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Total 156 documents matching your query.

121. Re: [Amps] 160m mosfet linear amplifier problem with ferrite cores (score: 1)
Author: "David Cutter" <d.cutter@ntlworld.com>
Date: Sun, 18 Apr 2010 11:50:21 +0100
I see you are using hex socket screws. It is very easy to over-tighten screws to fix plastic devices to a heatsink, I've seen them crack after a little time in the field due to expansion and contract
/archives//html/Amps/2010-04/msg00525.html (13,685 bytes)

122. Re: [Amps] 160m mosfet linear amplifier problem with ferrite cores (score: 1)
Author: "David Cutter" <d.cutter@ntlworld.com>
Date: Sun, 18 Apr 2010 12:56:18 +0100
Are you using the same manufacturer as your friends? If so, yours should be the similar performance unless something is wrong. David hi. i am not use insulators between mosfet and heatsink in order t
/archives//html/Amps/2010-04/msg00528.html (10,346 bytes)

123. Re: [Amps] 160m mosfet linear amplifier problem with ferrite cores (score: 1)
Author: "David Cutter" <d.cutter@ntlworld.com>
Date: Sun, 18 Apr 2010 19:25:47 +0100
Sasas I looked at the ARRL site for a similar power amplifier to compare notes. http://www.w6kan.com/ssamp.html The devices are completely different and so is the supply voltage, but the push pull ar
/archives//html/Amps/2010-04/msg00542.html (10,302 bytes)

124. Re: [Amps] 160m mosfet linear amplifier problem with ferrite cores (score: 1)
Author: "David Cutter" <d.cutter@ntlworld.com>
Date: Sun, 18 Apr 2010 20:20:58 +0100
Check the sense of all the windings, particularly T3 and check all your ferrites are isolated from the windings and everything else - the material is conductive. David _______________________________
/archives//html/Amps/2010-04/msg00543.html (9,514 bytes)

125. Re: [Amps] 160m mosfet linear amplifier problem with ferrite cores (score: 1)
Author: <d.cutter@ntlworld.com>
Date: Mon, 19 Apr 2010 13:09:47 +0100
Alex I'm not sure if you would call 500W 'high power' - I would from a UK perspective. In the classic EB104 I see ordinary transformers. Perhaps I'm not understanding something, you're the expert. Wh
/archives//html/Amps/2010-04/msg00557.html (10,406 bytes)

126. Re: [Amps] 160m mosfet linear amplifier problem with ferrite cores (score: 1)
Author: <d.cutter@ntlworld.com>
Date: Mon, 19 Apr 2010 15:38:57 +0100
Thanks, Joe, I lost site of that. David G3UNA _______________________________________________ Amps mailing list Amps@contesting.com http://lists.contesting.com/mailman/listinfo/amps
/archives//html/Amps/2010-04/msg00560.html (9,778 bytes)

127. Re: [Amps] 160m mosfet linear amplifier problem with ferrite cores (score: 1)
Author: "David Cutter" <d.cutter@ntlworld.com>
Date: Tue, 20 Apr 2010 06:46:56 +0100
Apparently, Sassas has friends who have done so. _______________________________________________ Amps mailing list Amps@contesting.com http://lists.contesting.com/mailman/listinfo/amps
/archives//html/Amps/2010-04/msg00566.html (10,082 bytes)

128. Re: [Amps] Custom Cabinets for Custom Amps. (score: 1)
Author: "David Cutter" <d.cutter@ntlworld.com>
Date: Sun, 2 May 2010 08:52:02 +0100
Also look at office filing cabinets, they are about 18.5" wide 2ft deep and 1,2,3,4 drawers high with heavy duty runners for easy access. Even new they are not expensive. Various colours and wood eff
/archives//html/Amps/2010-05/msg00009.html (8,351 bytes)

129. Re: [Amps] Cleaning air-wound coils (score: 1)
Author: "David Cutter" <d.cutter@ntlworld.com>
Date: Wed, 5 May 2010 18:15:33 +0100
"Radio Frequency Performance of Electroplated Finishes" by AM Fowler and an addendum page are ancient manuscripts that might bear looking at again. I'll send them to you if you can't find them via Go
/archives//html/Amps/2010-05/msg00063.html (10,949 bytes)

130. Re: [Amps] Salt water dummy loads (score: 1)
Author: "David Cutter" <d.cutter@ntlworld.com>
Date: Fri, 16 Jul 2010 17:56:48 +0100
Sea water freezes around 1.25 to 1.5C depending on depth and is about 5% "salt" if I remember rightly, ie much more than your dummy load which will still freeze at about the same as tap water. It wil
/archives//html/Amps/2010-07/msg00174.html (9,191 bytes)

