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Total 357 documents matching your query.

201. Re: [TenTec] Corsairs, Pro II, etc hi hi....interesting replies! (score: 1)
Author: "Dr. Gerald N. Johnson, electrical engineer" <geraldj@isunet.net>
Date: Fri, 31 Jan 2003 14:18:32 -0600
Both RSGB and the DL club magazine reviews of the 850 were most complimentary about the radio's handling of strong adjacent frequency signals. Glowing to be more precise. It was the best they'd ever
/archives//html/TenTec/2003-01/msg00744.html (8,854 bytes)

202. Re: [TenTec] Corsairs, Pro II, etc hi hi....interesting replies! (score: 1)
Author: "Dr. Gerald N. Johnson, electrical engineer" <geraldj@isunet.net>
Date: Fri, 31 Jan 2003 16:34:39 -0600
Sherwood (who sells receiver modifications) has a web page with many such IP3, dynamic range and phase noise tests. Many of the early (50s and 60s) radios didn't perform well. Often limited by the sm
/archives//html/TenTec/2003-01/msg00749.html (13,484 bytes)

203. Re: [TenTec] Corsairs, Pro II, etc hi hi (score: 1)
Author: "Dr. Gerald N. Johnson, electrical engineer" <geraldj@isunet.net>
Date: Fri, 31 Jan 2003 16:40:01 -0600
I'm not convinced the receivers ten years from now will have better performance. I fear that they will have greater versatility at the cost of poorer performance. Many steps supposedly forward in the
/archives//html/TenTec/2003-01/msg00750.html (8,986 bytes)

204. Re: [TenTec] Scout DC Supply Voltage sensitivity (score: 1)
Author: "Dr. Gerald N. Johnson, electrical engineer" <geraldj@isunet.net>
Date: Fri, 01 Nov 2002 17:42:00 -0600
Why should the PA draw MORE current on low voltage? If its being driven for all the impedance matching transformer can do, then the load line resistance is constant with supply voltage and the curren
/archives//html/TenTec/2002-11/msg00015.html (10,270 bytes)

205. Re: [TenTec] Scout DC Supply Voltage sensitivity (score: 1)
Author: "Dr. Gerald N. Johnson, electrical engineer" <geraldj@isunet.net>
Date: Fri, 01 Nov 2002 19:22:27 -0600
Its easy for a bit of excess voltage drop in fuses and back panel connectors (I seem to recall some comments in the past about those back panel connectors being a real problem in some Scouts) to drop
/archives//html/TenTec/2002-11/msg00019.html (10,426 bytes)

206. Re: [TenTec] Supply Voltage sensitivity. >=12.0Vdc (score: 1)
Author: "Dr. Gerald N. Johnson, electrical engineer" <geraldj@isunet.net>
Date: Sat, 02 Nov 2002 10:12:37 -0600
Doesn't need to be an "inverter" just a booster. Which could be a step down transformer coupled switcher making a variable output to be wired in series with the battery, or just a boost regulator whe
/archives//html/TenTec/2002-11/msg00022.html (9,740 bytes)

207. Re: [TenTec] Scout DC Supply Voltage sensitivity (score: 1)
Author: "Dr. Gerald N. Johnson, electrical engineer" <geraldj@isunet.net>
Date: Mon, 04 Nov 2002 20:14:27 -0600
What is the lowest voltage your "low voltage" scout will run on? 73, Jerry, K0CQ -- Entire content copyright Dr. Gerald N. Johnson, electrical engineer. Reproduction by permission only.
/archives//html/TenTec/2002-11/msg00074.html (8,670 bytes)

208. Re: [TenTec] Scout DC Supply Voltage sensitivity (score: 1)
Author: "Dr. Gerald N. Johnson, electrical engineer" <geraldj@isunet.net>
Date: Mon, 04 Nov 2002 22:39:40 -0600
Then those Scouts that drift at 12+ volts could be helped by changing to that LM2940 chip. Maybe in Mouser, 511-L4940V10 for 10 volts output. To replace LM7810 in TO-220 package. 73, Jerry, K0CQ -- E
/archives//html/TenTec/2002-11/msg00079.html (8,901 bytes)

209. Re: [TenTec] Scout DC Supply Voltage sensitivity (score: 1)
Author: "Dr. Gerald N. Johnson, electrical engineer" <geraldj@isunet.net>
Date: Tue, 05 Nov 2002 20:51:09 -0600
The classic LM7810 needs 2 to 2.5 volts minimum drop. When the input voltage gets too low, the regulator acts as a constant voltage drop, so any ripple on the input shows on the then unregulated outp
/archives//html/TenTec/2002-11/msg00114.html (9,233 bytes)

210. Re: [TenTec] Transistor Question? (score: 1)
Author: "Dr. Gerald N. Johnson, electrical engineer" <geraldj@isunet.net>
Date: Wed, 02 Oct 2002 17:52:34 -0500
I don't find any MPSV transistors. MPSU10 is in the ECG cross reference. Its replaced by an ECG 191, discontinued. No data in this book, was a Si NPN HV AF/Video amp in figure T36 case... Also not sh
/archives//html/TenTec/2002-10/msg00027.html (7,354 bytes)

