Author: "Dr. Gerald N. Johnson" <geraldj@weather.net>
Date: Thu, 21 Jan 2010 17:30:21 -0600
I downloaded the manual just to see. That board probably has a couple unobtainable parts now, the 80C32 controller and the AD8105(?) DSP chip. EPROM and memory may be old too, but newer stuff with ex
Author: "Dr. Gerald N. Johnson" <geraldj@weather.net>
Date: Thu, 21 Jan 2010 22:23:42 -0600
If the KHz digits read right, there no problem with the jumper or inside the PTO. The MHz digits come from diodes on the bandswitch. Look at page 3-29 for information on the presets. That page says l
Author: "Dr. Gerald N. Johnson" <geraldj@weather.net>
Date: Fri, 22 Jan 2010 11:46:52 -0600
And it will hear that fly while two horses and three cows are passing gas at 2 feet. 73, Jerry, K0CQ _______________________________________________ TenTec mailing list TenTec@contesting.com http://l
Author: "Dr. Gerald N. Johnson" <geraldj@weather.net>
Date: Fri, 22 Jan 2010 11:52:48 -0600
Pass band tuning is a handy feature. The better parts are the selectable RF stage and the mixers. All circuits with the greatest available dynamic range. The RF stage and first IF stage use transform
Author: "Dr. Gerald N. Johnson" <geraldj@weather.net>
Date: Sat, 23 Jan 2010 12:44:55 -0600
DeoxIT might work. I don't prefer it sprayed but you have not much other choice. More often miniature switches fail mechanically than get oxides to replacement may be the only solution. 73, Jerry, K0
Author: "Dr. Gerald N. Johnson" <geraldj@weather.net>
Date: Sat, 30 Jan 2010 10:21:34 -0600
I have a DSP-599. The 599zx is different and may work better. The 599 does a great job of adding selectivity, though you run a risk of strong signals outside its passband running the receiver AVC and
Author: "Dr. Gerald N. Johnson" <geraldj@weather.net>
Date: Sat, 30 Jan 2010 16:39:57 -0600
I sometimes use a passive and switchable low pass filter in the speaker circuit to trim off the audio stage distortion harmonic products. The only problem is it takes even more audio output to get a
Author: "Dr. Gerald N. Johnson" <geraldj@weather.net>
Date: Sat, 30 Jan 2010 16:45:52 -0600
I call a 25 Hz brick walled bandpass, SELECTIVITY! Whether at audio or IF or RF it still sets the spectrum limit on what I'm going to hear. Remember in the SSB receiver all it does is translate a sec
Author: "Dr. Gerald N. Johnson" <geraldj@weather.net>
Date: Thu, 04 Feb 2010 10:12:18 -0600
But that relaxation oscillator has one good feature. It starts and stops fast, so it doesn't hang behind fast keying. A low pass filter on the speaker can help it a lot. I'll have a circuit that I di
Author: "Dr. Gerald N. Johnson" <geraldj@weather.net>
Date: Sat, 06 Feb 2010 13:08:33 -0600
No ham gear needs the amplified microphone. All has enough audio gain and is in danger of being overdriven to distortion with any amplified microphone made for CB. Googling Turner "m+2" the first hit
Author: "Dr. Gerald N. Johnson" <geraldj@weather.net>
Date: Sat, 06 Feb 2010 17:53:15 -0600
Trane has had that kind of a problem with variable speed furnace fans and has supplied a filter to fix the problem. 73, Jerry, K0CQ _______________________________________________ TenTec mailing list
Author: "Dr. Gerald N. Johnson" <geraldj@weather.net>
Date: Sat, 06 Feb 2010 18:59:44 -0600
Except my passive LC filter introduces no DSP artifacts to the audio. No hum either. It does demand more power from the audio output stage though. In the Orion's DSP users can choose the number of st
Author: "Dr. Gerald N. Johnson" <geraldj@weather.net>
Date: Sat, 06 Feb 2010 19:14:30 -0600
I've just made and posted my 1991 vintage paper as .pdf. Look at http://www.geraldj.networkiowa.com/papers/speakerfilter.pdf Google won't find it, there's no web page for that directory. 73, Jerry, K
Author: "Dr. Gerald N. Johnson" <geraldj@weather.net>
Date: Mon, 08 Feb 2010 19:13:41 -0600
Try tuning the amp for maximum output, and mostly ignoring the current readings. Its easy to tune a grounded grid linear for DC readings and not get a whole lot of power. The worst example I've ever
Author: "Dr. Gerald N. Johnson" <geraldj@weather.net>
Date: Tue, 09 Feb 2010 10:18:48 -0600
Peak to average ratio as I said, depends on the relative frequency and phase responses of the voice, the microphone, the transmit ssb filter and the ALC characteristic. And the meter doing the observ
Author: "Dr. Gerald N. Johnson" <geraldj@weather.net>
Date: Tue, 09 Feb 2010 14:18:22 -0600
I've run more than one FD CW station on battery and at 25 watts to preserve battery power and made contacts just as fast as I did other field days with 100 watts. Funny thing that I found feeding an
Author: "Dr. Gerald N. Johnson" <geraldj@weather.net>
Date: Tue, 09 Feb 2010 14:21:41 -0600
John, I beg to differ. There is NOTHING automated about my posts. I type each one a character at a time. 73, Jerry, K0CQ _______________________________________________ TenTec mailing list TenTec@con
Author: "Dr. Gerald N. Johnson" <geraldj@weather.net>
Date: Tue, 09 Feb 2010 19:40:13 -0600
I prefer the dropper bottle of DeoxIT from Cramolin. I have no idea if its available in Europe. You only what a quarter drop on the metal contacts, nothing on the insulation. 73, Jerry, K0CQ ________
Author: "Dr. Gerald N. Johnson" <geraldj@weather.net>
Date: Wed, 17 Feb 2010 19:32:28 -0600
Or the keying line is stuck keyed to transmit. Might be a cable or the driver, not the PA. 73, Jerry, K0CQ _______________________________________________ TenTec mailing list TenTec@contesting.com ht
Author: "Dr. Gerald N. Johnson" <geraldj@weather.net>
Date: Thu, 18 Feb 2010 17:25:00 -0600
While the mark left by high voltage may be small, a low voltage supply can cause amputations, especially a lead acid battery. 12 volts at a 100 amps through a wedding ring can amputate that finger cl