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References: [ +from:dj7ww@t-online.de: 175 ]

Total 175 documents matching your query.

81. Re: [Amps] Which 2.5kw dissipation tetrode? (score: 1)
Author: "Peter Voelpel" <dj7ww@t-online.de>
Date: Wed, 8 Apr 2015 12:38:20 +0200
With much worse IMD performance then the 4CX1500B. The IMD is similar to the 4CX1000A. 73 Peter The other excellent tube that's actually still in current day production as opposed to surplus NOS stat
/archives//html/Amps/2015-04/msg00053.html (7,760 bytes)

82. Re: [Amps] SPE 2K RTTY Duty Cycle (score: 1)
Author: "Peter Voelpel" <dj7ww@t-online.de>
Date: Fri, 22 May 2015 16:08:07 +0200
What tetrodes do you mean? The Russian tetrodes? My YL1056 amp is better then -40dB and so is the 4CX3000A amp. The YL1056 is better then -58dB with three tones in tv translators, measured in accorda
/archives//html/Amps/2015-05/msg00149.html (9,466 bytes)

83. Re: [Amps] tetrode push-pull amp schematics (score: 1)
Author: "Peter Voelpel" <dj7ww@t-online.de>
Date: Fri, 19 Jun 2015 02:22:28 +0200
Which Japanese HAM transceiver is using LDMOS final transistors? And all I know without the "A" button are push-pull class AB. 73 Peter Every 100 Watt Japanese HAM transceiver that I have looked at e
/archives//html/Amps/2015-06/msg00063.html (9,447 bytes)

84. Re: [Amps] Ameritron ALS 500M (score: 1)
Author: "Peter Voelpel" <dj7ww@t-online.de>
Date: Thu, 3 Dec 2015 18:27:24 +0100
As far I remember IMD3 measured -26dB at ARRL lab. 73 Peter a splitter and combiner. As per usual, kenwood doesn't even mention TX IMD...on their spec sheet. http://www.kenwood.com/i/products/info/am
/archives//html/Amps/2015-12/msg00019.html (9,793 bytes)

85. Re: [Amps] SCR to adjust 240v to 200v (score: 1)
Author: "Peter Voelpel" <dj7ww@t-online.de>
Date: Mon, 15 Aug 2016 18:40:50 +0200
There is and was no European country with 200V mains. You donīt need a variac, just use a 40V transformer and put it in the primary of the hv transformer with the proper phasing to subtract 40V. 73 P
/archives//html/Amps/2016-08/msg00024.html (9,976 bytes)

86. Re: [Amps] SCR to adjust 240v to 200v (score: 1)
Author: "Peter Voelpel" <dj7ww@t-online.de>
Date: Fri, 19 Aug 2016 18:15:58 +0200
Racal regulated all power supplies in their TA1800 amp with SCRs except anode voltage. They used transformers with 205V primary for the heater, the bias and the screen of the 4CX10000. The screen vol
/archives//html/Amps/2016-08/msg00045.html (9,173 bytes)

87. Re: [Amps] 2x 4cx1500b Rl (score: 1)
Author: "Peter Voelpel" <dj7ww@t-online.de>
Date: Wed, 14 Sep 2016 19:36:13 +0200
I calculate about 1200 ohms as well by using the formula: (Ua-Ug2)/Ia*k with k=1.6 for Ab1 73 Peter, DJ7WW Hi all I brushing off a old project that I have been collecting parts for quite some time. W
/archives//html/Amps/2016-09/msg00046.html (7,906 bytes)

88. Re: [Amps] OM Power Amps (score: 1)
Author: "Peter Voelpel" <dj7ww@t-online.de>
Date: Sun, 18 Sep 2016 18:25:14 +0200
I have no idea why somebody might want an USB connector with an auto tune amplifier and more then one input and output connector. 73 Peter, DJ7WW OM2000A seems like a nice amp but disappointing to se
/archives//html/Amps/2016-09/msg00094.html (9,443 bytes)

89. Re: [Amps] Chimney for GS35B (score: 1)
Author: "Peter Voelpel" <dj7ww@t-online.de>
Date: Mon, 31 Oct 2016 17:18:10 +0100
The ceramic chimneys of GU-43B tubes fit very well. http://www.ebay.de/itm/Keramik-Kamin-fur-GU43-Rohrenfassung-/131961345338?ha sh=item1eb982553a:g:TdsAAOSwujFXF-vq 73 Peter I use Teflon sheet and n
/archives//html/Amps/2016-11/msg00000.html (7,947 bytes)

90. Re: [Amps] MOSFET amp filtering - was: auto-tune (score: 1)
Author: "Peter Voelpel" <dj7ww@t-online.de>
Date: Fri, 16 Dec 2016 17:30:53 +0100
The Collins ART-13 mode selector switch is voice-cw-mcw. Perhaps Collins took it over from ham radio or vice versa? 73 Peter, DJ7WW The confusion of "Morse" and "CW" is quite typical for amateur radi
/archives//html/Amps/2016-12/msg00394.html (13,198 bytes)

