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References: [ +from:4cx250b@miamioh.edu: 327 ]

Total 327 documents matching your query.

161. Re: [Amps] "Conventional" current flow (score: 1)
Author: "Jim Garland" <4cx250b@miamioh.edu>
Date: Thu, 8 Dec 2016 20:41:40 -0700
Hey Bill, Why're you picking on me? I'm just the messenger, here! Really, I'm not making this stuff up. What I've said is what the entire scientific community believes, and also virtually every elect
/archives//html/Amps/2016-12/msg00206.html (11,304 bytes)

162. Re: [Amps] 30L1 keying (score: 1)
Author: "Jim Garland" <4cx250b@miamioh.edu>
Date: Tue, 27 Dec 2016 16:35:44 -0700
Thanks for the plug, Jerry. Yes, the simple amplifier keying circuit in the StationPro is rated at 400V at 250 mA, AC or plus or minus DC. so it will key virtually any homebrew or commercial amplifie
/archives//html/Amps/2016-12/msg00451.html (10,241 bytes)

163. Re: [Amps] 30L1 keying (score: 1)
Author: "Jim Garland" <4cx250b@miamioh.edu>
Date: Tue, 27 Dec 2016 16:59:02 -0700
_______________________________________________ Amps mailing list Amps@contesting.com http://lists.contesting.com/mailman/listinfo/amps
/archives//html/Amps/2016-12/msg00452.html (7,435 bytes)

164. Re: [Amps] keying issue resolved (score: 1)
Author: Jim Garland <4cx250b@miamioh.edu>
Date: Wed, 28 Dec 2016 07:36:45 -0700
Better be careful, Brian! Most AC solid state relays use thyristors for switching and depend on the zero crossing of the AC load to switch off. In other words, if you try to use one of those relays t
/archives//html/Amps/2016-12/msg00464.html (8,430 bytes)

165. Re: [Amps] keying issue resolved (score: 1)
Author: Jim Garland <4cx250b@miamioh.edu>
Date: Wed, 28 Dec 2016 08:14:10 -0700
Yes, an optically coupled MOSFET relay will work fine, and is what I use in my StationPro keying circuit. Two other considerations are the on-state resistance and the switching time. The PLA140 relay
/archives//html/Amps/2016-12/msg00471.html (9,960 bytes)

166. Re: [Amps] Alpha 9500 Idling Current (score: 1)
Author: "Jim Garland" <4cx250b@miamioh.edu>
Date: Thu, 29 Dec 2016 14:05:08 -0700
That idle current sounds a bit high. I checked my 9500 and the idle current is 140mA, with a plate voltage of 3680V. The no-load plate voltage is a bit over 3800V. Re the EBS/QSK issue, I'm assuming
/archives//html/Amps/2016-12/msg00515.html (11,076 bytes)

167. Re: [Amps] FCC Denies Expert Linears' Request for Waiver of 15 dB Rule (score: 1)
Author: MU 4CX250B <4cx250b@miamioh.edu>
Date: Tue, 3 Jan 2017 13:31:37 -0700
I remember that with the Drake C-Line, some ops would short the T4XC ALC line, which would increase the power output to 175W. Most vacuum tube transmitters I am familiar with did not have a power adj
/archives//html/Amps/2017-01/msg00045.html (9,190 bytes)

168. Re: [Amps] FCC Denies Expert Linears' Request for Waiver of (score: 1)
Author: "Jim Garland" <4cx250b@miamioh.edu>
Date: Tue, 3 Jan 2017 16:37:25 -0700
You're right Jim. I was remembering wrong. I have a C-Line set up on one of my vintage station tables and just repeated the experiment. I loaded the T4XC to maximum output (measured with an LP-100A)
/archives//html/Amps/2017-01/msg00051.html (11,451 bytes)

169. Re: [Amps] HARRIS PP-7913/URC POWER SUPPLY (score: 1)
Author: MU 4CX250B <4cx250b@miamioh.edu>
Date: Thu, 5 Jan 2017 16:55:39 -0700
This is all good advice. Jeff wants to use a 150mA grid current meter, so after first isolating the HV return, the grid meter's negative terminal should be grounded and its positive terminal tied to
/archives//html/Amps/2017-01/msg00112.html (11,273 bytes)

170. Re: [Amps] Decline of homebrewing? (score: 1)
Author: Jim Garland <4cx250b@miamioh.edu>
Date: Fri, 06 Jan 2017 21:07:56 -0700
The fact that some young man or woman might decide to build a KW amp a week after getting their ham ticket (and coming here for help to do so) does not bother me at all, in fact it shows some common
/archives//html/Amps/2017-01/msg00142.html (14,326 bytes)

