- 61. Re: [Amps] Cathode Choke (score: 1)
- Author: "Gary Schafer" <garyschafer@largeriver.net>
- Date: Sat, 5 Oct 2019 18:34:01 -0500
- The choke in the filament circuit is there so that the cathode can be tied to one side of the filament. There is not much isolation between cathode and filament voltage wise on this tube. An arc from
- /archives//html/Amps/2019-10/msg00010.html (10,996 bytes)
- 62. Re: [Amps] SB-220 HV Transformer Wanted (score: 1)
- Author: "Gary Schafer" <garyschafer@largeriver.net>
- Date: Wed, 30 Oct 2019 21:12:54 -0500
- No. The amp runs AB2 meaning it draws grid current. The reason for the CW/SSB switch was to allow tune up at 1 KW DC input on CW. This was the regulation at the time the amp was designed. You were no
- /archives//html/Amps/2019-10/msg00105.html (11,990 bytes)
- 63. Re: [Amps] SB-220 HV Transformer Wanted ; thread stolen for bias question (score: 1)
- Author: "Gary Schafer" <garyschafer@largeriver.net>
- Date: Fri, 1 Nov 2019 00:01:08 -0500
- Mark, First let's define classes of operation: Class A, plate current flows over 100% of the cycle of the input signal. Class B, plate current flows over exactly only 50% of the cycle of the input. C
- /archives//html/Amps/2019-11/msg00000.html (15,631 bytes)
- 64. Re: [Amps] SB-220 HV Transformer Wanted ; thread stolen for (score: 1)
- Author: "Gary Schafer" <garyschafer@largeriver.net>
- Date: Fri, 1 Nov 2019 13:52:54 -0500
- "Push pull" or "single ended" does not define the class of operation. Because a pair of tubes in an RF amplifier are operated in push pull, it has nothing to do with what class they are operating in.
- /archives//html/Amps/2019-11/msg00013.html (12,495 bytes)
- 65. Re: [Amps] SB220 Meter blown...follow up hope (score: 1)
- Author: "Gary Schafer" <garyschafer@largeriver.net>
- Date: Fri, 15 May 2020 13:59:46 -0500
- 73 Gary K4FMX _______________________________________________ Amps mailing list Amps@contesting.com http://lists.contesting.com/mailman/listinfo/amps
- /archives//html/Amps/2020-05/msg00015.html (12,934 bytes)
- 66. Re: [Amps] SB220 Meter blown (score: 1)
- Author: "Gary Schafer" <garyschafer@largeriver.net>
- Date: Sat, 16 May 2020 13:57:58 -0500
- Jim is correct. It depends on the meter circuit that is used. You need to calculate how much voltage will appear at the meter. I have a drake L7 that I added protection diodes to. I was going to just
- /archives//html/Amps/2020-05/msg00028.html (12,082 bytes)
- 67. Re: [Amps] Caps,snubber, mov across diodes ? (score: 1)
- Author: "Gary Schafer" <garyschafer@largeriver.net>
- Date: Sun, 26 Jul 2020 12:46:00 -0500
- Hi Jim, Some time ago I built a homebrew receiver with a transformer that had too high a voltage for the circuit. So I put a choke between the diode rectifiers and the filter caps (choke input). I ch
- /archives//html/Amps/2020-07/msg00020.html (9,847 bytes)
- 68. Re: [Amps] W8ZR Autotune Amplifier Progress Report (score: 1)
- Author: "Gary Schafer" <garyschafer@largeriver.net>
- Date: Fri, 25 Dec 2020 15:34:45 -0600
- I have a switch like that on an old TMC amp. It was very hard to turn to change bands so I put a much weaker spring on it and it turns very easy now. There is a micro switch that gets activated whene
- /archives//html/Amps/2020-12/msg00064.html (14,969 bytes)
- 69. Re: [Amps] Alpha 87A Power Supply Question (score: 1)
- Author: "Gary Schafer" <garyschafer@largeriver.net>
- Date: Mon, 3 May 2021 22:46:37 -0500
- I think that I see your problem. The ground wire should never carry ANY current. It is not a substitute for neutral. With the old wiring system for dryers of 2 hot and neutral (3 wires total) it had
- /archives//html/Amps/2021-05/msg00005.html (18,522 bytes)
- 70. Re: [Amps] Alpha 87A Power Supply Question (score: 1)
- Author: "Gary Schafer" <garyschafer@largeriver.net>
- Date: Mon, 3 May 2021 22:57:46 -0500
- To clarify, the way you describe having the amp wired you have a loop with neutral tied to ground at the amp via the coax cables to the other equipment that is connected properly to ground. 73 Gary K
- /archives//html/Amps/2021-05/msg00006.html (21,317 bytes)
