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1. Re: [Amps] How about a Solid State MARS amp (score: 1): Author: "Tom Rauch" <w8ji@contesting.com>; Date: Fri, 12 Oct 2007 01:22:23 -0400; The cost of $1 per watt is unobtainable in a good quality production amplifier. Remember it has to meet FCC requirements, and that means a good filter. About the only capacitor that will work is a m; /archives//html/Amps/2007-10/msg00154.html (11,005 bytes)
2. Re: [Amps] How about a Solid State MARS amp (score: 1): Author: "Tom Rauch" <w8ji@contesting.com>; Date: Fri, 12 Oct 2007 00:37:45 -0400; A bipolar transistor amp like that running at 12V is almost never as clean as a better exciter. It just can't be done unless you back the power way down. By the time you reduced power enough to not; /archives//html/Amps/2007-10/msg00153.html (8,989 bytes)
3. Re: [Amps] How about a Solid State MARS amp (score: 1): Author: "Tom Rauch" <w8ji@contesting.com>; Date: Thu, 11 Oct 2007 07:23:46 -0400; I would never use a ALS500M at home. It really is intended for applications where you only have 12 volts and aren't using a good station. I would get the ALS600 FET amplifier. It is much cleaner. By; /archives//html/Amps/2007-10/msg00128.html (8,724 bytes)
4. Re: [Amps] CB etc Amps (score: 1): Author: "Tom Rauch" <w8ji@contesting.com>; Date: Thu, 11 Oct 2007 06:58:37 -0400; Perhaps for very high order odd IM products on 160 meters, but not on 80 or higher with normal mobile antennas. 73 Tom _______________________________________________ Amps mailing list Amps@contesti; /archives//html/Amps/2007-10/msg00126.html (7,781 bytes)
5. Re: [Amps] CB Amps or full spectrum??? (score: 1): Author: "Tom Rauch" <w8ji@contesting.com>; Date: Thu, 11 Oct 2007 06:56:52 -0400; ....because most people only measure the zero drive idle current and assume if it can be set to a certain value everything in the world is right. Unfortunately it is not. 73 Tom ____________________; /archives//html/Amps/2007-10/msg00125.html (8,608 bytes)
6. Re: [Amps] CB etc Amps (score: 1): Author: "Tom Rauch" <w8ji@contesting.com>; Date: Wed, 10 Oct 2007 16:40:19 -0400; That's true with tubes and many HV FET's, but with bipolar transistors the distortion starts to ramp up long before anything close to saturation occurs. 200 watt LV bipolar transistors used on big a; /archives//html/Amps/2007-10/msg00109.html (7,908 bytes)
7. Re: [Amps] CB Amps or full spectrum??? (score: 1): Author: "Tom Rauch" <w8ji@contesting.com>; Date: Wed, 10 Oct 2007 16:30:56 -0400; Not nearly as strange as I find when someone endorses a circuit without knowing how it works. 73 Tom _______________________________________________ Amps mailing list Amps@contesting.com http://list; /archives//html/Amps/2007-10/msg00108.html (8,190 bytes)
8. Re: [Amps] CB Amps or full spectrum??? (score: 1): Author: "Tom Rauch" <w8ji@contesting.com>; Date: Wed, 10 Oct 2007 14:11:25 -0400; You keep saying that Peter, but it isn't true. A simple pi network can easily make a class AB2 amp -55dB or more for harmonics. For example the AL-12 series of amps makes about -60dBc on bands where; /archives//html/Amps/2007-10/msg00105.html (9,361 bytes)
9. Re: [Amps] CB Amps or full spectrum??? (score: 1): Author: "Tom Rauch" <w8ji@contesting.com>; Date: Wed, 10 Oct 2007 14:03:36 -0400; Measure the voltage regulation of that method when you drive the amp with rated drive power and most people's opinion will change. It's a crummy system at more than a few watts. As the base is drive; /archives//html/Amps/2007-10/msg00104.html (8,359 bytes)
10. Re: [Amps] CB Amps or full spectrum??? (score: 1): Author: "Tom Rauch" <w8ji@contesting.com>; Date: Tue, 9 Oct 2007 11:42:02 -0400; There are at least four major problems with the amps, not two. 1.) Filtering. They need filters to reduce harmonics. 2.) Power output. These amps are all really ratty at rated power, and it has noth; /archives//html/Amps/2007-10/msg00088.html (10,601 bytes)
