Author: "Dr. Gerald N. Johnson" <geraldj@weather.net>
Date: Tue, 22 Feb 2011 16:12:17 -0600
If the looseness in the sockets isn't from the crystal socket pins not being solder to the board (radios of that vintage were hand soldered and the quality did vary) somtimes the contact pins can be
Author: "Dr. Gerald N. Johnson" <geraldj@weather.net>
Date: Wed, 23 Feb 2011 10:10:41 -0600
He wants Quebec French, not Paris French. They sound a lot different. 73, Jerry, K0CQ If it's spoken, or if you need very specialized help, I seem to recall at least several posters on this list who
Author: "Dr. Gerald N. Johnson" <geraldj@weather.net>
Date: Fri, 25 Feb 2011 08:01:33 -0600
Not many power stages are turned off in the receiver, and 2.1 amps isn't far out of line for several transmitter stages with idling current in the driver and PA stages, needed for linearity. But page
Author: "Dr. Gerald N. Johnson" <geraldj@weather.net>
Date: Sat, 26 Feb 2011 10:22:41 -0600
The catalogs tend to show them by the outside dimensions, not the mounting holes. MCM Electronics has a very wide selection of speakers, but their search engine didn't help thin down 3500 hits for sp
Author: "Dr. Gerald N. Johnson" <geraldj@weather.net>
Date: Sat, 26 Feb 2011 11:35:43 -0600
I've used an external audio filter on most of my receivers. Both DSP and passive (http://www.geraldj.networkiowa.com/papers/speakerfilter.pdf). The passive filter leaves no artifacts behind. I haven'
Author: "Dr. Gerald N. Johnson" <geraldj@weather.net>
Date: Sat, 26 Feb 2011 12:15:53 -0600
That's where I find my passive speaker filter shines. It passes no audio section noise and no IF noise, an few DSP HF artifacts. A fundamental of receiver design is that selectivity works best as clo
Author: "Dr. Gerald N. Johnson" <geraldj@weather.net>
Date: Sat, 26 Feb 2011 12:28:40 -0600
At one time FCC rules were clear about spares requirements for BC stations. One summer I was chief engineer for a big 250 watt class IV station (for two weeks) and thought I could see the up modulato
Author: "Dr. Gerald N. Johnson" <geraldj@weather.net>
Date: Sat, 26 Feb 2011 12:48:50 -0600
You want a matched pair. Push-pull PA stages usually don't bias the transistors independently, and setting the bias only sets the DC operating point, not the gain which varies from differences in the
Author: "Dr. Gerald N. Johnson" <geraldj@weather.net>
Date: Sat, 26 Feb 2011 15:01:15 -0600
My Corsair II's speaker is inside the bottom, not mounted to the bottom cover. At least not with visible fastenings through the bottom cover, just a punched grill. It doesn't show in the picture of t
Author: "Dr. Gerald N. Johnson" <geraldj@weather.net>
Date: Sat, 26 Feb 2011 15:16:43 -0600
It may be useful to draw a distinction between digging weak signals out of the noise and improving the SNR on stronger signals so they sound better. As we know, most of the intelligence in (male) hum
Author: "Dr. Gerald N. Johnson" <geraldj@weather.net>
Date: Sat, 26 Feb 2011 17:11:23 -0600
An extra high idling current doesn't mean instant disaster it just means extra PA transistor heat and probably actually better linearity than the rated current. Setting idling current for an amplifie
Author: "Dr. Gerald N. Johnson" <geraldj@weather.net>
Date: Sat, 26 Feb 2011 18:17:25 -0600
Some ears work better at copying below the noise level than others. W5WXV didn't do EME but he did long range terrestrial 2m CW contacts regularly and in the lab he claimed he could detect a signal 2
Author: "Dr. Gerald N. Johnson" <geraldj@weather.net>
Date: Sat, 26 Feb 2011 19:55:54 -0600
I don't have an Orion II. On my other radios I have used my own designs, one of which is at http://www.geraldj.networkiowa.com/papers/speakerfilter.pdf I have also used a Timewave DSP59+ but its not
Author: "Dr. Gerald N. Johnson" <geraldj@weather.net>
Date: Sat, 01 Jan 2011 13:26:50 -0600
Thank you. And since it was used for tactical communications in combat it probably was essentially classified for a while. Known only to US DOD and friendly forces by that name, though the concept wa
Author: "Dr. Gerald N. Johnson" <geraldj@weather.net>
Date: Sat, 01 Jan 2011 13:41:07 -0600
Miniature electrolytics are ripe for replacement due to old age. Go for low ESR high temperature rated for the best performance and long life. Don't forget those on the display board. I doubt Tentec
Author: "Dr. Gerald N. Johnson" <geraldj@weather.net>
Date: Sat, 01 Jan 2011 13:44:07 -0600
I'd think the pistol would need to be clear of the coil to allow moving the shaft and pistol sideways. I have been into my Corsair II PTO, but I don't remember much of a problem of diassembly. Its no
Author: "Dr. Gerald N. Johnson" <geraldj@weather.net>
Date: Sat, 01 Jan 2011 16:56:41 -0600
On 1/1/2011 4:12 PM, Bwana Bob wrote: Wow! John Brune and his sidekick John Gratalo are the guys that I ran into at Lakehurst NAEC in 1981 where they were flight testing the system. I didn't know tha
Author: "Dr. Gerald N. Johnson" <geraldj@weather.net>
Date: Sat, 01 Jan 2011 17:14:24 -0600
I have gone through a couple Tritons, Omni Cs, and an Omni V replacing all the electrolytic caps with amazing results. I want to restore a Corsair in 2011...new year's resolution. Use modern low ESR