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Total 357 documents matching your query.

221. [TenTec] Re: [Yaesu] VibroPlex Code Warrior Jr. problems (score: 1)
Author: geraldj@isunet.net (Dr. Gerald N. Johnson, electrical engineer)
Date: Mon, 08 Apr 2002 10:52:20 -0500
There often wasn't a problem when the key was running in a circuit carrying 30 to 100 volts and dozens or more milliamps. In the input to a CMOS keyer, the voltage is only a couple volts and the curr
/archives//html/TenTec/2002-04/msg00243.html (7,766 bytes)

222. [TenTec] My new TEN-TEC 526 (score: 1)
Author: geraldj@isunet.net (Dr. Gerald N. Johnson, electrical engineer)
Date: Mon, 08 Apr 2002 12:25:31 -0500
Some stage is probably oscillating to make the added signals. I've seen that in a prototype Motorola receiver we were using for our local repeater. A proper parasitic suppressor cured it. Else the PL
/archives//html/TenTec/2002-04/msg00248.html (6,986 bytes)

223. [TenTec] BNC vs UHF connectors for HF 100w use (score: 1)
Author: geraldj@isunet.net (Dr. Gerald N. Johnson, electrical engineer)
Date: Thu, 11 Apr 2002 17:00:12 -0500
Neither center pin will carry the 10 amps current required to feed a 50 ohm load 500 volts. Considering the center conductor of RG58 is only 18 or 20 gauge, the WIRE won't carry more than a couple am
/archives//html/TenTec/2002-04/msg00354.html (9,297 bytes)

224. [TenTec] BNC vs UHF connectors for HF 100w use (score: 1)
Author: geraldj@isunet.net (Dr. Gerald N. Johnson, electrical engineer)
Date: Thu, 11 Apr 2002 17:55:57 -0500
N males mate to BNC females without stretching the BNC female center pin excessively. Most of the pin pieces are larger in the N connector. The threaded ring of the N connector holds the connector pi
/archives//html/TenTec/2002-04/msg00362.html (10,545 bytes)

225. [TenTec] BNC vs UHF connectors for HF 100w use (score: 1)
Author: geraldj@isunet.net (Dr. Gerald N. Johnson, electrical engineer)
Date: Thu, 11 Apr 2002 20:48:19 -0500
Yes the UHF has a fat center pin, but it has a rotten ground connection. I burned one black in a 2m mobile with only 18 watts many years ago. The ground connection is only as good as the ring is tigh
/archives//html/TenTec/2002-04/msg00373.html (9,860 bytes)

226. [TenTec] BNC vs UHF connectors for HF 100w use (score: 1)
Author: geraldj@isunet.net (Dr. Gerald N. Johnson, electrical engineer)
Date: Fri, 12 Apr 2002 10:04:34 -0500
The mating parts of the pins of N and BNC are similar sizes. The rest of the pins are not. N is mostly air insulated so the outsides of the pin and socket beyond the mating portion is a different siz
/archives//html/TenTec/2002-04/msg00385.html (10,267 bytes)

227. [TenTec] ARRL Reviews 746PRO (score: 1)
Author: geraldj@isunet.net (Dr. Gerald N. Johnson, electrical engineer)
Date: Fri, 12 Apr 2002 22:28:10 -0500
The WWII Command Set VFO was and still IS as good as a Collins PTO, far better than any other receivers contemporary to the 10B. It couldn't be made today, though with good temperature control and so
/archives//html/TenTec/2002-04/msg00398.html (8,068 bytes)

228. [TenTec] Sidetone revisited (score: 1)
Author: geraldj@isunet.net (Dr. Gerald N. Johnson, electrical engineer)
Date: Sun, 14 Apr 2002 21:37:06 -0500
The sawtooth oscillator should be at full amplitude the first half cycle of the tone. And the start up chirp done in that time period. It won't hang over either when unkeyed. The twin-T undoubtedly t
/archives//html/TenTec/2002-04/msg00454.html (8,745 bytes)

229. [TenTec] Sidetone revisited (score: 1)
Author: geraldj@isunet.net (Dr. Gerald N. Johnson, electrical engineer)
Date: Mon, 15 Apr 2002 10:23:41 -0500
The filtered sawtooth will always have the least delay. The filter can be a simple two or three pole low pass. The effect of the twin T is to make a narrow bandpass filter and its high Q in the feedb
/archives//html/TenTec/2002-04/msg00459.html (7,804 bytes)

230. [TenTec] Titan multi-meter (score: 1)
Author: geraldj@isunet.net (Dr. Gerald N. Johnson, electrical engineer)
Date: Tue, 16 Apr 2002 17:24:00 -0500
Scherrer Instruments on Manchester in St. Louis or a suburb, used to do meter movements. But the last time I wished a fix for a broken taut band movement, it proved years faster and cheaper to buy a
/archives//html/TenTec/2002-04/msg00492.html (8,266 bytes)