11. Re: [Amps] HF amp output power dropping (score: 1): Author: "Tom Rauch" <w8ji@contesting.com>; Date: Sun, 7 Oct 2007 20:01:17 -0400; Sorry about that, I posted last week and and didn't know how to do a follow up on the thread. The amp is a homebrew 3CX3000a7. I did not build it myself. Plate current and plate voltage behave as alw; /archives//html/Amps/2007-10/msg00077.html (8,950 bytes)
12. Re: [Amps] HF amp output power dropping (score: 1): Author: "Tom Rauch" <w8ji@contesting.com>; Date: Sat, 6 Oct 2007 21:27:59 -0400; I'm not sure how to respond to my first thread. Sorry if this is a duplicate. I have been trying to find the cause of my amplifier's output power falling off. Last night I checked it by transmitting; /archives//html/Amps/2007-10/msg00065.html (7,884 bytes)
13. Re: [Amps] Anyone build a GU5B? (score: 1): Author: "Tom Rauch" <w8ji@contesting.com>; Date: Thu, 4 Oct 2007 20:29:53 -0400; I almost hate to ask a simple question on this reflector, but was that dB PEP or dB below one tone of the two?? That's terrible IM. I'd never use something like that. Are you sure it was similar to; /archives//html/Amps/2007-10/msg00047.html (7,932 bytes)
14. Re: [Amps] Anyone build a GU5B? (score: 1): Author: "Tom Rauch" <w8ji@contesting.com>; Date: Thu, 4 Oct 2007 20:27:30 -0400; That's too bad. That prevents use with 1500W output and I did not want to use much more than 4 kV. How much bias do they take Roman? It looks like the mu is low and the input impedance is high. I'm; /archives//html/Amps/2007-10/msg00046.html (8,113 bytes)
15. [Amps] Anyone build a GU5B? (score: 1): Author: "Tom Rauch" <w8ji@contesting.com>; Date: Thu, 4 Oct 2007 09:23:53 -0400; Anyone on here build a GU5B amplifier? If so how much gain did you get at what voltage? Is the grid connection to the base nice and short? 73, Tom W8JI _______________________________________________; /archives//html/Amps/2007-10/msg00036.html (6,420 bytes)
16. Re: [Amps] oil filled caps (score: 1): Author: "Tom Rauch" <w8ji@contesting.com>; Date: Thu, 4 Oct 2007 09:04:50 -0400; That's not true for the dc component, only for the AC component. The DC component divides by the leakage resistance, so in power supplies you can get most of the voltage across one cap even if the v; /archives//html/Amps/2007-10/msg00034.html (7,641 bytes)
17. Re: [Amps] 8877 Grid Trip timing (score: 1): Author: "Tom Rauch" <w8ji@contesting.com>; Date: Tue, 2 Oct 2007 11:28:29 -0400; <<seems like forever. This time constant would mean that momentary overcurrent in the grid circuit would be tolerated. Is this ok? I am considering lowering the value of the cap or even eliminating i; /archives//html/Amps/2007-10/msg00018.html (8,439 bytes)
18. Re: [Amps] Flashover and QSK board in TT Centurion (score: 1): Author: "Tom Rauch" <w8ji@contesting.com>; Date: Mon, 1 Oct 2007 12:39:54 -0400; Woops, had the two mixed up. With the quality of 3-500's today be sure to add a 20 ohm surge suppression resistor in the anode!!!! 73, Tom W8JI -- Original Message -- From: "Ignacy Misztal" <no9e@arr; /archives//html/Amps/2007-10/msg00014.html (9,885 bytes)
19. Re: [Amps] Flashover and QSK board in TT Centurion (score: 1): Author: "Tom Rauch" <w8ji@contesting.com>; Date: Mon, 1 Oct 2007 11:24:50 -0400; Ignacio, One problem with the TT amp is they have no positive protection for excessive grid current. A set of 3CX800's can be ruined in just seconds of operation with excessive grid dissipation. Wors; /archives//html/Amps/2007-10/msg00010.html (8,468 bytes)
20. Re: [Amps] 4CX250 IMD (score: 1): Author: "Tom Rauch" <w8ji@contesting.com>; Date: Sun, 30 Sep 2007 14:53:58 -0400; DC input power is power indicated on plate voltage and current meters. It is an average power. it would indicate the sum of the two tones in respect to input power. RF output power is PEP, which woul; /archives//html/Amps/2007-09/msg00517.html (9,553 bytes)

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