211. Re: [TenTec] CW Filters (score: 1)
Author: "Dr. Gerald N. Johnson, electrical engineer" <geraldj@isunet.net>
Date: Tue, 08 Oct 2002 21:14:07 -0500
No number of cascaded IF filters will cure front end overload. 73, Jerry, K0CQ -- Entire content copyright Dr. Gerald N. Johnson, electrical engineer. Reproduction by permission only.
/archives//html/TenTec/2002-10/msg00180.html (6,915 bytes)

212. Re: [TenTec] TWINCOM feedline ????????????? (score: 1)
Author: "Dr. Gerald N. Johnson, electrical engineer" <geraldj@isunet.net>
Date: Mon, 14 Oct 2002 18:46:59 -0500
Incredibly stretched truth. It has much affinity with the solid byproducts of a male bovine. Any alloy of aluminum has poorer conductivity than aluminum. Any alloy with lots of titanium will likely b
/archives//html/TenTec/2002-10/msg00259.html (10,102 bytes)

213. Re: [TenTec] TWINCOM feedline ????????????? (score: 1)
Author: "Dr. Gerald N. Johnson, electrical engineer" <geraldj@isunet.net>
Date: Tue, 15 Oct 2002 12:54:40 -0500
The wider the space the more the feed line radiates. The thin spacers of the TWINWIRE compared to the plastic ladder lines means its less affected by wind, and maybe by ice. I've used flat lines for
/archives//html/TenTec/2002-10/msg00274.html (10,305 bytes)

214. Re: [TenTec] Re: parallel lines rated by losses (score: 1)
Author: "Dr. Gerald N. Johnson, electrical engineer" <geraldj@isunet.net>
Date: Tue, 15 Oct 2002 13:10:16 -0500
If you neglect the radiation losses of the wide spaced open wire lines on the higher frequencies, there are no bends in the line, and there are no intrusions into the space about the line, open wire
/archives//html/TenTec/2002-10/msg00276.html (9,722 bytes)

215. Re: [TenTec] TWINCOM feedline ????????????? (score: 1)
Author: "Dr. Gerald N. Johnson, electrical engineer" <geraldj@isunet.net>
Date: Tue, 15 Oct 2002 19:57:41 -0500
But a wide spaced line WILL radiate. Antennas are made of slightly wider spaced parallel lines, for example the Quad, where the spacing is quarter wave. The connectors top and bottom (if horizontally
/archives//html/TenTec/2002-10/msg00281.html (11,980 bytes)

216. Re: [TenTec] TWINCOM feedline ????????????? (score: 1)
Author: "Dr. Gerald N. Johnson, electrical engineer" <geraldj@isunet.net>
Date: Wed, 16 Oct 2002 18:48:32 -0500
The classic transmission line theory that the fields cancel at all points in space IS a convenient ARTIFICE but its NOT absolutely true. When the conductors are at different distances from the observ
/archives//html/TenTec/2002-10/msg00302.html (11,396 bytes)

217. Re: [TenTec] Re: TWINCOM feedline? (score: 1)
Author: "Dr. Gerald N. Johnson, electrical engineer" <geraldj@isunet.net>
Date: Thu, 17 Oct 2002 09:44:55 -0500
A radiating feedline can cause TVI by radiating closer to the faulty TV than the elevated and relatively remote antenna. In some areas, the neighbor's TVs aren't very far from the ham station. There
/archives//html/TenTec/2002-10/msg00311.html (8,715 bytes)

218. Re: [TenTec] Digital readout Corsair II (score: 1)
Author: "Dr. Gerald N. Johnson, electrical engineer" <geraldj@isunet.net>
Date: Sun, 27 Oct 2002 20:52:18 -0600
Check the 5 volt supply to the CPU that drives the readout. Check the frequency lines from the band switch, and check or replace all the aluminum electrolytics in that readout driver. Old aluminum el
/archives//html/TenTec/2002-10/msg00532.html (7,389 bytes)

219. Re: [TenTec] QA - Filters: (score: 1)
Author: "Dr. Gerald N. Johnson, electrical engineer" <geraldj@isunet.net>
Date: Mon, 28 Oct 2002 23:15:32 -0600
I have, on several occasions. You might check the archives or ask again tomorrow. Its too late tonight to type all my opinions. There are crystal lattice filters and ladder filters (Tentec uses ladde
/archives//html/TenTec/2002-10/msg00568.html (8,260 bytes)

220. Re: [TenTec] Receivability (score: 1)
Author: "Dr. Gerald N. Johnson, electrical engineer" <geraldj@isunet.net>
Date: Wed, 30 Oct 2002 10:11:51 -0600
Lattice filter dynamic range is limited by the linearity of the crystals and the transformer cores. Extremely tiny cores may saturate far more easily than large cores, so that miniature filters may n
/archives//html/TenTec/2002-10/msg00590.html (9,152 bytes)

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