- 71. Re: [Amps] Alpha 87A Power Supply Question (score: 1)
- Author: "Gary Schafer" <garyschafer@largeriver.net>
- Date: Wed, 5 May 2021 22:47:00 -0500
- Hi Jim, The Drake L4 does not use a neutral wire when operating on 240 volts. So L1 and L2 should go to the two hot terminals in the amp and the chassis ground terminal should go to the ground wire o
- /archives//html/Amps/2021-05/msg00027.html (22,531 bytes)
- 72. Re: [Amps] 300Hz sidebands (score: 1)
- Author: "Gary Schafer" <garyschafer@largeriver.net>
- Date: Wed, 26 May 2021 20:18:29 -0500
- "Ripple modulation factor" has to do with the inability of a tetrode AB1 amplifier to be plate modulated by changing plate voltage. This goes along with the fact that changing the plate voltage has v
- /archives//html/Amps/2021-05/msg00065.html (12,481 bytes)
- 73. Re: [Amps] toroid tank coil heating up (score: 1)
- Author: Gary Schafer <garyschafer@largeriver.net>
- Date: Sun, 26 Sep 2021 12:27:23 -0500
- If the winding has taps for 80 and 40 and the taps get shorted with the band switch, then that is the problem. You should use separate cores for each band. If you were to leave the taps open then you
- /archives//html/Amps/2021-09/msg00021.html (7,900 bytes)
- 74. Re: [Amps] Verify "Q" (score: 1)
- Author: "Gary Schafer" <garyschafer@largeriver.net>
- Date: Thu, 14 Oct 2021 21:19:59 -0500
- Joe, What I sometimes do to set up a tank circuit once you have the values from a chart or calculation of the plate tune capacitor, load capacitor, and tank coil inductance is to measure the plate tu
- /archives//html/Amps/2021-10/msg00064.html (8,688 bytes)
- 75. [Amps] Amp input board (score: 1)
- Author: "Gary Schafer" <garyschafer@largeriver.net>
- Date: Thu, 27 Jan 2022 15:53:17 -0600
- I am looking for a tuned input board with relays to switch circuits. Anyone have anything they want to sell? I have an amp with a pair of 3-500Z's that needs an input circuit. A few years ago I thoug
- /archives//html/Amps/2022-01/msg00112.html (6,365 bytes)
- 76. Re: [Amps] Amp input board (score: 1)
- Author: "Gary Schafer" <garyschafer@largeriver.net>
- Date: Sat, 29 Jan 2022 20:36:10 -0600
- Thanks Ulf, I had forgotten about the WD7S boards. I have a few here that I bought some years ago but could not find them in all my junk. Finally dug them out the other day. 73 Gary K4FMX _____ Yes P
- /archives//html/Amps/2022-01/msg00115.html (8,276 bytes)
- 77. Re: [Amps] Delay timer. (score: 1)
- Author: "Gary Schafer" <garyschafer@largeriver.net>
- Date: Sat, 26 Feb 2022 22:43:14 -0600
- Thanks for that Jim! I think I will give them a try. 73 Gary K4FMX _______________________________________________ Amps mailing list Amps@contesting.com http://lists.contesting.com/mailman/listinfo/a
- /archives//html/Amps/2022-02/msg00014.html (7,500 bytes)
- 78. [Amps] Schematic needed for Henry 8K Ultra amp (score: 1)
- Author: "Gary Schafer" <garyschafer@largeriver.net>
- Date: Thu, 28 Apr 2022 21:49:42 -0500
- I am looking for more info on the interconnection of the Henry 8k ultra amp and the remote control box. I have the manual that comes with the amp but it has parts that are left out (very poor). They
- /archives//html/Amps/2022-04/msg00027.html (6,822 bytes)
- 79. Re: [Amps] .01uf caps across diodes ? (score: 1)
- Author: "Gary Schafer" <garyschafer@largeriver.net>
- Date: Wed, 14 Dec 2022 16:08:01 -0600
- Hi Tim, Years ago I built a receiver and needed a power supply but the transformer I had was to much voltage. So rather than just a capacitive input filter I put a choke of a few henrys between the d
- /archives//html/Amps/2022-12/msg00065.html (13,858 bytes)
- 80. Re: [Amps] Tiny SA (score: 1)
- Author: Gary Schafer <garyschafer@largeriver.net>
- Date: Wed, 26 Apr 2023 16:23:32 -0500
- Not a narrow enough bandwidth @ 2.6khz to see Im products of a two tone signal. Gary Schafer 715-589-2277 _______________________________________________ Amps mailing list Amps@contesting.com http://
- /archives//html/Amps/2023-04/msg00057.html (7,876 bytes)
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