[Drakelist] Volume control for 2B Receiver
Hi from down under I am looking for an volume knob for my Drake 2B receiver any one can help, will pay a Kings ransom. Wolfgang VK3WY___ Drakelist mailing list Drakelist@zerobeat.net http://mailman.zerobeat.net/mailman/listinfo/drakelist
[Drakelist] New L-4B Article Available
All, Anyone interested in the Drake L-4B amplifier may be interested in a new article I just released.This article is a redesign of the L-4B amplifier which requires no external high voltage power supply. It is completely self-contained.The article can be found on my Drake website. Follow the link, and click on the article link at the top of the page. http://www.wb4hfn.com/DRAKE/DrakePageHome.htm 73, Ron / WB4HFN ___ Drakelist mailing list Drakelist@zerobeat.net http://mailman.zerobeat.net/mailman/listinfo/drakelist
[Drakelist] Basic electronics
How does a tube amplify AC current if tubes are used to rectify current? ___ Drakelist mailing list Drakelist@zerobeat.net http://mailman.zerobeat.net/mailman/listinfo/drakelist
Re: [Drakelist] Basic electronics
Have a look here: http://www.radio-electronics.com/info/data/thermionic-valves/vacuum-tube-theory/tube-tutorial-basics.php Also look for the book Understanding Amateur Radio. It was published by the ARRL back in the 70s. IMO one of the best books ARRL ever published on radio and electronic theory in the tube era. 73, Ron WD8SBB --- On Sun, 5/1/11, Neil M Califano cchange...@yahoo.com wrote: From: Neil M Califano cchange...@yahoo.com Subject: [Drakelist] Basic electronics To: Drakelist@zerobeat.net Date: Sunday, May 1, 2011, 5:23 PM How does a tube amplify AC current if tubes are used to rectify current? ___ Drakelist mailing list Drakelist@zerobeat.net http://mailman.zerobeat.net/mailman/listinfo/drakelist ___ Drakelist mailing list Drakelist@zerobeat.net http://mailman.zerobeat.net/mailman/listinfo/drakelist
Re: [Drakelist] Basic electronics
Neil, In a Class A amplifier a D.C. bias voltage is applied to the input grid circuit. This prevents the A.C. output signal from being rectified. Since a Class A amplifier is the least efficient, other classes of amplifiers are used for CW, FM, etc. -Tom, AG9X On Sun, May 1, 2011 at 4:23 PM, Neil M Califano cchange...@yahoo.comwrote: How does a tube amplify AC current if tubes are used to rectify current? ___ Drakelist mailing list Drakelist@zerobeat.net http://mailman.zerobeat.net/mailman/listinfo/drakelist
[Drakelist] PTO compatibility
Will a PTO from a TR-4C work in an R-4A? The frequencies look the same and it appears the supply voltage is taken from the +150V supply. Are the dial drives different? TNX es 73, Steve Wedge, W1ES/4 I can't complain, but sometimes I still do. - Joe Walsh If the above message appears, it came from Steve's Son of Laptop!___ Drakelist mailing list Drakelist@zerobeat.net http://mailman.zerobeat.net/mailman/listinfo/drakelist
Re: [Drakelist] PTO compatibility
Steve - I've never tried it, but I would say the odds are not good. Aside from the dual disc readout (perhaps not mechanical clearance), the R-4A PTO tunes 500 kHz from 4.955 to 5.455 MHz in ten full turns. The TR-4C tunes 600 kHz from 4.9 - 5.5 MHz in eleven turns. The linearity might suffer if you 'retuned' 50 kHz higher. The circuitry is the same, both run on 10 VDC derived from the +150V bus dropped by a power resistor to emulate a true current source. The output levels are similar, although the TR PTOs are typically a little higher output. If you have a TR-4C PTO you could try it, and it would probably work although with an extra 100 kHz coverage. But if you're looking for a replacement I'd look for an R-4A or R-4B unit. They are essentially the same, a BJT oscillator and buffer, although R-4Bs above s/n 8000 had an FET oscillator. 73, Garey - K4OAH Glen Allen, VA Drake 2-B, 2-C/2-NT, 4-A, 4-B, C-Line and TR-4/C Service Supplement CDs www.k4oah.com Steve Wedge wrote: Will a PTO from a TR-4C work in an R-4A? The frequencies look the same and it appears the supply voltage is taken from the +150V supply. Are the dial drives different? ___ Drakelist mailing list Drakelist@zerobeat.net http://mailman.zerobeat.net/mailman/listinfo/drakelist