91. Re: [Amps] FCC Denies Expert Linears' Request for Waiver of 15 dBRule (score: 1)
Author: "Peter Voelpel" <dj7ww@t-online.de>
Date: Wed, 28 Dec 2016 16:04:30 +0100
A friend of mine, ex Telefunken design engineer, already built a class E amp around 2x8 cheap SIHP10N40D transistors at less then 1 Euro each. With 15W of drive output is 1200W. Even without predisto
/archives//html/Amps/2016-12/msg00468.html (8,962 bytes)

92. Re: [Amps] SS amps watercooling (score: 1)
Author: "Peter Voelpel" <dj7ww@t-online.de>
Date: Mon, 6 Mar 2017 18:14:47 +0100
You will need to home brew it. http://www.dl2nk.de/monobander_en.pdf 73 Peter, DJ7WW use.. like the 2-30 mhz variety. I keep looking, but dont see any....yet. ________________________________________
/archives//html/Amps/2017-03/msg00050.html (7,637 bytes)

93. Re: [Amps] Ham Tests, was Price per Watt Conversation (score: 1)
Author: "Peter Voelpel" <dj7ww@t-online.de>
Date: Sat, 29 Apr 2017 08:56:34 +0200
MRF458 and MRF 454 transistors are still available and you can also use 2SC2879. 73 Peter, DJ7WW <I wouldn't worry too much about transistors becoming unobtainable <because equivalents will nearly al
/archives//html/Amps/2017-04/msg00429.html (8,613 bytes)

94. Re: [Amps] Ham Tests, was Price per Watt Conversation (score: 1)
Author: "Peter Voelpel" <dj7ww@t-online.de>
Date: Mon, 1 May 2017 21:21:17 +0200
The last four I bought came from Henry Radio. Rfparts sell them as well. https://www.rfparts.com/catalogsearch/result/?q=mrf454 73 Peter, DJ7WW If you can find a real matched pair and not Chinese tra
/archives//html/Amps/2017-05/msg00017.html (10,096 bytes)

95. Re: [Amps] 144 MHz GS35B update (score: 1)
Author: "Peter Voelpel" <dj7ww@t-online.de>
Date: Tue, 2 May 2017 12:50:30 +0200
Efficiency seems to be better with lower voltage but more drive. http://www.qsl.net/dl4mea/2GS35B_de_en.pdf In that example of a W6PO design efficiency is: 43% with 20W drive at 2,8KV, output 450W 70
/archives//html/Amps/2017-05/msg00031.html (10,659 bytes)

96. Re: [Amps] Anyone got a 3CX3000 filament transformer they'd (score: 1)
Author: "Peter Voelpel" <dj7ww@t-online.de>
Date: Tue, 2 May 2017 19:25:53 +0200
No problem running them on 50Hz. I have two of them in use. Heater voltage measures exactly 7.5V when correctly tapped for 240V mains at my 235V. Source: Henry 2000D/3000D generators. I guess the 8K
/archives//html/Amps/2017-05/msg00038.html (8,151 bytes)

97. Re: [Amps] High voltage MOSFETs (score: 1)
Author: "Peter Voelpel" <dj7ww@t-online.de>
Date: Thu, 4 May 2017 08:26:24 +0200
Tokyo High Power used a pair of ARF1500 in their HL2.5KFX. http://www.ab4oj.com/dl/thp/hl2_5kfx/manual_hl2_5kfx_complete_schematics.pdf Two amps with those transistors were built in Germany: https://
/archives//html/Amps/2017-05/msg00047.html (8,356 bytes)

98. Re: [Amps] HV MOSFETs for RF (score: 1)
Author: "Peter Voelpel" <dj7ww@t-online.de>
Date: Mon, 8 May 2017 19:48:07 +0200
Its not that simple. My class A amp does 25W and consumes 280W continuously. Who would buy a K3 then? 73 Peter achieve low IMD products. Perhaps Elecraft should think of doing just that with their K3
/archives//html/Amps/2017-05/msg00097.html (8,249 bytes)

99. Re: [Amps] new amp race (score: 1)
Author: "Peter Voelpel" <dj7ww@t-online.de>
Date: Sun, 21 May 2017 10:56:01 +0200
You canīt compare antenna gain with transmit power. Antenna gain is one part but more important is the different elevation angles a directive antenna or the right antenna can supply. You canīt hear w
/archives//html/Amps/2017-05/msg00201.html (8,016 bytes)

100. Re: [Amps] new amp race (score: 1)
Author: "Peter Voelpel" <dj7ww@t-online.de>
Date: Tue, 23 May 2017 17:52:50 +0200
You will have that temperature pretty fast when you operate a 3CX3000 at half of its maximum dissipation in a relatively small shack. 73 Peter, DJ7WW Now you will never have 104 deg F in the shack __
/archives//html/Amps/2017-05/msg00261.html (8,115 bytes)

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