231. [TenTec] Followup - Jupiter Overheating (score: 1)
Author: geraldj@isunet.net (Dr. Gerald N. Johnson, electrical engineer)
Date: Wed, 17 Apr 2002 10:24:11 -0500
Leaky transistor... A bipolar transistor is operated with one junction reversed biased (base to collector). If that junction is leaky, not super high resistance, the collector voltage will leak some
/archives//html/TenTec/2002-04/msg00522.html (7,559 bytes)

232. [TenTec] 1320 T-Kit (score: 1)
Author: geraldj@isunet.net (Dr. Gerald N. Johnson, electrical engineer)
Date: Wed, 17 Apr 2002 10:24:07 -0500
Transistor tend to be fairly sensitive to heat. And most good oscillator circuits have large capacitors in shunt with the transistor so that changes in the transistor have minimal effect on the frequ
/archives//html/TenTec/2002-04/msg00523.html (7,968 bytes)

233. [TenTec] Antennas (score: 1)
Author: geraldj@isunet.net (Dr. Gerald N. Johnson, electrical engineer)
Date: Fri, 19 Apr 2002 15:56:48 -0500
I HAVE read the IEEE articles about the folded conical helix antenna. That has not convinced me that the skepticism expressed in the forum by others is unfounded. But I've kept quiet until now. 73, J
/archives//html/TenTec/2002-04/msg00569.html (6,833 bytes)

234. [TenTec] Bezel/tuning knob question (score: 1)
Author: geraldj@isunet.net (Dr. Gerald N. Johnson, electrical engineer)
Date: Sat, 20 Apr 2002 11:53:43 -0500
Gary, your Corsair VFOs are mucked up. The bezel is held on by a spring sliding in a groove on the outer PTO shaft (which is the one that has the thread to drive the slug through the pistol). The kno
/archives//html/TenTec/2002-04/msg00606.html (9,104 bytes)

235. [TenTec] Bezel/tuning knob question (score: 1)
Author: geraldj@isunet.net (Dr. Gerald N. Johnson, electrical engineer)
Date: Sat, 20 Apr 2002 12:17:56 -0500
You could be right. Still probably Gary needs to pull the bezel off and make sure it turns freely on the shaft and that it hasn't been glued in place when someone couldn't figure out the spring... 73
/archives//html/TenTec/2002-04/msg00609.html (8,405 bytes)

236. [TenTec] CW Dead? Apparently not... (score: 1)
Author: geraldj@isunet.net (Dr. Gerald N. Johnson, electrical engineer)
Date: Sat, 20 Apr 2002 21:53:01 -0500
That's a relatively cheap Japanese key of the 60s, ball bearing pivots. Its NOT a J-38. Not that a J-38 was ever a great key. I think I paid about $28 for a good E.F. Johnson "speed" key (conventiona
/archives//html/TenTec/2002-04/msg00630.html (8,984 bytes)

237. [TenTec] Balanced vs. unbalanced mic (score: 1)
Author: geraldj@isunet.net (Dr. Gerald N. Johnson, electrical engineer)
Date: Wed, 24 Apr 2002 08:54:09 -0500
When there's a transmitter in the area, there's only one GOOD circuit for connecting balanced to unbalanced audio. That's a shielded transformer. Any semiconductor circuit will have a tendency to act
/archives//html/TenTec/2002-04/msg00675.html (7,672 bytes)

238. [TenTec] Would like Corsair II comments (score: 1)
Author: geraldj@isunet.net (Dr. Gerald N. Johnson, electrical engineer)
Date: Mon, 29 Apr 2002 21:54:06 -0500
I see reports that the Corsair II is noisy. It just has lots of gain but the RF stage uses circuitry that should be very quiet. Practically quiet enough for VHF/UHF without a significant preamp. The
/archives//html/TenTec/2002-04/msg00767.html (9,258 bytes)

239. [TenTec] Would like Corsair II comments (score: 1)
Author: geraldj@isunet.net (Dr. Gerald N. Johnson, electrical engineer)
Date: Tue, 30 Apr 2002 08:19:55 -0500
Since the RF envelope and the audio envelope in SSB do not correspond, audio derived AGC tends to produce a smoother audio output. (Its analogous to audio clipping versus SSB RF clipping, where the f
/archives//html/TenTec/2002-04/msg00778.html (11,315 bytes)

240. [TenTec] Scout instability-was Orion direction (score: 1)
Author: geraldj@isunet.net (Dr. Gerald N. Johnson, electrical engineer)
Date: Sat, 02 Mar 2002 17:21:43 -0600
The Scout was planned for mobile where it would get more shock and vibration. Probably those that move the most need some care in soldering ALL the components solidly to the board. Then maybe the cas
/archives//html/TenTec/2002-03/msg00067.html (9,357 bytes)


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