171. Re: [Amps] Decline of homebrewing? (score: 1)
Author: Jim Garland <4cx250b@miamioh.edu>
Date: Sun, 08 Jan 2017 13:23:51 -0700
This interesting discussion about homebrewing techniques and safety brings to mind an experience I had a few years ago with my StationPro station controller. I designed the StationPro for myself, but
/archives//html/Amps/2017-01/msg00189.html (14,972 bytes)

172. Re: [Amps] Alpha Seventy HV Meter Readings (score: 1)
Author: MU 4CX250B <4cx250b@miamioh.edu>
Date: Thu, 12 Jan 2017 14:24:09 -0700
To compute the value of the bottom resistor in the divider string, don't you need to compute the parallel resistance of the bottom resistor and the resistance in series with the 1mA panel meter? Pres
/archives//html/Amps/2017-01/msg00244.html (8,395 bytes)

173. Re: [Amps] Alpha Seventy HV Meter Readings (score: 1)
Author: MU 4CX250B <4cx250b@miamioh.edu>
Date: Thu, 12 Jan 2017 16:44:57 -0700
I think you're half right! Yes, the divider string results in a voltage that is a fixed percentage of the voltage at the top of the string, e.g, 5V versus 5000 V. However, you'd need a high impedance
/archives//html/Amps/2017-01/msg00250.html (10,201 bytes)

174. Re: [Amps] Alpha Seventy HV Meter Readings (score: 1)
Author: MU 4CX250B <4cx250b@miamioh.edu>
Date: Thu, 19 Jan 2017 14:45:52 -0700
Paul, your method of measuring internal resistance of the meter is just fine, though it's easier just to use a DMM and measure the resistance directly. I imagine you have a fluke DMM and these normal
/archives//html/Amps/2017-01/msg00274.html (11,665 bytes)

175. Re: [Amps] Alpha Seventy HV Meter Readings (score: 1)
Author: Jim Garland <4cx250b@miamioh.edu>
Date: Fri, 20 Jan 2017 06:21:06 -0700
I've not looked at the Alpha 70 circuit, but from the discussion it appears that the HV is measured by putting a 1 mA meter in series with a high resistance voltage divider, with a shunt across the m
/archives//html/Amps/2017-01/msg00279.html (18,472 bytes)

176. Re: [Amps] PowerGenius XL Video (score: 1)
Author: MU 4CX250B <4cx250b@miamioh.edu>
Date: Sat, 11 Feb 2017 15:00:56 -0600
I built my first bandswitched 8877 amp back in the seventies for publication in the Bill Orr Handbook (which paid for the parts). When bench-testing the amp, I was surprised to see the efficiency on
/archives//html/Amps/2017-02/msg00060.html (9,204 bytes)

177. Re: [Amps] Alpha 77Dx two hole (score: 1)
Author: MU 4CX250B <4cx250b@miamioh.edu>
Date: Mon, 13 Feb 2017 13:34:51 -0600
I agree completely with Paul's comments. I had a 77SX for a few months and didn't care for the amplifier. Best I could tell, it was identical to the 77DX, except for the extra tube and changed multip
/archives//html/Amps/2017-02/msg00082.html (9,751 bytes)

178. Re: [Amps] Checking Filament Voltage (score: 1)
Author: MU 4CX250B <4cx250b@miamioh.edu>
Date: Tue, 21 Feb 2017 14:24:53 -0700
The simplest solution for amps with separate filament xfmrs is probably to install an inrush current limiter in series with the xfmr's primary winding. These look like disc capacitors and cost about
/archives//html/Amps/2017-02/msg00166.html (9,575 bytes)

179. Re: [Amps] Checking Filament Voltage (score: 1)
Author: MU 4CX250B <4cx250b@miamioh.edu>
Date: Tue, 21 Feb 2017 20:26:04 -0700
Sent from my iPhone Very good point, Jim. Yes, ICLs run hot and must be kept out of a cooling airflow. I normally do not shorten the leads to the ICL, and insulate the leads with teflon tubing. I pos
/archives//html/Amps/2017-02/msg00173.html (10,128 bytes)

180. Re: [Amps] 240 Volt Blowers needed (score: 1)
Author: Jim Garland <4cx250b@miamioh.edu>
Date: Mon, 20 Mar 2017 15:26:46 -0600
Carl is exactly right about this. 240VAC plate transformers often have center-tapped primary windings, or else two 120VAC windings in series. It's okay to connect 120V circuits from either L1 or L2 o
/archives//html/Amps/2017-03/msg00118.html (10,258 bytes)

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