- 1. [Amps] Parasitics (score: 1)
- Author: peter.chadwick@zarlink.com
- Date: Thu, 21 Aug 2003 07:58:26 +0100
- There's a header that should wake people up! I haven't the article with me here at work, but I don't remember seeing any advice about oiling fan/blower motor bearings, which I would have thought was
- /archives//html/Amps/2003-08/msg00001.html (7,476 bytes)
- 2. Re: [Amps] Parasitics (score: 1)
- Author: peter.chadwick@zarlink.com
- Date: Thu, 21 Aug 2003 15:40:54 +0100
- cathode amplifiers ( tuned >grid-tuned plate oscillation) but does show up in poorly constructed grounded grid amplifiers. The fundamental TPTG type mode is not one that in my experience is usually c
- /archives//html/Amps/2003-08/msg00008.html (8,502 bytes)
- 3. [Amps] Information Needed for Shipping Alpha && (score: 1)
- Author: peter.chadwick at Zarlink.Com (peter.chadwick@Zarlink.Com)
- Date: Fri Jul 11 09:00:16 2003
- I guess this is more advice for shipping you, rather than the Alpha......Bear in mind that if you're flying on a one way ticket, you are immediately more likely to get hauled out and searched etc bec
- /archives//html/Amps/2003-07/msg00062.html (8,257 bytes)
- 4. [Amps] Dual 8877 Alpha 77S final query (score: 1)
- Author: peter.chadwick at Zarlink.Com (peter.chadwick@Zarlink.Com)
- Date: Thu Jul 31 07:55:50 2003
- Rich in the past has also suggested allowing for extra air cooling of the tank: this seems exceedingly sensible. Some really big tx's (80kW) actually blow air down the tubing of the coil, but I don't
- /archives//html/Amps/2003-07/msg00171.html (7,224 bytes)
- 5. [Amps] Resonance in PiNetworks (score: 1)
- Author: peter.chadwick at Zarlink.Com (peter.chadwick@Zarlink.Com)
- Date: Mon Jun 2 08:07:41 2003
- the This must be somewhat dependent upon one's definition of resonance. I've always used the definition of the feed V and I being in phase (i.e. the input impedance is resistive) , which means of cou
- /archives//html/Amps/2003-06/msg00004.html (7,155 bytes)
- 6. [Amps] Re: 160M efficiency (score: 1)
- Author: peter.chadwick at Zarlink.Com (peter.chadwick@Zarlink.Com)
- Date: Mon Jun 2 08:07:43 2003
- So how did we get reasonable efficiency in plate modulated 160m PA stages, where we couldn't use a value as big as .01 uf to bypass the end of plate feed RF choke without serious effects on the modul
- /archives//html/Amps/2003-06/msg00005.html (7,094 bytes)
- 7. [Amps] Relay Contact Bounce (score: 1)
- Author: peter.chadwick at Zarlink.Com (peter.chadwick@Zarlink.Com)
- Date: Sun Jun 8 08:58:01 2003
- Question: for a given relay part number, what sort of production spread could one expect on bounce? (over batches as well as parts within a batch) My suspicion is that it could be very wide, especial
- /archives//html/Amps/2003-06/msg00039.html (6,680 bytes)
- 8. [Amps] electronic switching (score: 1)
- Author: peter.chadwick at Zarlink.Com (peter.chadwick@Zarlink.Com)
- Date: Tue Jun 17 08:21:54 2003
- I haven't seen any PINs that will handle more than 1500 volts. Additionally, you'll need 10 microsecond or so reverse recovery time to handle 160metres. Plus the tank circuit circulating current can
- /archives//html/Amps/2003-06/msg00114.html (7,912 bytes)
- 9. [Amps] electronic switching (score: 1)
- Author: peter.chadwick at Zarlink.Com (peter.chadwick@Zarlink.Com)
- Date: Thu Jun 19 08:32:29 2003
- The original question was about replacing ceramic switches - which in our context are usually used in the tank circuit. PINs used at 50 ohms are a totally different kettle of fish, and of course can
- /archives//html/Amps/2003-06/msg00142.html (11,211 bytes)
- 10. [Amps] electronic switching (score: 1)
- Author: peter.chadwick at Zarlink.Com (peter.chadwick@Zarlink.Com)
- Date: Thu Jun 19 08:32:33 2003
- Sorry chaps, I misled you. It's no longer MACOM, but Alpha Industries for the PIN info. Sugegsted URL for a good primer on PINs is <http://www.alphaind.com/products_display_item.asp?did=2311> 73 Pete
- /archives//html/Amps/2003-06/msg00143.html (8,322 bytes)
