Search String: Display: Description: Sort:

Results:

References: [ +from:g8on@fsmail.net: 246 ]

Total 246 documents matching your query.

221. Re: [Amps] Harbach metering board in SB-220 (score: 1)
Author: peter chadwick <g8on@fsmail.net>
Date: Sun, 09 Mar 2014 07:59:40 +0100
string to chassis. Its value is uncritical, as its function is only to prevent the bottom end of the 3x 4M7 string from soaring to HV when the meter switch is NOT in the "HV" position.< Which is mor
/archives//html/Amps/2014-03/msg00031.html (8,391 bytes)

222. Re: [Amps] Pi-L Network Question (score: 1)
Author: peter chadwick <g8on@fsmail.net>
Date: Tue, 11 Mar 2014 17:25:44 +0100
Jim, I used your values to calculate (by a series of parallel - series and series - parallel transforms, the back of the NCJ renewal notice and an HP41CV!) a plate impedance of 717 ohms at 1.8 MHz. I
/archives//html/Amps/2014-03/msg00036.html (7,749 bytes)

223. Re: [Amps] Pi-L Network Question (score: 1)
Author: peter chadwick <g8on@fsmail.net>
Date: Tue, 11 Mar 2014 19:21:55 +0100
1907 - 1912 kHz when they first got 160, Carl. I remember getting home from work one night at about 2130 (in about 1986-7), and they were very strong. We would transmit down around 1830 - 35: I worke
/archives//html/Amps/2014-03/msg00041.html (7,656 bytes)

224. Re: [Amps] new Freescale LDMOS part (score: 1)
Author: peter chadwick <g8on@fsmail.net>
Date: Wed, 12 Mar 2014 11:54:28 +0100
on board the missing Malaysia Airlines flight were en route to a business meeting in China, a spokeswoman for the tech firm said Sunday. The employees ? 12 from Malaysia and eight from China ?work a
/archives//html/Amps/2014-03/msg00049.html (7,929 bytes)

225. Re: [Amps] HV & temps (score: 1)
Author: peter chadwick <g8on@fsmail.net>
Date: Thu, 13 Mar 2014 09:01:37 +0100
The Acom 1500 monitors output air temperature: it doesn't tell me what I am supposed to do with the information. I suspect that it is part of fault diagnosis, because there is a warning about exceedi
/archives//html/Amps/2014-03/msg00064.html (7,626 bytes)

226. Re: [Amps] 4CX5000A in grounded-grid (score: 1)
Author: peter chadwick <g8on@fsmail.net>
Date: Tue, 18 Mar 2014 11:58:22 +0100
Without knowing the power factor, I presume it takes about 4kVA from the mains, maybe a bit more. Standard UK supply is 13 amps unless you have special circuit put in. What's the usual household wiri
/archives//html/Amps/2014-03/msg00097.html (7,295 bytes)

227. Re: [Amps] Triband balun (score: 1)
Author: peter chadwick <g8on@fsmail.net>
Date: Fri, 21 Mar 2014 10:33:24 +0100
For both my T2X and CD45 rotators, I replaced the terminal strip with an aluminium plate fitted with a proper IP66 rated cable gland and a 2 foot tail of cable. That joins the main run of cable, the
/archives//html/Amps/2014-03/msg00120.html (13,346 bytes)

228. Re: [Amps] HV limit for rfc-3 choke? (score: 1)
Author: peter chadwick <g8on@fsmail.net>
Date: Tue, 25 Mar 2014 23:18:14 +0100
Figure it this way: Suppose you have 5kV DC and a plate swing of 8kV p-p or 2800 RMS. 225 microhenries is 2545 ohms at 1.8 MHz so the RF current in the choke is 1.1 amps, in addition to the DC. If Q
/archives//html/Amps/2014-03/msg00149.html (9,402 bytes)

229. Re: [Amps] 3-500Zs inverted (score: 1)
Author: peter chadwick <g8on@fsmail.net>
Date: Fri, 04 Apr 2014 10:08:57 +0200
On a more serious note, make sure the tubes are firmly seated in the sockets and aren't likely to fall out when upside down. This is not unknown if the socket clips have started to weaken because of
/archives//html/Amps/2014-04/msg00044.html (7,938 bytes)

230. Re: [Amps] HF2500 Power Supply Caps (score: 1)
Author: peter chadwick <g8on@fsmail.net>
Date: Mon, 07 Apr 2014 08:24:52 +0200
Hi Paul, You might want to find details on the 'fast' fuses intended for protecting semiconductors - if that isn't an oxymoron. (I know any semiconductor will automatically blow to maximise damage in
/archives//html/Amps/2014-04/msg00071.html (8,028 bytes)