131. Re: [Amps] Salt water dummy loads (score: 1)
Author: "David Cutter" <d.cutter@ntlworld.com>
Date: Fri, 16 Jul 2010 18:48:26 +0100
Ooops, that should read minus 1.25 to minus 1.5C, sorry about that. David G3UNA _______________________________________________ Amps mailing list Amps@contesting.com http://lists.contesting.com/mailm
/archives//html/Amps/2010-07/msg00175.html (8,429 bytes)

132. Re: [Amps] Salt water load (score: 1)
Author: "David Cutter" <d.cutter@ntlworld.com>
Date: Sun, 18 Jul 2010 17:02:32 +0100
I read somewhere that salty string works as an antenna, so, if you forgot your real antenna for the dxpedition... David G3UNA _______________________________________________ Amps mailing list Amps@co
/archives//html/Amps/2010-07/msg00204.html (8,182 bytes)

133. Re: [Amps] Salt water load (score: 1)
Author: "David Cutter" <d.cutter@ntlworld.com>
Date: Sun, 18 Jul 2010 17:02:32 +0100
I read somewhere that salty string works as an antenna, so, if you forgot your real antenna for the dxpedition... David G3UNA _______________________________________________ Amps mailing list Amps@co
/archives//html/Amps/2010-07/msg00205.html (8,298 bytes)

134. Re: [Amps] replacement cost for 2KL (score: 1)
Author: "David Cutter" <d.cutter@ntlworld.com>
Date: Fri, 6 Aug 2010 14:52:26 +0100
I will be selling the complete line-up, ie with auto tuner. Looking at offers > GBP 1k David G3UNA _______________________________________________ Amps mailing list Amps@contesting.com http://lists.c
/archives//html/Amps/2010-08/msg00059.html (7,662 bytes)

135. Re: [Amps] Automotive Relays (score: 1)
Author: "David Cutter" <d.cutter@ntlworld.com>
Date: Sun, 8 Aug 2010 11:45:35 +0100
That begs a question I've often puzzled over: how does a contact rated at 10A cope with uV level signals, particularly after the gold flash has gone ? David G3UNA ____________________________________
/archives//html/Amps/2010-08/msg00082.html (9,751 bytes)

136. Re: [Amps] Automotive Relays (score: 1)
Author: "David Cutter" <d.cutter@ntlworld.com>
Date: Sun, 8 Aug 2010 20:14:55 +0100
Larry That's the sort of thing I was looking for. I have a book somewhere written I think by Schrack and my memory of it is that you can't do both jobs at the same time. Clearly, amateurs do with sev
/archives//html/Amps/2010-08/msg00093.html (15,050 bytes)

137. Re: [Amps] Automotive Relays (score: 1)
Author: "David Cutter" <d.cutter@ntlworld.com>
Date: Sun, 8 Aug 2010 23:41:54 +0100
Yes, it's on his site. Well, that's the sort of thing I had in mind and I've used it for heavy duty switches but it's the first time I've seen it on relays. Thank goodness I'm not going mad, I though
/archives//html/Amps/2010-08/msg00097.html (10,216 bytes)

138. Re: [Amps] Automotive Relays (score: 1)
Author: "David Cutter" <d.cutter@ntlworld.com>
Date: Sun, 8 Aug 2010 23:49:23 +0100
Yes, I see that in the schematic. Thanks for the info, it's more frequently used than I thought. David G3UNA _______________________________________________ Amps mailing list Amps@contesting.com http
/archives//html/Amps/2010-08/msg00098.html (9,998 bytes)

139. Re: [Amps] PCB test for the 12A & 16A power relays (score: 1)
Author: "David Cutter" <d.cutter@ntlworld.com>
Date: Mon, 9 Aug 2010 18:27:54 +0100
If memory serves: a 0.2" wide track of 2oz copper will take 10A for something like a 50C rise. I'd have to look up the reference to be sure. That's dc current of course. If you want to bring the trac
/archives//html/Amps/2010-08/msg00121.html (10,910 bytes)

140. Re: [Amps] Amps Digest, Vol 93, Issue 16 (score: 1)
Author: "David Cutter" <d.cutter@ntlworld.com>
Date: Sun, 12 Sep 2010 10:39:25 +0100
Make a simple plastic cap to fit over the EHT coax connector with a shaped lug to operate a microswitch inside the cabinet. When rotated and held in a keyway the microswitch is operated and EHT suppl
/archives//html/Amps/2010-09/msg00109.html (10,199 bytes)


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