Author: "Dr. Gerald N. Johnson" <geraldj@weather.net>
Date: Sat, 01 Jan 2011 17:52:09 -0600
When not going through authorized distributors it is possible to pick up counterfeit parts made to emulate good parts or good parts that are old or didn't pass inspection. That's most hazardous when
Author: "Dr. Gerald N. Johnson" <geraldj@weather.net>
Date: Sat, 01 Jan 2011 17:57:48 -0600
Sounds like a marginal power supply bypass though it could be a bad solder connection of a shunt resistor in the filter RC components around the OP amp. 73, Jerry, K0CQ On 1/1/2011 5:54 PM, Curt wrot
Author: "Dr. Gerald N. Johnson" <geraldj@weather.net>
Date: Sat, 01 Jan 2011 21:06:52 -0600
I use DeoxIT part number D100L-25C. Its a dropper bottle with a fine capilary out the cap. I think its enough to last a lifetime of full time servicing because a connector or switch contact really on
Author: "Dr. Gerald N. Johnson" <geraldj@weather.net>
Date: Sat, 01 Jan 2011 23:41:12 -0600
I suppose that's a working brew, but Caig admits to no naptha in the pure DeoxIT bottles, like D100L, in fact admits nothing in the MSDS except a flash point above 482 F. The spray version they admit
Author: "Dr. Gerald N. Johnson" <geraldj@weather.net>
Date: Sun, 02 Jan 2011 01:20:51 -0600
Mouser carries Vishay-Sprague Atoms. They seem to be the same high quality they originally were. Much larger for better heat dissipation than the miniatures too. I hadn't considered drilling new hole
Author: "Dr. Gerald N. Johnson" <geraldj@weather.net>
Date: Sun, 02 Jan 2011 12:29:16 -0600
I use ATC 15 amp fuses to protect my Corsair II. I built up a power cable with a relay so I can use my shack supply. I looked at the time-current curves for the Airpax breaker and for these fuses. Th
Author: "Dr. Gerald N. Johnson" <geraldj@weather.net>
Date: Sun, 02 Jan 2011 14:00:22 -0600
Ask them about a breaker with the same electrical ratings but different mountings. 73, Jerry, K0CQ _______________________________________________ TenTec mailing list TenTec@contesting.com http://lis
Author: "Dr. Gerald N. Johnson" <geraldj@weather.net>
Date: Sun, 02 Jan 2011 14:42:53 -0600
Crowbars are usually a fast shut down to protect from over voltage (like a shorted regulator transistor). Current limits shut down the supply when overloaded without shorting it out, they just cut ba
Author: "Dr. Gerald N. Johnson" <geraldj@weather.net>
Date: Sun, 02 Jan 2011 19:18:48 -0600
On 1/2/2011 8:05 AM, Joe Roberts wrote: On 1/2/2011 2:20 AM, Dr. Gerald N. Johnson wrote: Mouser carries Vishay-Sprague Atoms. They seem to be the same high quality they originally were. Much larger
Author: "Dr. Gerald N. Johnson" <geraldj@weather.net>
Date: Sun, 02 Jan 2011 19:30:07 -0600
I put a diode in series with the relay coil to make it an amplified polarity protector too. I also put a diode across the relay coil to squelch inductive kick. It was intended that the switch in the
Author: "Dr. Gerald N. Johnson" <geraldj@weather.net>
Date: Sun, 02 Jan 2011 20:51:57 -0600
From the 1140 Tentec wiki page: The 1140 is no longer available from Ten-Tec. Ten-Tec recommends an Airpax T-11 20 amp fast acting breaker (Data Sheet) available from Wards Electronics in Florida, (8
Author: "Dr. Gerald N. Johnson" <geraldj@weather.net>
Date: Mon, 03 Jan 2011 12:46:54 -0600
We didn't miss the prior two posts, just it didn't strike a need since I just bought an internal card with much faster sampling and handier software than a USB card. There's no need to repeat a for s
Author: "Dr. Gerald N. Johnson" <geraldj@weather.net>
Date: Mon, 03 Jan 2011 16:41:42 -0600
That index was for all issues of the year 2007 and referred to each article by issue, like Jan/Feb then PAGE number. It was coming out 6 times a year then, like now. 73, Jerry, K0CQ The index cited m
Author: "Dr. Gerald N. Johnson" <geraldj@weather.net>
Date: Mon, 03 Jan 2011 16:56:23 -0600
Antique Electronic Supply has some 50/50 at 450 or 500 volts: http://www.tubesandmore.com/scripts/foxweb.dll/catalog@d:/dfs/elevclients/cemirror/ELEVATOR.FXP?SEARCH_PAGENO=0&SEARCH_TREE01=ZCATALOG&SE
Author: "Dr. Gerald N. Johnson" <geraldj@weather.net>
Date: Mon, 03 Jan 2011 18:58:22 -0600
However, before going to that trouble, get the internal tuner exposed by taking off the cabinet, and if you have a DVM with diode check, check the diodes on the tuner board with the meter, (Radio off
Author: "Dr. Gerald N. Johnson" <geraldj@weather.net>
Date: Tue, 04 Jan 2011 20:21:40 -0600
Almost sure to use audio taper for audio gain. You can emulate an audio taper with a linear taper pot by adding a resistor from wiper to ground. Usually about the same resistance as the pot resistanc
Author: "Dr. Gerald N. Johnson" <geraldj@weather.net>
Date: Wed, 05 Jan 2011 10:00:15 -0600
I don't know if the low angle efficiency falls off faster than the high angle radiation. I can't remember ever reading that, but I have probably only read "a drop in the bucket" of all there is. Beca
Author: "Dr. Gerald N. Johnson" <geraldj@weather.net>
Date: Wed, 05 Jan 2011 11:17:25 -0600
1. I think a horizontal loop is a pretty good radiator, straight up. And those who like them find they work well for operations like SS and FD where working stations in surrounding states on 80 and 4
Author: "Dr. Gerald N. Johnson" <geraldj@weather.net>
Date: Wed, 05 Jan 2011 21:28:15 -0600
I have a long answer prepared, but I want to sleep on it and proof it a dozen more times before I send it. 73, Jerry, K0CQ On 1/5/2011 3:44 PM, Richards wrote: Er... ah... No joke. Do you doubt the p
Author: "Dr. Gerald N. Johnson" <geraldj@weather.net>
Date: Thu, 06 Jan 2011 11:07:39 -0600
On 1/5/2011 3:44 PM, Richards wrote: Er... ah... No joke. Do you doubt the proposition that a good ground plane lowers radiation take off angle? If so, I would be curious as to your reasons. (Serious