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References: [ +from:g8gsq@ic24.net: 257 ]

Total 257 documents matching your query.

201. Re: [Amps] Source for 8877 amp input tuning coil needed (score: 1)
Author: Steve Thompson <g8gsq@ic24.net>
Date: Fri, 22 Jul 2005 08:59:10 +0100
I ran one of these for many years in a contest station. Forget the slug tuning, wind two coils the same as the airspaced one, and stretch/sqeeze them, rewind if necessary until you find a good input
/archives//html/Amps/2005-07/msg00248.html (7,881 bytes)

202. Re: [Amps] 4CX250 bases (score: 1)
Author: Steve Thompson <g8gsq@ic24.net>
Date: Fri, 22 Jul 2005 10:15:18 +0100
The conduction cooled '250s I've used (out of Pye airband transmitters) had a BeO block between the anode and heatsink, but the bases were the same as used for air cooled valves, except for the addi
/archives//html/Amps/2005-07/msg00249.html (7,769 bytes)

203. Re: [Amps] Shorted turns reduce harmonics? (score: 1)
Author: Steve Thompson <g8gsq@ic24.net>
Date: Fri, 22 Jul 2005 15:35:24 +0100
It might be interesting to measure the actual impedance presented by the coil/switch assembly at the harmonic frequencies. Maybe it's not behaving like a simple inductor. Steve _____________________
/archives//html/Amps/2005-07/msg00258.html (6,815 bytes)

204. Re: [Amps] Tetrodes (score: 1)
Author: Steve Thompson <g8gsq@ic24.net>
Date: Wed, 27 Jul 2005 09:32:00 +0100
I have three articles that match Mike's description: One was in the ARRL handbook, probably around the early 70s, another in 60s/70s versions of the RSGB VHF/UHF manual, and a third from Short Wave M
/archives//html/Amps/2005-07/msg00328.html (9,274 bytes)

205. Re: [Amps] 8877 Time Delay Query (score: 1)
Author: Steve Thompson <g8gsq@ic24.net>
Date: Thu, 28 Jul 2005 16:05:03 +0100
In most cases gg triodes aren't actively biassed off, they are self biassed at a very low current level by having a high value resistor in the cathode. That limits the maximum cathode current to a l
/archives//html/Amps/2005-07/msg00341.html (7,350 bytes)

206. Re: [Amps] Splitter combiner question. (score: 1)
Author: Steve Thompson <g8gsq@ic24.net>
Date: Tue, 02 Aug 2005 11:09:15 +0100
nd There's some information in Motorola AN749. Steve _______________________________________________ Amps mailing list Amps@contesting.com http://lists.contesting.com/mailman/listinfo/amps
/archives//html/Amps/2005-08/msg00036.html (8,555 bytes)

207. Re: [Amps] Metric system (score: 1)
Author: Steve Thompson <g8gsq@ic24.net>
Date: Fri, 05 Aug 2005 17:16:26 +0100
Without telling anyone, I switched to counting in 12s (Babylonian?) for 'special' birthdays. Everyone thinks it's going to be a big deal when I hit 50, but I'm looking at 60 as the next big party. Th
/archives//html/Amps/2005-08/msg00180.html (8,084 bytes)

208. Re: [Amps] 3cx300a7 input impedance (score: 1)
Author: Steve Thompson <g8gsq@ic24.net>
Date: Tue, 09 Aug 2005 14:10:24 +0100
The datasheet I have gives values between 46 and 50 ohms for different conditions from 4 to 4.8kV, 300-400W drive and 6-7 kW out. Steve _______________________________________________ Amps mailing li
/archives//html/Amps/2005-08/msg00327.html (7,165 bytes)

209. Re: [Amps] Step-Starts (score: 1)
Author: Steve Thompson <g8gsq@ic24.net>
Date: Sat, 13 Aug 2005 14:16:08 +0100
My personal views: Running against most opinions, I see no problem in having a 'long' soft start - where there's going to be insignificant power drawn from the supply until after the soft start is ov
/archives//html/Amps/2005-08/msg00460.html (7,616 bytes)

210. Re: [Amps] 2nd grid resistor blow Ameritron AMP 811H (score: 1)
Author: Steve Thompson <g8gsq@ic24.net>
Date: Mon, 15 Aug 2005 22:04:35 +0100
Even with the amp in standby? Steve _______________________________________________ Amps mailing list Amps@contesting.com http://lists.contesting.com/mailman/listinfo/amps
/archives//html/Amps/2005-08/msg00537.html (8,565 bytes)