231. Re: [Amps] ALS-600 vs ALS-1300 (score: 1)
Author: peter chadwick <g8on@fsmail.net>
Date: Thu, 10 Apr 2014 18:45:56 +0200
The comments on eham.net in the Amplifiers Forum seem to suggest that the lack of reliability in ALS1300 lies in the power supply, which. There was a suggestion that the ALS1300 is two ALS-600s with
/archives//html/Amps/2014-04/msg00123.html (7,639 bytes)

232. Re: [Amps] AL572 for DXpedition, parts to take along (score: 1)
Author: peter chadwick <g8on@fsmail.net>
Date: Thu, 17 Apr 2014 00:17:34 +0200
Bearing in mind the reliability of available new tubes these days, 2 sets of known good, pre-tested spare tubes. 73 Peter G3RZP _______________________________________________ Amps mailing list Amps@
/archives//html/Amps/2014-04/msg00156.html (7,925 bytes)

233. Re: [Amps] Is this relay suitable for 1kw+ RF? (score: 1)
Author: peter chadwick <g8on@fsmail.net>
Date: Fri, 18 Apr 2014 09:49:39 +0200
Those Leach relays were designed for switching RF. Depending on the impedance and thus the voltage, they're OK for over 1kW. I have picked up 24 volt DC ones for $2 a time in the Dayton flea market..
/archives//html/Amps/2014-04/msg00171.html (8,382 bytes)

234. Re: [Amps] Filament Voltage Question (score: 1)
Author: peter chadwick <g8on@fsmail.net>
Date: Tue, 22 Apr 2014 20:33:08 +0200
Jim, In a directly heated cathode, i.e. a filament, the higher the filament voltage, the greater the induced grid swing caused by the filament voltage. If you had a 100 volt heater and the grid retur
/archives//html/Amps/2014-04/msg00193.html (13,022 bytes)

235. Re: [Amps] Filter capacitors (score: 1)
Author: peter chadwick <g8on@fsmail.net>
Date: Wed, 23 Apr 2014 11:07:20 +0200
Bigger capacitors also means bigger peak rectifier currents. Depending on the duty cycle of the load, it could lead to more transformer heating. If it's for an SSB application, there shouldn't be a p
/archives//html/Amps/2014-04/msg00206.html (7,483 bytes)

236. Re: [Amps] Amps Digest, Vol 136, Issue 42 (score: 1)
Author: peter chadwick <g8on@fsmail.net>
Date: Sun, 27 Apr 2014 10:42:10 +0200
Reversing the polarity of the DC filament supply occasionally will mitigate the effects of metal migration, which is exacerbated by high current density and high temperatures. So it makes good sense.
/archives//html/Amps/2014-04/msg00230.html (23,266 bytes)

237. Re: [Amps] Auto tune conversion using stepper motors? (score: 1)
Author: peter chadwick <g8on@fsmail.net>
Date: Sun, 27 Apr 2014 10:46:01 +0200
Being somewhat cynical, I would rather rely on a system with microswitches to detect the end points rather than electronics - far less to go wrong. It's not difficult to do. 73 Peter G3RZP == Message
/archives//html/Amps/2014-04/msg00231.html (8,585 bytes)

238. Re: [Amps] low pass filter fail ;) (score: 1)
Author: peter chadwick <g8on@fsmail.net>
Date: Mon, 28 Apr 2014 08:32:04 +0200
With a VSWR of only 1.2:1, I wouldn't have thought it was too close to the cut off frequency. Passive LC filters (other than the absorptive types) work by having a high VSWR in the stop-band. Accordi
/archives//html/Amps/2014-04/msg00237.html (8,621 bytes)

239. [Amps] Low Pass Filter capacitor failures (score: 1)
Author: peter chadwick <g8on@fsmail.net>
Date: Tue, 29 Apr 2014 10:15:21 +0200
Rogers 'Duroid' Teflon PCB material is very good for making suitable capacitors, and you can actually calculate quite easily the size and loss. It has an advantage over sheet Teflon and aluminium tha
/archives//html/Amps/2014-04/msg00244.html (7,412 bytes)

240. Re: [Amps] low pass filter fail (score: 1)
Author: peter chadwick <g8on@fsmail.net>
Date: Tue, 29 Apr 2014 12:23:03 +0200
Can you get 43 + 10log P dB attenuation (not exceeding 70dB) for each harmonic up to the 10th using stubs? (as required by ERC/REC 74-01) vy 73 Peter G3RZP == Message Received: Apr 29 2014, 11:14 AM
/archives//html/Amps/2014-04/msg00247.html (8,818 bytes)

Current List: 221 - 240
Page: [1] [2] [3] [4] [5] [6] [7] [8] [9] [10] [11] [12] [13]
This search system is powered by Namazu