107.html (9,217 bytes)
- 19. [Amps] Re: Thunderbolt (score: 1)
- Author: 2@vc.net (2)
- Date: Tue, 14 Jan 2003 04:23:32 -0800
- ** The reccomendations I made in "The Nearly Perfect Amplifier" [Jan 1994, QST] amplifier would add c. 10% to the price of an amplifier. What percentage of the Ham community wouldn't like to have an
- /archives//html/Amps/2003-01/msg00108.html (8,483 bytes)
- 20. [Amps] T'bolt ideas (score: 1)
- Author: 2@vc.net (2)
- Date: Tue, 14 Jan 2003 05:48:57 -0800
- ** Is Eimac talking about IMD cancellation in grid-driven AB2 or cathode-driven AB2. The Eimac reference, please. - R. L. Measures, a.k.a. Rich..., 805.386.3734,AG6K, www.vcnet.com/measures. end
- /archives//html/Amps/2003-01/msg00110.html (7,335 bytes)
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