211. Re: [Amps] 2nd grid resistor blow Ameritron AMP 811H (score: 1)
Author: Steve Thompson <g8gsq@ic24.net>
Date: Tue, 16 Aug 2005 06:57:57 +0100
The original post described resistor damage when the amp was in standby and with no rf applied. In that situation parasitic, or any other, oscillation seems highly unlikely. Steve ___________________
/archives//html/Amps/2005-08/msg00544.html (8,684 bytes)

212. Re: [Amps] Parasitic Oscillation (score: 1)
Author: Steve Thompson <g8gsq@ic24.net>
Date: Wed, 17 Aug 2005 21:44:51 +0100
The fundamental thing is that an oscillator (parasitic or otherwise) requires gain>1 and phase=0. There's more than one way of preventing this in an amplifier. The usual parasitic suppressor between
/archives//html/Amps/2005-08/msg00578.html (7,927 bytes)

213. Re: [Amps] Amplifier oscillating - any ideas? (score: 1)
Author: Steve Thompson <g8gsq@ic24.net>
Date: Fri, 19 Aug 2005 16:30:37 +0100
Without being able to probe with test gear looking for resonances etc., it's always difficult to comment. Apart from obvious things like the materials and construction of the box, some thoughts - the
/archives//html/Amps/2005-08/msg00604.html (8,177 bytes)

214. Re: [Amps] caps SB200 (score: 1)
Author: Steve Thompson <g8gsq@ic24.net>
Date: Sat, 20 Aug 2005 17:34:39 +0100
That tells you that the meter movement combined with the power monitoring circuit is reading right - it doesn't necessarily tell you that the meter itself is ok, or that the HV resistors are correct.
/archives//html/Amps/2005-08/msg00616.html (8,063 bytes)

215. Re: [Amps] !44Mhz Gi7B amp problems continued (score: 1)
Author: Steve Thompson <g8gsq@ic24.net>
Date: Sun, 21 Aug 2005 17:21:01 +0100
What was the fix? The impedance at the anodes is too high. The coupling between the output and the stripline needs to be increased. Steve _______________________________________________ Amps mailing
/archives//html/Amps/2005-08/msg00636.html (7,635 bytes)

216. Re: [Amps] Tokyo Hi-Power HL-2.5Kfx (score: 1)
Author: Steve Thompson <g8gsq@ic24.net>
Date: Sun, 21 Aug 2005 17:22:36 +0100
Any specification for the linearity? Thanks, Steve _______________________________________________ Amps mailing list Amps@contesting.com http://lists.contesting.com/mailman/listinfo/amps
/archives//html/Amps/2005-08/msg00637.html (8,114 bytes)

217. Re: [Amps] Spam and worms attachments from mailing list (score: 1)
Author: Steve Thompson <g8gsq@ic24.net>
Date: Sat, 27 Aug 2005 18:59:29 +0100
Not necessarily. There's many spam and/or virus generators out there that send to thousands, if not millions of random prefixes to common ISPs, in the expectation that a handful will be valid. Thunde
/archives//html/Amps/2005-08/msg00724.html (8,741 bytes)

218. Re: [Amps] powersupply/grid current query (score: 1)
Author: Steve Thompson <g8gsq@ic24.net>
Date: Sat, 27 Aug 2005 22:18:19 +0100
Did I miss some posts about grid current? The last thing I recall was about a 480MHz hoot - did you fix that, and how? Yes, it can. When the anode volts swing too low, grid current tends to rise. Wit
/archives//html/Amps/2005-08/msg00729.html (7,637 bytes)

219. [Amps] N1BUG 2m amp (score: 1)
Author: Steve Thompson <g8gsq@ic24.net>
Date: Fri, 02 Sep 2005 08:18:23 +0100
Someone was asking about this recently - it's just occurred to me that the the YU1AW 'lazy build' output side is basically the same, using a coil instead of stripline and airspaced variables where N1
/archives//html/Amps/2005-09/msg00004.html (6,626 bytes)

220. Re: [Amps] CW and High Voltage (score: 1)
Author: Steve Thompson <g8gsq@ic24.net>
Date: Sat, 03 Sep 2005 09:55:35 +0100
Very simplistically, 1 (correctly adjusted) gives you highest efficiency at the expense of gain and linearity. I think 3-500s were designed for class C and continuous operation, so there should be no
/archives//html/Amps/2005-09/msg00018.html (8,790 bytes)

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