Author: "Dr. Gerald N. Johnson" <geraldj@weather.net>
Date: Tue, 12 Oct 2010 20:03:10 -0500
Why the 1N4007? They are poor PIN diodes and too slow to be protective diodes. If you want strong signal protection you need much faster diodes, 1N4454 or 1N914 derivatives. If you do RF switching wi
Author: "Dr. Gerald N. Johnson" <geraldj@weather.net>
Date: Tue, 12 Oct 2010 23:07:57 -0500
Have you changed the battery lately? Its an active noise canceling headset, so may need a bit of power to work. 32 ohm cans ought to have enough sensitivity for the low impedance output of the Orion.
Author: "Dr. Gerald N. Johnson" <geraldj@weather.net>
Date: Wed, 13 Oct 2010 10:37:47 -0500
Very poor choice because the 1N4007 has a structure like a PIN diode and so is slow to recover at RF, once turned on it makes an attenuator for many cycles. That and considerable capacitance makes it
Author: "Dr. Gerald N. Johnson" <geraldj@weather.net>
Date: Sat, 16 Oct 2010 10:45:15 -0500
ITS DEAD! _______________________________________________ TenTec mailing list TenTec@contesting.com http://lists.contesting.com/mailman/listinfo/tentec
Author: "Dr. Gerald N. Johnson" <geraldj@weather.net>
Date: Thu, 21 Oct 2010 19:48:09 -0500
Tentec can probably supply a replacement crystal. If not International Crystal Manufacturing or some other crystal maker surely can. What is the frequency of the crystal? Sometimes you can find suita
Author: "Dr. Gerald N. Johnson" <geraldj@weather.net>
Date: Thu, 21 Oct 2010 20:08:09 -0500
I've downloaded the manual. Looks like a parallel mode crystal on 5.656 MHz. If you order from ICM or another crystal maker, send them a copy of the module schematic page 3-18 of the Scout/Argo manua
Author: "Dr. Gerald N. Johnson" <geraldj@weather.net>
Date: Thu, 21 Oct 2010 21:52:30 -0500
On the tentec web page they have a tab for support and parts. On it there's a place to identify the part and ask if they can supply it. You could make use of that. 73, Jerry, K0CQ ___________________
Author: "Dr. Gerald N. Johnson" <geraldj@weather.net>
Date: Thu, 28 Oct 2010 21:19:26 -0500
You are going to have to move the carrier frequencies out to the slopes of the filter to get back to SSB. That takes a lot of tweaking of the shifting trimmers which interact between CW, LSB, and USB
Author: "Dr. Gerald N. Johnson" <geraldj@weather.net>
Date: Fri, 29 Oct 2010 10:43:42 -0500
It would not be silly to test and with a receiver with a working S-meter and a calibrator signal or any other local steady signal you just tune across the signal and plot the S-meter readings vs. fre
Author: "Dr. Gerald N. Johnson" <geraldj@weather.net>
Date: Sat, 30 Oct 2010 19:25:52 -0500
A long insulated screwdriver. Perhaps a wooden dowel or plastic rod, probably a quarter inch diameter or less filed to fit the adjustment slots. Fiberglass rod like used to hold up a flag on a bicycl
Author: "Dr. Gerald N. Johnson" <geraldj@weather.net>
Date: Sun, 31 Oct 2010 16:31:31 -0600
Dynamic Noise Reduction is a nearly unachievable Holy Grail that means different things to different users and designers. It can mean reduction of circuit noise, natural atmospheric noise like lightn
Author: "Dr. Gerald N. Johnson" <geraldj@weather.net>
Date: Sun, 31 Oct 2010 18:53:28 -0600
Part of it is that music is much more coherent than voice or even CW and part of it is that noise reduction from vinyl may have removed some of the characteristics of some musical instruments that te
Author: "Dr. Gerald N. Johnson" <geraldj@weather.net>
Date: Sat, 06 Nov 2010 10:20:12 -0600
Might be a sign of running higher line voltage than it was designed for. Or that the design didn't quite include enough heat sink area. The fan is a good help. You might try lowering the line voltage
Author: "Dr. Gerald N. Johnson" <geraldj@weather.net>
Date: Sun, 07 Nov 2010 17:23:49 -0600
Yes, but it ought to be done gently and it ought to be spaced 4 to 6 inches from everything, especially metals. It should be twisted so both conductor approach objects evenly. Not a rapid spiral but
Author: "Dr. Gerald N. Johnson" <geraldj@weather.net>
Date: Mon, 08 Nov 2010 12:30:14 -0600
There are lengths that tune easier, depending on the feed point and feed line length. A center fed wire tune easiest when near a half wave long. An end fed wire tunes easiest when about a quarter wav
Author: "Dr. Gerald N. Johnson" <geraldj@weather.net>
Date: Mon, 08 Nov 2010 23:14:03 -0600
Many low priced aluminum electrolytics have a lot more series resistance than a quality tantalum. Many I fail fresh from the distributor when I check them for power factor, the capacitance bridge's m
Author: "Dr. Gerald N. Johnson" <geraldj@weather.net>
Date: Tue, 09 Nov 2010 03:20:30 -0600
Trouble with introducing a balun is that sometimes ladder line is used to allow a wide tuning range and so there can be a wild set of impedances and SWR on the ladder line that the balun can't handle
Author: "Dr. Gerald N. Johnson" <geraldj@weather.net>
Date: Tue, 09 Nov 2010 12:40:11 -0600
But Steve, the original post suggesting the balun specifically said 1:4 impedance ratio to transform open line impedances to a better match in coax where the coax is also far more tolerant to bends a
Author: "Dr. Gerald N. Johnson" <geraldj@weather.net>
Date: Wed, 10 Nov 2010 19:39:09 -0600
Hardware AGC pumping. Full RF gain and no attenuation invites it. A good post filter audio AGC to compensate should have cured it but that concept doesn't seem to have reached the DSP receiver. The s
Author: "Dr. Gerald N. Johnson" <geraldj@weather.net>
Date: Thu, 11 Nov 2010 12:30:39 -0600
From the on line Corsair II manual, pin 1 is audio, pin 2 is ground, pin 3 is PTT and pin 4 is +v for electret power. So white goes to 1, 2 gets shield, I'm not sure about black and red. But with a m