- 11. [Amps] anyone used 2 x 4-250b in parallel on six (score: 1)
- Author: peter.chadwick at Zarlink.Com (peter.chadwick@Zarlink.Com)
- Date: Fri Jun 20 08:21:25 2003
- Older ARRL handbooks have some designs using one. But I'd be inclined to go push pull - it's easier to neutralise, the second harmonic tends to cancel, and the tank circuit is easy to design - see an
- /archives//html/Amps/2003-06/msg00147.html (6,895 bytes)
- 12. [Amps] electronic switching (score: 1)
- Author: peter.chadwick at Zarlink.Com (peter.chadwick@Zarlink.Com)
- Date: Fri Jun 20 08:23:08 2003
- I intend to do a PIN switch for my next amplifier. I managed to get some Unitrode diodes rated at 1.2kv and 1 amp - 10 wire ended and 10 stud mount with tape leads, all with a long trr so they are go
- /archives//html/Amps/2003-06/msg00164.html (9,540 bytes)
- 13. [Amps] electronic switching (score: 1)
- Author: peter.chadwick at Zarlink.Com (peter.chadwick@Zarlink.Com)
- Date: Mon Jun 23 08:19:16 2003
- I took a dislike to QSK back in the days of separates and real radios that glow! Tried and didn't like it - OK with big strong signals and not too much noise. I expect it was fine for maritime stuff
- /archives//html/Amps/2003-06/msg00187.html (8,449 bytes)
- 14. [Amps] electronic switching (score: 1)
- Author: peter.chadwick at Zarlink.Com (peter.chadwick@Zarlink.Com)
- Date: Tue Jun 24 08:55:53 2003
- Yes, but the operating standards are marginally higher. Plus it takes skill, although these days, anything that does that appears to be taboo - such as trying to understand what is happening in the r
- /archives//html/Amps/2003-06/msg00189.html (7,979 bytes)
- 15. [Amps] See you at Dayton (score: 1)
- Author: peter.chadwick at Zarlink.Com (peter.chadwick@Zarlink.Com)
- Date: Sat May 10 13:42:47 2003
- I'll be there. Not bringing anything, though. 73 Peter G3RZP
- /archives//html/Amps/2003-05/msg00073.html (6,341 bytes)
- 16. [Amps] Spectrial purity and tank configuration (score: 1)
- Author: peter.chadwick at Zarlink.Com (peter.chadwick@Zarlink.Com)
- Date: Sat May 24 09:58:37 2003
- Norm asked: It all depends - as you might guess. If the tuner configuration is one with a low pass function, such as an L network, and if the working Q of the tuner is equal to that of the L section
- /archives//html/Amps/2003-05/msg00182.html (7,204 bytes)
- 17. [Amps] Capacitor checker (score: 1)
- Author: peter.chadwick at Zarlink.Com (peter.chadwick@Zarlink.Com)
- Date: Tue Apr 1 02:23:34 2003
- I find it very good, too. One change I've done to mine and suggested to AADE is that they replace the 5volt regulator with a low drop out device. This means that you can run the battery down a lot fu
- /archives//html/Amps/2003-04/msg00002.html (6,599 bytes)
- 18. [Amps] Re: PS project part2 (score: 1)
- Author: peter.chadwick at Zarlink.Com (peter.chadwick@Zarlink.Com)
- Date: Mon Apr 14 03:45:54 2003
- In the UK, protective circuit breakers doing earth leakage ( called RCD, residual Current Devices) are supposed to be tripped every 3 months because of them showing a tendency to stick. Since they in
- /archives//html/Amps/2003-04/msg00131.html (7,822 bytes)
- 19. [Amps] Re: PS project part2 (score: 1)
- Author: peter.chadwick at Zarlink.Com (peter.chadwick@Zarlink.Com)
- Date: Wed Apr 16 02:47:20 2003
- The dipole is fed with open wire line, so that it can be used on other bands. RF ammeters in the remote automatic antenna tuner suggest the currents in the two feed wires are substantially equal. One
- /archives//html/Amps/2003-04/msg00165.html (8,199 bytes)
- 20. [Amps] cord strain relief information (score: 1)
- Author: peter.chadwick at Zarlink.Com (peter.chadwick@Zarlink.Com)
- Date: Wed Apr 30 08:32:40 2003
- Interestingly enough, from here in Stockholm (at the plant here for the two weeks prior to Dayton and the week after!), the only hits on Heyco were for Europe. Glad to hear they're still going over t
- /archives//html/Amps/2003-04/msg00229.html (6,674 bytes)
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